uu.seUppsala University Publications
Change search
Refine search result
1 - 11 of 11
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Grieshop, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Lind, Martin I.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Goenaga, Julieta
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Maklakov, Alexei A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Intralocus Sexual Conflict and Environmental Stress2014In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 68, no 8, p. 2184-2196Article in journal (Refereed)
    Abstract [en]

    Intralocus sexual conflict (IaSC) occurs when selection at a given locus favors different alleles in males and females, placing a fundamental constraint on adaptation. However, the relative impact of IaSC on adaptation may become reduced in stressful environments that expose conditionally deleterious mutations to selection. The genetic correlation for fitness between males and females (r(MF)) provides a quantification of IaSC across the genome. We compared IaSC at a benign (29 degrees C) and a stressful (36 degrees C) temperature by estimating r(MF)s in two natural populations of the seed beetle Callosobruchus maculatus using isofemale lines. In one population, we found substantial IaSC under benign conditions signified by a negative r(MF) (-0.51) and, as predicted, a significant reduction of IaSC under stress signified by a reversed and positive r(MF) (0.21). The other population displayed low IaSC at both temperatures (r(MF): 0.38; 0.40). In both populations, isofemale lines harboring alleles beneficial to males but detrimental to females at benign conditions tended to show overall low fitness under stress. These results offer support for low IaSC under stress and suggest that environmentally sensitive and conditionally deleterious alleles that are sexually selected in males mediate changes in IaSC. We discuss implications for adaptive evolution in sexually reproducing populations.

  • 2.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Stångberg, Josefine
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Grieshop, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Martinossi-Allibert, Ivain
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Temperature effects on life-history trade-offs, germline maintenance and mutation rate under simulated climate warming2017In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, no 1866, article id 20171721Article in journal (Refereed)
    Abstract [en]

    Mutation has a fundamental influence over evolutionary processes, but how evolutionary processes shape mutation rate remains less clear. In asexual unicellular organism, increased mutation rates have been observed in stressful environments and the reigning paradigm ascribes this increase to selection for evolvability. However, this explanation does not apply in sexually reproducing species, where little is known about how the environment affects mutation rate. Here we challenged experimental lines of seed beetle, evolved at ancestral temperature or under simulated climate warming, to repair induced mutations at ancestral and stressful temperature. Results show that temperature stress causes individuals to pass on a greater mutation load to their grand-offspring. This suggests that stress-induced mutation rates, in unicellular and multicellular organisms alike, can result from compromised germline DNA repair in low condition individuals. Moreover, lines adapted to simulated climate warming had evolved increased longevity at the cost of reproduction, and this allocation decision improved germline repair. These results suggest that mutation rates can be modulated by resource allocation trade-offs encompassing life-history traits and the germline and have important implications for rates of adaptation and extinction as well as our understanding of genetic diversity in multicellular organisms.

  • 3.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Stångberg, Josefine
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Grieshop, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Martinossi-Allibert, Ivain
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Temperature effects on life-history trade-offs, germline maintenance and mutation rate under simulated climate warming2017In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 284, no 1866Article in journal (Refereed)
    Abstract [en]

    Mutation has a fundamental influence over evolutionary processes, but how evolutionary processes shape mutation rate remains less clear. In asexual unicellular organism, increased mutation rates have been observed in stressful environments and the reigning paradigm ascribes this increase to selection for evolvability. However, this explanation does not apply in sexually reproducing species, where little is known about how the environment affects mutation rate. Here we challenged experimental lines of seed beetle, evolved at ancestral temperature or under simulated climate warming, to repair induced mutations at ancestral and stressful temperature. Results show that temperature stress causes individuals to pass on a greater mutation load to their grand-offspring. This suggests that stress-induced mutation rates, in unicellular and multicellular organisms alike, can result from compromised germline DNA repair in low condition individuals. Moreover, lines adapted to simulated climate warming had evolved increased longevity at the cost of reproduction, and this allocation decision improved germline repair. These results suggest that mutation rates can be modulated by resource allocation trade-offs encompassing life-history traits and the germline and have important implications for rates of adaptation and extinction as well as our understanding of genetic diversity in multicellular organisms.

  • 4.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    You, Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Minano, Maravillas R.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Grieshop, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Lind, Martin I.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Maklakov, Alexei A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sexually antagonistic selection on genetic variation underlying both male and female same-sex sexual behavior2016In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 16, article id 88Article in journal (Refereed)
    Abstract [en]

    Background: Intralocus sexual conflict, arising from selection for different alleles at the same locus in males and females, imposes a constraint on sex-specific adaptation. Intralocus sexual conflict can be alleviated by the evolution of sex-limited genetic architectures and phenotypic expression, but pleiotropic constraints may hinder this process. Here, we explored putative intralocus sexual conflict and genetic (co)variance in a poorly understood behavior with near male-limited expression. Same-sex sexual behaviors (SSBs) generally do not conform to classic evolutionary models of adaptation but are common in male animals and have been hypothesized to result from perception errors and selection for high male mating rates. However, perspectives incorporating sex-specific selection on genes shared by males and females to explain the expression and evolution of SSBs have largely been neglected.

    Results: We performed two parallel sex-limited artificial selection experiments on SSB in male and female seed beetles, followed by sex-specific assays of locomotor activity and male sex recognition (two traits hypothesized to be functionally related to SSB) and adult reproductive success (allowing us to assess fitness consequences of genetic variance in SSB and its correlated components). Our experiments reveal both shared and sex-limited genetic variance for SSB. Strikingly, genetically correlated responses in locomotor activity and male sex-recognition were associated with sexually antagonistic fitness effects, but these effects differed qualitatively between male and female selection lines, implicating intralocus sexual conflict at both male-and female-specific genetic components underlying SSB.

    Conclusions: Our study provides experimental support for the hypothesis that widespread pleiotropy generates pervasive intralocus sexual conflict governing the expression of SSBs, suggesting that SSB in one sex can occur due to the expression of genes that carry benefits in the other sex.

  • 5.
    Grieshop, Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sexual conflict, sexual selection, and genetic variance in fitness2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Understanding sex-specific genetic variance for fitness is of fundamental importance to our understanding of evolution. This thesis presents the findings of empirical investigations into sex-specific genetic variance in fitness. The findings are discussed in terms of their implications for our understanding of the classic evolutionary paradoxes of what maintains genetic variance in fitness and what maintains sexual reproduction, as well as more specific implications regarding adaptation and population viability. Males and females reproduce and accrue fitness in fundamentally different ways, which inevitably comes at a detriment to the fitness of individuals of the opposite sex. This is known as sexual conflict, and because males and females use largely the same genome to develop, grow and reproduce, a genetic tug-of-war ensues. Alternative alleles at sexually antagonistic (SA) genes have opposing fitness effects in males and females. The consequence of this genetic tug-of-war is that alternative allelic variants at SA loci can be maintained in the population. Such SA genetic variation can therefore maintain genetic variance for fitness. Variance in fitness can also be maintained by a constant influx of mutations with weakly deleterious effects and weak selection against them, in what is referred to as mutation-selection balance. Because the average deleterious mutation will be detrimental to both sexes, this source of genetic variance in fitness will have predominantly sexually concordant (SC) effects. This thesis uses a wild-caught population of the seed beetle Callosobruchus maculatus to investigate these two mechanisms of maintaining genetic variance in fitness, as well as the consequences they bear on adaptation, population viability, and the maintenance of sexual reproduction. Results largely support much of the theoretical expectations for sexual conflict, sexual selection and maintenance of genetic variance in fitness, as well as stimulate new thoughts and hypotheses about the nature of SA genetic variation and its interaction with weakly deleterious partially recessive mutations.

    List of papers
    1. Intralocus Sexual Conflict and Environmental Stress
    Open this publication in new window or tab >>Intralocus Sexual Conflict and Environmental Stress
    Show others...
    2014 (English)In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 68, no 8, p. 2184-2196Article in journal (Refereed) Published
    Abstract [en]

    Intralocus sexual conflict (IaSC) occurs when selection at a given locus favors different alleles in males and females, placing a fundamental constraint on adaptation. However, the relative impact of IaSC on adaptation may become reduced in stressful environments that expose conditionally deleterious mutations to selection. The genetic correlation for fitness between males and females (r(MF)) provides a quantification of IaSC across the genome. We compared IaSC at a benign (29 degrees C) and a stressful (36 degrees C) temperature by estimating r(MF)s in two natural populations of the seed beetle Callosobruchus maculatus using isofemale lines. In one population, we found substantial IaSC under benign conditions signified by a negative r(MF) (-0.51) and, as predicted, a significant reduction of IaSC under stress signified by a reversed and positive r(MF) (0.21). The other population displayed low IaSC at both temperatures (r(MF): 0.38; 0.40). In both populations, isofemale lines harboring alleles beneficial to males but detrimental to females at benign conditions tended to show overall low fitness under stress. These results offer support for low IaSC under stress and suggest that environmentally sensitive and conditionally deleterious alleles that are sexually selected in males mediate changes in IaSC. We discuss implications for adaptive evolution in sexually reproducing populations.

    Keywords
    Adaptation, condition dependence, genetic quality, sexual selection, sexually antagonistic, temperature
    National Category
    Ecology Evolutionary Biology
    Identifiers
    urn:nbn:se:uu:diva-232012 (URN)10.1111/evo.12439 (DOI)000340470600003 ()
    Funder
    Swedish Research Council, 621-2010-5266EU, European Research Council, AdG-294333
    Available from: 2014-09-15 Created: 2014-09-12 Last updated: 2017-12-05Bibliographically approved
    2. Strong sexual selection in males against a mutation load that reduces offspring production in seed beetles
    Open this publication in new window or tab >>Strong sexual selection in males against a mutation load that reduces offspring production in seed beetles
    Show others...
    2016 (English)In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 29, no 6, p. 1201-1210Article in journal (Refereed) Published
    Abstract [en]

    Theory predicts that sexual reproduction can increase population viability relative to asexual reproduction by allowing sexual selection in males to remove deleterious mutations from the population without large demographic costs. This requires that selection acts more strongly in males than females and that mutations affecting male reproductive success have pleiotropic effects on population productivity, but empirical support for these assumptions is mixed. We used the seed beetle Callosobruchus maculatus to implement a three-generation breeding design where we induced mutations via ionizing radiation (IR) in the F-0 generation and measured mutational effects (relative to nonirradiated controls) on an estimate of population productivity in the F-1 and effects on sex-specific competitive lifetime reproductive success (LRS) in the F-2. Regardless of whether mutations were induced via F-0 males or females, they had strong negative effects on male LRS, but a nonsignificant influence on female LRS, suggesting that selection is more efficient in removing deleterious alleles in males. Moreover, mutations had seemingly shared effects on population productivity and competitive LRS in both sexes. Thus, our results lend support to the hypothesis that strong sexual selection on males can act to remove the mutation load on population viability, thereby offering a benefit to sexual reproduction.

    Keywords
    adaptation, genetic correlation, intralocus sexual conflict, pleiotropy, population viability, sexual antagonism, sexual selection
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-304536 (URN)10.1111/jeb.12862 (DOI)000382498900009 ()26991346 (PubMedID)
    Funder
    EU, European Research Council, AdG-294333Swedish Research Council, 621-2010-5266
    Available from: 2016-10-12 Created: 2016-10-06 Last updated: 2017-08-08Bibliographically approved
    3. Male-benefit sexually antagonistic genotypes show elevated vulnerability to inbreeding
    Open this publication in new window or tab >>Male-benefit sexually antagonistic genotypes show elevated vulnerability to inbreeding
    2017 (English)In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 17, article id 134Article in journal (Refereed) Published
    Abstract [en]

    Background

    There is theoretical and empirical evidence for strong sexual selection in males having positive effects on population viability by serving to purify the genome of its mutation load at a low demographic cost. However, there is also theoretical and empirical evidence for negative effects of sexual selection on female fitness, and therefore population viability, known as the gender load. This can take the form of sexually antagonistic (SA) genetic variation where alleles with a selective advantage in males pose a detriment to female fitness, and vice versa. Here, using seed beetles, we shed light on a previously unexplored manifestation of the gender load: the effect of SA genetic variation on tolerance to inbreeding.

    Results

    We found that genotypes encoding high male, but low female fitness exhibited significantly greater rates of extinction upon enforced inbreeding relative to genotypes encoding high female but low male fitness. Also, genotypes encoding low fitness in both sexes exhibited greater rates of extinction relative to generally high-fitness genotypes (though marginally non-significant), an expected finding attributable to variation in mutation load across genotypes. Despite follow-up investigations aiming to identify the mechanism(s) underlying these findings, it remains unclear whether the gender load and the mutation load have independent consequences for tolerance to inbreeding, or whether these two types of genetic architecture interact epistatically to render male-benefit genetic variation relatively intolerant to inbreeding.

    Conclusions

    Regardless of the underlying mechanism(s), our results show that male-benefit/female-detriment SA genetic variation poses a previously unseen detriment to population viability due to its elevated vulnerability to inbreeding/homozygosity. This suggests that sexual selection in the context of SA genetic variance for fitness may enhance the gender load on population viability more than previously appreciated, due to selecting for male-benefit SA genetic variation that engenders lineages to extinction upon inbreeding. We note that our results imply that SA alleles that are sexually selected for in males may be underrepresented or even lacking in panels of inbred lines.

    Keywords
    Antagonistic pleiotropy, Balancing selection, Fitness, Genetic variation, Inbreeding depression, Intralocus sexual conflict, Mutation load, Sexually antagonistic selection
    National Category
    Evolutionary Biology
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-327273 (URN)10.1186/s12862-017-0981-4 (DOI)000403408600001 ()28606137 (PubMedID)
    Funder
    EU, European Research Council, GENCON AdG-294333Swedish Research Council, 621-2010-5266Swedish Research Council, 621-2014-4523
    Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2017-11-29Bibliographically approved
    4. Sex-specific genetic variance for fitness characterized by sex-specific dominance and epistasis
    Open this publication in new window or tab >>Sex-specific genetic variance for fitness characterized by sex-specific dominance and epistasis
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The ubiquity of sexually antagonistic (SA) genetic variation for fitness suggests that antagonistic pleiotropy is one of the most likely and widespread mechanisms of balancing selection acting to maintain genetic variance for fitness. However, stable polymorphism via antagonistic pleiotropy requires dominance reversal for fitness—sex-specific dominance in the context of SA pleiotropy. Despite this possibly crucial role for sex-specific dominance reversal in maintaining genetic variance for fitness, it has rarely been addressed empirically. In addition to dominance reversal, SA epistasis, sex-biased gene expression (SBGE), and parental effects may also aid the maintenance genetic polymorphisms for fitness under SA selection. Here, we performed a full diallel cross among 16 inbred strains of a population of the seed beetle Callosobruchus maculatus. We measured sex-specific competitive lifetime reproductive success (i.e. fitness) in the F1, for a total of 3278 individual fitness assays over 512 possible genetic combinations. Using Bayesian and restricted maximum likelihood (REML) diallel analyses in parallel, we partitioned phenotypic variance for fitness (after accounting for the effect of inbreeding) into additive genetic variance, parental effects, dominance, epistasis, asymmetric epistasis, and sex-specific versions thereof. Sex-specific variance in fitness exhibited pronounced contributions from dominance, sex-specific dominance, epistasis, and sex-specific epistasis, supporting a role for sex-specific dominance reversal and SA epistasis in contributing to the maintenance of SA genetic variance for fitness. To our knowledge, this is the first detailed diallel partitioning of the sex-specific genetic architecture for fitness, shedding new light on an old question.

    National Category
    Natural Sciences
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-327275 (URN)
    Funder
    EU, European Research Council, GENCON AdG-294333Swedish Research Council, 621-2010-5266Swedish Research Council, 621-2014-4523
    Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2017-08-11Bibliographically approved
    5. Sexual selection in males, but not females, purges the standing genetic load in a seed beetle
    Open this publication in new window or tab >>Sexual selection in males, but not females, purges the standing genetic load in a seed beetle
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The concept of genic capture revealing the genetic quality in males is central to sexual selection theory and the potential for males to purge a population’s weakly deleterious partially recessive mutation load. However, empirical demonstrations of sexual selection in males purging the standing genetic load on a population are almost completely lacking, perhaps in part because of the partially hidden/recessive nature of mutation load limiting its detection. Here, we exposed mutation load by experimentally increasing homozygosity in 16 strains of the seed beetle Callosobruchus maculatus isolated from a natural population. We then assessed the potential for selection to purge load in males and females separately by correlating the breeding values for variance in competitive lifetime reproductive success (i.e. fitness) among the outbred combinations of those strains with the difference between outbred and inbred breeding values for fitness (i.e. mutation load), in a way that avoided correlating confounded variables. Outbred breeding values for male fitness were significantly negatively correlated with mutation load, demonstrating the ability of males to purge mutation load. Breeding values for female fitness, however, were uncorrelated to mutation load, likely because female fitness did not vary enough to reflect genetic quality. Thus, our results are consistent with an additional value to sexual reproduction beyond recombination: whereas females experience relatively weak selection, limiting purging of their own mutation load, this may be achieved by producing males and having them compete intensely for access to their eggs, such that only those of high genetic quality contribute to the next generation. These results have important implications for our understanding of sexual selection, the maintenance of variation in fitness-related traits, and the prevalence of sexual reproduction.

    National Category
    Natural Sciences
    Research subject
    Biology with specialization in Animal Ecology
    Identifiers
    urn:nbn:se:uu:diva-327303 (URN)
    Projects
    Karl Grieshop_Doctoral thesis
    Funder
    EU, European Research Council, GENCON AdG-294333Swedish Research Council, 621-2010-5266Swedish Research Council, 621-2014-4523Swedish Research Council, 2015-05223
    Available from: 2017-08-08 Created: 2017-08-08 Last updated: 2017-08-08
  • 6.
    Grieshop, Karl
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sex-specific dominance reversal of genetic variation for fitness2018In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 16, no 12, article id e2006810Article in journal (Refereed)
    Abstract [en]

    The maintenance of genetic variance in fitness represents one of the most longstanding enigmas in evolutionary biology. Sexually antagonistic (SA) selection may contribute substantially to maintaining genetic variance in fitness by maintaining alternative alleles with opposite fitness effects in the two sexes. This is especially likely if such SA loci exhibit sex-specific dominance reversal (SSDR)-wherein the allele that benefits a given sex is also dominant in that sex-which would generate balancing selection and maintain stable SA polymorphisms for fitness. However, direct empirical tests of SSDR for fitness are currently lacking. Here, we performed a full diallel cross among isogenic strains derived from a natural population of the seed beetle Callosobruchus maculatus that is known to exhibit SA genetic variance in fitness. We measured sex-specific competitive lifetime reproductive success (i.e., fitness) in >500 sex-by-genotype F-1 combinations and found that segregating genetic variation in fitness exhibited pronounced contributions from dominance variance and sex-specific dominance variance. A closer inspection of the nature of dominance variance revealed that the fixed allelic variation captured within each strain tended to be dominant in one sex but recessive in the other, revealing genome-wide SSDR for SA polymorphisms underlying fitness. Our findings suggest that SA balancing selection could play an underappreciated role in maintaining fitness variance in natural populations.

  • 7.
    Grieshop, Karl
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sex-specific genetic variance for fitness characterized by sex-specific dominance and epistasisManuscript (preprint) (Other academic)
    Abstract [en]

    The ubiquity of sexually antagonistic (SA) genetic variation for fitness suggests that antagonistic pleiotropy is one of the most likely and widespread mechanisms of balancing selection acting to maintain genetic variance for fitness. However, stable polymorphism via antagonistic pleiotropy requires dominance reversal for fitness—sex-specific dominance in the context of SA pleiotropy. Despite this possibly crucial role for sex-specific dominance reversal in maintaining genetic variance for fitness, it has rarely been addressed empirically. In addition to dominance reversal, SA epistasis, sex-biased gene expression (SBGE), and parental effects may also aid the maintenance genetic polymorphisms for fitness under SA selection. Here, we performed a full diallel cross among 16 inbred strains of a population of the seed beetle Callosobruchus maculatus. We measured sex-specific competitive lifetime reproductive success (i.e. fitness) in the F1, for a total of 3278 individual fitness assays over 512 possible genetic combinations. Using Bayesian and restricted maximum likelihood (REML) diallel analyses in parallel, we partitioned phenotypic variance for fitness (after accounting for the effect of inbreeding) into additive genetic variance, parental effects, dominance, epistasis, asymmetric epistasis, and sex-specific versions thereof. Sex-specific variance in fitness exhibited pronounced contributions from dominance, sex-specific dominance, epistasis, and sex-specific epistasis, supporting a role for sex-specific dominance reversal and SA epistasis in contributing to the maintenance of SA genetic variance for fitness. To our knowledge, this is the first detailed diallel partitioning of the sex-specific genetic architecture for fitness, shedding new light on an old question.

  • 8.
    Grieshop, Karl
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Berger, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sexual selection in males, but not females, purges the standing genetic load in a seed beetleManuscript (preprint) (Other academic)
    Abstract [en]

    The concept of genic capture revealing the genetic quality in males is central to sexual selection theory and the potential for males to purge a population’s weakly deleterious partially recessive mutation load. However, empirical demonstrations of sexual selection in males purging the standing genetic load on a population are almost completely lacking, perhaps in part because of the partially hidden/recessive nature of mutation load limiting its detection. Here, we exposed mutation load by experimentally increasing homozygosity in 16 strains of the seed beetle Callosobruchus maculatus isolated from a natural population. We then assessed the potential for selection to purge load in males and females separately by correlating the breeding values for variance in competitive lifetime reproductive success (i.e. fitness) among the outbred combinations of those strains with the difference between outbred and inbred breeding values for fitness (i.e. mutation load), in a way that avoided correlating confounded variables. Outbred breeding values for male fitness were significantly negatively correlated with mutation load, demonstrating the ability of males to purge mutation load. Breeding values for female fitness, however, were uncorrelated to mutation load, likely because female fitness did not vary enough to reflect genetic quality. Thus, our results are consistent with an additional value to sexual reproduction beyond recombination: whereas females experience relatively weak selection, limiting purging of their own mutation load, this may be achieved by producing males and having them compete intensely for access to their eggs, such that only those of high genetic quality contribute to the next generation. These results have important implications for our understanding of sexual selection, the maintenance of variation in fitness-related traits, and the prevalence of sexual reproduction.

  • 9.
    Grieshop, Karl
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Berger, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Arnqvist, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Male-benefit sexually antagonistic genotypes show elevated vulnerability to inbreeding2017In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 17, article id 134Article in journal (Refereed)
    Abstract [en]

    Background

    There is theoretical and empirical evidence for strong sexual selection in males having positive effects on population viability by serving to purify the genome of its mutation load at a low demographic cost. However, there is also theoretical and empirical evidence for negative effects of sexual selection on female fitness, and therefore population viability, known as the gender load. This can take the form of sexually antagonistic (SA) genetic variation where alleles with a selective advantage in males pose a detriment to female fitness, and vice versa. Here, using seed beetles, we shed light on a previously unexplored manifestation of the gender load: the effect of SA genetic variation on tolerance to inbreeding.

    Results

    We found that genotypes encoding high male, but low female fitness exhibited significantly greater rates of extinction upon enforced inbreeding relative to genotypes encoding high female but low male fitness. Also, genotypes encoding low fitness in both sexes exhibited greater rates of extinction relative to generally high-fitness genotypes (though marginally non-significant), an expected finding attributable to variation in mutation load across genotypes. Despite follow-up investigations aiming to identify the mechanism(s) underlying these findings, it remains unclear whether the gender load and the mutation load have independent consequences for tolerance to inbreeding, or whether these two types of genetic architecture interact epistatically to render male-benefit genetic variation relatively intolerant to inbreeding.

    Conclusions

    Regardless of the underlying mechanism(s), our results show that male-benefit/female-detriment SA genetic variation poses a previously unseen detriment to population viability due to its elevated vulnerability to inbreeding/homozygosity. This suggests that sexual selection in the context of SA genetic variance for fitness may enhance the gender load on population viability more than previously appreciated, due to selecting for male-benefit SA genetic variation that engenders lineages to extinction upon inbreeding. We note that our results imply that SA alleles that are sexually selected for in males may be underrepresented or even lacking in panels of inbred lines.

  • 10.
    Grieshop, Karl
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Polak, Michal
    University of Cincinnati.
    Evaluating the post-copulatory sexual selection hypothesis for genital evolution reveals evidence for pleiotropic harm exerted by the male genital spines of Drosophila ananassae2014In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 12, p. 2676-2686Article in journal (Refereed)
    Abstract [en]

    The contemporary explanation for the rapid evolutionary diversification ofanimal genitalia is that such traits evolve by post-copulatory sexual selection. Here, we test the hypothesis that the male genital spines of Drosophila ananassae play an adaptive role in post-copulatory sexual selection. Whereas previous work on two Drosophila species shows that these spines function in precopulatory sexual selection to initiate genital coupling and promote male competitive copulation success, further research is needed to evaluate the potential for Drosophila genital spines to have a post-copulatory function. Using a precision micron-scale laser surgery technique, we test the effect of spine length reduction on copulation duration, male competitive fertilization success, female fecundity and female remating behaviour. We find no evidence that male genital spines in this species have a post-copulatory adaptivefunction. Instead, females mated to males with surgically reduced/blunted genital spines exhibited comparatively greater short-term fecundity relative to those mated by control males, indicating that the natural (i.e.unaltered) form of the trait may be harmful to females. In the absence of an effect of genital spine reduction on measured components of post-copulatory fitness, the harm seems to be a pleiotropic side effect rather than adaptive. Results are discussed in the context of sexual conflict mediating the evolution of male genital spines in this species and likely other Drosophila.

  • 11. Grieshop, Karl
    et al.
    Polak, Michal
    The Precopulatory Function of Male Genital Spines in Drosophila Ananassae [Doleschall] (Diptera: Drosophilidae) Revealed by Laser Surgery2012In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 66, no 8, p. 2637-2645Article in journal (Refereed)
    Abstract [en]

    That male genital morphology evolves via postcopulatory sexual selection is a widely held view. In contrast, the precopulatory sexual selection hypothesis for genital evolution has received less attention. Here, we test the hypothesis that male genital spines of Drosophila ananassae promote competitive male copulation success. Using laser surgery to manipulate trait size, we demonstrate that incremental reductions of spine length progressively reduce male copulation success: males without spines failed entirely to copulate because of an inability to couple the genitalia together, whereas males with halfway ablated and blunted spines suffered reductions in copulation success of 87% and 13%, respectively. The decrease in copulation success resulting from spine length reduction was markedly stronger in sexually competitive environments than in noncompetitive environments, and females expressed resistance behaviors similarly toward competing male treatments, demonstrating directly the role of genital spines in promoting competitive copulation success. Because these spines are widespread within Drosophila, and because genital traits with precopulatory function are being discovered in a growing number of animal taxa, precopulatory sexual selection may have a more pervasive role in genital evolution than previously recognized.

1 - 11 of 11
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf