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Mobley KB, Barton HJ, Ellmén M, Ruokolainen A, Guttorm O, Pieski H, Orell P, Erkinaro J, Primmer CR. Sex-specific overdominance at the maturation vgll3 gene for reproductive fitness in wild Atlantic salmon. Mol Ecol 2024; 33:e17435. [PMID: 38877757 DOI: 10.1111/mec.17435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/11/2024] [Accepted: 05/15/2024] [Indexed: 06/16/2024]
Abstract
Linking reproductive fitness with adaptive traits at the genomic level can shed light on the mechanisms that produce and maintain sex-specific selection. Here, we construct a multigenerational pedigree to investigate sex-specific selection on a maturation gene, vgll3, in a wild Atlantic salmon population. The vgll3 locus is responsible for ~40% of the variation in maturation (sea age at first reproduction). Genetic parentage analysis was conducted on 18,265 juveniles (parr) and 685 adults collected at the same spawning ground over eight consecutive years. A high proportion of females (26%) were iteroparous and reproduced two to four times in their lifetime. A smaller proportion of males (9%) spawned at least twice in their lifetime. Sex-specific patterns of reproductive fitness were related to vgll3 genotype. Females showed a pattern of overdominance where vgll3*EL genotypes had three-fold more total offspring than homozygous females. In contrast, males demonstrated that late-maturing vgll3*LL individuals had two-fold more offspring than either vgll3*EE or vgll3*EL males. Taken together, these data suggest that balancing selection in females contributes to the maintenance of variation at this locus via increased fitness of iteroparous vgll3*EL females. This study demonstrates the utility of multigenerational pedigrees for uncovering complex patterns of reproduction, sex-specific selection and the maintenance of genetic variation.
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Affiliation(s)
- Kenyon B Mobley
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Department of Genetics, Norwegian College of Fishery Science, UiT the Arctic University of Norway, Tromsø, Norway
| | - Henry J Barton
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Mikko Ellmén
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Annukka Ruokolainen
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Olavi Guttorm
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Hans Pieski
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Panu Orell
- Natural Resources Institute Finland (Luke), Oulu, Finland
| | | | - Craig R Primmer
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Institute for Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
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2
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Grieshop K, Ho EKH, Kasimatis KR. Dominance reversals: the resolution of genetic conflict and maintenance of genetic variation. Proc Biol Sci 2024; 291:20232816. [PMID: 38471544 DOI: 10.1098/rspb.2023.2816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 02/05/2024] [Indexed: 03/14/2024] Open
Abstract
Beneficial reversals of dominance reduce the costs of genetic trade-offs and can enable selection to maintain genetic variation for fitness. Beneficial dominance reversals are characterized by the beneficial allele for a given context (e.g. habitat, developmental stage, trait or sex) being dominant in that context but recessive where deleterious. This context dependence at least partially mitigates the fitness consequence of heterozygotes carrying one non-beneficial allele for their context and can result in balancing selection that maintains alternative alleles. Dominance reversals are theoretically plausible and are supported by mounting empirical evidence. Here, we highlight the importance of beneficial dominance reversals as a mechanism for the mitigation of genetic conflict and review the theory and empirical evidence for them. We identify some areas in need of further research and development and outline three methods that could facilitate the identification of antagonistic genetic variation (dominance ordination, allele-specific expression and allele-specific ATAC-Seq (assay for transposase-accessible chromatin with sequencing)). There is ample scope for the development of new empirical methods as well as reanalysis of existing data through the lens of dominance reversals. A greater focus on this topic will expand our understanding of the mechanisms that resolve genetic conflict and whether they maintain genetic variation.
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Affiliation(s)
- Karl Grieshop
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada M5S 1A1
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691 Stockholm, Sweden
| | - Eddie K H Ho
- Department of Biology, Reed College, 3203 SE Woodstock Blvd, Portland, OR 97202, USA
| | - Katja R Kasimatis
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada M5S 1A1
- Department of Biology, University of Virginia, Charlottesville, VA 22904, USA
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3
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Prokkola JM, Chew KK, Anttila K, Maamela KS, Yildiz A, Åsheim ER, Primmer CR, Aykanat T. Tissue-specific metabolic enzyme levels covary with whole-animal metabolic rates and life-history loci via epistatic effects. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220482. [PMID: 38186275 PMCID: PMC10772610 DOI: 10.1098/rstb.2022.0482] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 12/03/2023] [Indexed: 01/09/2024] Open
Abstract
Metabolic rates, including standard (SMR) and maximum (MMR) metabolic rate have often been linked with life-history strategies. Variation in context- and tissue-level metabolism underlying SMR and MMR may thus provide a physiological basis for life-history variation. This raises a hypothesis that tissue-specific metabolism covaries with whole-animal metabolic rates and is genetically linked to life history. In Atlantic salmon (Salmo salar), variation in two loci, vgll3 and six6, affects life history via age-at-maturity as well as MMR. Here, using individuals with known SMR and MMR with different vgll3 and six6 genotype combinations, we measured proxies of mitochondrial density and anaerobic metabolism, i.e. maximal activities of the mitochondrial citrate synthase (CS) and lactate dehydrogenase (LDH) enzymes, in four tissues (heart, intestine, liver, white muscle) across low- and high-food regimes. We found enzymatic activities were related to metabolic rates, mainly SMR, in the intestine and heart. Individual loci were not associated with the enzymatic activities, but we found epistatic effects and genotype-by-environment interactions in CS activity in the heart and epistasis in LDH activity in the intestine. These effects suggest that mitochondrial density and anaerobic capacity in the heart and intestine may partly mediate variation in metabolic rates and life history via age-at-maturity. This article is part of the theme issue 'The evolutionary significance of variation in metabolic rates'.
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Affiliation(s)
- Jenni M. Prokkola
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
- Natural Resources Institute Finland (Luke), Paavo Havaksen tie 3, 90570 Oulu, Finland
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900 Lammi, Finland
| | - Kuan Kiat Chew
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Katja Anttila
- Department of Biology, University of Turku, 20014 Turku, Finland
| | - Katja S. Maamela
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900 Lammi, Finland
- Institute of Biotechnology, Helsinki Institute of Life Sciences (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Atakan Yildiz
- Biotechnology Institute, Ankara University, Ankara 06135, Turkey
| | - Eirik R. Åsheim
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
- Lammi Biological Station, University of Helsinki, Pääjärventie 320, 16900 Lammi, Finland
- Institute of Biotechnology, Helsinki Institute of Life Sciences (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Craig R. Primmer
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
- Institute of Biotechnology, Helsinki Institute of Life Sciences (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Tutku Aykanat
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
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4
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Prokkola JM, Åsheim ER, Morozov S, Bangura P, Erkinaro J, Ruokolainen A, Primmer CR, Aykanat T. Genetic coupling of life-history and aerobic performance in Atlantic salmon. Proc Biol Sci 2022; 289:20212500. [PMID: 35078367 PMCID: PMC8790367 DOI: 10.1098/rspb.2021.2500] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/24/2021] [Indexed: 11/12/2022] Open
Abstract
A better understanding of the genetic and phenotypic architecture underlying life-history variation is a longstanding aim in biology. Theories suggest energy metabolism determines life-history variation by modulating resource acquisition and allocation trade-offs, but the genetic underpinnings of the relationship and its dependence on ecological conditions have rarely been demonstrated. The strong genetic determination of age-at-maturity by two unlinked genomic regions (vgll3 and six6) makes Atlantic salmon (Salmo salar) an ideal model to address these questions. Using more than 250 juveniles in common garden conditions, we quantified the covariation between metabolic phenotypes-standard and maximum metabolic rates (SMR and MMR), and aerobic scope (AS)-and the life-history genomic regions, and tested if food availability modulates the relationships. We found that the early maturation genotype in vgll3 was associated with higher MMR and consequently AS. Additionally, MMR exhibited physiological epistasis; it was decreased when late maturation genotypes co-occurred in both genomic regions. Contrary to our expectation, the life-history genotypes had no effects on SMR. Furthermore, food availability had no effect on the genetic covariation, suggesting a lack of genotype-by-environment interactions. Our results provide insights on the key organismal processes that link energy use at the juvenile stage to age-at-maturity, indicating potential mechanisms by which metabolism and life-history can coevolve.
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Affiliation(s)
- Jenni M. Prokkola
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Eirik R. Åsheim
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Sergey Morozov
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Paul Bangura
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | | | - Annukka Ruokolainen
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
| | - Craig R. Primmer
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Tutku Aykanat
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland
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5
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Willis SC, Hess JE, Fryer JK, Whiteaker JM, Brun C, Gerstenberger R, Narum SR. Steelhead ( Oncorhynchus mykiss) lineages and sexes show variable patterns of association of adult migration timing and age-at-maturity traits with two genomic regions. Evol Appl 2020; 13:2836-2856. [PMID: 33294026 PMCID: PMC7691471 DOI: 10.1111/eva.13088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 12/15/2022] Open
Abstract
As life history diversity plays a critical role in supporting the resilience of exploited populations, understanding the genetic basis of those life history variations is important for conservation management. However, effective application requires a robust understanding of the strength and universality of genetic associations. Here, we examine genetic variation of single nucleotide polymorphisms in genomic regions previously associated with migration phenology and age-at-maturity in steelhead (Oncorhynchus mykiss) from the Columbia River. We found chromosome 28 markers (GREB1L, ROCK1 genes) explained significant variance in migration timing in both coastal and inland steelhead. However, strength of association was much greater in coastal than inland steelhead (R 2 0.51 vs. 0.08), suggesting that genomic background and challenging inland migration pathways may act to moderate effects of this region. Further, we found that chromosome 25 candidate markers (SIX6 gene) were significantly associated with age and size at first return migration for inland steelhead, and this pattern was mediated by sex in a predictable pattern (males R 2 = 0.139-0.170; females R 2 = 0.096-0.111). While this encourages using these candidate regions in predicting life history characteristics, we suggest that stock-specific associations and haplotype frequencies will be useful in guiding implementation of genetic assays to inform management.
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Affiliation(s)
- Stuart C. Willis
- Hagerman Genetics LaboratoryColumbia River Inter‐Tribal Fish CommissionHagermanIDUSA
| | - Jon E. Hess
- Hagerman Genetics LaboratoryColumbia River Inter‐Tribal Fish CommissionHagermanIDUSA
| | - Jeff K. Fryer
- Fishery Science DepartmentColumbia River Inter‐Tribal Fish CommissionPortlandORUSA
| | - John M. Whiteaker
- Fishery Science DepartmentColumbia River Inter‐Tribal Fish CommissionPortlandORUSA
| | - Chris Brun
- Branch of Natural Resources – Fisheries, Confederated Tribes of Warm SpringsPortlandORUSA
| | - Ryan Gerstenberger
- Branch of Natural Resources – Fisheries, Confederated Tribes of Warm SpringsPortlandORUSA
| | - Shawn R. Narum
- Hagerman Genetics LaboratoryColumbia River Inter‐Tribal Fish CommissionHagermanIDUSA
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6
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Aykanat T, Rasmussen M, Ozerov M, Niemelä E, Paulin L, Vähä JP, Hindar K, Wennevik V, Pedersen T, Svenning MA, Primmer CR. Life-history genomic regions explain differences in Atlantic salmon marine diet specialization. J Anim Ecol 2020; 89:2677-2691. [PMID: 33460064 DOI: 10.1111/1365-2656.13324] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 07/14/2020] [Indexed: 01/04/2023]
Abstract
Animals employ various foraging strategies along their ontogeny to acquire energy, and with varying degree of efficiencies, to support growth, maturation and subsequent reproduction events. Individuals that can efficiently acquire energy early are more likely to mature at an earlier age, as a result of faster energy gain which can fuel maturation and reproduction. We aimed to test the hypothesis that heritable resource acquisition variation that covaries with efficiency along the ontogeny would influence maturation timing of individuals. To test this hypothesis, we utilized Atlantic salmon as a model which exhibits a simple, hence trackable, genetic control of maturation age. We then monitored the variation in diet acquisition (quantified as stomach fullness and composition) of individuals with different ages, and linked it with genomic regions (haploblocks) that were previously identified to be associated with age-at-maturity. Consistent with the hypothesis, we demonstrated that one of the life-history genomic regions tested (six6) was indeed associated with age-dependent differences in stomach fullness. Prey composition was marginally linked to six6, and suggestively (but non-significantly) to vgll3 genomic regions. We further showed Atlantic salmon switched to the so-called 'feast and famine' strategy along the ontogeny, where older age groups exhibited heavier stomach content, but that came at the expense of running on empty more often. These results suggest genetic variation underlying resource utilization may explain the genetic basis of age structure in Atlantic salmon. Given that ontogenetic diet has a genetic component and the strong spatial diversity associated with these genomic regions, we predict populations with diverse maturation age will have diverse evolutionary responses to future changes in marine food web structures.
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Affiliation(s)
- Tutku Aykanat
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Martin Rasmussen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Mikhail Ozerov
- Department of Biology, University of Turku, Turku, Finland.,Kevo Subarctic Research Institute, University of Turku, Turku, Finland
| | - Eero Niemelä
- Department of Biology, University of Turku, Turku, Finland.,Natural Resources Institute Finland (Luke), Oulu, Finland
| | - Lars Paulin
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Juha-Pekka Vähä
- Association for Water and Environment of Western Uusimaa, Lohja, Finland
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | | | - Torstein Pedersen
- Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Martin-A Svenning
- Arctic Ecology Department, Norwegian Institute for Nature Research (NINA), Tromsø, Norway
| | - Craig R Primmer
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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7
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Pardo SA, Hutchings JA. Estimating marine survival of Atlantic salmon using an inverse matrix approach. PLoS One 2020; 15:e0232407. [PMID: 32427992 PMCID: PMC7236976 DOI: 10.1371/journal.pone.0232407] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022] Open
Abstract
The marine phase of anadromous Atlantic salmon (Salmo salar) is the least known yet one of the most crucial with regards to population persistence. Recently, declines in many salmon populations in eastern Canada have been attributed to changes in the conditions at sea, thus reducing their survival. However, marine survival estimates are difficult to obtain given that many individuals spend multiple winters in the ocean before returning to freshwater to spawn; therefore, multiple parameters need to be estimated. We develop a model that uses an age-structured projection matrix which, coupled with yearly smolt and return abundance estimates, allows us to resample a distribution of matrices weighted by how close the resulting return estimates match the simulated returns, using a sample-importance-resampling algorithm. We test this model by simulating a simple time series of salmon abundances, and generate six different scenarios of varying salmon life histories where we simulate data for one-sea-winter (1SW)-dominated and non-1SW dominated populations, as well as scenarios where the proportion returning as 1SW is stable or highly variable. We find that our model provides reasonable estimates of marine survival for the first year at sea (S1), but highly uncertain estimates of proportion returning as 1SW (Pr) and survival in the second year at sea (S2). Our exploration of variable scenarios suggests the model is able to detect temporal trends in S1 for populations that have a considerable 1SW component in the returns; the ability of the model to detect trends in S1 diminishes as the proportion of two-sea-winter fish increases. Variability in the annual proportion of fish returning as 1SW does not seem to impact model accuracy. Our approach provides an instructive stepping-stone towards a model that can be applied to empirical abundance estimates of Atlantic salmon, and anadromous fishes in general, and therefore improve our knowledge of the marine phase of their life cycles as well as examining spatial and temporal trends in their variability.
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Affiliation(s)
- Sebastián A. Pardo
- Department of Biology, Dalhousie University, Halifax, NS, Canada
- * E-mail:
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8
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Mobley KB, Granroth‐Wilding H, Ellmén M, Orell P, Erkinaro J, Primmer CR. Time spent in distinct life history stages has sex‐specific effects on reproductive fitness in wild Atlantic salmon. Mol Ecol 2020; 29:1173-1184. [DOI: 10.1111/mec.15390] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Kenyon B. Mobley
- Organismal and Evolutionary Biology Research Program Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland
| | - Hanna Granroth‐Wilding
- Organismal and Evolutionary Biology Research Program Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland
| | - Mikko Ellmén
- Department of Biology University of Turku Turku Finland
| | - Panu Orell
- Natural Resources Institute Finland (Luke) Oulu Finland
| | | | - Craig R. Primmer
- Organismal and Evolutionary Biology Research Program Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland
- Institute for Biotechnology University of Helsinki Helsinki Finland
- Helsinki Institute of Sustainability Science University of Helsinki Helsinki Finland
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9
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Ferguson A, Reed TE, Cross TF, McGinnity P, Prodöhl PA. Anadromy, potamodromy and residency in brown trout Salmo trutta: the role of genes and the environment. JOURNAL OF FISH BIOLOGY 2019; 95:692-718. [PMID: 31197849 PMCID: PMC6771713 DOI: 10.1111/jfb.14005] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/09/2019] [Indexed: 05/10/2023]
Abstract
Brown trout Salmo trutta is endemic to Europe, western Asia and north-western Africa; it is a prominent member of freshwater and coastal marine fish faunas. The species shows two resident (river-resident, lake-resident) and three main facultative migratory life histories (downstream-upstream within a river system, fluvial-adfluvial potamodromous; to and from a lake, lacustrine-adfluvial (inlet) or allacustrine (outlet) potamodromous; to and from the sea, anadromous). River-residency v. migration is a balance between enhanced feeding and thus growth advantages of migration to a particular habitat v. the costs of potentially greater mortality and energy expenditure. Fluvial-adfluvial migration usually has less feeding improvement, but less mortality risk, than lacustrine-adfluvial or allacustrine and anadromous, but the latter vary among catchments as to which is favoured. Indirect evidence suggests that around 50% of the variability in S. trutta migration v. residency, among individuals within a population, is due to genetic variance. This dichotomous decision can best be explained by the threshold-trait model of quantitative genetics. Thus, an individual's physiological condition (e.g., energy status) as regulated by environmental factors, genes and non-genetic parental effects, acts as the cue. The magnitude of this cue relative to a genetically predetermined individual threshold, governs whether it will migrate or sexually mature as a river-resident. This decision threshold occurs early in life and, if the choice is to migrate, a second threshold probably follows determining the age and timing of migration. Migration destination (mainstem river, lake, or sea) also appears to be genetically programmed. Decisions to migrate and ultimate destination result in a number of subsequent consequential changes such as parr-smolt transformation, sexual maturity and return migration. Strong associations with one or a few genes have been found for most aspects of the migratory syndrome and indirect evidence supports genetic involvement in all parts. Thus, migratory and resident life histories potentially evolve as a result of natural and anthropogenic environmental changes, which alter relative survival and reproduction. Knowledge of genetic determinants of the various components of migration in S. trutta lags substantially behind that of Oncorhynchus mykiss and other salmonines. Identification of genetic markers linked to migration components and especially to the migration-residency decision, is a prerequisite for facilitating detailed empirical studies. In order to predict effectively, through modelling, the effects of environmental changes, quantification of the relative fitness of different migratory traits and of their heritabilities, across a range of environmental conditions, is also urgently required in the face of the increasing pace of such changes.
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Affiliation(s)
- Andrew Ferguson
- School of Biological SciencesQueen's University BelfastBelfastUK
| | - Thomas E. Reed
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Tom F. Cross
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Philip McGinnity
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Paulo A. Prodöhl
- School of Biological SciencesQueen's University BelfastBelfastUK
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10
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Bordeleau X, Hatcher BG, Denny S, Whoriskey FG, Patterson DA, Crossin GT. Nutritional correlates of the overwintering and seaward migratory decisions and long-term survival of post-spawning Atlantic salmon. CONSERVATION PHYSIOLOGY 2019; 7:coz107. [PMID: 31879564 PMCID: PMC6919299 DOI: 10.1093/conphys/coz107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/31/2019] [Accepted: 12/06/2019] [Indexed: 05/04/2023]
Abstract
Despite the importance of iteroparity (i.e. repeated spawning) for the viability of Atlantic salmon populations, little is known about the factors influencing the migratory behaviour and survival prospect of post-spawned individuals (kelts). To test the hypothesis that post-spawning nutritional condition underlies differences in spatiotemporal aspects of the habitat use and survival of migrating Atlantic salmon kelts, we physiologically sampled and acoustically tagged 25 individuals from the Middle River, Nova Scotia in autumn 2015. Kelts were subsequently tracked within their natal river during the winter months, and as far as 650 km away along known migration pathways towards the Labrador Sea and Greenland. Some kelts were detected nearly 2 years later, upon their return to the natal river for repeat spawning. Overall, kelts in poor or depleted post-spawning nutritional state (i.e. low body condition index or plasma triglyceride level): (i) initiated down-river migration earlier than higher condition kelts; (ii) experienced higher overwinter mortality in the natal river; (iii) tended to spend greater time in the estuary before moving to sea and (iv) did not progress as far in the marine environment, with a reduced probability of future, repeat spawning. Our findings suggest that initial differences in post-spawning condition are carried through subsequent migratory stages, which can ultimately affect repeat-spawning potential. These results point to the importance of lipid storage and mobilisation in Atlantic salmon kelts for mediating post-spawning migratory behaviour and survival.
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Affiliation(s)
- X Bordeleau
- Department of Biology, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada
- Corresponding author: Department of Biology, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada.
| | - B G Hatcher
- Bras d'Or Institute for Ecosystem Research, Cape Breton University, 1250 Grand Lake Road, Sydney, NS B1M 1A2, Canada
| | - S Denny
- Unama'ki Institute of Natural Resources, 4102 Shore Rd, Eskasoni, NS B1W 1C2, Canada
| | - F G Whoriskey
- Ocean Tracking Network, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada
| | - D A Patterson
- Fisheries and Oceans Canada, Cooperative Research Management Institute, Resource and Environmental Management, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - G T Crossin
- Department of Biology, Dalhousie University, 1355 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada
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