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  • 251.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Uncoupling of chitinase activity and uptake of hydrolyses products in freshwater bacterioplankton2011In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, no 4, p. 1179-1188Article in journal (Refereed)
    Abstract [en]

    We investigated to what extent chitinolytic bacteria subsidize bacterial populations that do not produce chitinolytic enzymes but still use the products of chitin hydrolysis. Applying single-cell techniques to untreated and chitin-enriched lake water, we show that the number of planktonic cells taking up chitin hydrolysis products by far exceeds the number of cells expressing chitinases. Flavobacteria, Actinobacteria, and specifically members of the abundant and ubiquitous freshwater Ac1 cluster of the Actinobacteria, increased in abundance and were enriched in response to the chitin amendment. Flavobacteria were frequently observed in dense clusters on chitin particles, suggesting that they are actively involved in the hydrolysis and solubilization of chitin. In contrast, Actinobacteria were exclusively planktonic. We propose that planktonic Actinobacteria contain commensals specialized in the uptake of small hydrolysis products without expressing or possibly even possessing the machinery for chitin hydrolysis. More research is needed to assess the importance of such "cheater'' substrate acquisition strategies in the turnover and degradation of polymeric organic matter in aquatic ecosystems.

  • 252.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Jones, Christopher M.
    Mohit, Vani
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Hallin, Sara
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Global Phylogeography of Chitinase Genes in Aquatic Metagenomes2011In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 77, no 3, p. 1101-1106Article in journal (Refereed)
    Abstract [en]

    Phylogeny-based analysis of chitinase and 16S rRNA genes from metagenomic data suggests that salinity is a major driver for the distribution of both chitinolytic and total bacterial communities in aquatic systems. Additionally, more acidic chitinase proteins were observed with increasing salinity. Congruent habitat separation was further observed for both genes according to latitude and proximity to the coastline. However, comparison of chitinase and 16S rRNA genes extracted from different geographic locations showed little congruence in distribution. There was no indication that dispersal limited the global distribution of either gene.

  • 253.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Kim, Ok-Sun
    Junier, Pilar
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Witzel, Karl-Paul
    Betaproteobacterial ammonia oxidizers in root zones of aquatic macrophytes2010In: Fundamental and Applied Limnology, ISSN 1863-9135, Vol. 177, no 4, p. 241-255Article in journal (Refereed)
    Abstract [en]

    Enhanced nitrification and coupled denitrification in macrophyte root zones may contribute to the depletion of nitrogen from the rhizosphere and are both critical processes for agriculture and rhizoremediation. We examined one factor likely to affect these processes: the ammonia oxidizing betaproteobacterial community composition, and whether or not it is influenced by plant species (Eleocharis acicularis, Eleocharis palustris, Typha angustifolia) or sediment characteristics. Genes coding for ammonia monooxygenase (amoA) and 16S rRNA of betaproteobacterial ammonia oxidizers were targeted. The betaproteobacterial ammonia oxidizing community in root surface biofilms was distinct from the surrounding rhizosphere sediment. In contrast, communities in rhizosphere and bulk sediment samples were very similar. Our results showed the occurrence of Nitrosomonas europaea-like bacteria nearly exclusively in the rhizoplane biofilms, while sequences affiliated with the Nitrosomonas oligotropha, Nitrosomonas communis and Nitrosospira-lineages were more frequently detected in the surrounding sediment. Our results further suggest that the presence of N. europaea on macrophyte roots depends on the sampling site rather than on the studied macrophyte species. We propose that the rhizoplane of aquatic macrophytes is a natural habitat for N. europaea.

  • 254.
    Beier, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Mohit, Vani
    Département de Biologie, Québec-Océan and Institut de biologie integrative et des systèmes, Université Laval.
    Ettema, Thijs J. G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution.
    Östman, Örjan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Population and Conservation Biology.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Pronounced seasonal dynamics of freshwater chitinase genes and chitin processing2012In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 14, no 9, p. 2467-2479Article in journal (Refereed)
    Abstract [en]

    Seasonal variation in activity of enzymes involved in polymer degradation, including chitinases, has been observed previously in freshwater environments. However, it is not known whether the seasonal dynamics are due to shifts in the activity of bacteria already present, or shifts in community structure towards emergence or disappearance of chitinolytic organisms. We traced seasonal shifts in the chitinase gene assemblage in a temperate lake and linked these communities to variation in chitinase activity. Chitinase genes from 20 samples collected over a full yearly cycle were characterized by pyrosequencing. Pronounced temporal shifts in composition of the chitinase gene pool (beta diversity) occurred along with distinct shifts in richness (alpha diversity) as well as chitin processing. Changes in the chitinase gene pool correlated mainly with temperature, abundance of crustacean zooplankton and phytoplankton blooms. Also changes in the physical structure of the lake, e.g. stratification and mixing were associated with changes in the chitinolytic community, while differences were minor between surface and suboxic hypolimnetic water. The lake characteristics influencing the chitinolytic community are all linked to changes in organic particles and we suggest that seasonal changes in particle quality and availability foster microbial communities adapted to efficiently degrade them.

  • 255. Beisner, Beatrix E.
    et al.
    Peres-Neto, Pedro R.
    Lindström, Eva S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Barnett, Alain
    Longhi, Maria Lorena
    The role of environmental and spatial processes in structuring lake communities from bacteria to fish2006In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 87, no 12, p. 2985-2991Article in journal (Refereed)
    Abstract [en]

    We assessed the relative roles of local environmental conditions and dispersal on community structure in a landscape of lakes for the major trophic groups. We use taxonomic presence–absence and abundance data for bacteria, phytoplankton, zooplankton, and fish from 18 lakes in southern Quebec, Canada. The question of interest was whether communities composed of organisms with more limited dispersal abilities, because of size and life history (zooplankton and fish) would show a different effect of lake distribution than communities composed of good dispersers (bacteria and phytoplankton). We examine the variation in structure attributable to local environmental (i.e., lake chemical and physical variables) vs. dispersal predictors (i.e., overland and watercourse distances between lakes) using variation partitioning techniques. Overall, we show that less motile species (crustacean zooplankton and fish) are better predicted by spatial factors than by local environmental ones. Furthermore, we show that for zooplankton abundances, both overland and watercourse dispersal pathways are equally strong, though they may select for different components of the community, while for fish, only watercourses are relevant dispersal pathways. These results suggest that crustacean zooplankton and fish are more constrained by dispersal and therefore more likely to operate as a metacommunity than are bacteria and phytoplankton within this studied landscape.

  • 256. Bella, Eleni
    et al.
    Liepelt, Sascha
    Parducci, Laura
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Drouzas, Andreas D.
    Genetic insights into the hybrid origin of Abies borisii-regis Mattf.2015In: Plant Systematics and Evolution, ISSN 0378-2697, E-ISSN 1615-6110, Vol. 301, no 2, p. 749-759Article in journal (Refereed)
    Abstract [en]

    Abies × borisii-regis Mattf. (King Boris fir) is a taxon endemic to the southern Balkan Peninsula, described as a hybrid between the widespread A. alba Mill. (Silver fir) and the Greek endemic A. cephalonica Loud (Greek fir). Even though A. × borisii-regis has attracted much research attention in the past, its origin, geographical distribution and taxonomic status are not fully elucidated and molecular evidence for hybridization is missing. To shed more light on this issue, we analyzed representative populations from these three Abies taxa using paternally inherited (chloroplast) and maternally inherited (mitochondrial) DNA markers. Both Silver and Greek fir could be clearly distinguished using mitochondrial markers, while we observed a mixture of maternal lineages in theA. × borisii-regis populations. In contrast, using chloroplast markers, we could not identify species-specific haplotypes, but a neighbor-joining analysis of population genetic distances revealed two separate clusters for the Silver fir and the Greek fir, while the A. × borisii-regis populations were placed in intermediate positions. Our results are in agreement with the hypothesis that the A. ×borisii-regis populations investigated are a result of hybridization between A. cephalonica and A. alba.

  • 257. Bellis, Emily S
    et al.
    Kelly, Elizabeth A
    Lorts, Claire M
    Gao, Huirong
    DeLeo, Victoria L
    Rouhan, Germinal
    Budden, Andrew
    Bhaskara, Govinal B
    Hu, Zhenbin
    Muscarella, Robert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Timko, Michael P
    Nebie, Baloua
    Runo, Steven M
    Chilcoat, N Doane
    Juenger, Thomas E
    Morris, Geoffrey P
    dePamphilis, Claude W
    Lasky, Jesse R
    Genomics of sorghum local adaptation to a parasitic plant2020In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 117, no 8, p. 4243-4251Article in journal (Refereed)
    Abstract [en]

    Host-parasite coevolution can maintain high levels of genetic diversity in traits involved in species interactions. In many systems, host traits exploited by parasites are constrained by use in other functions, leading to complex selective pressures across space and time. Here, we study genome-wide variation in the staple crop Sorghum bicolor (L.) Moench and its association with the parasitic weed Striga hermonthica (Delile) Benth., a major constraint to food security in Africa. We hypothesize that geographic selection mosaics across gradients of parasite occurrence maintain genetic diversity in sorghum landrace resistance. Suggesting a role in local adaptation to parasite pressure, multiple independent loss-of-function alleles at sorghum LOW GERMINATION STIMULANT 1 (LGS1) are broadly distributed among African landraces and geographically associated with S. hermonthica occurrence. However, low frequency of these alleles within S. hermonthica-prone regions and their absence elsewhere implicate potential trade-offs restricting their fixation. LGS1 is thought to cause resistance by changing stereochemistry of strigolactones, hormones that control plant architecture and below-ground signaling to mycorrhizae and are required to stimulate parasite germination. Consistent with trade-offs, we find signatures of balancing selection surrounding LGS1 and other candidates from analysis of genome-wide associations with parasite distribution. Experiments with CRISPR-Cas9-edited sorghum further indicate that the benefit of LGS1-mediated resistance strongly depends on parasite genotype and abiotic environment and comes at the cost of reduced photosystem gene expression. Our study demonstrates long-term maintenance of diversity in host resistance genes across smallholder agroecosystems, providing a valuable comparison to both industrial farming systems and natural communities.

  • 258. Bendall, Matthew L
    et al.
    Stevens, Sarah LR
    Chan, Leong-Keat
    Malfatti, Stephanie
    Schwientek, Patrick
    Tremblay, Julien
    Schackwitz, Wendy
    Martin, Joel
    Pati, Amrita
    Bushnell, Brian
    Froula, Jeff
    Kang, Dongwan
    Tringe, Susannah G
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Moran, Mary A
    Shade, Ashley
    Newton, Ryan J
    McMahon, Katherine D
    Malmstrom, Rex R
    Genome-wide selective sweeps and gene-specific sweeps in natural bacterial populations2016In: The ISME Journal, ISSN 1751-7362, E-ISSN 1751-7370, Vol. 10, no 7, p. 1589-1601Article in journal (Refereed)
    Abstract [en]

    Multiple models describe the formation and evolution of distinct microbial phylogenetic groups. These evolutionary models make different predictions regarding how adaptive alleles spread through populations and how genetic diversity is maintained. Processes predicted by competing evolutionary models, for example, genome-wide selective sweeps vs gene-specific sweeps, could be captured in natural populations using time-series metagenomics if the approach were applied over a sufficiently long time frame. Direct observations of either process would help resolve how distinct microbial groups evolve. Here, from a 9-year metagenomic study of a freshwater lake (2005-2013), we explore changes in single-nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in 30 bacterial populations. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied by >1000-fold among populations. SNP allele frequencies also changed dramatically over time within some populations. Interestingly, nearly all SNP variants were slowly purged over several years from one population of green sulfur bacteria, while at the same time multiple genes either swept through or were lost from this population. These patterns were consistent with a genome-wide selective sweep in progress, a process predicted by the /`ecotype model/' of speciation but not previously observed in nature. In contrast, other populations contained large, SNP-free genomic regions that appear to have swept independently through the populations prior to the study without purging diversity elsewhere in the genome. Evidence for both genome-wide and gene-specific sweeps suggests that different models of bacterial speciation may apply to different populations coexisting in the same environment.

  • 259.
    Bengtsson, Fia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Functional Traits in Sphagnum2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Peat mosses (Sphagnum) are ecosystem engineers that largely govern carbon sequestration in northern hemisphere peatlands. I investigated functional traits in Sphagnum species and addressed the questions: (I) Are growth, photosynthesis and decomposition and the trade-offs between these traits related to habitat or phylogeny?, (II) Which are the determinants of decomposition and are there trade-offs between metabolites that affect decomposition?, (III) How do macro-climate and local environment determine growth in Sphagnum across the Holarctic?, (IV) How does N2 fixation vary among different species and habitats?, (V) How do species from different microtopographic niches avoid or tolerate desiccation, and are leaf and structural traits adaptations to growth high above the water table?

    Photosynthetic rate and decomposition in laboratory conditions (innate growth and decay resistance) were related to growth and decomposition in their natural habitats. We found support for a trade-off between growth and decay resistance, but innate qualities translated differently to field responses in different species. There were no trade-offs between production of different decay-affecting metabolites. Their production is phylogenetically controlled, but their effects on decay are modified by nutrient availability in the habitat. Modelling growth of two species across the Holarctic realm showed that precipitation, temperature and vascular plant cover are the best predictors of performance, but responses were stronger for the wetter growing species. N2 fixation rates were positively related to moss decomposability, field decomposition and tissue phosphorus concentration. Hence, higher decomposition can lead to more nutrients available to N2-fixing microorganisms, while higher concentrations of decomposition-hampering metabolites may impede N2 fixation. A mesocosm experiment, testing effects of water level drawdown on water content and chlorophyll fluorescence, showed that either slow water loss or high maximum water holding capacity can lead to desiccation avoidance. Furthermore, leaf anatomical traits rather than structural traits affected the water economy.

    This thesis has advanced the emerging field of trait ecology in Sphagnum by comparing many species and revealing novel mechanisms and an ever more complex picture of Sphagnum ecology. In addition, the species-specific trait measurements of this work offers opportunities for improvements of peatland ecosystem models.

    List of papers
    1. Photosynthesis, growth, and decay traits in Sphagnum – a multispecies comparison
    Open this publication in new window or tab >>Photosynthesis, growth, and decay traits in Sphagnum – a multispecies comparison
    2016 (English)In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 10, p. 3325-3341Article in journal (Refereed) Published
    Abstract [en]

    Peat mosses (Sphagnum) largely govern carbon sequestration in Northern Hemisphere peatlands. We investigated functional traits related to growth and decomposition in Sphagnum species. We tested the importance of environment and phylogeny in driving species traits and investigated trade-offs among them. We selected 15 globally important Sphagnum species, representing four sections (subgenera) and a range of peatland habitats. We measured rates of photosynthesis and decomposition in standard laboratory conditions as measures of innate growth and decay potential, and related this to realized growth, production, and decomposition in their natural habitats. In general, we found support for a trade-off between measures of growth and decomposition. However, the relationships are not strong, with r ranging between 0.24 and 0.45 for different measures of growth versus decomposition. Using photosynthetic rate to predict decomposition in standard conditions yielded R2 = 0.20. Habitat and section (phylogeny) affected the traits and the trade-offs. In a wet year, species from sections Cuspidata and Sphagnum had the highest production, but in a dry year, differences among species, sections, and habitats evened out. Cuspidata species in general produced easily decomposable litter, but their decay in the field was hampered, probably due to near-surface anoxia in their wet habitats. In a principal components analysis, PCA, photosynthetic capacity, production, and laboratory decomposition acted in the same direction. The species were imperfectly clustered according to vegetation type and phylogeny, so that some species clustered with others in the same section, whereas others clustered more clearly with others from similar vegetation types. Our study includes a wider range of species and habitats than previous trait analyses in Sphagnum and shows that while the previously described growth–decay trade-off exists, it is far from perfect. We therefore suggest that our species-specific trait measures offer opportunities for improvements of peatland ecosystem models. Innate qualities measured in laboratory conditions translate differently to field responses. Most dramatically, fast-growing species could only realize their potential in a wet year. The same species decompose fast in laboratory, but their decomposition was more retarded in the field than that of other species. These relationships are crucial for understanding the long-term dynamics of peatland communities.

    National Category
    Ecology
    Identifiers
    urn:nbn:se:uu:diva-284287 (URN)10.1002/ece3.2119 (DOI)000376646700024 ()27103989 (PubMedID)
    Funder
    Swedish Research CouncilSwedish Research Council FormasThe Royal Swedish Academy of Sciences
    Available from: 2016-04-16 Created: 2016-04-16 Last updated: 2019-02-01Bibliographically approved
    2. Biochemical determinants of litter quality in 15 species of Sphagnum
    Open this publication in new window or tab >>Biochemical determinants of litter quality in 15 species of Sphagnum
    2018 (English)In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 425, no 1-2, p. 161-176Article in journal (Refereed) Published
    Abstract [en]

    Background and aims Sphagnum mosses are ecosystem engineers that create and maintain boreal peatlands. With unique biochemistry, waterlogging and acidifying capacities, they build up meters-thick layers of peat, reducing competition and impeding decomposition. We quantify within-genus differences in biochemical composition to make inferences about decay rates, related to hummock-hollow and fen-bog gradients and to phylogeny. Methods We sampled litter from 15 Sphagnum species, abundant over the whole northern hemisphere. We used regression and Principal Components Analysis (PCA) to evaluate general relationships between litter quality parameters and decay rates measured under laboratory and field conditions. Results Both concentrations of the polysaccharide sphagnan and the soluble phenolics were positively correlated with intrinsic decay resistance, however, so were the previously understudied lignin-like phenolics. More resistant litter had more of all the important metabolites; consequently, PC1 scores were related to lab mass loss (R-2 = 0.57). There was no such relationship with field mass loss, which is also affected by the environment. PCA also revealed that metabolites clearly group Sphagnum sections (subgenera). Conclusions We suggest that the commonly stated growth-decomposition trade-off is largely due to litter quality. We show a strong phylogenetic control on Sphagnum metabolites, but their effects on decay are affected by nutrient availability in the habitat.

    Keywords
    Peatland, Decay resistance, Sphagnan, Phenolics, Lignin, Hummock-hollow
    National Category
    Botany
    Identifiers
    urn:nbn:se:uu:diva-354249 (URN)10.1007/s11104-018-3579-8 (DOI)000430992300011 ()
    Funder
    Swedish Research CouncilThe Royal Swedish Academy of Sciences
    Note

    Correction in: PLANT AND SOIL, Volume: 439, Issue: 1-2, Pages: 569-572, Special Issue: SI, DOI: 10.1007/s11104-019-04046-5

    Available from: 2018-06-29 Created: 2018-06-29 Last updated: 2019-08-16Bibliographically approved
    3. Environmental drivers of Sphagnum growth in mires across the Holarctic region
    Open this publication in new window or tab >>Environmental drivers of Sphagnum growth in mires across the Holarctic region
    (English)Manuscript (preprint) (Other academic)
    Keywords
    climate, global change, NPP, peatlands, peat mosses, nitrogen deposition
    National Category
    Natural Sciences
    Research subject
    Biology with specialization in Ecological Botany; Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-375010 (URN)
    Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-02-01
    4. Variation in symbiotic Nfixation among Sphagnum and feather mosses
    Open this publication in new window or tab >>Variation in symbiotic Nfixation among Sphagnum and feather mosses
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Keywords
    diazotrophs, peat moss, bog, peatland, nitrogen, phosphorus, carbon, nutrient cycling, traits, boreal forest
    National Category
    Natural Sciences
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-375008 (URN)
    Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-02-01
    5. Mechanisms behind species-specific water economy responses to water level drawdown in peat mosses
    Open this publication in new window or tab >>Mechanisms behind species-specific water economy responses to water level drawdown in peat mosses
    (English)Manuscript (preprint) (Other academic)
    Keywords
    peat mosses, water economy, capitulum water content, bulk density, hyaline cell, pore size, leaf anatomy
    National Category
    Natural Sciences
    Research subject
    Biology with specialization in Ecological Botany
    Identifiers
    urn:nbn:se:uu:diva-375009 (URN)
    Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2020-03-02
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  • 260.
    Bengtsson, Fia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Granath, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Cronberg, Nils
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Mechanisms behind species-specific water economy responses to water level drawdown in peat mossesManuscript (preprint) (Other academic)
  • 261.
    Bengtsson, Fia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Granath, Gustaf
    Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Photosynthesis, growth, and decay traits in Sphagnum – a multispecies comparison2016In: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 6, no 10, p. 3325-3341Article in journal (Refereed)
    Abstract [en]

    Peat mosses (Sphagnum) largely govern carbon sequestration in Northern Hemisphere peatlands. We investigated functional traits related to growth and decomposition in Sphagnum species. We tested the importance of environment and phylogeny in driving species traits and investigated trade-offs among them. We selected 15 globally important Sphagnum species, representing four sections (subgenera) and a range of peatland habitats. We measured rates of photosynthesis and decomposition in standard laboratory conditions as measures of innate growth and decay potential, and related this to realized growth, production, and decomposition in their natural habitats. In general, we found support for a trade-off between measures of growth and decomposition. However, the relationships are not strong, with r ranging between 0.24 and 0.45 for different measures of growth versus decomposition. Using photosynthetic rate to predict decomposition in standard conditions yielded R2 = 0.20. Habitat and section (phylogeny) affected the traits and the trade-offs. In a wet year, species from sections Cuspidata and Sphagnum had the highest production, but in a dry year, differences among species, sections, and habitats evened out. Cuspidata species in general produced easily decomposable litter, but their decay in the field was hampered, probably due to near-surface anoxia in their wet habitats. In a principal components analysis, PCA, photosynthetic capacity, production, and laboratory decomposition acted in the same direction. The species were imperfectly clustered according to vegetation type and phylogeny, so that some species clustered with others in the same section, whereas others clustered more clearly with others from similar vegetation types. Our study includes a wider range of species and habitats than previous trait analyses in Sphagnum and shows that while the previously described growth–decay trade-off exists, it is far from perfect. We therefore suggest that our species-specific trait measures offer opportunities for improvements of peatland ecosystem models. Innate qualities measured in laboratory conditions translate differently to field responses. Most dramatically, fast-growing species could only realize their potential in a wet year. The same species decompose fast in laboratory, but their decomposition was more retarded in the field than that of other species. These relationships are crucial for understanding the long-term dynamics of peatland communities.

    Download full text (pdf)
    fulltext
  • 262.
    Bengtsson, Fia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Granath, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Environmental drivers of Sphagnum growth in mires across the Holarctic regionManuscript (preprint) (Other academic)
  • 263.
    Bengtsson, Fia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Hajek, Tomas
    Univ South Bohemia, Dept Expt Plant Biol, Fac Sci, Branisovska 1760, CZ-37005 Ceske Budejovice, Czech Republic;Czech Acad Sci, Inst Bot, Dept Funct Ecol, Dukelska 135, CZ-37982 Trebon, Czech Republic.
    Biochemical determinants of litter quality in 15 species of Sphagnum2018In: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 425, no 1-2, p. 161-176Article in journal (Refereed)
    Abstract [en]

    Background and aims Sphagnum mosses are ecosystem engineers that create and maintain boreal peatlands. With unique biochemistry, waterlogging and acidifying capacities, they build up meters-thick layers of peat, reducing competition and impeding decomposition. We quantify within-genus differences in biochemical composition to make inferences about decay rates, related to hummock-hollow and fen-bog gradients and to phylogeny. Methods We sampled litter from 15 Sphagnum species, abundant over the whole northern hemisphere. We used regression and Principal Components Analysis (PCA) to evaluate general relationships between litter quality parameters and decay rates measured under laboratory and field conditions. Results Both concentrations of the polysaccharide sphagnan and the soluble phenolics were positively correlated with intrinsic decay resistance, however, so were the previously understudied lignin-like phenolics. More resistant litter had more of all the important metabolites; consequently, PC1 scores were related to lab mass loss (R-2 = 0.57). There was no such relationship with field mass loss, which is also affected by the environment. PCA also revealed that metabolites clearly group Sphagnum sections (subgenera). Conclusions We suggest that the commonly stated growth-decomposition trade-off is largely due to litter quality. We show a strong phylogenetic control on Sphagnum metabolites, but their effects on decay are affected by nutrient availability in the habitat.

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  • 264. Bengtsson, J.
    et al.
    Fagerström, T.
    Rydin, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Competition and coexistence in plant communities1994In: Trends in Ecology & Evolution, Vol. 9, p. 246-250Article in journal (Refereed)
  • 265.
    Bengtsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
    Fumana procumbens on Öland: population dynamics of a disjunct species at the northern limit of its range.1993In: Journal of Ecology, ISSN 0022-0477, E-ISSN 1365-2745, Vol. 81, p. 745-758Article in journal (Refereed)
  • 266.
    Bengtsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
    Long-term demographic variation in range-margin populations of Gypsophila fastigiata2000In: Folia Geobotanica, ISSN 1211-9520, E-ISSN 1874-9348, Vol. 35, p. 143-160Article in journal (Refereed)
  • 267.
    Bengtsson, Mia M.
    et al.
    Ernst Moritz Arndt Univ Greifswald, Inst Microbiol, Felix Hausdorff Str 8, D-17489 Greifswald, Germany.
    Attermeyer, Katrin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. WasserCluster Lunz, Dr Carl Kupelwieser Promenade 5, A-3293 Lunz Am See, Austria.
    Catalan, Nuria
    Catalan Inst Water Res ICRA, Emili Grahit 101, Girona 17003, Spain.
    Interactive effects on organic matter processing from soils to the ocean: are priming effects relevant in aquatic ecosystems?2018In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 822, no 1, p. 1-17Article, review/survey (Refereed)
    Abstract [en]

    Organic matter (OM) is degraded during transport from soils to oceans. However, there are spatial and temporal variabilities along the aquatic continuum, which hamper the development of carbon cycling models. One concept that has been applied in this context is the priming effect (PE), describing non-additive effects on OM degradation after mixing sources of contrasting bioavailability. Studies on the aquatic PE report divergent results from positive (increased OM degradation rates) to neutral, to negative (decreased OM degradation rates) effects upon mixing. Here, we aim to condense the outcomes of these studies on aquatic PE. Based on a literature review, we discuss differences in the reported PEs across freshwater and marine ecosystems, identifying system-specific features that could favour non-additive effects on OM degradation. Using a quantitative meta-analysis approach, we evaluated the occurrence, direction (positive vs. negative) and magnitude of aquatic PE. The meta-analysis revealed a mean PE of 12.6%, which was not significantly different from zero across studies. Hence, mixing of contrasting OM sources in aquatic ecosystems does not necessarily result in a change in OM degradation rates. Therefore, we suggest to focus on molecular and microbial diversity and function, which could provide a better mechanistic understanding of processes driving OM interactions.

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  • 268. Bennett, G. F.
    et al.
    Siikamaki, P.
    Ratti, O.
    Allander, K.
    Gustafsson, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Squiresparsons, D.
    TRYPANOSOMES OF SOME FENNOSCANDIAN BIRDS1994In: Memorias Do Instituto Oswaldo Cruz, Vol. 89, no 4, p. 531-537Article in journal (Refereed)
  • 269.
    Bennett, J. M.
    et al.
    Martin Luther Univ Halle Wittenberg, Inst Biol, Kirchtor 1, D-06108 Halle, Saale, Germany;German Ctr Integrat Biodivers Res iDiv, Deutsch Pl 5e, D-04103 Leipzig, Germany.
    Steets, J. A.
    Oklahoma State Univ, Dept Plant Biol Ecol & Evolut, Stillwater, OK 74078 USA;Illuminat Works, 2689 Commons Blvd Suite 120, Beavercreek, OH 45431 USA.
    Burns, J. H.
    German Ctr Integrat Biodivers Res iDiv, Deutsch Pl 5e, D-04103 Leipzig, Germany;Case Western Reserve Univ, Dept Biol, Cleveland, OH 44106 USA.
    Durka, W.
    UFZ Helmholtz Ctr Environm Res, Dept Community Ecol, Theodor Lieser Str 4, D-06120 Halle, Saale, Germany.
    Vamosi, J. C.
    Univ Calgary, Dept Biol Sci, Calgary, AB, Canada.
    Arceo-Gómez, G.
    Eastern Tennessee State Univ, Dept Biol Sci, Johnson City, TN USA.
    Burd, M.
    Monash Univ, Sch Biol Sci, Melbourne, Vic 3800, Australia.
    Burkle, L. A.
    Montana State Univ, Dept Ecol, Bozeman, MT 59715 USA.
    Ellis, A. G.
    Univ Stellenbosch, Dept Bot & Zool, Private Bag X1, ZA-7602 Matieland, South Africa.
    Freitas, L.
    Inst Pesquisas Jardim Bot Rio de Janeiro, Rua Pacheco Leao 915, BR-22460030 Rio De Janeiro, RJ, Brazil.
    Li, J.
    Taizhou Univ, Taizhou City, Zhejiang, Peoples R China.
    Rodger, J. G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. Univ Stellenbosch, Dept Bot & Zool, Private Bag X1, ZA-7602 Matieland, South Africa.
    Wolowski, M.
    Univ Fed Alfenas, Inst Nat Sci, Gabriel Monteiro da Silva St 700, BR-37130001 Alfenas, MG, Brazil.
    Xia, J.
    South Cent Univ Nationalities, Coll Life Sci, Wuhan, Hubei, Peoples R China.
    Ashman, T-L
    Univ Pittsburgh, Dept Biol Sci, Pittsburgh, PA 15260 USA.
    Knight, T. M.
    Martin Luther Univ Halle Wittenberg, Inst Biol, Kirchtor 1, D-06108 Halle, Saale, Germany;German Ctr Integrat Biodivers Res iDiv, Deutsch Pl 5e, D-04103 Leipzig, Germany;UFZ Helmholtz Ctr Environm Res, Dept Community Ecol, Theodor Lieser Str 4, D-06120 Halle, Saale, Germany.
    Publisher Correction: GloPL, a global data base on pollen limitation of plant reproduction2019In: Scientific Data, E-ISSN 2052-4463, Vol. 6, article id 2Article in journal (Refereed)
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  • 270.
    Bennett, J. M.
    et al.
    Martin Luther Univ Halle Wittenberg, Inst Biol, Kirchtor 1, D-06108 Halle, Saale, Germany;German Ctr Integrat Biodivers Res iDiv Halle Jana, Deutsch Pl 5e, D-04103 Leipzig, Germany.
    Steets, J. A.
    Oklahoma State Univ, Dept Plant Biol Ecol & Evolut, Stillwater, OK 74078 USA;Illuminat Works, 2689 Commons Blvd,Suite 120, Beavercreek, OH 45431 USA.
    Durka, W.
    German Ctr Integrat Biodivers Res iDiv Halle Jana, Deutsch Pl 5e, D-04103 Leipzig, Germany;UFZ Helmholtz Ctr Environm Res, Dept Community Ecol, Theodor Lieser Str 4, D-06120 Halle, Saale, Germany.
    Vamosi, J. C.
    Univ Calgary, Dept Biol Sci, Calgary, AB, Canada.
    Arceo-Gomez, G.
    Eastern Tennessee State Univ, Dept Biol Sci, Johnson City, TN USA.
    Burd, M.
    Monash Univ, Sch Biol Sci, Melbourne, Vic 3800, Australia.
    Burkle, L. A.
    Montana State Univ, Dept Ecol, Bozeman, MT 59715 USA.
    Ellis, A. G.
    Univ Stellenbosch, Dept Bot & Zool, Private Bag X1, ZA-7602 Matieland, South Africa.
    Freitas, L.
    Inst Pesquisas Jardim Bot Rio de Janeiro, Rua Pacheco Leao 915, BR-22460030 Rio De Janeiro, RJ, Brazil.
    Li, J.
    Taizhou Univ, Taizhou City, Zhejiang, Peoples R China.
    Rodger, J. G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution. Univ Stellenbosch, Dept Bot & Zool, Private Bag X1, ZA-7602 Matieland, South Africa.
    Wolowski, M.
    Univ Fed Alfenas, Inst Nat Sci, Gabriel Monteiro da Silva St 700, BR-37130001 Alfenas, MG, Brazil.
    Xia, J.
    South Cent Univ Nationalities, Coll Life Sci, Wuhan, Hubei, Peoples R China.
    Ashman, T-L
    Knight, T. M.
    Martin Luther Univ Halle Wittenberg, Inst Biol, Kirchtor 1, D-06108 Halle, Saale, Germany;German Ctr Integrat Biodivers Res iDiv Halle Jana, Deutsch Pl 5e, D-04103 Leipzig, Germany;UFZ Helmholtz Ctr Environm Res, Dept Community Ecol, Theodor Lieser Str 4, D-06120 Halle, Saale, Germany.
    GloPL, a global data base on pollen limitation of plant reproduction2018In: Scientific Data, E-ISSN 2052-4463, Vol. 5, article id 180249Article in journal (Refereed)
    Abstract [en]

    Plant reproduction relies on transfer of pollen from anthers to stigmas, and the majority of flowering plants depend on biotic or abiotic agents for this transfer. A key metric for characterizing if pollen receipt is insufficient for reproduction is pollen limitation, which is assessed by pollen supplementation experiments. In a pollen supplementation experiment, fruit or seed production by flowers exposed to natural pollination is compared to that following hand pollination either by pollen supplementation (i.e. manual outcross pollen addition without bagging) or manual outcrossing of bagged flowers, which excludes natural pollination. The GloPL database brings together data from 2969 unique pollen supplementation experiments reported in 927 publications published from 1981 to 2015, allowing assessment of the strength and variability of pollen limitation in 1265 wild plant species across all biomes and geographic regions globally. The GloPL database will be updated and curated with the aim of enabling the continued study of pollen limitation in natural ecosystems and highlighting significant gaps in our understanding of pollen limitation.

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  • 271.
    Bennke, Christin M.
    et al.
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Reintjes, Greta
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Schattenhofer, Martha
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Ellrott, Andreas
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Wulf, Jörg
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Zeder, Michael
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany.;Technobiol GmbH, Buchrain, Switzerland..
    Fuchs, Bernhard M.
    Max Planck Inst Marine Microbiol, Dept Mol Ecol, Bremen, Germany..
    Modification of a High-Throughput Automatic Microbial Cell Enumeration System for Shipboard Analyses2016In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 82, no 11, p. 3289-3296Article in journal (Refereed)
    Abstract [en]

    In the age of ever-increasing "-omics" studies, the accurate and statistically robust determination of microbial cell numbers within often-complex samples remains a key task in microbial ecology. Microscopic quantification is still the only method to enumerate specific subgroups of microbial clades within complex communities by, for example, fluorescence in situ hybridization (FISH). In this study, we improved an existing automatic image acquisition and cell enumeration system and adapted it for usage at high seas on board an oceanographic research ship. The system was evaluated by testing settings such as minimal pixel area and image exposure times ashore under stable laboratory conditions before being brought on board and tested under various wind and wave conditions. The system was robust enough to produce high-quality images even with ship heaves of up to 3m and pitch and roll angles of up to 6.3 degrees. On board the research ship, on average, 25% of the images acquired from plankton samples on filter membranes could be used for cell enumeration. Automated enumeration was highly correlated with manual counts (r(2)>0.9). Even the smallest of microbial cells in the open ocean, members of the alphaproteobacterial SAR11 clade, could be confidently detected and enumerated. The automated image acquisition and cell enumeration system developed here enables an accurate and reproducible determination of microbial cell counts in planktonic samples and allows insight into the abundance and distribution of specific microorganisms already on board within a few hours.

    IMPORTANCE In this research article, we report on a new system and software pipeline, which allows for an easy and quick image acquisition and the subsequent enumeration of cells in the acquired images. We put this pipeline through vigorous testing and compared it to manual microscopy counts of microbial cells on membrane filters. Furthermore, we tested this system at sea on board a marine research vessel and counted bacteria on board within a few hours after the retrieval of water samples. The imaging and counting system described here has been successfully applied to a number of laboratory-based studies and allowed the quantification of thousands of samples and FISH preparations (see, e.g., H. Teeling, B. M. Fuchs, D. Becher, C. Klockow, A. Gardebrecht, C. M. Bennke, M. Kassabgy, S. Huang, A. J. Mann, J. Waldmann, M. Weber, A. Klindworth, A. Otto, J. Lange, J. Bernhardt, C. Reinsch, M. Hecker, J. Peplies, F. D. Bockelmann, U. Callies, G. Gerdts, A. Wichels, K. H. Wiltshire, F. O. Glockner, T. Schweder, and R. Amann, Science 336:608-611, 2012, http://dx.doi.org/10.1126/science.1218344). We adjusted the standard image acquisition software to withstand ship movements. This system will allow for more targeted sampling of the microbial community, leading to a better understanding of the role of microorganisms in the global oceans.

  • 272. Benson, Barbara J.
    et al.
    Magnuson, John J.
    Jensen, Olaf P.
    Card, Virginia M.
    Hodgkins, Glenn
    Korhonen, Johanna
    Livingstone, David M.
    Stewart, Kenton M.
    Weyhenmeyer, Gesa
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Granin, Nick G.
    Extreme events, trends, and variability in Northern Hemisphere lake-ice phenology (1855-2005)2012In: Climatic Change, ISSN 0165-0009, E-ISSN 1573-1480, Vol. 112, no 2, p. 299-323Article in journal (Refereed)
    Abstract [en]

    Often extreme events, more than changes in mean conditions, have the greatest impact on the environment and human well-being. Here we examine changes in the occurrence of extremes in the timing of the annual formation and disappearance of lake ice in the Northern Hemisphere. Both changes in the mean condition and in variability around the mean condition can alter the probability of extreme events. Using long-term ice phenology data covering two periods 1855-6 to 2004-5 and 1905-6 to 2004-5 for a total of 75 lakes, we examined patterns in long-term trends and variability in the context of understanding the occurrence of extreme events. We also examined patterns in trends for a 30-year subset (1975-6 to 2004-5) of the 100-year data set. Trends for ice variables in the recent 30-year period were steeper than those in the 100- and 150-year periods, and trends in the 150-year period were steeper than in the 100-year period. Ranges of rates of change (days per decade) among time periods based on linear regression were 0.3-1.6 later for freeze, 0.5-1.9 earlier for breakup, and 0.7-4.3 shorter for duration. Mostly, standard deviation did not change, or it decreased in the 150-year and 100-year periods. During the recent 50-year period, standard deviation calculated in 10-year windows increased for all ice measures. For the 150-year and 100-year periods changes in the mean ice dates rather than changes in variability most strongly influenced the significant increases in the frequency of extreme lake ice events associated with warmer conditions and decreases in the frequency of extreme events associated with cooler conditions.

  • 273.
    Berg, Elena C.
    et al.
    Amer Univ Paris, Dept Comp Sci Math & Environm Sci, Paris, France.
    Lind, Martin I.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Monahan, Shannon
    Amer Univ Paris, Dept Comp Sci Math & Environm Sci, Paris, France.
    Bricout, Sophie
    Amer Univ Paris, Dept Comp Sci Math & Environm Sci, Paris, France.
    Maklakov, Alexei A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kin but less than kind: within-group male relatedness does not increase female fitness in seed beetles2019In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 286, no 1910, p. 1471-2954, article id 20191664Article in journal (Refereed)
    Abstract [en]

    Theory maintains within-group male relatedness can mediate sexual conflict by reducing male-male. competition and collateral harm to females. We tested whether male relatedness can lessen female harm in the seed beetle Callosobruchus maculatus. Male relatedness did not influence female lifetime reproductive success or individual fitness across two different ecologically relevant scenarios of mating competition. However, male relatedness marginally improved female survival. Because male relatedness improved female-survival in late life when C. maculatus females are no longer producing offspring, our results do not provide support for the role of within-group male relatedness in mediating sexual conflict. The fact that male relatedness improves the post-reproductive part of the female life cycle strongly suggests that the effect is non-adaptive. We discuss adaptive and non-adaptive mechanisms that could result in reduced female harm in this and previous studies, and suggest that cognitive error is a likely explanation.

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  • 274.
    Berg, Elena C.
    et al.
    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.
    Sexes suffer from suboptimal lifespan because of genetic conflict in a seed beetle2012In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 279, no 1745, p. 4296-4302Article in journal (Refereed)
    Abstract [en]

    Males and females have different routes to successful reproduction, resulting in sex differences in lifespan and age-specific allocation of reproductive effort. The trade-off between current and future reproduction is often resolved differently by males and females, and both sexes can be constrained in their ability to reach their sex-specific optima owing to intralocus sexual conflict. Such genetic antagonism may have profound implications for evolution, but its role in ageing and lifespan remains unresolved. We provide direct experimental evidence that males live longer and females live shorter than necessary to maximize their relative fitness in Callosobruchus maculatus seed beetles. Using artificial selection in a genetically heterogeneous population, we created replicate long-life lines where males lived on average 27 per cent longer than in short-life lines. As predicted by theory, subsequent assays revealed that upward selection on male lifespan decreased relative male fitness but increased relative female fitness compared with downward selection. Thus, we demonstrate that lifespan-extending genes can help one sex while harming the other. Our results show that sexual antagonism constrains adaptive life-history evolution, support a novel way of maintaining genetic variation for lifespan and argue for better integration of sex effects into applied research programmes aimed at lifespan extension.

  • 275.
    Berga, Mercè
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Yinghua, Zha
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Székely, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Testing responses of bacterial communities to environmental change using whole ecosystem manipulation experimentsManuscript (preprint) (Other academic)
  • 276.
    Berga, Mercè
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Germany.
    Zha, Yinghua
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Székely, Anna J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Functional and Compositional Stability of Bacterial Metacommunities in Response to Salinity Changes2017In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 8, article id 948Article in journal (Refereed)
    Abstract [en]

    Disturbances and environmental change are important factors determining the diversity,composition, and functioning of communities. However, knowledge about how naturalbacterial communities are affected by such perturbations is still sparse. We performeda whole ecosystem manipulation experiment with freshwater rock pools where weapplied salinity disturbances of different intensities. The aim was to test how thecompositional and functional resistance and resilience of bacterial communities,alpha- and beta-diversity and the relative importance of stochastic and deterministiccommunity assembly processes changed along a disturbance intensity gradient.We found that bacterial communities were functionally resistant to all salinity levels (3, 6, and 12 psu) and compositionally resistant to a salinity increase to 3 psu andresilient to increases of 6 and 12 psu. Increasing salinities had no effect on local richnessand evenness, beta-diversity and the proportion of deterministically vs. stochasticallyassembled communities. Our results show a high functional and compositional stabilityof bacterial communities to salinity changes of different intensities both at localand regional scales, which possibly reflects long-term adaptation to environmentalconditions in the study system.

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  • 277.
    Berga, Mercè
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Östman, Örjan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Lindström, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Effects of predation and dispersal on the diversity an functioning of bacterial metacommunitiesManuscript (preprint) (Other academic)
  • 278.
    Berga, Mercè
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Östman, Örjan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Lindström, Eva S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Combined effects of zooplankton grazing and dispersal on the diversity and assembly mechanisms of bacterial metacommunities2015In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 17, no 7, p. 2275-2287Article in journal (Refereed)
    Abstract [en]

    Effects of dispersal and the presence of predators on diversity, assembly and functioning of bacterial communities are well studied in isolation. In reality, however, dispersal and trophic interactions act simultaneously and can therefore have combined effects, which are poorly investigated. We performed an experiment with aquatic metacommunities consisting of three environmentally different patches and manipulated dispersal rates among them as well as the presence or absence of the keystone species Daphnia magnaDaphnia magnareduced both local and regional diversity, whereas dispersal increased local diversity but decreased beta-diversity having no net effect on regional diversity. Dispersal modified the assembly mechanisms of bacterial communities by increasing the degree of determinism. Additionally, the combination of the D. magna and dispersal increased the importance of deterministic processes, presumably because predator-tolerant taxa were spread in the metacommunity via dispersal. Moreover, the presence of D. magna affected community composition, increased community respiration rates but did not affect bacterial production or abundance, whereas dispersal slightly increased bacterial production. In conclusion, our study suggests that predation by a keystone species such as D. magna and dispersal additively influence bacterial diversity, assembly processes and ecosystem functioning.

  • 279.
    Berga, Mercé
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Székely, Anna J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Effects of Disturbance Intensity and Frequency on Bacterial Community Composition and Function2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 5, p. e36959-Article in journal (Refereed)
    Abstract [en]

    Disturbances influence community structure and ecosystem functioning. Bacteria are key players in ecosystems and it is therefore crucial to understand the effect of disturbances on bacterial communities and how they respond to them, both compositionally and functionally. The main aim of this study was to test the effect of differences in disturbance strength on bacterial communities. For this, we implemented two independent short-term experiments with dialysis bags containing natural bacterial communities, which were transplanted between ambient and 'disturbed' incubation tanks, manipulating either the intensity or the frequency of a salinity disturbance. We followed changes in community composition by terminal restriction fragment analysis (T-RFLP) and measured various community functions (bacterial production, carbon substrate utilization profiles and rates) directly after and after a short period of recovery under ambient conditions. Increases in disturbance strength resulted in gradually stronger changes in bacterial community composition and functions. In the disturbance intensity experiment, the sensitivity to the disturbance and the ability of recovery differed between different functions. In the disturbance frequency experiment, effects on the different functions were more consistent and recovery was not observed. Moreover, in case of the intensity experiment, there was also a time lag in the responses of community composition and functions, with functional responses being faster than compositional ones. To summarize, our study shows that disturbance strength has the potential to change the functional performance and composition of bacterial communities. It further highlights that the overall effects, rates of recovery and the degree of congruence in the response patterns of community composition and functioning along disturbance gradients depend on the type of function and the character of the disturbance.

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  • 280.
    Berga Quintana, Mercè
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Assembly Mechanisms in Aquatic Bacterial Communities: The Role of Disturbances, Dispersal and History2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Environmental conditions, biotic interactions, dispersal and history have been suggested to be important processes influencing the spatial distribution of organisms and thus to affect community assembly. Understanding how these processes influence community assembly is important, particularly because community diversity and composition are suggested to be relevant for ecosystem functioning. Moreover, bacteria are strongly contributing to nutrient and carbon cycle. Bacteria are highly abundant and ubiquitous, and thus it is relevant to study how they are assembled. This thesis aims to gain insight on the role of these processes on aquatic bacterial community assembly, diversity and functioning. The studies included in this thesis involve transplant and microcosm experiments performed in the lab as well as manipulation experiments and field surveys in a natural rock pool systems. Bacterial community composition was addressed by analysis of 16S rRNA gene and community functioning by measuring bacterial production, community respiration and the ability to use different carbon substrates. This thesis highlights that species sorting is a very important assembly mechanism for bacterial communities, but also finds that other processes such as dispersal and history contribute to the patterns observed. Dispersal caused rescuing effects compensating for losses of diversity; at the same time it increased the similarity between communities. Moreover, bacteria have shown a high level of functional plasticity when colonizing a new locality. Interestingly, past environmental conditions explained the structure of bacterial communities better than present-day environmental conditions. Disturbances and biotic interactions are also important in the assembly of communities. Disturbance caused temporary shifts in bacterial function and changes in composition, the magnitude of which depended on the intensity and the frequency of the disturbance. However, natural aquatic bacterial communities showed quite high resilience capacities. Competition can shift the proportion of generalists and specialists species whereas predation or trophic interactions have been found to decrease diversity and to modify the importance of stochasticity. Both caused alterations of community functioning. Finally, this thesis shows that the diversity-functioning relationship is context dependent. Further research should be directed to understanding the intensity and direction of changes in composition and how this affects the functionality of bacterial communities

    List of papers
    1. Effects of Disturbance Intensity and Frequency on Bacterial Community Composition and Function
    Open this publication in new window or tab >>Effects of Disturbance Intensity and Frequency on Bacterial Community Composition and Function
    2012 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 5, p. e36959-Article in journal (Refereed) Published
    Abstract [en]

    Disturbances influence community structure and ecosystem functioning. Bacteria are key players in ecosystems and it is therefore crucial to understand the effect of disturbances on bacterial communities and how they respond to them, both compositionally and functionally. The main aim of this study was to test the effect of differences in disturbance strength on bacterial communities. For this, we implemented two independent short-term experiments with dialysis bags containing natural bacterial communities, which were transplanted between ambient and 'disturbed' incubation tanks, manipulating either the intensity or the frequency of a salinity disturbance. We followed changes in community composition by terminal restriction fragment analysis (T-RFLP) and measured various community functions (bacterial production, carbon substrate utilization profiles and rates) directly after and after a short period of recovery under ambient conditions. Increases in disturbance strength resulted in gradually stronger changes in bacterial community composition and functions. In the disturbance intensity experiment, the sensitivity to the disturbance and the ability of recovery differed between different functions. In the disturbance frequency experiment, effects on the different functions were more consistent and recovery was not observed. Moreover, in case of the intensity experiment, there was also a time lag in the responses of community composition and functions, with functional responses being faster than compositional ones. To summarize, our study shows that disturbance strength has the potential to change the functional performance and composition of bacterial communities. It further highlights that the overall effects, rates of recovery and the degree of congruence in the response patterns of community composition and functioning along disturbance gradients depend on the type of function and the character of the disturbance.

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-177625 (URN)10.1371/journal.pone.0036959 (DOI)000305339400046 ()
    Available from: 2012-07-18 Created: 2012-07-17 Last updated: 2017-12-07Bibliographically approved
    2. Testing responses of bacterial communities to environmental change using whole ecosystem manipulation experiments
    Open this publication in new window or tab >>Testing responses of bacterial communities to environmental change using whole ecosystem manipulation experiments
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Microbiology
    Identifiers
    urn:nbn:se:uu:diva-207179 (URN)
    Available from: 2013-09-10 Created: 2013-09-10 Last updated: 2014-05-08
    3. Mechanisms determining the fate of dispersed bacterial communities in new environments
    Open this publication in new window or tab >>Mechanisms determining the fate of dispersed bacterial communities in new environments
    2013 (English)In: ISME Journal, ISSN 1751-7362, Vol. 7, no 1, p. 61-71Article in journal (Refereed) Published
    Abstract [en]

    Recent work has shown that dispersal has an important role in shaping microbial communities. However, little is known about how dispersed bacteria cope with new environmental conditions and how they compete with local resident communities. To test this, we implemented two full-factorial transplant experiments with bacterial communities originating from two sources (freshwater or saline water), which were incubated, separately or in mixes, under both environmental conditions. Thus, we were able to separately test for the effects of the new environment with and without interactions with local communities. We determined community composition using 454-pyrosequencing of bacterial 16S rRNA to specifically target the active fraction of the communities, and measured several functional parameters. In absence of a local resident community, the net functional response was mainly affected by the environmental conditions, suggesting successful functional adaptation to the new environmental conditions. Community composition was influenced both by the source and the incubation environment, suggesting simultaneous effects of species sorting and functional plasticity. In presence of a local resident community, functional parameters were higher compared with those expected from proportional mixes of the unmixed communities in three out of four cases. This was accompanied by an increase in the relative abundance of generalists, suggesting that competitive interactions among local and immigrant taxa could explain the observed functional overachievement. In summary, our results suggest that environmental filtering, functional plasticity and competition are all important mechanisms influencing the fate of dispersed communities.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-192014 (URN)10.1038/ismej.2012.80 (DOI)000313236000006 ()
    Available from: 2013-01-24 Created: 2013-01-15 Last updated: 2014-01-23Bibliographically approved
    4. The spatial structure of bacterial communities is influenced by historical environmental conditions
    Open this publication in new window or tab >>The spatial structure of bacterial communities is influenced by historical environmental conditions
    2014 (English)In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 95, no 5, p. 1134-1140Article in journal (Refereed) Published
    Abstract [en]

    The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.

    National Category
    Ecology Microbiology
    Identifiers
    urn:nbn:se:uu:diva-207181 (URN)10.1890/13-1300.1 (DOI)000336740500003 ()
    Available from: 2013-09-10 Created: 2013-09-10 Last updated: 2017-12-06Bibliographically approved
    5. Effects of predation and dispersal on the diversity an functioning of bacterial metacommunities
    Open this publication in new window or tab >>Effects of predation and dispersal on the diversity an functioning of bacterial metacommunities
    (English)Manuscript (preprint) (Other academic)
    National Category
    Ecology Microbiology
    Identifiers
    urn:nbn:se:uu:diva-207177 (URN)
    Available from: 2013-09-10 Created: 2013-09-10 Last updated: 2014-01-23
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  • 281.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Berg, Elena C
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Widegren, William
    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.
    Multivariate intralocus sexual conflict in seed beetles2014In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 68, no 12, p. 3457-69Article in journal (Refereed)
    Abstract [en]

    Intralocus sexual conflict (IaSC) is pervasive because males and females experience differences in selection but share much of the same genome. Traits with integrated genetic architecture should be reservoirs of sexually antagonistic genetic variation for fitness, but explorations of multivariate IaSC are scarce. Previously, we showed that upward artificial selection on male life span decreased male fitness but increased female fitness compared with downward selection in the seed beetle Callosobruchus maculatus. Here, we use these selection lines to investigate sex-specific evolution of four functionally integrated traits (metabolic rate, locomotor activity, body mass, and life span) that collectively define a sexually dimorphic life-history syndrome in many species. Male-limited selection for short life span led to correlated evolution in females toward a more male-like multivariate phenotype. Conversely, males selected for long life span became more female-like, implying that IaSC results from genetic integration of this suite of traits. However, while life span, metabolism, and body mass showed correlated evolution in the sexes, activity did not evolve in males but, surprisingly, did so in females. This led to sexual monomorphism in locomotor activity in short-life lines associated with detrimental effects in females. Our results thus support the general tenet that widespread pleiotropy generates IaSC despite sex-specific genetic architecture.

  • 282.
    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.

  • 283.
    Berger, David
    et al.
    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.
    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.
    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 the Tragedy of the Commons in Seed Beetles2016In: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 188, no 4, p. E98-E112Article in journal (Refereed)
    Abstract [en]

    The evolution of male traits that inflict direct harm on females during mating interactions can result in a so-called tragedy of the commons, where selfish male strategies depress population viability. This tragedy of the commons can be magnified by intralocus sexual conflict (IaSC) whenever alleles that reduce fecundity when expressed in females spread in the population because of their benefits in males. We evaluated this prediction by detailed phenotyping of 73 isofemale lines of the seed beetle Callosobruchus maculatus. We quantified genetic variation in life history andmorphology, as well as associated covariance in male and female adult reproductive success. In parallel, we created replicated artificial populations of each line and measured their productivity. Genetic constraints limited independent trait expression in the sexes, and we identified several instances of sexually antagonistic covariance between traits and fitness, signifying IaSC. Population productivity was strongly positively correlated to female adult reproductive success but uncorrelated with male reproductive success. Moreover, male (female) phenotypic optima for several traits under sexually antagonistic selection were exhibited by the genotypes with the lowest (highest) population productivity. Our study forms a direct link between individuallevel sex-specific selection and population demography and places lifehistory traits at the epicenter of these dynamics.

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  • 284.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Olofsson, M.
    Friberg, M.
    Karlsson, B.
    Wiklund, C.
    Gotthard, K.
    Intraspecific variation in body size and the rate of reproduction in female insects - adaptive allometry or biophysical constraint?2012In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 81, no 6, p. 1244-1258Article in journal (Refereed)
    Abstract [en]

    1. A high rate of reproduction may be costly if ecological factors limit immediate reproductive output as a fast metabolism compromises own future survival. Individuals with more reserves need more time and opportunity to realize their reproductive potential. Theory therefore predicts that the reproductive rate, defined as the investment in early reproduction in proportion to total potential, should decrease with body size within species. 2. However, metabolic constraints on body size- and temperature-dependent biological rates may impede biophysical adaptation. Furthermore, the sequential manner resources that are allocated to somatic vs. reproductive tissue during ontogeny may, when juveniles develop in unpredictable environments, further contribute to non-adaptive variation in adult reproductive rates. 3. With a model on female egg laying in insects, we demonstrate how variation in body reserves is predicted to affect reproductive rate under different ecological scenarios. Small females always have higher reproductive rates but shorter lifespans. However, incorporation of female host selectivity leads to more similar reproductive rates among female size classes, and oviposition behaviour is predicted to co-evolve with reproductive rate, resulting in small females being more selective in their choice and gaining relatively more from it. 4. We fed simulations with data on the butterfly Pararge aegeria to compare model predictions with reproductive rates of wild butterflies. However, simulated reproductive allometry was a poor predictor of that observed. Instead, reproductive rates were better explained as a product of metabolic constraints on rates of egg maturation, and an empirically derived positive allometry between reproductive potential and size. However, fitness is insensitive to moderate deviations in reproductive rate when oviposition behaviour is allowed to co-evolve in the simulations, suggesting that behavioural compensation may mitigate putative metabolic and developmental constraints. 5. More work is needed to understand how physiology and development together with compensatory behaviours interact in shaping reproductive allometry. Empirical studies should evaluate adaptive hypotheses against proper null hypotheses, including prediction from metabolic theory, preferentially by studying reproductive physiology in combination with behaviour. Conversely, inferences of constraint explanations on reproductive rates must take into consideration that adaptive scenarios may predict similar allometric exponents.

  • 285.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Olofsson, Martin
    Gotthard, Karl
    Wiklund, Christer
    Friberg, Magne
    Ecological Constraints on Female Fitness in a Phytophagous Insect2012In: American Naturalist, ISSN 0003-0147, E-ISSN 1537-5323, Vol. 180, no 4, p. 464-480Article in journal (Refereed)
    Abstract [en]

    Although understanding female reproduction is crucial for population demography, determining how and to what relative extent it is constrained by different ecological factors is complicated by difficulties in studying the links between individual behavior, life history, and fitness in nature. We present data on females in a natural population of the butterfly Leptidea sinapis. These data were combined with climate records and laboratory estimates of life-history parameters to predict the relative impact of different ecological constraints on female fitness in the wild. Using simulation models, we partitioned effects of male courtship, host plant availability, and temperature on female fitness. Results of these models indicate that temperature is the most constraining factor on female fitness, followed by host plant availability; the short-term negative effects of male courtship that were detected in the field study were less important in models predicting female reproductive success over the entire life span. In the simulations, females with more reproductive reserves were more limited by the ecological variables. Reproductive physiology and egg-laying behavior were therefore predicted to be co-optimized but reach different optima for females of different body sizes; this prediction is supported by the empirical data. This study thus highlights the need for studying behavioral and life-history variation in orchestration to achieve a more complete picture of both demographic and evolutionary processes in naturally variable and unpredictable environments.

  • 286.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Postma, Erik
    Biased Estimates of Diminishing-Returns Epistasis?: Empirical Evidence Revisited2014In: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 198, no 4, p. 1417-1420Article in journal (Refereed)
    Abstract [en]

    Empirical evidence for diminishing fitness returns of beneficial mutations supports Fisher's geometric model. We show that a similar pattern emerges through the phenomenon of regression to the mean and that few studies correct for it. Although biases are often small, regression to the mean has overemphasized diminishing returns and will hamper cross-study comparisons unless corrected for.

  • 287.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Postma, Erik
    Blanckenhorn, Wolf U.
    Walters, Richard J.
    Quantitative genetic divergence and standing genetic (CO)variance in thermal reaction norms along latitude2013In: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 67, no 8, p. 2385-2399Article in journal (Refereed)
    Abstract [en]

    Although the potential to adapt to warmer climate is constrained by genetic trade-offs, our understanding of how selection and mutation shape genetic (co)variances in thermal reaction norms is poor. Using 71 isofemale lines of the fly Sepsis punctum, originating from northern, central, and southern European climates, we tested for divergence in juvenile development rate across latitude at five experimental temperatures. To investigate effects of evolutionary history in different climates on standing genetic variation in reaction norms, we further compared genetic (co) variances between regions. Flies were reared on either high or low food resources to explore the role of energy acquisition in determining genetic trade-offs between different temperatures. Although the latter had only weak effects on the strength and sign of genetic correlations, genetic architecture differed significantly between climatic regions, implying that evolution of reaction norms proceeds via different trajectories at high latitude versus low latitude in this system. Accordingly, regional genetic architecture was correlated to region-specific differentiation. Moreover, hot development temperatures were associated with low genetic variance and stronger genetic correlations compared to cooler temperatures. We discuss the evolutionary potential of thermal reaction norms in light of their underlying genetic architectures, evolutionary histories, and the materialization of trade-offs in natural environments.

  • 288.
    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.

  • 289.
    Berger, David
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology.
    Walters, R. J.
    Blanckenhorn, W. U.
    Experimental evolution for generalists and specialists reveals multivariate genetic constraints on thermal reaction norms2014In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 27, no 9, p. 1975-1989Article in journal (Refereed)
    Abstract [en]

    Theory predicts the emergence of generalists in variable environments and antagonistic pleiotropy to favour specialists in constant environments, but empirical data seldom support such generalist-specialist trade-offs. We selected for generalists and specialists in the dung fly Sepsis punctum (Diptera: Sepsidae) under conditions that we predicted would reveal antagonistic pleiotropy and multivariate trade-offs underlying thermal reaction norms for juvenile development. We performed replicated laboratory evolution using four treatments: adaptation at a hot (31 degrees C) or a cold (15 degrees C) temperature, or under regimes fluctuating between these temperatures, either within or between generations. After 20 generations, we assessed parental effects and genetic responses of thermal reaction norms for three correlated life-history traits: size at maturity, juvenile growth rate and juvenile survival. We find evidence for antagonistic pleiotropy for performance at hot and cold temperatures, and a temperature-mediated trade-off between juvenile survival and size at maturity, suggesting that trade-offs associated with environmental tolerance can arise via intensified evolutionary compromises between genetically correlated traits. However, despite this antagonistic pleiotropy, we found no support for the evolution of increased thermal tolerance breadth at the expense of reduced maximal performance, suggesting low genetic variance in the generalist-specialist dimension.

  • 290.
    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.

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  • 291.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    The ups and downs of parental care2013In: Trends in Ecology & Evolution, ISSN 0169-5347, E-ISSN 1872-8383, Vol. 28, no 7, p. 387-388Article, book review (Other academic)
  • 292.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Why are sexually selected weapons almost absent in females?2013In: Current Zoology, ISSN 1674-5507, Vol. 59, no 4, p. 564-568Article in journal (Refereed)
    Abstract [en]

    In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role reversed or not. However, sexually selected female weapons seem totally absent except for small wing spurs in three jacana species, present in both males and females. This poor female weaponry is in sharp contrast to the situation in species with conventional sex roles: males commonly have evolved sexually selected weapons as well as ornaments. At the same time, females in many taxa have naturally selected weapons, used in competition over resources or in predator defence. Why are sexually selected weapons then so rare, almost absent, in females? Here I briefly review weaponry in females and the function of these weapons, conclude that the near absence of sexually selected weapons begs an explanation, and suggest that costs of sexually selected weapons may exceed costs of ornaments. Females are more constrained when evolving sexually selected traits compared to males, at least compared to those males that do not provide direct benefits, as trait costs reduce a female’s fecundity. I suggest that this constraining trade-off between trait and fecundity restricts females to evolve ornaments but rarely weapons. The same may apply to paternally investing males. Whether sexually selected weapons actually are more costly than sexually selected ornaments remains to be investigated.

  • 293.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Sundin, Josefin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Rosenqvist, Gunilla
    Norwegian University of Science and Technology.
    Baltic pipefish females need twice as many males as they get2017In: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 28, no 3, p. 827-832Article in journal (Refereed)
    Abstract [en]

    Sex role reversal in 2 pipefish species, Syngnathus typhle and Nerophis ophidion, is potentially explained by females reproducing twice as fast as males. Moreover, in oceanic populations from the Swedish west coast, females compete for males with males pre- ferring to mate with larger females. However, in a brackish Baltic population of S. typhle, males do not prefer larger mates, whereas choosiness remains in the local N. ophidion population. We explore whether this absence of male choice in brackish S. typhle can be explained by males and females having more similar potential reproductive rates here, whereas the sex difference may remain in the local N. ophidion population. Contrary to our expectations, in both species, females out-reproduced males by a factor of more than 2, just as in the oceanic populations. We measured this experimentally as the number of males a female potentially could fill with eggs within the time span of 1 male pregnancy, in relation to males available in nature. Thus, we conclude that sexual selection on females is as strong in brackish as in oceanic populations of both species but that targets of selection via male choice are shifted to traits other than body size in S. typhle. Hence, costs and benefits of choice are probably more important than potential reproductive rates to understand mate choice. We suggest that it may be misleading to use targets of sexual selection, such as choice for large body size, as an indicator of the strength of sexual selection. 

  • 294.
    Bergqvist, Louise
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics.
    Ridsportens miljö- och klimatpåverkan: Miljöarbete bland Sveriges ridklubbar2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Our society is facing challenges from a changing climate and environmental issues, which makes it important for everyone to take action for a better future. Equestrian sports, one of Sweden’s biggest sports, also have a part to play. The Swedish Equestrian Federation has a sustainability and environmental strategy since 2016, and seeks to continuously improve their environmental work. The present study aims to investigate how riding clubs work with two out of five sections presented in the strategy: Education and Operational management of stables. Impact from equestrian activities includes the six categories fodder, manure handling, electricity comsumption, transportation, horse and rider equipment. and chemicals, which, in this study are linked to Sweden’s environmental objective. It is clear that horses and stabling have significant impact on both the nearby environment and is a contributing factor to global warming, though the level of impact ranges depending on the type of actions taken to reduce the ecological footprint. A survey was conducted to find out how the Swedish riding associations works with environmental and climate issues, including education and the operational management of the categories listed above. The main finding in the survey is a communication gap between the Swedish Equestrian Federation and the riding associations, as well as a lack of knowledge of the environmental and climate impact from equestrian activities.

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    Ridsportens miljö- och klimatpåverkan
  • 295. Berlin, S.
    et al.
    Trybush, S. O.
    Fogelqvist, J.
    Gyllenstrand, N.
    Hallingbaeck, H. R.
    Ahman, I.
    Nordh, N-E
    Shield, I.
    Powers, S. J.
    Weih, M.
    Lagercrantz, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Roennberg-Waestljung, A-C
    Karp, A.
    Hanley, S. J.
    Genetic diversity, population structure and phenotypic variation in European Salix viminalis L. (Salicaceae)2014In: Tree Genetics & Genomes, ISSN 1614-2942, E-ISSN 1614-2950, Vol. 10, no 6, p. 1595-1610Article in journal (Refereed)
    Abstract [en]

    To investigate the potential of association genetics for willow breeding, Salix viminalis germplasm was assembled from UK and Swedish collections (comprising accessions from several European countries) and new samples collected from nature. A subset of the germplasm was planted at two sites (UK and Sweden), genotyped using 38 SSR markers and assessed for phenological and biomass traits. Population structure, genetic differentiation (F-ST) and quantitative trait differentiation (Q(ST)) were investigated. The extent and patterns of trait adaptation were assessed by comparing F-ST and Q(ST) parameters. Of the 505 genotyped diploid accessions, 27 % were not unique. Genetic diversity was high: 471 alleles was amplified; the mean number of alleles per locus was 13.46, mean observed heterozygosity was 0.55 and mean expected heterozygosity was 0.62. Bayesian clustering identified four subpopulations which generally corresponded to Western Russia, Western Europe, Eastern Europe and Sweden. All pairwise F-ST values were highly significant (p<0.001) with the greatest genetic differentiation detected between the Western Russian and the Western European subpopulations (F-ST = 0.12), and the smallest between the Swedish and Eastern European populations (F-ST = 0.04). The Swedish population also had the highest number of identical accessions, supporting the view that S. viminalis was introduced into this country and has been heavily influenced by humans. Q(ST) values were high for growth cessation and leaf senescence, and to some extent stem diameter, but low for bud burst time and shoot number. Overall negative clines between longitudinal coordinates and leaf senescence, bud burst and stem diameter were also found.

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    fulltext
  • 296.
    Berlin, Sofia
    et al.
    Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences.
    Fogelqvist, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Lascoux, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Lagercrantz, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Plant Ecology and Evolution.
    Rönnberg-Wästljung, Ann Christin
    Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences.
    Polymorphism and divergence of two willow species, Salix viminalis L. and Salix schwerinii E. Wolf2011In: G3: Genes, Genomes, Genetics, ISSN 2160-1836, E-ISSN 2160-1836, Vol. 1, no 5, p. 387-400Article in journal (Refereed)
    Abstract [en]

    We investigated species divergence, present and past gene flow, levels of nucleotide polymorphism, and linkage disequilibrium in two willows from the plant genus Salix. Salix belongs together with Populus to the Salicaceae family; however, most population genetic studies of Salicaceae have been performed in Populus, the model genus in forest biology. Here we present a study on two closely related willow species Salix viminalis and S. schwerinii, in which we have resequenced 33 and 32 nuclear gene segments representing parts of 18 nuclear loci in 24 individuals for each species. We used coalescent simulations and estimated the split time to around 600,000 years ago and found that there is currently limited gene flow between the species. Mean intronic nucleotide diversity across gene segments was slightly higher in S. schwerinii (πi = 0.00849) than in S. viminalis (πi = 0.00655). Compared with other angiosperm trees, the two willows harbor intermediate levels of silent polymorphisms. The decay of linkage disequilibrium was slower in S. viminalis compared with S. schwerinii, and we speculate that this is due to different demographic histories as S. viminalis has been partly domesticated in Europe.

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    fulltext
  • 297. Berlin, Sofia
    et al.
    Lagercrantz, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Functional Genomics.
    von Arnold, Sara
    Öst, Torbjörn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Rönnberg-Wästljung, Ann Christin
    High-density linkage mapping and evolution of paralogs and orthologs in Salix and Populus2010In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 11, no 1, p. 129-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Salix (willow) and Populus (poplar) are members of the Salicaceae family and they share many ecological as well as genetic and genomic characteristics. The interest of using willow for biomass production is growing, which has resulted in increased pressure on breeding of high yielding and resistant clones adapted to different environments. The main purpose of this work was to develop dense genetic linkage maps for mapping of traits related to yield and resistance in willow. We used the Populus trichocarpa genome to extract evenly spaced markers and mapped the orthologous loci in the willow genome. The marker positions in the two genomes were used to study genome evolution since the divergence of the two lineages some 45 mya. RESULTS: We constructed two linkage maps covering the 19 linkage groups in willow. The most detailed consensus map, S1, contains 495 markers with a total genetic distance of 2477 cM and an average distance of 5.0 cM between the markers. The S3 consensus map contains 221 markers and has a total genetic distance of 1793 cM and an average distance of 8.1 cM between the markers. We found high degree of synteny and gene order conservation between willow and poplar. There is however evidence for two major interchromosomal rearrangements involving poplar LG I and XVI and willow LG Ib, suggesting a fission or a fusion in one of the lineages, as well as five intrachromosomal inversions. The number of silent substitutions were three times lower (median: 0.12) between orthologs than between paralogs (median: 0.37 - 0.41). CONCLUSIONS: The relatively slow rates of genomic change between willow and poplar mean that the genomic resources in poplar will be most useful in genomic research in willow, such as identifying genes underlying QTLs of important traits. Our data suggest that the whole-genome duplication occurred long before the divergence of the two genera, events which have until now been regarded as contemporary. Estimated silent substitution rates were 1.28 x 10-9 and 1.68 x 10-9 per site and year, which are close to rates found in other perennials but much lower than rates in annuals.

  • 298.
    Berner, D.
    et al.
    Univ Basel, Inst Zool, CH-4051 Basel, Switzerland..
    Thibert-Plante, Xavier
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics. Univ Tennessee, Natl Inst Math & Biol Synth, Knoxville, TN USA.;Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden.;Umea Univ, IceLab, Umea, Sweden..
    How mechanisms of habitat preference evolve and promote divergence with gene flow2015In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 28, no 9, p. 1641-1655Article in journal (Refereed)
    Abstract [en]

    Habitat preference may promote adaptive divergence and speciation, yet the conditions under which this is likely are insufficiently explored. We use individual-based simulations to study the evolution and consequence of habitat preference during divergence with gene flow, considering four different underlying genetically based behavioural mechanisms: natal habitat imprinting, phenotype-dependent, competition-dependent and direct genetic habitat preference. We find that the evolution of habitat preference generally requires initially high dispersal, is facilitated by asymmetry in population sizes between habitats, and is hindered by an increasing number of underlying genetic loci. Moreover, the probability of habitat preference to emerge and promote divergence differs greatly among the underlying mechanisms. Natal habitat imprinting evolves most easily and can allow full divergence in parameter ranges where no divergence is possible in the absence of habitat preference. The reason is that imprinting represents a one-allele mechanism of assortative mating linking dispersal behaviour very effectively to local selection. At the other extreme, direct genetic habitat preference, a two-allele mechanism, evolves under restricted conditions only, and even then facilitates divergence weakly. Overall, our results indicate that habitat preference can be a strong reproductive barrier promoting divergence with gene flow, but that this is highly contingent on the underlying preference mechanism.

  • 299.
    Bernhardsson, Carolina
    et al.
    Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden;Swedish Univ Agr Sci, Umea Plant Sci Ctr, Dept Forest Genet & Plant Physiol, Umea, Sweden;Swedish Univ Agr Sci, Dept Plant Biol, Uppsala BioCtr, Uppsala, Sweden.
    Vidalis, Amaryllis
    Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden;Tech Univ Munich, Dept Populat Genet, Ctr Life & Food Sci Weihenstephan, D-85354 Freising Weihenstephan, Germany.
    Wang, Xi
    Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden;Swedish Univ Agr Sci, Dept Plant Biol, Uppsala BioCtr, Uppsala, Sweden.
    Scofield, Douglas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Evolutionary Biology. Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden.
    Schiffthaler, Bastian
    Umea Univ, Umea Plant Sci Ctr, Dept Plant Physiol, Umea, Sweden.
    Baison, John
    Swedish Univ Agr Sci, Umea Plant Sci Ctr, Dept Forest Genet & Plant Physiol, Umea, Sweden.
    Street, Nathaniel R.
    Umea Univ, Umea Plant Sci Ctr, Dept Plant Physiol, Umea, Sweden.
    Garcia-Gil, M. Rosario
    Swedish Univ Agr Sci, Umea Plant Sci Ctr, Dept Forest Genet & Plant Physiol, Umea, Sweden.
    Ingvarsson, Pär K.
    Umea Univ, Dept Ecol & Environm Sci, Umea, Sweden;Swedish Univ Agr Sci, Dept Plant Biol, Uppsala BioCtr, Uppsala, Sweden.
    An Ultra-Dense Haploid Genetic Map for Evaluating the Highly Fragmented Genome Assembly of Norway Spruce (Picea abies)2019In: G3: Genes, Genomes, Genetics, ISSN 2160-1836, E-ISSN 2160-1836, Vol. 9, no 5, p. 1623-1632Article in journal (Refereed)
    Abstract [en]

    Norway spruce (Picea abies (L.) Karst.) is a conifer species of substanital economic and ecological importance. In common with most conifers, the P. abies genome is very large (similar to 20 Gbp) and contains a high fraction of repetitive DNA. The current P. abies genome assembly (v1.0) covers approximately 60% of the total genome size but is highly fragmented, consisting of >10 million scaffolds. The genome annotation contains 66,632 gene models that are at least partially validated (), however, the fragmented nature of the assembly means that there is currently little information available on how these genes are physically distributed over the 12 P. abies chromosomes. By creating an ultra-dense genetic linkage map, we anchored and ordered scaffolds into linkage groups, which complements the fine-scale information available in assembly contigs. Our ultra-dense haploid consensus genetic map consists of 21,056 markers derived from 14,336 scaffolds that contain 17,079 gene models (25.6% of the validated gene models) that we have anchored to the 12 linkage groups. We used data from three independent component maps, as well as comparisons with previously published Picea maps to evaluate the accuracy and marker ordering of the linkage groups. We demonstrate that approximately 3.8% of the anchored scaffolds and 1.6% of the gene models covered by the consensus map have likely assembly errors as they contain genetic markers that map to different regions within or between linkage groups. We further evaluate the utility of the genetic map for the conifer research community by using an independent data set of unrelated individuals to assess genome-wide variation in genetic diversity using the genomic regions anchored to linkage groups. The results show that our map is sufficiently dense to enable detailed evolutionary analyses across the P. abies genome.

  • 300.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    How to see more: double hybridization to reveal ecological differentiation among close bacterial relatives2017In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, no 6, p. 2110-2111Article in journal (Other academic)
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