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Perry D, Tamarit E, Sundell E, Axelsson M, Bergman S, Gräns A, Gullström M, Sturve J, Wennhage H. Physiological responses of Atlantic cod to climate change indicate that coastal ecotypes may be better adapted to tolerate ocean stressors. Sci Rep 2024; 14:12896. [PMID: 38839894 PMCID: PMC11153577 DOI: 10.1038/s41598-024-62700-0] [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: 11/02/2023] [Accepted: 05/20/2024] [Indexed: 06/07/2024] Open
Abstract
Healthy ecosystems and species have some degree of resilience to changing conditions, however as the frequency and severity of environmental changes increase, resilience may be diminished or lost. In Sweden, one example of a species with reduced resilience is the Atlantic cod (Gadus morhua). This species has been subjected to overfishing, and with additional pressures such as habitat degradation and changing environmental conditions there has been little to no recovery, despite more than a decade of management actions. Given the historical ecological, economical, and cultural significance of cod, it is important to understand how Atlantic cod respond to global climate change to recover and sustainably manage this species in the future. A multi-stressor experiment was conducted to evaluate physiological responses of juvenile cod exposed to warming, ocean acidification, and freshening, changes expected to occur in their nursery habitat. The response to single drivers showed variable effects related to fish biometrics and increased levels of oxidative stress dependent parameters. Importantly, two separate responses were seen within a single treatment for the multi-stressor and freshening groups. These within-treatment differences were correlated to genotype, with the offshore ecotype having a heightened stress response compared to the coastal ecotype, which may be better adapted to tolerate future changes. These results demonstrate that, while Atlantic cod have some tolerance for future changes, ecotypes respond differently, and cumulative effects of multiple stressors may lead to deleterious effects for this important species.
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Affiliation(s)
- Diana Perry
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden.
| | - Elena Tamarit
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Erika Sundell
- Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Gothenburg, Sweden
| | - Michael Axelsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Sanne Bergman
- The Arctic University Museum of Norway, UiT - the Arctic University of Norway, Tromsø, Norway
| | - Albin Gräns
- Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Gothenburg, Sweden
| | - Martin Gullström
- School of Natural Sciences, Technology and Environmental Studies, Södertörn University, Huddinge, Sweden
| | - Joachim Sturve
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Håkan Wennhage
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
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2
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Jentoft S, Tørresen OK, Tooming-Klunderud A, Skage M, Kollias S, Jakobsen KS. The genome sequence of the Atlantic cod, Gadus morhua (Linnaeus, 1758). Wellcome Open Res 2024; 9:189. [PMID: 39224768 PMCID: PMC11367075 DOI: 10.12688/wellcomeopenres.21122.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2024] [Indexed: 09/04/2024] Open
Abstract
We present a genome assembly from an individual male Gadus morhua (the Atlantic cod; Chordata; Actinopteri; Gadiformes; Gadidae). The genome sequence is 669.9 megabases in span. Most of the assembly is scaffolded into 23 chromosomal pseudomolecules. Gene annotation of this assembly on Ensembl identified 23,515 protein coding genes.
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Affiliation(s)
- Sissel Jentoft
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Ole K. Tørresen
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Ave Tooming-Klunderud
- Norwegian Sequencing Centre, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Morten Skage
- Norwegian Sequencing Centre, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Spyridon Kollias
- Norwegian Sequencing Centre, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Kjetill S. Jakobsen
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | | | | | | | - Tree of Life Core Informatics collective
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
- Norwegian Sequencing Centre, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Darwin Tree of Life Consortium
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
- Norwegian Sequencing Centre, Department of Biosciences, University of Oslo, Oslo, Norway
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3
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Andersson L, Bekkevold D, Berg F, Farrell ED, Felkel S, Ferreira MS, Fuentes-Pardo AP, Goodall J, Pettersson M. How Fish Population Genomics Can Promote Sustainable Fisheries: A Road Map. Annu Rev Anim Biosci 2024; 12:1-20. [PMID: 37906837 DOI: 10.1146/annurev-animal-021122-102933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Maintenance of genetic diversity in marine fishes targeted by commercial fishing is a grand challenge for the future. Most of these species are abundant and therefore important for marine ecosystems and food security. Here, we present a road map of how population genomics can promote sustainable fisheries. In these species, the development of reference genomes and whole genome sequencing is key, because genetic differentiation at neutral loci is usually low due to large population sizes and gene flow. First, baseline allele frequencies representing genetically differentiated populations within species must be established. These can then be used to accurately determine the composition of mixed samples, forming the basis for population demographic analysis to inform sustainably set fish quotas. SNP-chip analysis is a cost-effective method for determining baseline allele frequencies and for population identification in mixed samples. Finally, we describe how genetic marker analysis can transform stock identification and management.
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Affiliation(s)
- Leif Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Dorte Bekkevold
- National Institute of Aquatic Resources, Technical University of Denmark, Silkeborg, Denmark
| | | | - Edward D Farrell
- Killybegs Fishermen's Organisation, Killybegs, County Donegal, Ireland
| | - Sabine Felkel
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
| | - Mafalda S Ferreira
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
| | - Angela P Fuentes-Pardo
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
| | - Jake Goodall
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
| | - Mats Pettersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden;
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4
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Olsen EM, Karlsen Ø, Skjæraasen JE. Large females connect Atlantic cod spawning sites. Science 2023; 382:1181-1184. [PMID: 38060630 DOI: 10.1126/science.adi1826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023]
Abstract
The Earth's ecosystems are increasingly deprived of large animals. Global simulations suggest that this downsizing of nature has serious consequences for biosphere functioning. However, the historical loss of large animals means that it is now often impossible to secure empirical data revealing their true ecological importance. We tracked 465 mature Atlantic cod (Gadus morhua) during their winter spawning season and show that large females (up to 114 centimeters in length), which are still found in mid-Norway, were characterized by more complex movement networks compared with smaller females. Large males were sparse but displayed similar movement patterns. Our finding implies that management programs promoting large fish will have positive impacts on population resilience by facilitating the continued use of a diversity of spawning habitats and the connectivity between them.
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Affiliation(s)
- Esben Moland Olsen
- Institute of Marine Research; Flødevigen, Arendal 4817, Norway
- Centre for Coastal Research, Department of Natural Sciences, University of Agder; Kristiansand 4604, Norway
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Helmerson C, Weist P, Brieuc MSO, Maurstad MF, Schade FM, Dierking J, Petereit C, Knutsen H, Metcalfe J, Righton D, André C, Krumme U, Jentoft S, Hanel R. Evidence of hybridization between genetically distinct Baltic cod stocks during peak population abundance(s). Evol Appl 2023; 16:1359-1376. [PMID: 37492148 PMCID: PMC10363836 DOI: 10.1111/eva.13575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 06/06/2023] [Accepted: 06/14/2023] [Indexed: 07/27/2023] Open
Abstract
Range expansions can lead to increased contact of divergent populations, thus increasing the potential of hybridization events. Whether viable hybrids are produced will most likely depend on the level of genomic divergence and associated genomic incompatibilities between the different entities as well as environmental conditions. By taking advantage of historical Baltic cod (Gadus morhua) otolith samples combined with genotyping and whole genome sequencing, we here investigate the genetic impact of the increased spawning stock biomass of the eastern Baltic cod stock in the mid 1980s. The eastern Baltic cod is genetically highly differentiated from the adjacent western Baltic cod and locally adapted to the brackish environmental conditions in the deeper Eastern basins of the Baltic Sea unsuitable for its marine counterparts. Our genotyping results show an increased proportion of eastern Baltic cod in western Baltic areas (Mecklenburg Bay and Arkona Basin)-indicative of a range expansion westwards-during the peak population abundance in the 1980s. Additionally, we detect high frequencies of potential hybrids (including F1, F2 and backcrosses), verified by whole genome sequencing data for a subset of individuals. Analysis of mitochondrial genomes further indicates directional gene flow from eastern Baltic cod males to western Baltic cod females. Our findings unravel that increased overlap in distribution can promote hybridization between highly divergent populations and that the hybrids can be viable and survive under specific and favourable environmental conditions. However, the observed hybridization had seemingly no long-lasting impact on the continuous separation and genetic differentiation between the unique Baltic cod stocks.
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Affiliation(s)
- Cecilia Helmerson
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
| | - Peggy Weist
- Thünen Institute of Fisheries EcologyBremerhavenGermany
| | - Marine Servane Ono Brieuc
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
- Institute of Marine ResearchBergenNorway
| | - Marius F. Maurstad
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
| | | | - Jan Dierking
- GEOMAR Helmholtz Centre for Ocean Research KielGermany
| | | | - Halvor Knutsen
- Institute of Marine ResearchBergenNorway
- Centre for Coastal ResearchUniversity of AgderKristiansandNorway
| | - Julian Metcalfe
- Centre for Environment Fisheries and Aquaculture ScienceLowestoftUK
| | - David Righton
- Centre for Environment Fisheries and Aquaculture ScienceLowestoftUK
| | - Carl André
- Department of Marine Sciences – TjärnöUniversity of GothenburgStrömstadSweden
| | - Uwe Krumme
- Thünen Institute of Baltic Sea FisheriesRostockGermany
| | - Sissel Jentoft
- Centre for Ecological and Evolutionary SynthesisDepartment of BiosciencesUniversity of OsloOsloNorway
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Nunes I, Passos K, Mourão Ximenes A, Hrbek T, Farias IP. Spatial and temporal population genetic analysis of Semaprochilodus insignis (Prochilodontidae), an overexploited fish from the Amazon basin. PeerJ 2023; 11:e15503. [PMID: 37361032 PMCID: PMC10289084 DOI: 10.7717/peerj.15503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 05/14/2023] [Indexed: 06/28/2023] Open
Abstract
Background Semaprochilodus insignis is a migratory fish of commercial and subsistence importance to communities in the Amazon. Despite the high intensity of exploitation, recent studies have not been carried out to assess the genetic status of its stocks. Methods This study is the first to estimate genetic diversity and to test the existence of spatial and temporal structuring of S. insignis through sequencing of the mtDNA control region (n = 241) and eight microsatellite loci (n = 180) of individuals sampled at 11 sites distributed in the Brazilian Amazon basin. Results Results for both markers were congruent, revealing a homogeneous genetic diversity in all the sampled locations, in addition to the absence of spatial and temporal genetic structure, indicating that the species forms a large panmictic population in the Brazilian Amazon. Discussion Although overfishing does not yet appear to have affected the levels of genetic variability of S. insignis, signals of reduction of the effective population size and a bottleneck provide an early alert to the effects of overfishing. Thus, the ever-decreasing populations may threaten S. insignis in the future. Therefore, it is hoped that the results of this study may contribute to the elaboration of management plans or any other measures that aim at the management and conservation of this species of great importance for the Amazon basin.
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Affiliation(s)
- Ingrid Nunes
- Departamento de Genética, Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas, Manaus, Amazonas, Brasil
| | - Kelmer Passos
- Departamento de Genética, Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas, Manaus, Amazonas, Brasil
| | - Aline Mourão Ximenes
- Departamento de Genética, Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas, Manaus, Amazonas, Brasil
- Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva, Instituto Nacional de Pesquisas da Amazônia, Manaus, Amazonas, Brasil
| | - Tomas Hrbek
- Departamento de Genética, Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas, Manaus, Amazonas, Brasil
- Department of Biology, Trinity University, San Antonio, TX, United States of America
| | - Izeni Pires Farias
- Departamento de Genética, Laboratório de Evolução e Genética Animal (LEGAL), Universidade Federal do Amazonas, Manaus, Amazonas, Brasil
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7
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De León LF, Silva B, Avilés-Rodríguez KJ, Buitrago-Rosas D. Harnessing the omics revolution to address the global biodiversity crisis. Curr Opin Biotechnol 2023; 80:102901. [PMID: 36773576 DOI: 10.1016/j.copbio.2023.102901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/10/2023] [Accepted: 01/18/2023] [Indexed: 02/12/2023]
Abstract
Human disturbances are altering global biodiversity in unprecedented ways. We identify three fundamental challenges underpinning our understanding of global biodiversity (namely discovery, loss, and preservation), and discuss how the omics revolution (e.g. genomics, transcriptomics, proteomics, metabolomics, and meta-omics) can help address these challenges. We also discuss how omics tools can illuminate the major drivers of biodiversity loss, including invasive species, pollution, urbanization, overexploitation, and climate change, with a special focus on highly diverse tropical environments. Although omics tools are transforming the traditional toolkit of biodiversity research, their application to addressing the current biodiversity crisis remains limited and may not suffice to offset current rates of biodiversity loss. Despite technical and logistical challenges, omics tools need to be fully integrated into global biodiversity research, and better strategies are needed to improve their translation into biodiversity policy and practice. It is also important to recognize that although the omics revolution can be considered the biologist's dream, socioeconomic disparity limits their application in biodiversity research.
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Affiliation(s)
- Luis F De León
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA.
| | - Bruna Silva
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Kevin J Avilés-Rodríguez
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA; Department of Biology, Fordham University, Bronx, NY, USA
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8
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Devi A, Jain K. Polygenic adaptation dynamics in large, finite populations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.25.525607. [PMID: 36747829 PMCID: PMC9901025 DOI: 10.1101/2023.01.25.525607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although many phenotypic traits are determined by a large number of genetic variants, how a polygenic trait adapts in response to a change in the environment is not completely understood. In the framework of diffusion theory, we study the steady state and the adaptation dynamics of a large but finite population evolving under stabilizing selection and symmetric mutations when selection and mutation are moderately large. We find that in the stationary state, the allele frequency distribution at a locus is unimodal if its effect size is below a threshold effect and bimodal otherwise; these results are the stochastic analog of the deterministic ones where the stable allele frequency becomes bistable when the effect size exceeds a threshold. It is known that following a sudden shift in the phenotypic optimum, in an infinitely large population, selective sweeps at a large-effect locus are prevented and adaptation proceeds exclusively via subtle changes in the allele frequency; in contrast, we find that the chance of sweep is substantially enhanced in large, finite populations and the allele frequency at a large-effect locus can reach a high frequency at short times even for small shifts in the phenotypic optimum.
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Affiliation(s)
- Archana Devi
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85287, USA
| | - Kavita Jain
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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9
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Westram AM, Faria R, Johannesson K, Butlin R, Barton N. Inversions and parallel evolution. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210203. [PMID: 35694747 PMCID: PMC9189493 DOI: 10.1098/rstb.2021.0203] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Local adaptation leads to differences between populations within a species. In many systems, similar environmental contrasts occur repeatedly, sometimes driving parallel phenotypic evolution. Understanding the genomic basis of local adaptation and parallel evolution is a major goal of evolutionary genomics. It is now known that by preventing the break-up of favourable combinations of alleles across multiple loci, genetic architectures that reduce recombination, like chromosomal inversions, can make an important contribution to local adaptation. However, little is known about whether inversions also contribute disproportionately to parallel evolution. Our aim here is to highlight this knowledge gap, to showcase existing studies, and to illustrate the differences between genomic architectures with and without inversions using simple models. We predict that by generating stronger effective selection, inversions can sometimes speed up the parallel adaptive process or enable parallel adaptation where it would be impossible otherwise, but this is highly dependent on the spatial setting. We highlight that further empirical work is needed, in particular to cover a broader taxonomic range and to understand the relative importance of inversions compared to genomic regions without inversions. This article is part of the theme issue ‘Genomic architecture of supergenes: causes and evolutionary consequences’.
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Affiliation(s)
- Anja M Westram
- ISTA (Institute of Science and Technology Austria), Klosterneuburg, Austria.,Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
| | - Rui Faria
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO, Laboratório Associado, Universidade do Porto, Vairão, Portugal.,BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal.,Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield, UK
| | | | - Roger Butlin
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield, UK.,Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Nick Barton
- ISTA (Institute of Science and Technology Austria), Klosterneuburg, Austria
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10
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Supergenes promote ecological stasis in a keystone species. Trends Genet 2022; 38:629-631. [PMID: 35487824 DOI: 10.1016/j.tig.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/05/2022] [Indexed: 10/18/2022]
Abstract
Structural variation can create supergene architectures through tight genomic linkages that maintain traits in favourable combinations. A new study by Sodeland et al. links such supergenes in Atlantic cod with species persistence over millennia, despite the fisheries-induced decline in populations. This links intraspecific supergene diversity to ecological stasis, with significant consequences for ecosystem stability.
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11
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Stabilizing selection on Atlantic cod supergenes through a millennium of extensive exploitation. Proc Natl Acad Sci U S A 2022; 119:2114904119. [PMID: 35165196 PMCID: PMC8872764 DOI: 10.1073/pnas.2114904119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2022] [Indexed: 12/21/2022] Open
Abstract
Ecological disruption due to human impacts is evident worldwide, and a key to mitigation lies in characterizing the underlying mechanisms of species and ecosystem stability. Here we show that three extensive “supergenes” are maintained in Atlantic cod by stabilizing selection, tying these genes to the persistence of a keystone species distributed across the northern Atlantic Ocean. Removal of this species has caused severe ecosystem reshuffling in several areas of its range. Genomic inference of historic stock sizes further shows that cod has been under pressure in the North Sea system since the Viking period, in line with zooarchaeological records. Expansion of fisheries in Northern Europe through the past millennium is well documented and supports the inferred long-term declines. Life on Earth has been characterized by recurring cycles of ecological stasis and disruption, relating biological eras to geological and climatic transitions through the history of our planet. Due to the increasing degree of ecological abruption caused by human influences many advocate that we now have entered the geological era of the Anthropocene, or “the age of man.” Considering the ongoing mass extinction and ecosystem reshuffling observed worldwide, a better understanding of the drivers of ecological stasis will be a requisite for identifying routes of intervention and mitigation. Ecosystem stability may rely on one or a few keystone species, and the loss of such species could potentially have detrimental effects. The Atlantic cod (Gadus morhua) has historically been highly abundant and is considered a keystone species in ecosystems of the northern Atlantic Ocean. Collapses of cod stocks have been observed on both sides of the Atlantic and reported to have detrimental effects that include vast ecosystem reshuffling. By whole-genome resequencing we demonstrate that stabilizing selection maintains three extensive “supergenes” in Atlantic cod, linking these genes to species persistence and ecological stasis. Genomic inference of historic effective population sizes shows continued declines for cod in the North Sea–Skagerrak–Kattegat system through the past millennia, consistent with an early onset of the marine Anthropocene through industrialization and commercialization of fisheries throughout the medieval period.
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