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Craig R. Primmer - One of the best experts on this subject based on the ideXlab platform.
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Heterogeneous genetic basis of Age at maturity in salmonid fishes
2020Co-Authors: Charles D. Waters, Anthony J. Clemento, Tutku Aykanat, John Carlos Garza, Kerry A. Naish, Shawn R. Narum, Craig R. PrimmerAbstract:Abstract Understanding the genetic basis of repeated evolution of the same phenotype across taxa is a fundamental aim in evolutionary biology and has applications to conservation and manAgement. However, the extent to which interspecific life-history trait polymorphisms share evolutionary pathways remains under-explored. We address this gap by studying the genetic basis of a key life-history trait, Age at maturity, in four species of Pacific salmon (genus Oncorhynchus) that exhibit intra- and interspecific variation in this trait – Chinook Salmon, Coho Salmon, Sockeye Salmon, and Steelhead Trout. We tested for associations in all four species between Age at maturity and two genome regions, six6 and vgll3, that are strongly associated with the same trait in atlantic Salmon (Salmo salar). We also conducted a genome-wide association analysis in Steelhead to assess whether additional regions were associated with this trait. We found the genetic basis of Age at maturity to be heterogeneous across salmonid species. Significant associations between six6 and Age at maturity were observed in two of the four species, Sockeye and Steelhead, with the association in Steelhead being particularly strong in both sexes (p = 4.46×10−9 after adjusting for genomic inflation). However, no significant associations were detected between Age at maturity and the vgll3 genome region in any of the species, despite its strong association with the same trait in atlantic Salmon. We discuss possible explanations for the heterogeneous nature of the genetic architecture of this key life-history trait, as well as the implications of our findings for conservation and manAgement.
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Beyond large-effect loci: large-scale GWAS reveals a mixed large-effect and polygenic architecture for Age at maturity of atlantic salmon
Genetics Selection Evolution, 2020Co-Authors: Marion Sinclair-waters, Craig R. Primmer, Jørgen Ødegård, Sven Arild Korsvoll, Thomas Moen, Sigbjørn Lien, Nicola J. BarsonAbstract:Background Understanding genetic architecture is essential for determining how traits will change in response to evolutionary processes such as selection, genetic drift and/or gene flow. In atlantic salmon, Age at maturity is an important life history trait that affects factors such as survival, reproductive success, and growth. Furthermore, Age at maturity can seriously impact aquaculture production. Therefore, characterizing the genetic architecture that underlies variation in Age at maturity is of key interest. Results Here, we refine our understanding of the genetic architecture for Age at maturity of male atlantic salmon using a genome-wide association study of 11,166 males from a single aquaculture strain, using imputed genotypes at 512,397 single nucleotide polymorphisms (SNPs). All individuals were genotyped with a 50K SNP array and imputed to higher density using parents genotyped with a 930K SNP array and pedigree information. We found significant association signals on 28 of 29 chromosomes ( P -values: 8.7 × 10^−133–9.8 × 10^−8), including two very strong signals spanning the six6 and vgll3 gene regions on chromosomes 9 and 25, respectively. Furthermore, we identified 116 independent signals that tagged 120 candidate genes with varying effect sizes. Five of the candidate genes found here were previously associated with Age at maturity in other vertebrates, including humans. Discussion These results reveal a mixed architecture of large-effect loci and a polygenic component that consists of multiple smaller-effect loci, suggesting a more complex genetic architecture of atlantic salmon Age at maturity than previously thought. This more complex architecture will have implications for selection on this key trait in aquaculture and for manAgement of wild salmon populations.
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Beyond large-effect loci: large-scale GWAS reveals a mixed large-effect and polygenic architecture for Age at maturity of atlantic salmon
Genetics selection evolution : GSE, 2020Co-Authors: Marion Sinclair-waters, Craig R. Primmer, Jørgen Ødegård, Sven Arild Korsvoll, Thomas Moen, Sigbjørn Lien, Nicola J. BarsonAbstract:Understanding genetic architecture is essential for determining how traits will change in response to evolutionary processes such as selection, genetic drift and/or gene flow. In atlantic salmon, Age at maturity is an important life history trait that affects factors such as survival, reproductive success, and growth. Furthermore, Age at maturity can seriously impact aquaculture production. Therefore, characterizing the genetic architecture that underlies variation in Age at maturity is of key interest. Here, we refine our understanding of the genetic architecture for Age at maturity of male atlantic salmon using a genome-wide association study of 11,166 males from a single aquaculture strain, using imputed genotypes at 512,397 single nucleotide polymorphisms (SNPs). All individuals were genotyped with a 50K SNP array and imputed to higher density using parents genotyped with a 930K SNP array and pedigree information. We found significant association signals on 28 of 29 chromosomes (P-values: 8.7 × 10−133–9.8 × 10−8), including two very strong signals spanning the six6 and vgll3 gene regions on chromosomes 9 and 25, respectively. Furthermore, we identified 116 independent signals that tagged 120 candidate genes with varying effect sizes. Five of the candidate genes found here were previously associated with Age at maturity in other vertebrates, including humans. These results reveal a mixed architecture of large-effect loci and a polygenic component that consists of multiple smaller-effect loci, suggesting a more complex genetic architecture of atlantic salmon Age at maturity than previously thought. This more complex architecture will have implications for selection on this key trait in aquaculture and for manAgement of wild salmon populations.
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transcription profiles of Age at maturity associated genes suggest cell fate commitment regulation as a key factor in the atlantic salmon maturation process
G3: Genes Genomes Genetics, 2020Co-Authors: Johanna Kurko, Tutku Aykanat, Jaakko Erkinaro, Paul V. Debes, Andrew H House, Craig R. PrimmerAbstract:Despite recent taxonomic diversification in studies linking genotype with phenotype, follow-up studies aimed at understanding the molecular processes of such genotype-phenotype associations remain rare. The Age at which an individual reaches sexual maturity is an important fitness trait in many wild species. However, the molecular mechanisms regulating maturation timing processes remain obscure. A recent genome-wide association study in atlantic salmon (Salmo salar) identified large-effect Age-at-maturity-associated chromosomal regions including genes vgll3, akap11 and six6, which have roles in adipogenesis, spermatogenesis and the hypothalamic-pituitary-gonadal (HPG) axis, respectively. Here, we determine expression patterns of these genes during salmon development and their potential molecular partners and pathways. Using Nanostring transcription profiling technology, we show development- and tissue-specific mRNA expression patterns for vgll3, akap11 and six6 Correlated expression levels of vgll3 and akap11, which have adjacent chromosomal location, suggests they may have shared regulation. Further, vgll3 correlating with arhgap6 and yap1, and akap11 with lats1 and yap1 suggests that Vgll3 and Akap11 take part in actin cytoskeleton regulation. Tissue-specific expression results indicate that vgll3 and akap11 paralogs have sex-dependent expression patterns in gonads. Moreover, six6 correlating with slc38a6 and rtn1, and Hippo signaling genes suggests that Six6 could have a broader role in the HPG neuroendrocrine and cell fate commitment regulation, respectively. We conclude that Vgll3, Akap11 and Six6 may influence atlantic salmon maturation timing via affecting adipogenesis and gametogenesis by regulating cell fate commitment and the HPG axis. These results may help to unravel general molecular mechanisms behind maturation.
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Co‐inheritance of sea Age at maturity and iteroparity in the atlantic salmon vgll3 genomic region
Journal of evolutionary biology, 2019Co-Authors: Tutku Aykanat, Jaakko Erkinaro, Panu Orell, Mikhail Ozerov, Juha-pekka Vähä, Eero Niemelä, Craig R. PrimmerAbstract:Co-inheritance in life-history traits may result in unpredictable evolutionary trajectories if not accounted for in life-history models. Iteroparity (the reproductive strategy of reproducing more than once) in atlantic salmon (Salmo salar) is a fitness trait with substantial variation within and among populations. In the Teno River in northern Europe, iteroparous individuals constitute an important component of many populations and have experienced a sharp increase in abundance in the last 20 years, partly overlapping with a general decrease in Age structure. The physiological basis of iteroparity bears similarities to that of Age at first maturity, another life-history trait with substantial fitness effects in salmon. Sea Age at maturity in atlantic salmon is controlled by a major locus around the vgll3 gene, and we used this opportunity demonstrate that these two traits are co-inherited around this genome region. The odds ratio of survival until second reproduction was up to 2.4 (1.8-3.5 90% CI) times higher for fish with the early-maturing vgll3 genotype (EE) compared to fish with the late-maturing genotype (LL). The L allele was dominant in individuals remaining only one year at sea before maturation, but the dominance was reversed, with the E allele being dominant in individuals maturing after two or more years at sea. Post hoc analysis indicated that iteroparous fish with the EE genotype had accelerated growth prior to first reproduction compared to first-time spawners, across all Age groups, whereas this effect was not detected in fish with the LL genotype. These results broaden the functional link around the vgll3 genome region and help us understand constraints in the evolution of life-history variation in salmon. Our results further highlight the need to account for genetic correlations between fitness traits when predicting demographic changes in changing environments.
Tutku Aykanat - One of the best experts on this subject based on the ideXlab platform.
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Heterogeneous genetic basis of Age at maturity in salmonid fishes
2020Co-Authors: Charles D. Waters, Anthony J. Clemento, Tutku Aykanat, John Carlos Garza, Kerry A. Naish, Shawn R. Narum, Craig R. PrimmerAbstract:Abstract Understanding the genetic basis of repeated evolution of the same phenotype across taxa is a fundamental aim in evolutionary biology and has applications to conservation and manAgement. However, the extent to which interspecific life-history trait polymorphisms share evolutionary pathways remains under-explored. We address this gap by studying the genetic basis of a key life-history trait, Age at maturity, in four species of Pacific salmon (genus Oncorhynchus) that exhibit intra- and interspecific variation in this trait – Chinook Salmon, Coho Salmon, Sockeye Salmon, and Steelhead Trout. We tested for associations in all four species between Age at maturity and two genome regions, six6 and vgll3, that are strongly associated with the same trait in atlantic Salmon (Salmo salar). We also conducted a genome-wide association analysis in Steelhead to assess whether additional regions were associated with this trait. We found the genetic basis of Age at maturity to be heterogeneous across salmonid species. Significant associations between six6 and Age at maturity were observed in two of the four species, Sockeye and Steelhead, with the association in Steelhead being particularly strong in both sexes (p = 4.46×10−9 after adjusting for genomic inflation). However, no significant associations were detected between Age at maturity and the vgll3 genome region in any of the species, despite its strong association with the same trait in atlantic Salmon. We discuss possible explanations for the heterogeneous nature of the genetic architecture of this key life-history trait, as well as the implications of our findings for conservation and manAgement.
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transcription profiles of Age at maturity associated genes suggest cell fate commitment regulation as a key factor in the atlantic salmon maturation process
G3: Genes Genomes Genetics, 2020Co-Authors: Johanna Kurko, Tutku Aykanat, Jaakko Erkinaro, Paul V. Debes, Andrew H House, Craig R. PrimmerAbstract:Despite recent taxonomic diversification in studies linking genotype with phenotype, follow-up studies aimed at understanding the molecular processes of such genotype-phenotype associations remain rare. The Age at which an individual reaches sexual maturity is an important fitness trait in many wild species. However, the molecular mechanisms regulating maturation timing processes remain obscure. A recent genome-wide association study in atlantic salmon (Salmo salar) identified large-effect Age-at-maturity-associated chromosomal regions including genes vgll3, akap11 and six6, which have roles in adipogenesis, spermatogenesis and the hypothalamic-pituitary-gonadal (HPG) axis, respectively. Here, we determine expression patterns of these genes during salmon development and their potential molecular partners and pathways. Using Nanostring transcription profiling technology, we show development- and tissue-specific mRNA expression patterns for vgll3, akap11 and six6 Correlated expression levels of vgll3 and akap11, which have adjacent chromosomal location, suggests they may have shared regulation. Further, vgll3 correlating with arhgap6 and yap1, and akap11 with lats1 and yap1 suggests that Vgll3 and Akap11 take part in actin cytoskeleton regulation. Tissue-specific expression results indicate that vgll3 and akap11 paralogs have sex-dependent expression patterns in gonads. Moreover, six6 correlating with slc38a6 and rtn1, and Hippo signaling genes suggests that Six6 could have a broader role in the HPG neuroendrocrine and cell fate commitment regulation, respectively. We conclude that Vgll3, Akap11 and Six6 may influence atlantic salmon maturation timing via affecting adipogenesis and gametogenesis by regulating cell fate commitment and the HPG axis. These results may help to unravel general molecular mechanisms behind maturation.
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Regulatory divergence in vgll3 underlies variation in Age at maturity in male atlantic salmon
2019Co-Authors: Jukka-pekka Verta, Tutku Aykanat, Paul V. Debes, Nikolai Piavchenko, Annukka Ruokolainen, Outi Ovaskainen, Jacqueline E. Moustakas-verho, Seija Tillanen, Noora Parre, Jaakko ErkinaroAbstract:Abstract The optimal phenotypes to survive and reproduce in given evolutionary settings are often in conflict, which manifest as trade-offs in life history traits. Genome-wide association studies have been successful in uncovering genome regions controlling for life history trade-offs in a range of species 1–8. However, lack of functional studies of the discovered genotype-phenotype associations restrains our understanding how alternative life history traits evolved and are mediated at the molecular level. Here we establish a molecular mechanism by which allele-specific expression differences of the transcription co-factor vgll3 mediate variation in Age at maturity in male atlantic salmon (Salmo salar). By way of a common-garden experiment and temporal sampling of vgll3 expression, we show that vgll3 genotype and expression control male puberty timing in one-year old salmon. Vgll3 expression was high in immature testicular tissue and males entering puberty reduced their vgll3 expression by 66% compared to immature males. Testicular expression of the early maturation associated allele in immature males was constitutively lower compared to the late maturation allele, shifting the liability of early allele carriers towards earlier maturation. These results reveal how gene regulatory differences can be a central mechanism for the evolution of life history variation.
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Co‐inheritance of sea Age at maturity and iteroparity in the atlantic salmon vgll3 genomic region
Journal of evolutionary biology, 2019Co-Authors: Tutku Aykanat, Jaakko Erkinaro, Panu Orell, Mikhail Ozerov, Juha-pekka Vähä, Eero Niemelä, Craig R. PrimmerAbstract:Co-inheritance in life-history traits may result in unpredictable evolutionary trajectories if not accounted for in life-history models. Iteroparity (the reproductive strategy of reproducing more than once) in atlantic salmon (Salmo salar) is a fitness trait with substantial variation within and among populations. In the Teno River in northern Europe, iteroparous individuals constitute an important component of many populations and have experienced a sharp increase in abundance in the last 20 years, partly overlapping with a general decrease in Age structure. The physiological basis of iteroparity bears similarities to that of Age at first maturity, another life-history trait with substantial fitness effects in salmon. Sea Age at maturity in atlantic salmon is controlled by a major locus around the vgll3 gene, and we used this opportunity demonstrate that these two traits are co-inherited around this genome region. The odds ratio of survival until second reproduction was up to 2.4 (1.8-3.5 90% CI) times higher for fish with the early-maturing vgll3 genotype (EE) compared to fish with the late-maturing genotype (LL). The L allele was dominant in individuals remaining only one year at sea before maturation, but the dominance was reversed, with the E allele being dominant in individuals maturing after two or more years at sea. Post hoc analysis indicated that iteroparous fish with the EE genotype had accelerated growth prior to first reproduction compared to first-time spawners, across all Age groups, whereas this effect was not detected in fish with the LL genotype. These results broaden the functional link around the vgll3 genome region and help us understand constraints in the evolution of life-history variation in salmon. Our results further highlight the need to account for genetic correlations between fitness traits when predicting demographic changes in changing environments.
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Rapid sex-specific evolution of Age at maturity is shaped by genetic architecture in atlantic salmon.
Nature ecology & evolution, 2018Co-Authors: Yann Czorlich, Tutku Aykanat, Jaakko Erkinaro, Panu Orell, Craig R. PrimmerAbstract:Understanding the mechanisms by which populations adapt to their environments is a fundamental aim in biology. However, it remains challenging to identify the genetic basis of traits, provide evidence of genetic changes and quantify phenotypic responses. Age at maturity in atlantic salmon represents an ideal trait to study contemporary adaptive evolution as it has been associated with a single locus in the vgll3 region and has also strongly changed in recent decades. Here, we provide an empirical example of contemporary adaptive evolution of a large-effect locus driving contrasting sex-specific evolutionary responses at the phenotypic level. We identified an 18% decrease in the vgll3 allele associated with late maturity in a large and diverse salmon population over 36 years, induced by sex-specific selection during sea migration. Those genetic changes resulted in a significant evolutionary response only in males, due to sex-specific dominance patterns and vgll3 allelic effects. The vgll3 allelic and dominance effects differed greatly in a second population and were likely to generate different selection and evolutionary patterns. Our study highlights the importance of knowledge of genetic architecture to better understand fitness trait evolution and phenotypic diversity. It also emphasizes the potential role of adaptive evolution in the trend towards earlier maturation observed in numerous atlantic salmon populations worldwide. Age at maturity in atlantic salmon has been associated with a single locus with sex-specific effects. Here, the authors show rapid evolution towards early maturity in males of a large salmon population induced by sex-specific selection during sea migration.
Yaming Cheny. Chen - One of the best experts on this subject based on the ideXlab platform.
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unnatural random mating policies select for younger Age at maturity in hatchery chinook salmon oncorhynchus tshawytscha populations
Canadian Journal of Fisheries and Aquatic Sciences, 2009Co-Authors: David G. Hankin, Jacqueline Fitzgibbonsj. Fitzgibbons, Yaming Cheny. ChenAbstract:We explored the long-term consequences of three mating regimes ((1) completely random, (2) completely random but excluding jacks (Age 2 males), and (3) male length ≥ female length) on Age and sex s...
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Unnatural random mating policies select for younger Age at maturity in hatchery Chinook salmon (Oncorhynchus tshawytscha) populations.
Canadian Journal of Fisheries and Aquatic Sciences, 2009Co-Authors: David G. Hankin, Jacqueline Fitzgibbonsj. Fitzgibbons, Yaming Cheny. ChenAbstract:We explored the long-term consequences of three mating regimes ((1) completely random, (2) completely random but excluding jacks (Age 2 males), and (3) male length ≥ female length) on Age and sex structure of wild and hatchery populations of Chinook salmon (Oncorhynchus tshawytscha). Regimes similar to regimes 1 or 2 are used at most salmon hatcheries, whereas regime 3 emulates the outcomes of natural spawning behaviors that favor larger males. Inheritance of Age at maturity is captured in Age- and sex-structured models via matrices of Age- and sex-specific conditional maturation probabilities that depend on Age and sex of parents. In unexploited populations, regime 1 leads to substantial long-term selection for younger Age at maturity, an effect that is somewhat reduced by regime 2, but greatly reduced under regime 3. Equilibrium Age and sex structures for wild and hatchery populations under regime 3 are similar to those of natural populations, whereas mating regime 1 generates Age structure that is grea...
Nicola J. Barson - One of the best experts on this subject based on the ideXlab platform.
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Beyond large-effect loci: large-scale GWAS reveals a mixed large-effect and polygenic architecture for Age at maturity of atlantic salmon
Genetics Selection Evolution, 2020Co-Authors: Marion Sinclair-waters, Craig R. Primmer, Jørgen Ødegård, Sven Arild Korsvoll, Thomas Moen, Sigbjørn Lien, Nicola J. BarsonAbstract:Background Understanding genetic architecture is essential for determining how traits will change in response to evolutionary processes such as selection, genetic drift and/or gene flow. In atlantic salmon, Age at maturity is an important life history trait that affects factors such as survival, reproductive success, and growth. Furthermore, Age at maturity can seriously impact aquaculture production. Therefore, characterizing the genetic architecture that underlies variation in Age at maturity is of key interest. Results Here, we refine our understanding of the genetic architecture for Age at maturity of male atlantic salmon using a genome-wide association study of 11,166 males from a single aquaculture strain, using imputed genotypes at 512,397 single nucleotide polymorphisms (SNPs). All individuals were genotyped with a 50K SNP array and imputed to higher density using parents genotyped with a 930K SNP array and pedigree information. We found significant association signals on 28 of 29 chromosomes ( P -values: 8.7 × 10^−133–9.8 × 10^−8), including two very strong signals spanning the six6 and vgll3 gene regions on chromosomes 9 and 25, respectively. Furthermore, we identified 116 independent signals that tagged 120 candidate genes with varying effect sizes. Five of the candidate genes found here were previously associated with Age at maturity in other vertebrates, including humans. Discussion These results reveal a mixed architecture of large-effect loci and a polygenic component that consists of multiple smaller-effect loci, suggesting a more complex genetic architecture of atlantic salmon Age at maturity than previously thought. This more complex architecture will have implications for selection on this key trait in aquaculture and for manAgement of wild salmon populations.
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Beyond large-effect loci: large-scale GWAS reveals a mixed large-effect and polygenic architecture for Age at maturity of atlantic salmon
Genetics selection evolution : GSE, 2020Co-Authors: Marion Sinclair-waters, Craig R. Primmer, Jørgen Ødegård, Sven Arild Korsvoll, Thomas Moen, Sigbjørn Lien, Nicola J. BarsonAbstract:Understanding genetic architecture is essential for determining how traits will change in response to evolutionary processes such as selection, genetic drift and/or gene flow. In atlantic salmon, Age at maturity is an important life history trait that affects factors such as survival, reproductive success, and growth. Furthermore, Age at maturity can seriously impact aquaculture production. Therefore, characterizing the genetic architecture that underlies variation in Age at maturity is of key interest. Here, we refine our understanding of the genetic architecture for Age at maturity of male atlantic salmon using a genome-wide association study of 11,166 males from a single aquaculture strain, using imputed genotypes at 512,397 single nucleotide polymorphisms (SNPs). All individuals were genotyped with a 50K SNP array and imputed to higher density using parents genotyped with a 930K SNP array and pedigree information. We found significant association signals on 28 of 29 chromosomes (P-values: 8.7 × 10−133–9.8 × 10−8), including two very strong signals spanning the six6 and vgll3 gene regions on chromosomes 9 and 25, respectively. Furthermore, we identified 116 independent signals that tagged 120 candidate genes with varying effect sizes. Five of the candidate genes found here were previously associated with Age at maturity in other vertebrates, including humans. These results reveal a mixed architecture of large-effect loci and a polygenic component that consists of multiple smaller-effect loci, suggesting a more complex genetic architecture of atlantic salmon Age at maturity than previously thought. This more complex architecture will have implications for selection on this key trait in aquaculture and for manAgement of wild salmon populations.
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Sex-dependent dominance at a single locus maintains variation in Age at maturity in salmon
Nature, 2015Co-Authors: Nicola J. Barson, Tutku Aykanat, Kjetil Hindar, Matthew Baranski, Geir H. Bolstad, Peder Fiske, Celeste Jacq, Arne Jensen, Susan E. Johnston, Sten KarlssonAbstract:Males and females share many traits that have a common genetic basis; however, selection on these traits often differs between the sexes, leading to sexual conflict. Under such sexual antagonism, theory predicts the evolution of genetic architectures that resolve this sexual conflict. Yet, despite intense theoretical and empirical interest, the specific loci underlying sexually antagonistic phenotypes have rarely been identified, limiting our understanding of how sexual conflict impacts genome evolution and the maintenance of genetic diversity. Here we identify a large effect locus controlling Age at maturity in atlantic salmon (Salmo salar), an important fitness trait in which selection favours earlier maturation in males than females, and show it is a clear example of sex-dependent dominance that reduces intralocus sexual conflict and maintains adaptive variation in wild populations. Using high-density single nucleotide polymorphism data across 57 wild populations and whole genome re-sequencing, we find that the vestigial-like family member 3 gene (VGLL3) exhibits sex-dependent dominance in salmon, promoting earlier and later maturation in males and females, respectively. VGLL3, an adiposity regulator associated with size and Age at maturity in humans, explained 39% of phenotypic variation, an unexpectedly large proportion for what is usually considered a highly polygenic trait. Such large effects are predicted under balancing selection from either sexually antagonistic or spatially varying selection. Our results provide the first empirical example of dominance reversal allowing greater optimization of phenotypes within each sex, contributing to the resolution of sexual conflict in a major and widespread evolutionary trade-off between Age and size at maturity. They also provide key empirical evidence for how variation in reproductive strategies can be maintained over large geographical scales. We anticipate these findings will have a substantial impact on population manAgement in a range of harvested species where trends towards earlier maturation have been observed.
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Sex-dependent dominance at a single locus maintains variation in Age at maturity in atlantic salmon
2015Co-Authors: Nicola J. Barson, Tutku Aykanat, Kjetil Hindar, Matthew Baranski, Geir H. Bolstad, Peder Fiske, Celeste Jacq, Arne Jensen, Susan E. Johnston, Sten KarlssonAbstract:Males and females share many traits that have a common genetic basis, however selection on these traits often differs between the sexes leading to sexual conflict. Under such sexual antagonism, theory predicts the evolution of genetic architectures that resolve this sexual conflict. Yet, despite intense theoretical and empirical interest, the specific genetic loci behind sexually antagonistic phenotypes have rarely been identified, limiting our understanding of how sexual conflict impacts genome evolution and the maintenance of genetic diversity. Here, we identify a large effect locus controlling Age at maturity in 57 salmon populations, an important fitness trait in which selection favours earlier maturation in males than females, and show it is a clear example of sex dependent dominance reducing intralocus sexual conflict and maintaining adaptive variation in wild populations. Using high density SNP data and whole genome re-sequencing, we found that vestigial-like family member 3 (VGLL3) exhibits sex-dependent dominance in salmon, promoting earlier and later maturation in males and females, respectively. VGLL3, an adiposity regulator associated with size and Age at maturity in humans, explained 39.4% of phenotypic variation, an unexpectedly high effect size for what is usually considered a highly polygenic trait. Such large effects are predicted under balancing selection from either sexually antagonistic or spatially varying selection. Our results provide the first empirical example of dominance reversal permitting greater optimisation of phenotypes within each sex, contributing to the resolution of sexual conflict in a major and widespread evolutionary trade-off between Age and size at maturity. They also provide key empirical evidence for how variation in reproductive strategies can be maintained over large geographical scales. We further anticipate these findings will have a substantial impact on population manAgement in a range of harvested species where trends towards earlier maturation have been observed
Carl J. Walters - One of the best experts on this subject based on the ideXlab platform.
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Patterns of covariation in length and Age at maturity of British Columbia and Alaska sockeye salmon (Oncorhynchus nerka) stocks
Canadian Journal of Fisheries and Aquatic Sciences, 1999Co-Authors: Brian J. Pyper, Randall M. Peterman, Michael F. Lapointe, Carl J. WaltersAbstract:We examined patterns of covariation in Age-specific adult body length and in mean Age at maturity among 31 sockeye salmon (Oncorhynchus nerka) stocks from western Alaska to southern British Columbia. Positive covariation in body length was prevalent across stocks of all regions (e.g., correlations (r) from 0.2 to 0.6), suggesting either that growth periods critical to final body length of sockeye salmon occur while ocean distributions of these stocks overlap or that large-scale environmental processes influence these stocks similarly while they do not overlap. We also found stronger covariation among body length of stocks within regions (r from 0.4 to 0.7), indicating that unique regional-scale processes were also important. Mean Age at maturity also showed positive covariation both among and within regions, but correlations were weaker than those for length. We also examined patterns of covariation between length and mean Age at maturity and between these variables and survival rate. Although length and ...