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  • 1.
    Agnas, Axel Jönses Bernard
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Non-Independent Mate Choice in Female Humans (Homo sapiens): Progression to the Field 2016Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    There is much evidence that mate-choice decisions made by humans are affected by social/contextual information. Women seem to rate men portrayed in a relationship as more desirable than the same men when portrayed as single. Laboratory studies have found evidence suggesting that human mate choice, as in other species, is dependent on the mate choice decisions made by same-sex rivals. Even though non-independent mate choice is an established and well-studied area of mate choice, very few field studies have been performed. This project aims to test whether women’s evaluation of potential mates desirability is dependent/non-independent of same-sex rivals giving the potential mates sexual interest. This is the first field study performed in a modern human’s natural habitat aiming to test for non- independent mate choice in humans.

    No desirability enhancement effect was found. The possibilities that earlier studies have found an effect that is only present in laboratory environments or have measured effects other than non-independent mate choice are discussed. I find differences in experimental design to be the most likely reason why the present study failed to detect the effect found in previous studies. This field study, the first of its sort, has generated important knowledge for future experimenters, where the most important conclusion is that major limitations in humans ability to register and remember there surrounding should be taken in consideration when designing any field study investigating human mate choice. 

  • 2.
    Agnolin, Federico L.
    et al.
    Museo Argentino Ciencias Nat Bernardino Rivadavia, Lab Anat Comparada & Evoluc Vertebrados, Buenos Aires, DF, Argentina.; Univ Maimonides, CEBBAD, Dept Ciencias Nat & Antropol, Fundac Hist Nat Felix de Azara, Buenos Aires, DF, Argentina.
    Powell, Jaime E.
    Inst Miguel Lillo, RA-4000 San Miguel De Tucuman, Tucuman, Argentina.; Consejo Nacl Invest Cient & Tecn, RA-1033 Buenos Aires, DF, Argentina.
    Novas, Fernando E.
    Museo Argentino Ciencias Nat Bernardino Rivadavia, Lab Anat Comparada & Evoluc Vertebrados, Buenos Aires, DF, Argentina.; Consejo Nacl Invest Cient & Tecn, RA-1033 Buenos Aires, DF, Argentina.
    Kundrát, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    New alvarezsaurid (Dinosauria, Theropoda) from Latest Cretaceous of North-western Patagonia with associated eggs2012In: Cretaceous research (Print), ISSN 0195-6671, E-ISSN 1095-998X, Vol. 35, p. 33-56Article in journal (Refereed)
    Abstract [en]

    The Alvarezsauridae represents a branch of peculiar basal coelurosaurs with an increasing representationof their Cretaceous radiation distributed worldwide. Here we describe a new member of the group, Bonapartenykus ultimus gen. et sp. nov. from Campanian-Maastrichtian strata of Northern Patagonia, Argentina. Bonapartenykus is represented by a single, incomplete postcranial skeleton. The morphologyof the known skeletal elements suggests close affinities with the previously described taxon from Patagonia, Patagonykus, and both conform to a new clade, here termed Patagonykinae nov. Two incomplete eggs have been discovered in association with the skeletal remains of Bonapartenykus, andseveral clusters of broken eggshells of the same identity were also found in a close proximity. These belong to the new ooparataxon Arriagadoolithus patagoniensis of the new oofamily Arriagadoolithidae, which provides first insights into unique shell microstructure and fungal contamination of eggs laid by alvarezsaurid theropods. The detailed study of the eggs sheds new light on the phylogenetic position of alvarezsaurids within the Theropoda, and the evolution of eggs among Coelurosauria. We suggest thatplesiomorphic alvarezsaurids survived in Patagonia until the latest Cretaceous, whereas these basal forms became extinct elsewhere.

  • 3. Agnès E., Sjöstrand
    et al.
    Per, Sjödin
    Carina, Schlebusch
    Thijessen, Naidoo
    Lucie, Gattepaille
    Nina, Hollfelder
    Torsten, Günther
    Mattias, Jakobsson
    Patterns of local adaptation in AfricansManuscript (preprint) (Other academic)
  • 4. Agnès E., Sjöstrand
    et al.
    Per, Sjödin
    Farhad, Shayimkulov
    Tatiana, Hegay
    Michael G. B., Blum
    Evelyne, Heyer
    Mattias, Jakobsson
    Taste and lifestyle: insights from SNP-chip data.Manuscript (preprint) (Other academic)
  • 5.
    Ah-King, Malin
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research. Dept Ecol & Evolutionary Biol, 621 Charles E Young Dr S, Los Angeles, CA 90095 USA.;Stockholm Univ, Dept Ethnol Hist Relig & Gender Studies, Univ Vagen 10 E, SE-10691 Stockholm, Sweden..
    Gowaty, Patricia Adair
    Dept Ecol & Evolutionary Biol, 621 Charles E Young Dr S, Los Angeles, CA 90095 USA.;Smithsonian Trop Res Inst, DPO, Box 0948,AA 34002-9998, Washington, DC USA.;Univ Calif Los Angeles, Inst Environm & Sustainabil, Los Angeles, CA 90095 USA..
    A conceptual review of mate choice: stochastic demography, within-sex phenotypic plasticity, and individual flexibility2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 14, p. 4607-4642Article, review/survey (Refereed)
    Abstract [en]

    Mate choice hypotheses usually focus on trait variation of chosen individuals. Recently, mate choice studies have increasingly attended to the environmental circumstances affecting variation in choosers' behavior and choosers' traits. We reviewed the literature on phenotypic plasticity in mate choice with the goal of exploring whether phenotypic plasticity can be interpreted as individual flexibility in the context of the switch point theorem, SPT (Gowaty and Hubbell ). We found >3000 studies; 198 were empirical studies of within-sex phenotypic plasticity, and sixteen showed no evidence of mate choice plasticity. Most studies reported changes from choosy to indiscriminate behavior of subjects. Investigators attributed changes to one or more causes including operational sex ratio, adult sex ratio, potential reproductive rate, predation risk, disease risk, chooser's mating experience, chooser's age, chooser's condition, or chooser's resources. The studies together indicate that choosiness of potential mates is environmentally and socially labile, that is, induced - not fixed - in the choosy sex with results consistent with choosers' intrinsic characteristics or their ecological circumstances mattering more to mate choice than the traits of potential mates. We show that plasticity-associated variables factor into the simpler SPT variables. We propose that it is time to complete the move from questions about within-sex plasticity in the choosy sex to between- and within-individual flexibility in reproductive decision-making of both sexes simultaneously. Currently, unanswered empirical questions are about the force of alternative constraints and opportunities as inducers of individual flexibility in reproductive decision-making, and the ecological, social, and developmental sources of similarities and differences between individuals. To make progress, we need studies (1) of simultaneous and symmetric attention to individual mate preferences and subsequent behavior in both sexes, (2) controlled for within-individual variation in choice behavior as demography changes, and which (3) report effects on fitness from movement of individual's switch points.

  • 6.
    Akiyama, Reiko
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Life History and Tolerance and Resistance against Herbivores in Natural Populations of Arabidopsis thaliana2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, I combined observational studies with field and greenhouse experiments to examine selection on life history traits and variation in tolerance and resistance against herbivores in natural populations of the annual herb Arabidopsis thaliana in its native range. I investigated (1) phenotypic selection on flowering time and plant size, (2) the effects of timing of germination on plant fitness, (3) the effect of leaf damage on seed production, and (4) correlations between resistance against a specialist and a generalist insect herbivore.

    In all three study populations, flowering time was negatively related to plant fitness, but in only one of the populations, significant selection on flowering time was detected when controlling for size prior to the flowering season. The results show that correlations between flowering time and plant fecundity may be confounded by variation in plant size prior to the reproductive season.

    A field experiment detected conflicting selection on germination time: Early germination was associated with low seedling survival, but also with large leaf rosette before winter and high survival and fecundity among established plants. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination, and that the optimal timing of germination should vary in space and time as a function of the relative strength of selection acting during different life-history stages.

    Experimental leaf damage demonstrated that tolerance to damage was lowest among vegetative plants early in the season, and highest among flowering plants later in the season. Given similar damage levels, leaf herbivores feeding on plants before flowering should thus exert stronger selection on defence traits than those feeding on plants during flowering.

    Resistance against larval feeding by the specialist Plutella xylostella was negatively correlated with resistance against larval feeding by the generalist Mamestra brassicae and with resistance against oviposition by P. xylostella when variation in resistance was examined within and among two Swedish and two Italian A. thaliana populations. The results suggest that negative correlations between resistance against different herbivores and different life-history stages of herbivores may contribute to the maintenance of genetic variation in resistance.

    List of papers
    1. Selection on flowering time in three natural populations of Arabidopsis thaliana
    Open this publication in new window or tab >>Selection on flowering time in three natural populations of Arabidopsis thaliana
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159506 (URN)
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-03 Last updated: 2011-11-10
    2. Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana
    Open this publication in new window or tab >>Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana
    2014 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 1, p. 193-199Article in journal (Refereed) Published
    Abstract [en]

    The timing of germination is a key life-history trait that may strongly influence plant fitness and that sets the stage for selection on traits expressed later in the life cycle. In seasonal environments, the period favourable for germination and the total length of the growing season are limited. The optimal timing of germination may therefore be governed by conflicting selection through survival and fecundity. We conducted a field experiment to examine the effects of timing of germination on survival, fecundity and overall fitness in a natural population of the annual herb Arabidopsis thaliana in north-central Sweden. Seedlings were transplanted at three different times in late summer and in autumn covering the period of seed germination in the study population. Early germination was associated with low seedling survival, but also with high survival and fecundity among established plants. The advantages of germinating early more than balanced the disadvantage and selection favoured early germination. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination and that the optimal timing of germination should vary in space and time as a function of the direction and strength of selection acting during different life-history stages.

    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159664 (URN)10.1111/jeb.12293 (DOI)000329254500018 ()
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2017-12-08Bibliographically approved
    3. Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)
    Open this publication in new window or tab >>Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. e30015-Article in journal (Refereed) Published
    Abstract [en]

    Background: The effect of herbivory on plant fitness varies widely. Understanding the causes of this variation is of considerable interest because of its implications for plant population dynamics and trait evolution. We experimentally defoliated the annual herb Arabidopsis thaliana in a natural population in Sweden to test the hypotheses that (a) plant fitness decreases with increasing damage, (b) tolerance to defoliation is lower before flowering than during flowering, and (c) defoliation before flowering reduces number of seeds more strongly than defoliation during flowering, but the opposite is true for effects on seed size.

    Methodology/Principal Findings: In a first experiment, between 0 and 75% of the leaf area was removed in May from plants that flowered or were about to start flowering. In a second experiment, 0, 25%, or 50% of the leaf area was removed from plants on one of two occasions, in mid April when plants were either in the vegetative rosette or bolting stage, or in mid May when plants were flowering. In the first experiment, seed production was negatively related to leaf area removed, and at the highest damage level, also mean seed size was reduced. In the second experiment, removal of 50% of the leaf area reduced seed production by 60% among plants defoliated early in the season at the vegetative rosettes, and by 22% among plants defoliated early in the season at the bolting stage, but did not reduce seed output of plants defoliated one month later. No seasonal shift in the effect of defoliation on seed size was detected.

    Conclusions/Significance: The results show that leaf damage may reduce the fitness of A. thaliana, and suggest that in this population leaf herbivores feeding on plants before flowering should exert stronger selection on defence traits than those feeding on plants during flowering, given similar damage levels.

    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159665 (URN)10.1371/journal.pone.0030015 (DOI)000301457200028 ()
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2017-12-08Bibliographically approved
    4. Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thaliana
    Open this publication in new window or tab >>Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thaliana
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Evolutionary Biology Botany
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-159685 (URN)
    Funder
    Swedish Research Council
    Available from: 2011-10-06 Created: 2011-10-06 Last updated: 2011-11-10
  • 7.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Noack, Sibylle
    Department of Zoology, Stockholm University.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Genetic variation in leaf morphology and resistance against specialist and generalist insect herbivores in natural populations of Arabidopsis thalianaManuscript (preprint) (Other academic)
  • 8.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Conflicting selection on the timing of germination in a natural population of Arabidopsis thaliana2014In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 1, p. 193-199Article in journal (Refereed)
    Abstract [en]

    The timing of germination is a key life-history trait that may strongly influence plant fitness and that sets the stage for selection on traits expressed later in the life cycle. In seasonal environments, the period favourable for germination and the total length of the growing season are limited. The optimal timing of germination may therefore be governed by conflicting selection through survival and fecundity. We conducted a field experiment to examine the effects of timing of germination on survival, fecundity and overall fitness in a natural population of the annual herb Arabidopsis thaliana in north-central Sweden. Seedlings were transplanted at three different times in late summer and in autumn covering the period of seed germination in the study population. Early germination was associated with low seedling survival, but also with high survival and fecundity among established plants. The advantages of germinating early more than balanced the disadvantage and selection favoured early germination. The results suggest that low survival among early germinating seeds is the main force opposing the evolution of earlier germination and that the optimal timing of germination should vary in space and time as a function of the direction and strength of selection acting during different life-history stages.

  • 9.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Magnitude and timing of leaf damage affect seed production in a natural population of Arabidopsis thaliana (Brassicaceae)2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. e30015-Article in journal (Refereed)
    Abstract [en]

    Background: The effect of herbivory on plant fitness varies widely. Understanding the causes of this variation is of considerable interest because of its implications for plant population dynamics and trait evolution. We experimentally defoliated the annual herb Arabidopsis thaliana in a natural population in Sweden to test the hypotheses that (a) plant fitness decreases with increasing damage, (b) tolerance to defoliation is lower before flowering than during flowering, and (c) defoliation before flowering reduces number of seeds more strongly than defoliation during flowering, but the opposite is true for effects on seed size.

    Methodology/Principal Findings: In a first experiment, between 0 and 75% of the leaf area was removed in May from plants that flowered or were about to start flowering. In a second experiment, 0, 25%, or 50% of the leaf area was removed from plants on one of two occasions, in mid April when plants were either in the vegetative rosette or bolting stage, or in mid May when plants were flowering. In the first experiment, seed production was negatively related to leaf area removed, and at the highest damage level, also mean seed size was reduced. In the second experiment, removal of 50% of the leaf area reduced seed production by 60% among plants defoliated early in the season at the vegetative rosettes, and by 22% among plants defoliated early in the season at the bolting stage, but did not reduce seed output of plants defoliated one month later. No seasonal shift in the effect of defoliation on seed size was detected.

    Conclusions/Significance: The results show that leaf damage may reduce the fitness of A. thaliana, and suggest that in this population leaf herbivores feeding on plants before flowering should exert stronger selection on defence traits than those feeding on plants during flowering, given similar damage levels.

  • 10.
    Akiyama, Reiko
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Ågren, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Selection on flowering time in three natural populations of Arabidopsis thalianaManuscript (preprint) (Other academic)
  • 11.
    Alatalo, Juha M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Little, Chelsea J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Jagerbrand, Annika K.
    Molau, Ulf
    Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change2014In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 2, p. e406-Article in journal (Refereed)
    Abstract [en]

    We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years) responses are good predictors for medium-term (7 years) changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-termresponses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years. The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both), different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity-diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant-plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the Arctic.

  • 12.
    Alavioon, Ghazal
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Haploid selection in animals: Exploring the fitness consequences and underlying mechanisms2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    A consequence of sexual reproduction in eukaryotes is the evolution of a biphasic life cycle with alternating diploid and haploid gametic phases. While our focus in evolutionary biology is on selection during the diploid phase, we know relatively little about selection occurring during the haploid gametic stage. This is particularly true in predominantly diploid animals, where gene expression and hence selection have long been thought to be absent in haploid cells like gametes and particularly sperm. During my PhD, I tested the idea of selection during the haploid gametic phase using zebrafish Danio rario as a study species. I combined a large-scale selection experiment over three generations with fitness assays and next-generation sequencing to assess the importance of haploid selection. We measured offspring fitness in all three generations.  In addition, we compared gene expression in brain and testes of F1 and F3 adult male from each treatment by RNA sequencing. We found that offspring sired by longer-lived sperm showed higher survival rate and higher early- and late-life reproductive fitness compared to offspring sired by shorter-lived sperm. We also found differentially expressed genes between the two treatments with functions in metabolic and developmental pathways. These findings suggest that the observed fitness differences to be caused by small expression changes in many basic genes. We also tested for a genetic underpinning of the selected sperm phenotypes and identified allelic differences across the entire genome. Finally, we investigated the additive genetic component and parental effect of different sperm phenotypes. We found generally low additive genetic variation and high parental effects on sperm performance traits. In conclusion, this thesis provides evidence that the phenotypic variation among intact fertile sperm within an ejaculate affects offspring fitness throughout life and provides a clear link between sperm phenotype and offspring fitness and between sperm phenotype and sperm genotype.

    List of papers
    1. Haploid selection within a single ejaculate increases offspring fitness
    Open this publication in new window or tab >>Haploid selection within a single ejaculate increases offspring fitness
    Show others...
    2017 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, no 30, p. 8053-8058Article in journal (Refereed) Published
    Abstract [en]

    An inescapable consequence of sex in eukaryotes is the evolution of a biphasic life cycle with alternating diploid and haploid phases. The occurrence of selection during the haploid phase can have far-reaching consequences for fundamental evolutionary processes including the rate of adaptation, the extent of inbreeding depression, and the load of deleterious mutations, as well as for applied research into fertilization technology. Although haploid selection is well established in plants, current dogma assumes that in animals, intact fertile sperm within a single ejaculate are equivalent at siring viable offspring. Using the zebrafish Danio rerio, we show that selection on phenotypic variation among intact fertile sperm within an ejaculate affects offspring fitness. Longer-lived sperm sired embryos with increased survival and a reduced number of apoptotic cells, and adult male offspring exhibited higher fitness. The effect on embryo viability was carried over into the second generation without further selection and was equally strong in both sexes. Sperm pools selected by motile phenotypes differed genetically at numerous sites throughout the genome. Our findings clearly link within-ejaculate variation in sperm phenotype to offspring fitness and sperm genotype in a vertebrate and have major implications for adaptive evolution.

    National Category
    Evolutionary Biology
    Identifiers
    urn:nbn:se:uu:diva-320335 (URN)10.1073/pnas.1705601114 (DOI)000406189900080 ()28698378 (PubMedID)
    Funder
    Swedish Research CouncilEU, European Research Council
    Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2018-05-07Bibliographically approved
    2. Within-ejaculate selection for sperm longevity reduces male reproductive ageing
    Open this publication in new window or tab >>Within-ejaculate selection for sperm longevity reduces male reproductive ageing
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Males produce numerous sperm in the single ejaculate that greatly outnumber their potential egg targets. Recent studies found that phenotypic variation among sperm in the single ejaculate of a male reflects the phenotype and the genotype of the resulting offspring. Specifically, within-ejaculate sperm selection (WESS) for sperm longevity increased the performance of the resulting offspring in several key life-history traits in early-life. Because increased early-life reproductive performance often correlates with rapid ageing, it is possible that WESS increases early-life fitness at the cost of accelerated senescence. Alternatively, WESS can improve offspring quality throughout the life cycle, including reduced age-specific deterioration. We found that WESS for sperm longevity reduced age-specific deterioration of male fertility and embryo survival, while there is no effect on fertilization success. Remarkably, we found opposing effect of WESS on female fecundity, where selection for sperm longevity resulted in increased early-life performance followed by a slow decline, while unselected controls started low but increased their fecundity with age. Intriguingly, WESS also reduced the age-specific decline in fertilization success in females, suggesting that selection for sperm longevity improves at least some aspects of female reproductive ageing. These results demonstrate that within-ejaculate variation in sperm phenotype contributes to individual variation in animal life histories in the two sexes and have important implications for assisted fertilization programs in livestock and humans. 

    Keywords
    Ageing, Reproductive Success, Sperm Selection, Sperm Competition, Senescence
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Evolutionary Genetics
    Identifiers
    urn:nbn:se:uu:diva-350186 (URN)
    Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-05-07
    3. The fitness consequences of selection among sperm within an ejaculate across generations
    Open this publication in new window or tab >>The fitness consequences of selection among sperm within an ejaculate across generations
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The evolution of a biphasic life cycle with alternating diploid and haploid phases is a necessary consequence of sexual reproduction in eukaryotes. Selection in each of the phases may have far reaching consequences for many evolutionary processes. While our focus in evolutionary biology lies mainly on selection during the diploid phase, we know relatively little about the role and consequences of selection occurring during the haploid gametic stage. This is particularly true in predominantly diploid animals where the haploid gametic phase is very short. To test the importance of haploid selection in animals, we performed a large-scale selection experiment with selection acting on haploid sperm. We selected on sperm longevity within an ejaculate and tested the effects of such selection over three generation. We performed fitness assays for every generation and found that offspring sired by longer-lived sperm generally exhibit higher fitness from early development into adulthood compared to offspring sired by their shorter-lived sibling sperm in all three generations. These fitness effects were carried over into the second generation without further selection in all three generations. Moreover, using RNA sequencing, we assessed differences in tissue specific gene expression between the offspring sired by the two sperm phenotypes in generation F1 and F3. The transcriptomes in both tissues differed significantly between the two treatments. Many very basic housekeeping genes involved in metabolism and development showed small differences in expression in both tissues. Our study provides solid evidence for the far-reaching consequences of selection on different sperm within a single ejaculate in three consecutive generations, and offers exciting new insights into the possible underlying mechanisms. Our results further highlight the importance of selection at the haploid gametic stages for fundamental evolutionary processes and assisted fertilization technologies.

    Keywords
    Haploid selection, sperm selection, offspring fitness, gene expression
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Evolutionary Genetics
    Identifiers
    urn:nbn:se:uu:diva-350190 (URN)
    Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-05-07
    4. Sperm performance traits exhibit low additive genetic component and strong parental effects in external fertilizer
    Open this publication in new window or tab >>Sperm performance traits exhibit low additive genetic component and strong parental effects in external fertilizer
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Despite their key role in determining reproductive success and with that Darwinian fitness, the heritability and underlying additive genetic variance of reproductive traits is still not fully understood. While some traits show relatively high genetic variance, others show very low genetic variance, which is particularly true for complex non-morphological traits. In line with these general patterns, morphological sperm traits show surprisingly high heritability, whereas heritability reported for sperm quality and performance traits generally is lower. A possible explanation for this is the general notion that more fitness related traits show lower levels of additive genetic variance and heritability. We investigated the additive genetic variance and heritability of sperm swimming velocity, the percentage of motile sperm, sperm concentration in the ejaculate and sperm longevity in the externally fertilizing zebrafish Danio rerio. All sperm traits showed low but significant additive genetic variance and high parental components. While the additive genetic variance was significant it was lower than reported in many other studies. A possible explanation for this is that in externally fertilizing species, sperm traits are the prime determinant of fertilization success and high plasticity is crucial for swift adaptations to changes in the environmental conditions such as competition but also water temperature and currents. Given that this is the first study looking into the heritability of sperm traits in an external fertilizer it will be interesting to understand, whether this is true for other externally fertilizing species and taxa.

    Keywords
    additive genetic, parental effect, sperm traits, reproduction
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Evolutionary Genetics
    Identifiers
    urn:nbn:se:uu:diva-350191 (URN)
    Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-06-01
  • 13.
    Alavioon, Ghazal
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Baños-Villalba, Adrian
    University Pablo de Olavide, Ctra.
    Schielzeth, Holger
    Friedrich Schiller University Jena.
    Immler, Simone
    University of East Anglia.
    Sperm performance traits exhibit low additive genetic component and strong parental effects in external fertilizerManuscript (preprint) (Other academic)
    Abstract [en]

    Despite their key role in determining reproductive success and with that Darwinian fitness, the heritability and underlying additive genetic variance of reproductive traits is still not fully understood. While some traits show relatively high genetic variance, others show very low genetic variance, which is particularly true for complex non-morphological traits. In line with these general patterns, morphological sperm traits show surprisingly high heritability, whereas heritability reported for sperm quality and performance traits generally is lower. A possible explanation for this is the general notion that more fitness related traits show lower levels of additive genetic variance and heritability. We investigated the additive genetic variance and heritability of sperm swimming velocity, the percentage of motile sperm, sperm concentration in the ejaculate and sperm longevity in the externally fertilizing zebrafish Danio rerio. All sperm traits showed low but significant additive genetic variance and high parental components. While the additive genetic variance was significant it was lower than reported in many other studies. A possible explanation for this is that in externally fertilizing species, sperm traits are the prime determinant of fertilization success and high plasticity is crucial for swift adaptations to changes in the environmental conditions such as competition but also water temperature and currents. Given that this is the first study looking into the heritability of sperm traits in an external fertilizer it will be interesting to understand, whether this is true for other externally fertilizing species and taxa.

  • 14.
    Alavioon, Ghazal
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Cabrera, Andrea
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    LeChatelier, Magali
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Maklakov, Alexei A.
    University of East Anglia.
    Immler, Simone
    University of East Anglia.
    Within-ejaculate selection for sperm longevity reduces male reproductive ageingManuscript (preprint) (Other academic)
    Abstract [en]

    Males produce numerous sperm in the single ejaculate that greatly outnumber their potential egg targets. Recent studies found that phenotypic variation among sperm in the single ejaculate of a male reflects the phenotype and the genotype of the resulting offspring. Specifically, within-ejaculate sperm selection (WESS) for sperm longevity increased the performance of the resulting offspring in several key life-history traits in early-life. Because increased early-life reproductive performance often correlates with rapid ageing, it is possible that WESS increases early-life fitness at the cost of accelerated senescence. Alternatively, WESS can improve offspring quality throughout the life cycle, including reduced age-specific deterioration. We found that WESS for sperm longevity reduced age-specific deterioration of male fertility and embryo survival, while there is no effect on fertilization success. Remarkably, we found opposing effect of WESS on female fecundity, where selection for sperm longevity resulted in increased early-life performance followed by a slow decline, while unselected controls started low but increased their fecundity with age. Intriguingly, WESS also reduced the age-specific decline in fertilization success in females, suggesting that selection for sperm longevity improves at least some aspects of female reproductive ageing. These results demonstrate that within-ejaculate variation in sperm phenotype contributes to individual variation in animal life histories in the two sexes and have important implications for assisted fertilization programs in livestock and humans. 

  • 15.
    Alavioon, Ghazal
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Hotzy, Cosima
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Nakhro, Khriezhanuo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Rudolf, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Scofield, Douglas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Zajitschek, Susanne
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Spanish Natl Res Council, Donana Biol Stn, Seville 41092, Spain.
    Maklakov, Alex A
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Univ East Anglia, Sch Biol Sci, Norwich NR4 7TJ, Norfolk, England.
    Immler, Simone
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Univ East Anglia, Sch Biol Sci, Norwich NR4 7TJ, Norfolk, England.
    Haploid selection within a single ejaculate increases offspring fitness2017In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, no 30, p. 8053-8058Article in journal (Refereed)
    Abstract [en]

    An inescapable consequence of sex in eukaryotes is the evolution of a biphasic life cycle with alternating diploid and haploid phases. The occurrence of selection during the haploid phase can have far-reaching consequences for fundamental evolutionary processes including the rate of adaptation, the extent of inbreeding depression, and the load of deleterious mutations, as well as for applied research into fertilization technology. Although haploid selection is well established in plants, current dogma assumes that in animals, intact fertile sperm within a single ejaculate are equivalent at siring viable offspring. Using the zebrafish Danio rerio, we show that selection on phenotypic variation among intact fertile sperm within an ejaculate affects offspring fitness. Longer-lived sperm sired embryos with increased survival and a reduced number of apoptotic cells, and adult male offspring exhibited higher fitness. The effect on embryo viability was carried over into the second generation without further selection and was equally strong in both sexes. Sperm pools selected by motile phenotypes differed genetically at numerous sites throughout the genome. Our findings clearly link within-ejaculate variation in sperm phenotype to offspring fitness and sperm genotype in a vertebrate and have major implications for adaptive evolution.

  • 16.
    Alavioon, Ghazal
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Roy M, Francis
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Wyszkowska, Julia
    Jagiellonian University.
    Immler, Simone
    University of East Anglia.
    The fitness consequences of selection among sperm within an ejaculate across generationsManuscript (preprint) (Other academic)
    Abstract [en]

    The evolution of a biphasic life cycle with alternating diploid and haploid phases is a necessary consequence of sexual reproduction in eukaryotes. Selection in each of the phases may have far reaching consequences for many evolutionary processes. While our focus in evolutionary biology lies mainly on selection during the diploid phase, we know relatively little about the role and consequences of selection occurring during the haploid gametic stage. This is particularly true in predominantly diploid animals where the haploid gametic phase is very short. To test the importance of haploid selection in animals, we performed a large-scale selection experiment with selection acting on haploid sperm. We selected on sperm longevity within an ejaculate and tested the effects of such selection over three generation. We performed fitness assays for every generation and found that offspring sired by longer-lived sperm generally exhibit higher fitness from early development into adulthood compared to offspring sired by their shorter-lived sibling sperm in all three generations. These fitness effects were carried over into the second generation without further selection in all three generations. Moreover, using RNA sequencing, we assessed differences in tissue specific gene expression between the offspring sired by the two sperm phenotypes in generation F1 and F3. The transcriptomes in both tissues differed significantly between the two treatments. Many very basic housekeeping genes involved in metabolism and development showed small differences in expression in both tissues. Our study provides solid evidence for the far-reaching consequences of selection on different sperm within a single ejaculate in three consecutive generations, and offers exciting new insights into the possible underlying mechanisms. Our results further highlight the importance of selection at the haploid gametic stages for fundamental evolutionary processes and assisted fertilization technologies.

  • 17.
    Albrecht, Lisa M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Antibiotic Resistance: Selection in the Presence of Metals and Antimicrobials2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The external environment is complex: Antibiotics, metals and antimicrobials do not exist in isolation but in mixtures. Human activities such as animal husbandry, fertilization of agricultural fields and human medicine release high amounts these compounds into the environment. The work in this thesis contributes to our understanding of how the selection of bacterial antibiotic resistance can be facilitated by the pollution by metals and antimicrobials. We show that low levels of antibiotics, metals and combinations thereof can lead to the selection of chromosomally encoded antibiotic resistance genes as well as a multidrug resistance plasmid. The underlying genetic and cellular mechanisms of selection identified relate to mutational changes in a plasmid-encoded metal resistance operon, and metal-associated increases in cellular membrane permeability. We further show that exposure to quaternary ammonium compounds can result in cross-resistance to antibiotics following genetic changes in genes related to efflux, membrane synthesis and transcription/translation. Taken together, the work in this thesis suggests that the stewardship of antibiotics should include prudent use of metals and antimicrobials. 

    List of papers
    1. Selection of a multidrug resistance plasmid by sublethal levels of antibiotics and heavy metals
    Open this publication in new window or tab >>Selection of a multidrug resistance plasmid by sublethal levels of antibiotics and heavy metals
    Show others...
    2014 (English)In: mBio, ISSN 2161-2129, E-ISSN 2150-7511, Vol. 5, no 5, p. e01918-14-Article in journal (Refereed) Published
    Abstract [en]

    How sublethal levels of antibiotics and heavy metals select for clinically important multidrug resistance plasmids is largely unknown. Carriage of plasmids generally confers substantial fitness costs, implying that for the plasmid-carrying bacteria to be maintained in the population, the plasmid cost needs to be balanced by a selective pressure conferred by, for example, antibiotics or heavy metals. We studied the effects of low levels of antibiotics and heavy metals on the selective maintenance of a 220-kbp extended-spectrum β-lactamase (ESBL) plasmid identified in a hospital outbreak of Klebsiella pneumoniae and Escherichia coli. The concentrations of antibiotics and heavy metals required to maintain plasmid-carrying bacteria, the minimal selective concentrations (MSCs), were in all cases below (almost up to 140-fold) the MIC of the plasmid-free susceptible bacteria. This finding indicates that the very low antibiotic and heavy metal levels found in polluted environments and in treated humans and animals might be sufficiently high to maintain multiresistance plasmids. When resistance genes were moved from the plasmid to the chromosome, the MSC decreased, showing that MSC for a specific resistance conditionally depends on genetic context. This finding suggests that a cost-free resistance could be maintained in a population by an infinitesimally low concentration of antibiotic. By studying the effect of combinations of several compounds, it was observed that for certain combinations of drugs each new compound added lowered the minimal selective concentration of the others. This combination effect could be a significant factor in the selection of multidrug resistance plasmids/bacterial clones in complex multidrug environments.

    IMPORTANCE: Antibiotic resistance is in many pathogenic bacteria caused by genes that are carried on large conjugative plasmids. These plasmids typically contain multiple antibiotic resistance genes as well as genes that confer resistance to biocides and heavy metals. In this report, we show that very low concentrations of single antibiotics and heavy metals or combinations of compounds can select for a large plasmid that carries resistance to aminoglycosides, β-lactams, tetracycline, macrolides, trimethoprim, sulfonamide, silver, copper, and arsenic. Our findings suggest that the low levels of antibiotics and heavy metals present in polluted external environments and in treated animals and humans could allow for selection and enrichment of bacteria with multiresistance plasmids and thereby contribute to the emergence, maintenance, and transmission of antibiotic-resistant disease-causing bacteria.

    National Category
    Microbiology in the medical area
    Research subject
    Microbiology; Molecular Genetics
    Identifiers
    urn:nbn:se:uu:diva-235222 (URN)10.1128/mBio.01918-14 (DOI)000345459000067 ()25293762 (PubMedID)
    Available from: 2014-10-29 Created: 2014-10-29 Last updated: 2018-08-10Bibliographically approved
    2. Mutation in the Copper-Induced sil Operon Enables High-Level Silver Resistance and Silver Facilitated Co-Selection of Multidrug Resistance Plasmid
    Open this publication in new window or tab >>Mutation in the Copper-Induced sil Operon Enables High-Level Silver Resistance and Silver Facilitated Co-Selection of Multidrug Resistance Plasmid
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Human activities are responsible for an accumulation of metals in health care and agricultural environments, and plasmid-encoded metal tolerance operons enable bacteria to rapidly adapt to metal exposure under such conditions. While the mechanisms of action of many metal resistance systems have been described, there is still limited understanding of their role in co-selection of antibiotic resistance in metal-containing environments. Whether plasmid-encoded metal resistance genes confer significant selective advantages is of interest as it has implications for plasmid enrichment and the spread of plasmid-borne antibiotic resistance genes. To increase our understanding of plasmid-mediated metal resistance, we studied the sil operon and its phenotypes in E. coli during growth in the absence and presence of silver and copper. We found that the sil operon provides resistance to both silver and copper. However, it is induced by copper only, and constitutive expression due to point mutations in the two-component silS gene provides high-level silver resistance. Furthermore, we showed that a high-level silver resistant mutant could be enriched in the presence of silver. This enrichment entailed co-selection of the multidrug resistance plasmid pUUH239.2. Our results show that a copper resistance operon can provide high-level silver resistance following a single point mutation, and that the silver resistance phenotype subsequently can co-select for antibiotic resistance in the presence of silver. 

    National Category
    Other Medical Sciences not elsewhere specified
    Identifiers
    urn:nbn:se:uu:diva-356961 (URN)
    Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-10
    3. Potentiation of the Selective Effect of Antibiotics by Metal Ions
    Open this publication in new window or tab >>Potentiation of the Selective Effect of Antibiotics by Metal Ions
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Complex mixtures of antibiotics and metals are present in many environments ranging from municipal sewage to irrigation water and manure used as agricultural fertilizer. Such mixtures of drugs and metals exert unique selection pressures on local bacterial communities and could function as hotspots for enrichment of antibiotic resistance genes. The presence of metals in the environment has previously been linked to increases in tolerance to antibiotics. In this study, we investigated metal-potentiated selection of antibiotic resistant Salmonella enterica strains. Six environmentally relevant metals were examined in combinations with three different antibiotics. By performing competitions between an antibiotic resistant mutant and the isogenic wild type in each metal-antibiotic combination, we assessed the minimal selective concentration (MSC) of the antibiotic for the resistant strain. The metals silver, cadmium and mercury all exhibited potentiating effects, reducing the MSC of the antibiotic up to 5-fold as compared to in the absence of the metal. We further show that the potentiating metals increased permeability of the cellular outer membrane. These results demonstrate that the presence of a metal can decrease the concentration of an antibiotic required to select for an antibiotic resistant strain, and they indicate that this process involves metal-facilitated uptake of the antibiotic following damage to the outer membrane.

    Keywords
    Antibiotic resistance, Selection
    National Category
    Other Medical Sciences not elsewhere specified
    Identifiers
    urn:nbn:se:uu:diva-356966 (URN)
    Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-10
    4. Cross-Resistance to Antibiotics After Exposure to Qaternary Ammonium Compounds
    Open this publication in new window or tab >>Cross-Resistance to Antibiotics After Exposure to Qaternary Ammonium Compounds
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Quaternary ammonium compounds (QACs) are common antimicrobials that are used in a variety of consumer products, such as lotions, sunscreen, hair conditioners and hand sanitizers, to inhibit bacterial growth. However, it has been noted that bacteria exposed to QACs can develop resistance, and additionally, resistance to QACs has been observed to provide cross-resistance to antibiotics. In order to identify genetic adaptations for this resistance pattern, we exposed E. coli to three different QACs at sub-MIC and above-MIC concentrations, and identified genetic changes by whole genome sequencing. We found that initial adaptation, at sub-MIC levels, happened through efflux mechanisms, and that subsequent genetic changes, during above-MIC exposure, involved genes associated with the cell membranes and with transcription/translation. We also found that these genetic changes provided cross-resistance to other QACs as well as to several antibiotics.

    Keywords
    Antibiotic resistance, Antimicrobials, Cross-resistance
    National Category
    Other Medical Sciences not elsewhere specified
    Identifiers
    urn:nbn:se:uu:diva-356967 (URN)
    Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-10
  • 18.
    Alexander, Michelle
    et al.
    Univ York, York YO10 5DD, N Yorkshire, England.;Univ Aberdeen, Sch Geosci, Dept Archaeol, Aberdeen AB24 3UF, Scotland..
    Ho, Simon Y. W.
    Univ Sydney, Sch Biol Sci, Sydney, NSW 2006, Australia..
    Molak, Martyna
    Polish Acad Sci, Museum & Inst Zool, PL-00679 Warsaw, Poland..
    Barnett, Ross
    Palaeogen & Bioarchaeol Res Network, Res Lab Archaeol, Oxford OX1 3QY, England..
    Carlborg, Örjan
    Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Dorshorst, Ben
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Honaker, Christa
    Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Besnier, Francois
    Inst Marine Res, Sect Populat Genet, N-5024 Bergen, Norway..
    Wahlberg, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular Medicine.
    Dobney, Keith
    Univ Aberdeen, Sch Geosci, Dept Archaeol, Aberdeen AB24 3UF, Scotland..
    Siegel, Paul
    Virginia Tech, Dept Anim & Poultry Sci, Blacksburg, VA 24061 USA..
    Andersson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Swedish Univ Agr Sci, Dept Anim Breeding & Genet, S-75007 Uppsala, Sweden..
    Larson, Greger
    Palaeogen & Bioarchaeol Res Network, Res Lab Archaeol, Oxford OX1 3QY, England..
    Mitogenomic analysis of a 50-generation chicken pedigree reveals a rapid rate of mitochondrial evolution and evidence for paternal mtDNA inheritance2015In: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 11, no 10, article id 20150561Article in journal (Refereed)
    Abstract [en]

    Mitochondrial genomes represent a valuable source of data for evolutionary research, but studies of their short-term evolution have typically been limited to invertebrates, humans and laboratory organisms. Here we present a detailed study of 12 mitochondrial genomes that span a total of 385 transmissions in a well-documented 50-generation pedigree in which two lineages of chickens were selected for low and high juvenile body weight. These data allowed us to test the hypothesis of time-dependent evolutionary rates and the assumption of strict maternal mitochondrial transmission, and to investigate the role of mitochondrial mutations in determining phenotype. The identification of a non-synonymous mutation in ND4L and a synonymous mutation in CYTB, both novel mutations in Gallus, allowed us to estimate a molecular rate of 3.13 x 10(-7) mutations/site/year (95% confidence interval 3.75 x 10(-8)-1.12 x 10(-6)). This is substantially higher than avian rate estimates based upon fossil calibrations. Ascertaining which of the two novel mutations was present in an additional 49 individuals also revealed an instance of paternal inheritance of mtDNA. Lastly, an association analysis demonstrated that neither of the point mutations was strongly associated with the phenotypic differences between the two selection lines. Together, these observations reveal the highly dynamic nature of mitochondrial evolution over short time periods.

  • 19. Alfoeldi, Jessica
    et al.
    Di Palma, Federica
    Grabherr, Manfred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Williams, Christina
    Kong, Lesheng
    Mauceli, Evan
    Russell, Pamela
    Lowe, Craig B.
    Glor, Richard E.
    Jaffe, Jacob D.
    Ray, David A.
    Boissinot, Stephane
    Shedlock, Andrew M.
    Botka, Christopher
    Castoe, Todd A.
    Colbourne, John K.
    Fujita, Matthew K.
    Moreno, Ricardo Godinez
    ten Hallers, Boudewijn F.
    Haussler, David
    Heger, Andreas
    Heiman, David
    Janes, Daniel E.
    Johnson, Jeremy
    de Jong, Pieter J.
    Koriabine, Maxim Y.
    Lara, Marcia
    Novick, Peter A.
    Organ, Chris L.
    Peach, Sally E.
    Poe, Steven
    Pollock, David D.
    de Queiroz, Kevin
    Sanger, Thomas
    Searle, Steve
    Smith, Jeremy D.
    Smith, Zachary
    Swofford, Ross
    Turner-Maier, Jason
    Wade, Juli
    Young, Sarah
    Zadissa, Amonida
    Edwards, Scott V.
    Glenn, Travis C.
    Schneider, Christopher J.
    Losos, Jonathan B.
    Lander, Eric S.
    Breen, Matthew
    Ponting, Chris P.
    Lindblad-Toh, Kerstin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    The genome of the green anole lizard and a comparative analysis with birds and mammals2011In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 477, no 7366, p. 587-591Article in journal (Refereed)
    Abstract [en]

    The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments(1). Among amniotes, genome sequences are available for mammals and birds(2-4), but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes(2). Also, A. carolinensis mobile elements are very young and diverse-more so than in any other sequenced amniote genome. The GC content of this lizard genome is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds(5). We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations.

  • 20. Alho, J. S.
    et al.
    Herczeg, G.
    Laugen, A. T.
    Raesaenen, K.
    Laurila, Anssi
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Merila, J.
    Allen's rule revisited: quantitative genetics of extremity length in the common frog along a latitudinal gradient2011In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 24, no 1, p. 59-70Article in journal (Refereed)
    Abstract [en]

    Ecogeographical rules linking climate to morphology have gained renewed interest because of climate change. Yet few studies have evaluated to what extent geographical trends ascribed to these rules have a genetic, rather than environmentally determined, basis. This applies especially to Allen's rule, which states that the relative extremity length decreases with increasing latitude. We studied leg length in the common frog (Rana temporaria) along a 1500 km latitudinal gradient utilizing wild and common garden data. In the wild, the body size-corrected femur and tibia lengths did not conform to Allen's rule but peaked at mid-latitudes. However, the ratio of femur to tibia length increased in the north, and the common garden data revealed a genetic cline consistent with Allen's rule in some trait and treatment combinations. While selection may have shortened the leg length in the north, the genetic trend seems to be partially masked by environmental effects.

  • 21.
    Ali, Raja Hashim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Bogusz, Marcin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Whelan, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    A graph-based approach for improving the homologyinference in multiple sequence alignmentsManuscript (preprint) (Other academic)
    Abstract [en]

    Multiple sequence alignment (MSA) is ubiquitous in evolutionary studies and other areas ofbioinformatics. In nearly all cases MSAs are taken to be a known and xed quantity on which toperform downstream analysis despite extensive evidence that MSA accuracy and uncertainty aectsresults. Mistakes in the MSA are known to cause a wide range of problems for downstream evolutionaryinference, ranging from false inference of positive selection to long branch attraction artifacts. The mostpopular approach to dealing with this problem is to remove (lter) specic columns in the MSA thatare thought to be prone to error, either through proximity to gaps or through some scoring function.Although popular, this approach has had mixed success and several studies have even suggested thatltering might be detrimental to phylogenetic studies. Here we present a dierent approach to dealingwith MSA accuracy and uncertainty through a graph-based approach implemented in the freely availablesoftware Divvier. The aim of Divvier is to identify clusters of characters that have strong statisticalevidence of shared homology, based on the output of a pair hidden Markov model. These clusters canthen be used to either lter characters out the MSA, through a process we call partial ltering, or torepresent each of the clusters in a new column, through a process we call divvying up. We validateour approach through its performance on real and simulated benchmarks, nding Divvier substantiallyoutperforms all other ltering software for treating MSAs by retaining more true positive homology callsand removing more false positive homology calls. We also nd that Divvier, in contrast to other lteringtools, can alleviate long branch attraction artifacts induced by MSA and reduces the variation in treeestimates caused by MSA uncertainty.

  • 22.
    Amcoff, Mirjam
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Fishing for Females: Sensory Exploitation in the Swordtail Characin2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mate choice plays an important role in sexual selection and speciation. The evolution of mate choice is intriguing in cases where choosy individuals gain little except for genetic material from the mate and where the trait used as a criterion for the choice is costly to its bearer. The sensory exploitation hypothesis is an interesting idea that applies to such cases because it suggests that sexual preferences may arise as side-effects of preferences that are under selection in other contexts. The role of mate choice in speciation is strong but is debated because the reasons for population divergence in mate preferences and sexual traits are sometimes hard to explain. Also in this context sensory exploitation offers a potential explanation in that a link between natural and sexual selection may result in divergence in sexual selection whenever populations differ in natural selection.

    In this thesis, I test several aspects of this hypothesis in a species of fish, the swordtail characin (Corynopoma riisei). In this species males display a flag-like ornament that grows from the operculum. Because females respond to this ornament by biting at it, it has been proposed to act as a food-mimic. By manipulating female food type and quantity, and testing the resulting female preference for the male ornament, I find support for the theory that the preference has evolved through sensory exploitation and that females indeed appear to relate the ornament to a food item. Furthermore, I show that sensory exploitation can lead to morphological divergence among natural populations in this species. Apart from the flag-ornament, other courtship signals are also investigated. The results show that the relative importance of different signals may vary depending on receiver motivation. This suggests that various aspects of both male courtship signals and the conditions during which they are being signalled should be considered to gain a full understanding of mate choice and its role in sexual selection and speciation.

    List of papers
    1. Does female feeding motivation affect the response to a food-mimicking male ornament in the swordtail characin Corynopoma riisei?
    Open this publication in new window or tab >>Does female feeding motivation affect the response to a food-mimicking male ornament in the swordtail characin Corynopoma riisei?
    2013 (English)In: Journal of Fish Biology, ISSN 0022-1112, E-ISSN 1095-8649, Vol. 83, no 2, p. 343-354Article in journal (Refereed) Published
    Abstract [en]

    Female response to various aspects of male trait morphology and the effect of female feeding motivation were investigated in the swordtail characin Corynopoma riisei, a species where males are equipped with a flag-like food-mimicking ornament that grows from the operculum. Unfed females responded more strongly to the male ornament and showed a stronger preference for larger ornaments than did fed females. Females were shown not to discriminate between artificial male ornaments of either undamaged or damaged shape.

    Keywords
    diet, mate preference, plasticity, sensory exploitation, signalling
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-206572 (URN)10.1111/jfb.12175 (DOI)000322547900007 ()
    Available from: 2013-09-02 Created: 2013-09-02 Last updated: 2017-12-06Bibliographically approved
    2. Sensory exploitation and plasticity in female mate choice in the swordtail characin
    Open this publication in new window or tab >>Sensory exploitation and plasticity in female mate choice in the swordtail characin
    2013 (English)In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 85, no 5, p. 891-898Article in journal (Refereed) Published
    Abstract [en]

    Despite extensive research in the field of sexual selection, the evolutionary origin and maintenance of preferences for sexual ornaments are still debated. Recent studies have pointed out that plasticity in mate choice might be more common than previously thought, but little is still known about the factors that affect such plasticity. The swordtail characin, Corynopoma riisei, is a tropical fish species in which males use a food-mimicking ornament to attract females. We tested whether ecological factors, more specifically prior foraging experience, can affect female preference for male ornaments. For this, we habituated females on a diet consisting of either red-coloured food or standard-coloured green food items and then we tested whether female preferences for artificially red-coloured male ornaments matched their previous foraging experience. We found a strong effect of food treatment: females trained on red food showed a stronger response to males with red-coloured ornaments than females trained on green food. Our results show that ecological variation can generate divergence of female preferences for male ornaments and that the response in preference to environmental change can be rapid if the bias is partly learnt.

    Keywords
    Corynopoma riisei, diet, mate choice, sensory exploitation, sexual selection, swordtail characin
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-203305 (URN)10.1016/j.anbehav.2013.02.001 (DOI)000319332000004 ()
    Available from: 2013-07-08 Created: 2013-07-08 Last updated: 2017-12-06Bibliographically approved
    3. Diversification of a Food-Mimicking Male Ornament via Sensory Drive
    Open this publication in new window or tab >>Diversification of a Food-Mimicking Male Ornament via Sensory Drive
    2012 (English)In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 22, no 15, p. 1440-1443Article in journal (Refereed) Published
    Abstract [en]

    The evolutionary divergence of sexual signals is often important during the formation of new animal species, but our understanding of the origin of signal diversity is limited [1, 2]. Sensory drive, the optimization of communication signal efficiency through matching to the local environment, has been highlighted as a potential promoter of diversification and speciation [3]. The swordtail characin (Corynopoma riisei) is a tropical fish in which males display a flag-like ornament that elicits female foraging behavior during courtship. We show that the shape of the male ornament covaries with female diet across natural populations. More specifically, natural populations in which the female diet is more dominated by ants exhibit male ornaments more similar to the shape of an ant. Feeding experiments confirm that females habituated to a diet of ants prefer to bite at male ornaments from populations with a diet more dominated by ants. Our results show that the male ornament functions as a "fishing lure" that is diversifying in shape to match local variation in female search images employed during foraging. This direct link between variation in female feeding ecology and the evolutionary diversification of male sexual ornaments suggests that sensory drive may be a common engine of signal divergence.

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-181121 (URN)10.1016/j.cub.2012.05.050 (DOI)000307415000026 ()
    Available from: 2012-09-19 Created: 2012-09-17 Last updated: 2017-12-07Bibliographically approved
    4. Courtship signalling with a labile bilateral signal: males show their best side
    Open this publication in new window or tab >>Courtship signalling with a labile bilateral signal: males show their best side
    2009 (English)In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 63, no 12, p. 1717-1725Article in journal (Refereed) Published
    Abstract [en]

    Asymmetries in courtship signals can result from both developmental instability during ontogeny and from temporary or permanent damage following mating, fighting, or interactions with predators. These two types of asymmetries, which can be divided into fluctuating asymmetry (FA) and damage asymmetry (DA), have both been suggested to play an important role in mate choice as potential honest indicators of phenotypic and/or genetic quality, while at the same time, DA may affect ornament asymmetry in a random manner. Interestingly, despite the massive research effort that has been devoted to the study of asymmetry during the past decades, very little is known about how an individual's behaviour relates to asymmetry. Here, we measure and characterise asymmetry in morphological courtship signals in Corynopoma riisei, a fish where males carry elaborate paddle-like appendices on each side of the body that they display in front of females during courtship. Moreover, we investigate whether male courtship display, employing this bilateral morphological trait, reflects trait asymmetry. Finally, we assess whether males respond to phenotypic manipulations of DA with corresponding changes in courtship behaviour. We show that male display behaviour is asymmetric in a manner that reflects asymmetry of their morphological courtship trait and that male display behaviour responds to manipulations of asymmetry of these paddles. Our results thus suggest that males preferentially use their best side and, hence, that males respond adaptively to temporary changes in signal trait asymmetry.

    Keywords
    Sexual signalling, Sexual selection, Lateralization, Mate choice, Sensory bias, Indicator, Self-awareness
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-127482 (URN)10.1007/s00265-009-0785-7 (DOI)000270684200003 ()
    Available from: 2010-07-15 Created: 2010-07-13 Last updated: 2017-12-12Bibliographically approved
    5. Multiple male sexual signals and female responsiveness in the swordtail characin, Corynopoma riisei
    Open this publication in new window or tab >>Multiple male sexual signals and female responsiveness in the swordtail characin, Corynopoma riisei
    2015 (English)In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 98, no 7, p. 1731-1740Article in journal (Refereed) Published
    Abstract [en]

    In the courtship process, multiple signals are often used between the signaller and the receiver. Here we describe female response to multiple male visual morphological and behavioural signals in the swordtail characin, Corynopoma riisei. The swordtail characin is a species in which males display several morphological ornaments as well as a rich courtship repertoire. Our results show that high courtship intensity was associated with an increased female response towards the male ornament, increased number of mating attempts and a reduction in female aggression. The morphological aspects investigated here did not seem to correlate with female response. This may indicate that, when both behaviour and morphology are considered simultaneously, courtship behaviour may have priority over morphological cues in this species.

    Keywords
    courtship, multiple signalling, visual cues, morphology, mate choice
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-207333 (URN)10.1007/s10641-015-0388-2 (DOI)000355620700001 ()
    Available from: 2013-09-12 Created: 2013-09-12 Last updated: 2017-12-06Bibliographically approved
  • 23.
    Amcoff, Mirjam
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kolm, Niclas
    Multiple male sexual signals and female responsiveness in the swordtail characin, Corynopoma riisei2015In: Environmental Biology of Fishes, ISSN 0378-1909, E-ISSN 1573-5133, Vol. 98, no 7, p. 1731-1740Article in journal (Refereed)
    Abstract [en]

    In the courtship process, multiple signals are often used between the signaller and the receiver. Here we describe female response to multiple male visual morphological and behavioural signals in the swordtail characin, Corynopoma riisei. The swordtail characin is a species in which males display several morphological ornaments as well as a rich courtship repertoire. Our results show that high courtship intensity was associated with an increased female response towards the male ornament, increased number of mating attempts and a reduction in female aggression. The morphological aspects investigated here did not seem to correlate with female response. This may indicate that, when both behaviour and morphology are considered simultaneously, courtship behaviour may have priority over morphological cues in this species.

  • 24.
    Ament Velásquez, Sandra Lorena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Genomic insights into the reproductive biology of Icmadophilaceae species (lichenized ascomycetes)2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sexual reproduction or its absence has significant consequences for the evolutionary potential of a species, but little is known of the molecular basis of mating systems in non-model organisms. In Fungi, an extremely diverse and ecologically important group of Eukaryotes, sexual identity is regulated by mating type (MAT) genes with specific protein domains. The MAT genes determine if a species is capable of selfing (homothallism) or not (heterothallism). Among Fungi, almost one fifth of the species establish symbiotic associations with algae or cyanobacteria, that is, they form lichens. Yet, very few studies have explored the reproductive genetics of lichenized species. In this work, I extended current research to a poorly known family of lichen-forming fungi: the Icmadophilaceae. I used Next Generation Sequencing (NGS) genomic and transcriptomic data to produce gene models of the MAT genes and its flanking regions of four representative species. I found that the putative asexual Thamnolia vermicularis and Siphula ceratites, as well as the sexual Dibaeis baeomyces have a gene configuration concordant with heterothallism, while the sexual Icmadophila ericetorum is most likely homothallic. Additionally, I applied a number of methods to detect recombination as a proxy for cryptic sex in T. vermiculars populations from the Northern Hemisphere. Like previous studies, I found no evidence of recombination and very little genetic variation, which is at odds with the recovered structure of the MAT locus. On the other hand, a preliminary exploration of the GC content of the metagenome (including all the genomes within the lichen thallus) of S. ceratites revealed that the symbiotic association involves Alphaproteobacteria, as has been described before for taxonomically unrelated lichens but never before for this species. Overall, my results offer a wealth of information for new and more advance research into the reproductive and evolutionary biology of Icmadophilaceae species, an unexplored portion of fungal biodiversity.

  • 25.
    Ament-Velasquez, Sandra Lorena
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology. Univ Montpellier, Inst Evolutionary Sci, CNRS, IRD,EPHE, Pl Eugene Bataillon, F-34095 Montpellier, France..
    Figuet, E.
    Univ Montpellier, Inst Evolutionary Sci, CNRS, IRD,EPHE, Pl Eugene Bataillon, F-34095 Montpellier, France..
    Ballenghien, M.
    Univ Montpellier, Inst Evolutionary Sci, CNRS, IRD,EPHE, Pl Eugene Bataillon, F-34095 Montpellier, France..
    Zattara, E. E.
    Indiana Univ, Dept Biol, 107 S Indiana Ave, Bloomington, IN 47405 USA.;Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, 10th St & Constitut Ave NW, Washington, DC 20560 USA..
    Norenburg, J. L.
    Smithsonian Inst, Natl Museum Nat Hist, Dept Invertebrate Zool, 10th St & Constitut Ave NW, Washington, DC 20560 USA..
    Fernandez-Alvarez, F. A.
    CSIC Barcelona, Inst Ciencies Mar, Barcelona 08003, Spain..
    Bierne, J.
    Univ Reims, Lab Biol Cellulaire & Mol, 9 Blvd Paix, F-51100 Reims, France..
    Bierne, N.
    Univ Montpellier, Inst Evolutionary Sci, CNRS, IRD,EPHE, Pl Eugene Bataillon, F-34095 Montpellier, France..
    Galtier, N.
    Univ Montpellier, Inst Evolutionary Sci, CNRS, IRD,EPHE, Pl Eugene Bataillon, F-34095 Montpellier, France..
    Population genomics of sexual and asexual lineages in fissiparous ribbon worms (Lineus, Nemertea): hybridization, polyploidy and the Meselson effect2016In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, no 14, p. 3356-3369Article in journal (Refereed)
    Abstract [en]

    Comparative population genetics in asexual vs. sexual species offers the opportunity to investigate the impact of asexuality on genome evolution. Here, we analyse coding sequence polymorphism and divergence patterns in the fascinating Lineus ribbon worms, a group of marine, carnivorous nemerteans with unusual regeneration abilities, and in which asexual reproduction by fissiparity is documented. The population genomics of the fissiparous L. pseudolacteus is characterized by an extremely high level of heterozygosity and unexpectedly elevated pi(N)/pi(S) ratio, in apparent agreement with theoretical expectations under clonal evolution. Analysis of among-species allele sharing and read-count distribution, however, reveals that L. pseudolacteus is a triploid hybrid between Atlantic populations of L. sanguineus and L. lacteus. We model and quantify the relative impact of hybridity, polyploidy and asexuality on molecular variation patterns in L. pseudolacteus and conclude that (i) the peculiarities of L. pseudolacteus population genomics result in the first place from hybridization and (ii) the accumulation of new mutations through the Meselson effect is more than compensated by processes of heterozygosity erosion, such as gene conversion or gene copy loss. This study illustrates the complexity of the evolutionary processes associated with asexuality and identifies L. pseudolacteus as a promising model to study the first steps of polyploid genome evolution in an asexual context.

  • 26. Andersen, G
    et al.
    Merico, A
    Björnberg, O
    Andersen, B
    Schnackerz, K D
    Dobritzsch, Doreen
    Karolinska Institutet.
    Piskur, J
    Compagno, C
    Catabolism of pyrimidines in yeast: a tool to understand degradation of anticancer drugs2006In: Nucleosides, Nucleotides & Nucleic Acids, ISSN 1525-7770, E-ISSN 1532-2335, Vol. 25, no 9-11, p. 991-996Article in journal (Refereed)
    Abstract [en]

    The pyrimidine catabolic pathway is of crucial importance in cancer patients because it is involved in degradation of several chemotherapeutic drugs, such as 5-fluorouracil; it also is important in plants, unicellular eukaryotes, and bacteria for the degradation of pyrimidine-based biocides/antibiotics. During the last decade we have developed a yeast species, Saccharomyces kluyveri, as a model and tool to study the genes and enzymes of the pyrimidine catabolic pathway. In this report, we studied degradation of uracil and its putative degradation products in 38 yeasts and showed that this pathway was present in the ancient yeasts but was lost approximately 100 million years ago in the S. cerevisiae lineage.

  • 27.
    Andersson, Dan I.
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Jerlström-Hultqvist, Jon
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Näsvall, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology.
    Evolution of New Functions De Novo and from Preexisting Genes2015In: Cold Spring Harbor Perspectives in Biology, ISSN 1943-0264, E-ISSN 1943-0264, Vol. 7, no 6, article id a017996Article, review/survey (Refereed)
    Abstract [en]

    How the enormous structural and functional diversity of new genes and proteins was generated (estimated to be 10^10-€“10^12 different proteins in all organisms on earth [Choi I-G, Kim S-H. 2006. Evolution of protein structural classes and protein sequence families. Proc Natl Acad Sci 103: 14056–14061] is a central biological question that has a long and rich history. Extensive work during the last 80 years have shown that new genes that play important roles in lineage-specific phenotypes and adaptation can originate through a multitude of different mechanisms, including duplication, lateral gene transfer, gene fusion/fission, and de novo origination. In this review, we focus on two main processes as generators of new functions: evolution of new genes by duplication and divergence of pre-existing genes and de novo gene origination in which a whole protein-coding gene evolves from a noncoding sequence.

  • 28.
    Andersson, Jan O
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology. Mikrobiologi.
    A review of "Microbial Phylogeny and Evolution: Concepts and Controversies"2006In: Systematic Biology, ISSN 1063-5157, E-ISSN 1076-836X, Vol. 55, no 2, p. 359-361Article, book review (Other (popular science, discussion, etc.))
  • 29.
    Andersson, Jan O
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Double peaks reveal rare diplomonad sex2012In: Trends in Parasitology, ISSN 1471-4922, E-ISSN 1471-5007, Vol. 28, no 2, p. 46-52Article in journal (Refereed)
    Abstract [en]

    Diplomonads, single-celled eukaryotes, are unusual in having two nuclei. Each nucleus contains two copies of the genome and is transcriptionally active. It has long been assumed that diplomonads in general and Giardia intestinalis in particular are asexual. Genomic and population genetic data now challenge that assumption and extensive allelic sequence heterogeneity has been reported in some but not all examined diplomonad lineages. Here it is argued, in contrast to common assumptions, that allelic differences indicate recent sexual events, and isolates that have divided asexually for many generations have lost their allelic variation owing to within-cell recombination. Consequently, directed studies of the allelic sequence heterogeneity in diverse diplomonad lineages are likely to reveal details about the enigmatic diplomonad sexual life cycle.

  • 30.
    Andersson, Jan O
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution.
    Gene Transfer and the Chimeric Nature of Eukaryotic Genomes2013In: Lateral Gene Transfer in Evolution / [ed] Uri Gophna, New York: Springer Science+Business Media B.V., 2013, p. 181-197Chapter in book (Other academic)
  • 31.
    Andersson, Jan O
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Phylogenomic approaches underestimate eukaryotic gene transfer2012In: Mobile Genetic Elements, Vol. 2, no 1, p. 59-62Article in journal (Refereed)
    Abstract [en]

    Phylogenomic approaches have shown that eukaryotes acquire genes via gene transfer. However, there are two fundamental problems for most of these analyses; only transfers from prokaryotes are analyzed and the screening procedures applied assume that gene transfer is rare for eukaryotes. Directed studies of the impact of gene transfer on diverse eukaryotic lineages produce a much more complex picture. Many gene families are affected by multiple transfer events from prokaryotes to eukaryotes, and transfers between eukaryotic lineages are routinely detected. This suggests that the assumptions applied in traditional phylogenomic approaches are too naïve and result in many false negatives. This issue was recently addressed by identifying and analyzing the evolutionary history of 49 patchily distributed proteins shared between Dictyostelium and bacteria. The vast majority of these gene families showed strong indications of gene transfers, both between and within the three domains of life. However, only one of these was previously reported as a gene transfer candidate using a traditional phylogenomic approach. This clearly illustrates that more realistic assumptions are urgently needed in genome-wide studies of eukaryotic gene transfer.

  • 32.
    Andersson, Jan O
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Andersson, Siv GE
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Genome degradation is an ongoing process in Rickettsia1999In: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, ISSN 0737-403, Vol. 16, no 9, p. 1178-1191Article in journal (Other academic)
    Abstract [en]

    To study reductive evolutionary processes in bacterial genomes, we examine sequences in the Rickettsia genomes which are unconstrained by selection and evolve as pseudogenes, one of which is the metK gene, which codes for AdoMet synthetase. Here, we sequenced the metK gene and three surrounding genes in eight different species of the genus Rickettsia. The metK gene was found to contain a high incidence of deletions in six lineages, while the three genes in its surroundings were functionally conserved in all eight lineages. A more drastic example of gene degradation was identified in the metK downstream region, which contained an open reading frame in Rickettsia felis. Remnants of this open reading frame could be reconstructed in five additional species by eliminating sites of frameshift mutations and termination codons. A detailed examination of the two reconstructed genes revealed that deletions strongly predominate over insertions and that there is a strong transition bias for point mutations which is coupled to an excess of GC-to-AT substitutions. Since the molecular evolution of these inactive genes should reflect the rates and patterns of neutral mutations, our results strongly suggest that there is a high spontaneous rate of deletions as well as a strong mutation bias toward AT pairs in the Rickettsia genomes. This may explain the low genomic G + C content (29%), the small genome size (1.1 Mb), and the high noncoding content (24%), as well as the presence of several pseudogenes in the Rickettsia prowazekii genome.

  • 33.
    Andersson, Jan O
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Andersson, Siv GE
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Genomic rearrangements during evolution of the obligate intracellular parasite Rickettsia prowazekii as inferred from an analysis of 52015 bp nucleotide sequence1997In: Microbiology, ISSN 1350-0872, E-ISSN 1465-2080, Vol. 143, no 8, p. 2783-2795Article in journal (Other academic)
    Abstract [en]

    In this study a description is given of the sequence and analysis of 52 kb from the 1.1 Mb genome of Rickettsia prowazekii, a member of the alpha-Proteobacteria. An investigation was made of nucleotide frequencies and amino acid composition patterns of 41 coding sequences, distributed in 10 genomic contigs, of which 32 were found to have putative homologues in the public databases. Overall, the coding content of the individual contigs ranged from 59 to 97%, with a mean of 81%. The genes putatively identified included genes involved in the biosynthesis of nucleotides, macromolecules and cell wall structures as well as citric acid cycle component genes. In addition, a putative identification was made of a member of the regulatory response family of two-component signal transduction systems as well as a gene encoding haemolysin. For one gene, the homologue of metK, an internal stop codon was discovered within a region that is otherwise highly conserved. Comparisons with the genomic structures of Escherichia coli, Haemophilus influenzae and Bacillus subtilis have revealed several atypical gene organization patterns in the R. prowazekii genome. For example, R. prowazekii was found to have a unique arrangement of genes upstream of dnaA in a region that is highly conserved among other microbial genomes and thought to represent the origin of replication of a primordial replicon. The results presented in this paper support the hypothesis that the R. prowazekii genome is a highly derived genome and provide examples of gene order structures that are unique for the Rickettsia.

  • 34.
    Andersson, Jan O
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Andersson, Siv GE
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Insights into the evolutionary process of genome degradation1999In: Current Opinion in Genetics and Development, ISSN 0959-437X, E-ISSN 1879-0380, Vol. 9, no 6, p. 664-671Article in journal (Refereed)
    Abstract [en]

    Studies of noncoding and pseudogene sequence diversity, particularly in Rickettsia, have begun to reveal the basic principles of genome degradation in microorganisms. Increasingly, studies of genes and genomes suggest that there has been an extensive amount of horizontal gene transfer among microorganisms. As this inflow of genetic material does not seem generally to have resulted in genome size expansions, however, degenerative processes must be at the very least as widespread as horizontal gene transfer. The basic principles of gene degradation and elimination that are being explored in Rickettsia are likely to be of major importance for our understanding of how microbial genomes evolve.

  • 35.
    Andersson, Jan O
    et al.
    Canadian Institute for Advanced Research, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
    Doolittle, W Ford
    Nesbø, Camilla L
    Genomics. Are there bugs in our genome?2001In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 292, no 5523, p. 1848-1850Article in journal (Refereed)
  • 36.
    Andersson, Jan O.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Hirt, Robert P.
    Foster, Peter G.
    Roger, Andrew J.
    Evolution of four gene families with patchy phylogenetic distributions: influx of genes into protist genomes2006In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 6, article id 27Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Lateral gene transfer (LGT) in eukaryotes from non-organellar sources is a controversial subject in need of further study. Here we present gene distribution and phylogenetic analyses of the genes encoding the hybrid-cluster protein, A-type flavoprotein, glucosamine-6-phosphate isomerase, and alcohol dehydrogenase E. These four genes have a limited distribution among sequenced prokaryotic and eukaryotic genomes and were previously implicated in gene transfer events affecting eukaryotes. If our previous contention that these genes were introduced by LGT independently into the diplomonad and Entamoeba lineages were true, we expect that the number of putative transfers and the phylogenetic signal supporting LGT should be stable or increase, rather than decrease, when novel eukaryotic and prokaryotic homologs are added to the analyses. RESULTS: The addition of homologs from phagotrophic protists, including several Entamoeba species, the pelobiont Mastigamoeba balamuthi, and the parabasalid Trichomonas vaginalis, and a large quantity of sequences from genome projects resulted in an apparent increase in the number of putative transfer events affecting all three domains of life. Some of the eukaryotic transfers affect a wide range of protists, such as three divergent lineages of Amoebozoa, represented by Entamoeba, Mastigamoeba, and Dictyostelium, while other transfers only affect a limited diversity, for example only the Entamoeba lineage. These observations are consistent with a model where these genes have been introduced into protist genomes independently from various sources over a long evolutionary time. CONCLUSION: Phylogenetic analyses of the updated datasets using more sophisticated phylogenetic methods, in combination with the gene distribution analyses, strengthened, rather than weakened, the support for LGT as an important mechanism affecting the evolution of these gene families. Thus, gene transfer seems to be an on-going evolutionary mechanism by which genes are spread between unrelated lineages of all three domains of life, further indicating the importance of LGT from non-organellar sources into eukaryotic genomes.

  • 37.
    Andersson, Jan O
    et al.
    The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
    Roger, Andrew J
    A cyanobacterial gene in nonphotosynthetic protists: an early chloroplast acquisition in eukaryotes?2002In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 12, no 2, p. 115-119Article in journal (Refereed)
    Abstract [en]

    Since the incorporation of mitochondria and chloroplasts (plastids) into the eukaryotic cell by endosymbiosis, genes have been transferred from the organellar genomes to the nucleus of the host, via an ongoing process known as endosymbiotic gene transfer. Accordingly, in photosynthetic eukaryotes, nuclear genes with cyanobacterial affinity are believed to have originated from endosymbiotic gene transfer from chloroplasts. Analysis of the Arabidopsis thaliana genome has shown that a significant fraction (2%-9%) of the nuclear genes have such an endosymbiotic origin. Recently, it was argued that 6-phosphogluconate dehydrogenase (gnd)-the second enzyme in the oxidative pentose phosphate pathway-was one such example. Here we show that gnd genes with cyanobacterial affinity also are present in several nonphotosynthetic protistan lineages, such as Heterolobosea, Apicomplexa, and parasitic Heterokonta. Current data cannot definitively resolve whether these groups acquired the gnd gene by primary and/or secondary endosymbiosis or via an independent lateral gene transfer event. Nevertheless, our data suggest that chloroplasts were introduced into eukaryotes much earlier than previously thought and that several major groups of heterotrophic eukaryotes have secondarily lost photosynthetic plastids.

  • 38.
    Andersson, Jan O
    et al.
    The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada..
    Roger, Andrew J
    Evolutionary analyses of the small subunit of glutamate synthase: gene order conservation, gene fusions, and prokaryote-to-eukaryote lateral gene transfers2002In: Eukaryotic Cell, ISSN 1535-9778, E-ISSN 1535-9786, Vol. 1, no 2, p. 304-310Article in journal (Refereed)
    Abstract [en]

    Lateral gene transfer has been identified as an important mode of genome evolution within prokaryotes. Except for the special case of gene transfer from organelle genomes to the eukaryotic nucleus, only a few cases of lateral gene transfer involving eukaryotes have been described. Here we present phylogenetic and gene order analyses on the small subunit of glutamate synthase (encoded by gltD) and its homologues, including the large subunit of sulfide dehydrogenase (encoded by sudA). The scattered distribution of the sudA and sudB gene pair and the phylogenetic analysis strongly suggest that lateral gene transfer was involved in the propagation of the genes in the three domains of life. One of these transfers most likely occurred between a prokaryote and an ancestor of diplomonad protists. Furthermore, phylogenetic analyses indicate that the gene for the small subunit of glutamate synthase was transferred from a low-GC gram-positive bacterium to a common ancestor of animals, fungi, and plants. Interestingly, in both examples, the eukaryotes encode a single gene that corresponds to a conserved operon structure in prokaryotes. Our analyses, together with several recent publications, show that lateral gene transfers from prokaryotes to unicellular eukaryotes occur with appreciable frequency. In the case of the genes for sulfide dehydrogenase, the transfer affected only a limited group of eukaryotes--the diplomonads--while the transfer of the glutamate synthase gene probably happened earlier in evolution and affected a wider range of eukaryotes.

  • 39.
    Andersson, Jan O
    et al.
    The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada.
    Sjögren, Åsa M
    Davis, Lesley A M
    Embley, T Martin
    Roger, Andrew J
    Phylogenetic analyses of diplomonad genes reveal frequent lateral gene transfers affecting eukaryotes2003In: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 13, no 2, p. 94-104Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Lateral gene transfer (LGT) is an important evolutionary mechanism among prokaryotes. The situation in eukaryotes is less clear; the human genome sequence failed to give strong support for any recent transfers from prokaryotes to vertebrates, yet a number of LGTs from prokaryotes to protists (unicellular eukaryotes) have been documented. Here, we perform a systematic analysis to investigate the impact of LGT on the evolution of diplomonads, a group of anaerobic protists.

    RESULTS: Phylogenetic analyses of 15 genes present in the genome of the Atlantic Salmon parasite Spironucleus barkhanus and/or the intestinal parasite Giardia lamblia show that most of these genes originated via LGT. Half of the genes are putatively involved in processes related to an anaerobic lifestyle, and this finding suggests that a common ancestor, which most probably was aerobic, of Spironucleus and Giardia adapted to an anaerobic environment in part by acquiring genes via LGT from prokaryotes. The sources of the transferred diplomonad genes are found among all three domains of life, including other eukaryotes. Many of the phylogenetic reconstructions show eukaryotes emerging in several distinct regions of the tree, strongly suggesting that LGT not only involved diplomonads, but also involved other eukaryotic groups.

    CONCLUSIONS: Our study shows that LGT is a significant evolutionary mechanism among diplomonads in particular and protists in general. These findings provide insights into the evolution of biochemical pathways in early eukaryote evolution and have important implications for studies of eukaryotic genome evolution and organismal relationships. Furthermore, "fusion" hypotheses for the origin of eukaryotes need to be rigorously reexamined in the light of these results.

  • 40.
    Andersson, Siv G. E.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution.
    Stress management strategies in single bacterial cells2016In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 113, no 15, p. 3921-3923Article in journal (Other academic)
  • 41. Andersson, Siv G E
    et al.
    Alsmark, Cecilia
    Canbäck, Björn
    Davids, Wagied
    Frank, Carolin
    Karlberg, Olof
    Klasson, Lisa
    Antoine-Legault, Boris
    Mira, Alex
    Tamas, Ivica
    Comparative genomics of microbial pathogens and symbionts.2002In: Bioinformatics, ISSN 1367-4803, E-ISSN 1367-4811, Vol. 18 Suppl 2, p. S17-Article in journal (Refereed)
    Abstract [en]

    We are interested in quantifying the contribution of gene acquisition, loss, expansion and rearrangements to the evolution of microbial genomes. Here, we discuss factors influencing microbial genome divergence based on pair-wise genome comparisons of closely related strains and species with different lifestyles. A particular focus is on intracellular pathogens and symbionts of the genera Rickettsia, Bartonella and BUCHNERA: Extensive gene loss and restricted access to phage and plasmid pools may provide an explanation for why single host pathogens are normally less successful than multihost pathogens. We note that species-specific genes tend to be shorter than orthologous genes, suggesting that a fraction of these may represent fossil-orfs, as also supported by multiple sequence alignments among species. The results of our genome comparisons are placed in the context of phylogenomic analyses of alpha and gamma proteobacteria. We highlight artefacts caused by different rates and patterns of mutations, suggesting that atypical phylogenetic placements can not a priori be taken as evidence for horizontal gene transfer events. The flexibility in genome structure among free-living microbes contrasts with the extreme stability observed for the small genomes of aphid endosymbionts, in which no rearrangements or inflow of genetic material have occurred during the past 50 millions years (1). Taken together, the results suggest that genomic stability correlate with the content of repeated sequences and mobile genetic elements, and thereby indirectly with bacterial lifestyles.

  • 42.
    Andersson, Siv GE
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Zomorodipour, A
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Andersson, Jan O
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Sicheritz-Ponten, T
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Alsmark, UCM
    Uppsala University.
    Podowski, RM
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Näslund, A Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Eriksson, Ann-Sofie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    Winkler, HH
    Kurland, Charles G
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Biology.
    The genome sequence of Rickettsia prowazekii and the origin of mitochondria1998In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 396, no 6707, p. 133-140Article in journal (Refereed)
    Abstract [en]

    We describe here the complete genome sequence (1,111,523 base pairs) of the obligate intracellular parasite Rickettsia prowazekii, the causative agent of epidemic typhus. This genome contains 834 protein-coding genes. The functional profiles of these genes show similarities to those of mitochondrial genes: no genes required for anaerobic glycolysis are found in either R. prowazekii or mitochondrial genomes, but a complete set of genes encoding components of the tricarboxylic acid cycle and the respiratory-chain complex is found in R. prowazekii. In effect, ATP production in Rickettsia is the same as that in mitochondria. Many genes involved in the biosynthesis and regulation of biosynthesis of amino acids and nucleosides in free-living bacteria are absent from R. prowazekii and mitochondria. Such genes seem to have been replaced by homologues in the nuclear (host) genome. The R. prowazekii genome contains the highest proportion of non-coding DNA (24%) detected so far in a microbial genome. Such non-coding sequences may be degraded remnants of 'neutralized' genes that await elimination from the genome. Phylogenetic analyses indicate that R. prowazekii is more closely related to mitochondria than is any other microbe studied so far.

  • 43.
    Andreasen, Katarina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Manktelow, Mariette
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Systematic Biology.
    Sehic, Jasna
    Garkava-Gustavsson, Larisa
    Genetic identity of putative Linnaean plants: Successful DNA amplification of Linnaeus's crab apple Malus baccata2014In: Taxon, ISSN 0040-0262, E-ISSN 1996-8175, Vol. 63, no 2, p. 408-416Article in journal (Other academic)
    Abstract [en]

    Advancements in molecular techniques enable us to extract DNA from historic herbarium specimens and facilitate genetic comparisons between herbarium material and living plant collections. These recent advances offer an exciting opportunity for identifying extant Linnaean plants by genetic comparisons of Linnaeus's own herbarium specimens with potentially remnant plants from his cultivations. DNA from the lectotype of Malus baccata (L.) Borkh. in the Linnaean Herbarium was successfully extracted and amplified for five of twelve loci of microsatellites. Results of genetic comparisons with M. baccata trees from Linnaeus's Hammarby, Sweden, show that the trees at Hammarby are closely related to each other, but not to the lectotype, which is closer to material from Russia. This suggests that Linnaeus received M. baccata from more than one source. Although not close to the lectotype and not represented by a specimen in the Linnaean Herbarium, the extant M. baccata at Hammarby may still represent Linnaean plants, that were grown by Linnaeus himself, or the descendants to such plants. Future studies on the almost 50 living, potential Linnaean plants may reveal an invaluable biological, scientific and cultural heritage from the era that saw the rise of systematic biology.

  • 44. Andres, J A
    et al.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Genetic divergence of the seminal signal-receptor system in houseflies: the footprints of sexually antagonistic coevolution?2001In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 268, no 1465, p. 399-405Article in journal (Refereed)
  • 45. Antoniazza, Sylvain
    et al.
    Burri, Reto
    Fumagalli, Luca
    Goudet, Jérôme
    Roulin, Alexandre
    Local adaptation maintains clinal variation in melanin-based coloration of European barn owls (Tyto alba).2010In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 64, no 7, p. 1944-1954Article in journal (Refereed)
    Abstract [en]

    Ecological parameters vary in space, and the resulting heterogeneity of selective forces can drive adaptive population divergence. Clinal variation represents a classical model to study the interplay of gene flow and selection in the dynamics of this local adaptation process. Although geographic variation in phenotypic traits in discrete populations could be remainders of past adaptation, maintenance of adaptive clinal variation requires recurrent selection. Clinal variation in genetically determined traits is generally attributed to adaptation of different genotypes to local conditions along an environmental gradient, although it can as well arise from neutral processes. Here, we investigated whether selection accounts for the strong clinal variation observed in a highly heritable pheomelanin-based color trait in the European barn owl by comparing spatial differentiation of color and of neutral genes among populations. Barn owl's coloration varies continuously from white in southwestern Europe to reddish-brown in northeastern Europe. A very low differentiation at neutral genetic markers suggests that substantial gene flow occurs among populations. The persistence of pronounced color differentiation despite this strong gene flow is consistent with the hypothesis that selection is the primary force maintaining color variation among European populations. Therefore, the color cline is most likely the result of local adaptation.

  • 46. Aplin, Lucy M.
    et al.
    Farine, Damien R.
    Morand-Ferron, Julie
    Cockburn, Andrew
    Thornton, Alex
    Sheldon, Ben C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Experimentally induced innovations lead to persistent culture via conformity in wild birds2015In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 518, no 7540, p. 538-541Article in journal (Refereed)
    Abstract [en]

    In human societies, cultural norms arise when behaviours are transmitted through social networks via high-fidelity social learning'. However, a paucity of experimental studies has meant that there is no comparable understanding of the process by which socially transmitted behaviours might spread and persist in animal populations'''. Here we show experimental evidence of the establishment of foraging traditions in a wild bird population. We introduced alternative novel foraging techniques into replicated wild sub-populations of great tits (Parus major) and used automated tracking to map the diffusion, establishment and long-term persistence of the seeded innovations. Furthermore, we used social network analysis to examine the social factors that influenced diffusion dynamics. From only two trained birds in each sub-population, the information spread rapidly through social network ties, to reach an average of 75% of individuals, with a total of 414 knowledgeable individuals performing 57,909 solutions over all replicates. The sub-populations were heavily biased towards using the technique that was originally introduced, resulting in established local traditions that were stable over two generations, despite a high population turnover. Finally, we demonstrate a strong effect of social conformity, with individuals disproportionately adopting the most frequent local variant when first acquiring an innovation, and continuing to favour social information over personal information. Cultural conformity is thought to be a key factor in the evolution of complex culture in humans''. In providing the first experimental demonstration of conformity in a wild non-primate, and of cultural norms in foraging techniques in any wild animal, our results suggest a much broader taxonomic occurrence of such an apparently complex cultural behaviour.

  • 47.
    Appelgren, Anais S. C.
    et al.
    Univ Bern, Inst Ecol & Evolut, Evolutionary Ecol Lab, Baltzerstr 6, Bern, Switzerland;Univ Lyon, CNRS, F-69000 Lyon, France;LBBE UMR 5558, Dept Biometry & Evolutionary Biol, Batiment Gregor Mendel,43 Blvd 11 Novembre 1918, F-69622 Villeurbanne, France;Univ Lyon 1, Dept Biometry & Evolutionary Biol, LBBE UMR 5558, Batiment Gregor Mendel,43 Blvd 11 Novembre 1918, F-69622 Villeurbanne, France;Univ Montpellier, Ctr IRD, Agropolis, MIVEGEC,CNRS,IRD, 911 Ave,BP 64501, F-34000 Montpellier, France.
    Saladin, Verena
    Univ Bern, Inst Ecol & Evolut, Evolutionary Ecol Lab, Baltzerstr 6, Bern, Switzerland.
    Richner, Heinz
    Univ Bern, Inst Ecol & Evolut, Evolutionary Ecol Lab, Baltzerstr 6, Bern, Switzerland.
    Doligez, Blandine
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology. Univ Lyon, CNRS, F-69000 Lyon, France;LBBE UMR 5558, Dept Biometry & Evolutionary Biol, Batiment Gregor Mendel,43 Blvd 11 Novembre 1918, F-69622 Villeurbanne, France;Univ Lyon 1, Dept Biometry & Evolutionary Biol, LBBE UMR 5558, Batiment Gregor Mendel,43 Blvd 11 Novembre 1918, F-69622 Villeurbanne, France.
    McCoy, Karen D.
    Univ Montpellier, Ctr IRD, Agropolis, MIVEGEC,CNRS,IRD, 911 Ave,BP 64501, F-34000 Montpellier, France.
    Gene flow and adaptive potential in a generalist ectoparasite2018In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 18, article id 99Article in journal (Refereed)
    Abstract [en]

    Background: In host-parasite systems, relative dispersal rates condition genetic novelty within populations and thus their adaptive potential. Knowledge of host and parasite dispersal rates can therefore help us to understand current interaction patterns in wild populations and why these patterns shift over time and space. For generalist parasites however, estimates of dispersal rates depend on both host range and the considered spatial scale. Here, we assess the relative contribution of these factors by studying the population genetic structure of a common avian ectoparasite, the hen flea Ceratophyllus gallinae, exploiting two hosts that are sympatric in our study population, the great tit Paws major and the collared flycatcher Ficedula albicollis. Previous experimental studies have indicated that the hen flea is both locally maladapted to great tit populations and composed of subpopulations specialized on the two host species, suggesting limited parasite dispersal in space and among hosts, and a potential interaction between these two structuring factors. Results: C gallinae fleas were sampled from old nests of the two passerine species in three replicate wood patches and were genotyped at microsatellite markers to assess population genetic structure at different scales (among individuals within a nest among nests and between host species within a patch and among patches). As expected, significant structure was found at all spatial scales and between host species, supporting the hypothesis of limited dispersal in this parasite. Clustering analyses and estimates of relatedness further suggested that inbreeding regularly occurs within nests. Patterns of isolation by distance within wood patches indicated that flea dispersal likely occurs in a stepwise manner among neighboring nests. From these data, we estimated that gene flow in the hen flea is approximately half that previously described for its great tit hosts. Conclusion: Our results fall in line with predictions based on observed patterns of adaptation in this host-parasite system, suggesting that parasite dispersal is limited and impacts its adaptive potential with respect to its hosts. More generally, this study sheds light on the complex interaction between parasite gene flow, local adaptation and host specialization within a single host-parasite system.

  • 48.
    Arbuthnott, Devin
    et al.
    Univ British Columbia, Dept Zool, 4200-6270 Univ Blvd, Vancouver, BC V6T 1Z4, Canada.;Univ British Columbia, Biodivers Res Ctr, 4200-6270 Univ Blvd, Vancouver, BC V6T 1Z4, Canada..
    Mautz, Brian S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Rundle, Howard D.
    Univ Ottawa, Dept Biol, Ottawa, ON, Canada..
    Rugged fitness landscapes and by-product adaptation in experimental populations of Drosophila melanogaster2018In: Evolutionary Ecology Research, ISSN 1522-0613, E-ISSN 1937-3791, Vol. 19, no 1, p. 15-28Article in journal (Refereed)
    Abstract [en]

    Background: While the concept of the fitness landscape is central to evolutionary theory, empirical characterizations of fitness landscapes have remained difficult. Recently, a number of laboratory experiments using microbes have suggested that fitness landscapes are often rugged, though there is some variation across environments and species. However, there have been very few characterizations of fitness landscapes in sexual organisms, making it unclear whether the conclusions from studies of microbes are applicable to other groups. Questions: Are fitness landscapes smooth or rugged in simplified laboratory environments for sexual organisms? How does landscape topography influence patterns of adaptation? Methods: We conducted a series of experiments using replicate populations of Drosophila melanogaster adapted to either cadmium-or ethanol-enriched food to characterize the fitness and phenotypes of these populations in a simplified laboratory environment (ethanol-enriched media). Results: We found that replicate populations adapted to different laboratory environments have diverged phenotypically in physiology, mating behaviour, and offspring production in alternate environments. However, both ethanol-and cadmium-adapted populations show high fitness in the ethanol-enriched environment relative to their founding population, and cadmium-adapted males actually outcompete ethanol-adapted males for mates in an ethanol environment. Conclusions: Our data indicate that the simplified ethanol-enriched medium represents a rugged fitness landscape, and that alternately adapted populations occupy different fitness peaks on this landscape. Because cadmium-adapted populations were never exposed to ethanol previously, it appears that these populations adapted to ethanol as a by-product of adaptation to their cadmium-enriched environment. Therefore, even in simplified laboratory environments, we find evidence for rugged fitness landscapes, and the overlap of fitness peaks on the phenotypic landscape allowed for by-product adaptation.

  • 49.
    Arct, Aneta
    et al.
    Jagiellonian Univ, Inst Environm Sci, Gronostajowa 7, PL-30387 Krakow, Poland..
    Sudyka, Joanna
    Jagiellonian Univ, Inst Environm Sci, Gronostajowa 7, PL-30387 Krakow, Poland..
    Podmoka, Edyta
    Jagiellonian Univ, Inst Environm Sci, Gronostajowa 7, PL-30387 Krakow, Poland..
    Drobniak, Szymon M.
    Jagiellonian Univ, Inst Environm Sci, Gronostajowa 7, PL-30387 Krakow, Poland..
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Cichon, Mariusz
    Jagiellonian Univ, Inst Environm Sci, Gronostajowa 7, PL-30387 Krakow, Poland..
    Heterozygosity-fitness correlations in blue tit nestlings (Cyanistis caeruleus) under contrasting rearing conditions2017In: Evolutionary Ecology, ISSN 0269-7653, E-ISSN 1573-8477, Vol. 31, no 5, p. 803-814Article in journal (Refereed)
    Abstract [en]

    Understanding the relation between genetic variation and fitness remains a key question in evolutionary biology. Although heterozygosity has been reported to correlate with many fitness-related traits, the strength of the heterozygosity-fitness correlations (HFCs) is usually weak and it is still difficult to assess the generality of these associations in natural populations. It has been suggested that HFCs may become meaningful only under particular environmental conditions. Moreover, existing evidence suggests that HFCs may also differ between sexes. The aim of this study was to investigate correlations between heterozygosity in neutral markers (microsatellites) and fitness-related traits in a natural population of blue tits (Cyanistes caeruleus). Additionally, we tested whether sex and environmental conditions may influence the magnitude and direction of HFCs. We found a positive relationship between heterozygosity and body mass of 14 days post-hatching nestlings, but only among females. Our results suggest that the correlation between heterozygosity and nestling body mass observed among female offspring could be attributed to within-brood effects. We failed to find any evidence that environmental conditions as simulated by brood size manipulation affect HFCs.

  • 50. Arnegard, Matthew E.
    et al.
    McGee, Matthew D.
    Matthews, Blake
    Marchinko, Kerry B.
    Conte, Gina L.
    Kabir, Sahriar
    Bedford, Nicole
    Bergek, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Chan, Yingguang Frank
    Jones, Felicity C.
    Kingsley, David M.
    Peichel, Catherine L.
    Schluter, Dolph
    Genetics of ecological divergence during speciation2014In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 511, no 7509, p. 307-311Article in journal (Refereed)
    Abstract [en]

    Ecological differences often evolve early in speciation as divergent natural selection drives adaptation to distinct ecological niches, leading ultimately to reproductive isolation. Although this process is a major generator of biodiversity, its genetic basis is still poorly understood. Here we investigate the genetic architecture of niche differentiation in a sympatric species pair of threespine stickleback fish by mapping the environment-dependent effects of phenotypic traits on hybrid feeding and performance under semi-natural conditions. We show that multiple, unlinked loci act largely additively to determine position along the major niche axis separating these recently diverged species. We also find that functional mismatch between phenotypic traits reduces the growth of some stickleback hybrids beyond that expected from an intermediate phenotype, suggesting a role for epistasis between the underlying genes. This functional mismatch might lead to hybrid incompatibilities that are analogous to those underlying intrinsic reproductive isolation but depend on the ecological context.

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