1
|
Chain FJJ, Meyer BS, Heckwolf MJ, Franzenburg S, Eizaguirre C, Reusch TBH. Epigenetic diversity of genes with copy number variations among natural populations of the three-spined stickleback. Evol Appl 2024; 17:e13753. [PMID: 39006007 PMCID: PMC11246597 DOI: 10.1111/eva.13753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 06/11/2024] [Accepted: 06/23/2024] [Indexed: 07/16/2024] Open
Abstract
Duplicated genes provide the opportunity for evolutionary novelty and adaptive divergence. In many cases, having more gene copies increases gene expression, which might facilitate adaptation to stressful or novel environments. Conversely, overexpression or misexpression of duplicated genes can be detrimental and subject to negative selection. In this scenario, newly duplicate genes may evade purifying selection if they are epigenetically silenced, at least temporarily, leading them to persist in populations as copy number variations (CNVs). In animals and plants, younger gene duplicates tend to have higher levels of DNA methylation and lower levels of gene expression, suggesting epigenetic regulation could promote the retention of gene duplications via expression repression or silencing. Here, we test the hypothesis that DNA methylation variation coincides with young duplicate genes that are segregating as CNVs in six populations of the three-spined stickleback that span a salinity gradient from 4 to 30 PSU. Using reduced-representation bisulfite sequencing, we found DNA methylation and CNV differentiation outliers rarely overlapped. Whereas lineage-specific genes and young duplicates were found to be highly methylated, just two gene CNVs showed a significant association between promoter methylation level and copy number, suggesting that DNA methylation might not interact with CNVs in our dataset. If most new duplications are regulated for dosage by epigenetic mechanisms, our results do not support a strong contribution from DNA methylation soon after duplication. Instead, our results are consistent with a preference to duplicate genes that are already highly methylated.
Collapse
Affiliation(s)
- Frédéric J J Chain
- Department of Biological Sciences University of Massachusetts Lowell Lowell Massachusetts USA
| | - Britta S Meyer
- Marine Evolutionary Ecology GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
- Present address: Research Unit for Evolutionary Immunogenomics, Department of Biology University of Hamburg Hamburg Germany
| | - Melanie J Heckwolf
- Marine Evolutionary Ecology GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
- Present address: Fish Ecology and Evolution, Leibniz Centre for Tropical Marine Research Bremen Germany
| | - Sören Franzenburg
- Institute of Clinical Molecular Biology, Kiel University Kiel Germany
| | - Christophe Eizaguirre
- School of Biological and Behavioural Sciences Queen Mary University of London London UK
| | - Thorsten B H Reusch
- Marine Evolutionary Ecology GEOMAR Helmholtz Centre for Ocean Research Kiel Kiel Germany
| |
Collapse
|
2
|
Pokrovac I, Rohner N, Pezer Ž. The prevalence of copy number increase at multiallelic copy number variants associated with cave colonization. Mol Ecol 2024; 33:e17339. [PMID: 38556927 DOI: 10.1111/mec.17339] [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: 01/09/2024] [Revised: 03/16/2024] [Accepted: 03/22/2024] [Indexed: 04/02/2024]
Abstract
Copy number variation is a common contributor to phenotypic diversity, yet its involvement in ecological adaptation is not easily discerned. Instances of parallelly evolving populations of the same species in a similar environment marked by strong selective pressures present opportunities to study the role of copy number variants (CNVs) in adaptation. By identifying CNVs that repeatedly occur in multiple populations of the derived ecotype and are not (or are rarely) present in the populations of the ancestral ecotype, the association of such CNVs with adaptation to the novel environment can be inferred. We used this paradigm to identify CNVs associated with recurrent adaptation of the Mexican tetra (Astyanax mexicanus) to cave environment. Using a read-depth approach, we detected CNVs from previously re-sequenced genomes of 44 individuals belonging to two ancestral surfaces and three derived cave populations. We identified 102 genes and 292 genomic regions that repeatedly diverge in copy number between the two ecotypes and occupy 0.8% of the reference genome. Functional analysis revealed their association with processes previously recognized to be relevant for adaptation, such as vision, immunity, oxygen consumption, metabolism, and neural function and we propose that these variants have been selected for in the cave or surface waters. The majority of the ecotype-divergent CNVs are multiallelic and display copy number increases in cavefish compared to surface fish. Our findings suggest that multiallelic CNVs - including gene duplications - and divergence in copy number provide a fast route to produce novel phenotypes associated with adaptation to subterranean life.
Collapse
Affiliation(s)
| | - Nicolas Rohner
- Stowers Institute for Medical Research, Kansas City, Missouri, USA
| | | |
Collapse
|
3
|
Pollen AA, Kilik U, Lowe CB, Camp JG. Human-specific genetics: new tools to explore the molecular and cellular basis of human evolution. Nat Rev Genet 2023; 24:687-711. [PMID: 36737647 PMCID: PMC9897628 DOI: 10.1038/s41576-022-00568-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2022] [Indexed: 02/05/2023]
Abstract
Our ancestors acquired morphological, cognitive and metabolic modifications that enabled humans to colonize diverse habitats, develop extraordinary technologies and reshape the biosphere. Understanding the genetic, developmental and molecular bases for these changes will provide insights into how we became human. Connecting human-specific genetic changes to species differences has been challenging owing to an abundance of low-effect size genetic changes, limited descriptions of phenotypic differences across development at the level of cell types and lack of experimental models. Emerging approaches for single-cell sequencing, genetic manipulation and stem cell culture now support descriptive and functional studies in defined cell types with a human or ape genetic background. In this Review, we describe how the sequencing of genomes from modern and archaic hominins, great apes and other primates is revealing human-specific genetic changes and how new molecular and cellular approaches - including cell atlases and organoids - are enabling exploration of the candidate causal factors that underlie human-specific traits.
Collapse
Affiliation(s)
- Alex A Pollen
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA.
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
| | - Umut Kilik
- Institute of Human Biology (IHB), Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Craig B Lowe
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, USA.
| | - J Gray Camp
- Institute of Human Biology (IHB), Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland.
- University of Basel, Basel, Switzerland.
| |
Collapse
|
4
|
Chen HI, Turakhia Y, Bejerano G, Kingsley DM. Whole-genome Comparisons Identify Repeated Regulatory Changes Underlying Convergent Appendage Evolution in Diverse Fish Lineages. Mol Biol Evol 2023; 40:msad188. [PMID: 37739926 PMCID: PMC10516590 DOI: 10.1093/molbev/msad188] [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] [Indexed: 09/24/2023] Open
Abstract
Fins are major functional appendages of fish that have been repeatedly modified in different lineages. To search for genomic changes underlying natural fin diversity, we compared the genomes of 36 percomorph fish species that span over 100 million years of evolution and either have complete or reduced pelvic and caudal fins. We identify 1,614 genomic regions that are well-conserved in fin-complete species but missing from multiple fin-reduced lineages. Recurrent deletions of conserved sequences in wild fin-reduced species are enriched for functions related to appendage development, suggesting that convergent fin reduction at the organismal level is associated with repeated genomic deletions near fin-appendage development genes. We used sequencing and functional enhancer assays to confirm that PelA, a Pitx1 enhancer previously linked to recurrent pelvic loss in sticklebacks, has also been independently deleted and may have contributed to the fin morphology in distantly related pelvic-reduced species. We also identify a novel enhancer that is conserved in the majority of percomorphs, drives caudal fin expression in transgenic stickleback, is missing in tetraodontiform, syngnathid, and synbranchid species with caudal fin reduction, and alters caudal fin development when targeted by genome editing. Our study illustrates a broadly applicable strategy for mapping phenotypes to genotypes across a tree of vertebrate species and highlights notable new examples of regulatory genomic hotspots that have been used to evolve recurrent phenotypes across 100 million years of fish evolution.
Collapse
Affiliation(s)
- Heidi I Chen
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Yatish Turakhia
- Department of Electrical and Computer Engineering, University of California, San Diego, CA, USA
| | - Gill Bejerano
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biomedical Data Science, Stanford University School of Medicine, Stanford, CA, USA
- Department of Computer Science, Stanford University School of Engineering, Stanford, CA, USA
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - David M Kingsley
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| |
Collapse
|
5
|
Ishikawa A, Yamanouchi S, Iwasaki W, Kitano J. Convergent copy number increase of genes associated with freshwater colonization in fishes. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200509. [PMID: 35634928 PMCID: PMC9149799 DOI: 10.1098/rstb.2020.0509] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/14/2022] [Indexed: 07/20/2023] Open
Abstract
Copy number variation (CNV) can cause phenotypic changes. However, in contrast to amino acid substitutions and cis-regulatory changes, little is known about the functional categories of genes in which CNV is important for adaptation to novel environments. It is also unclear whether the same genes repeatedly change the copy numbers for adapting to similar environments. Here, we investigate CNV associated with freshwater colonization in fishes, which was observed multiple times across different lineages. Using 48 ray-finned fishes across diverse orders, we identified 23 genes whose copy number increases were associated with freshwater colonization. These genes showed enrichment for peptide receptor activity, hexosyltransferase activity and unsaturated fatty acid metabolism. We further revealed that three of the genes showed copy number increases in freshwater populations compared to marine ancestral populations of the stickleback genus Gasterosteus. These results indicate that copy number increases of genes involved in fatty acid metabolism (FADS2), immune function (PSMB8a) and thyroid hormone metabolism (UGT2) may be important for freshwater colonization at both the inter-order macroevolutionary scale and at the intra-genus microevolutionary scale. Further analysis across diverse taxa will help to understand the role of CNV in the adaptation to novel environments. This article is part of the theme issue 'Genetic basis of adaptation and speciation: from loci to causative mutations'.
Collapse
Affiliation(s)
- Asano Ishikawa
- Ecological Genetics Laboratory, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Shun Yamanouchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Wataru Iwasaki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Jun Kitano
- Ecological Genetics Laboratory, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| |
Collapse
|
6
|
Abstract
The repeated adaptation of oceanic threespine sticklebacks to fresh water has made it a premier organism to study parallel evolution. These small fish have multiple distinct ecotypes that display a wide range of diverse phenotypic traits. Ecotypes are easily crossed in the laboratory, and families are large and develop quickly enough for quantitative trait locus analyses, positioning the threespine stickleback as a versatile model organism to address a wide range of biological questions. Extensive genomic resources, including linkage maps, a high-quality reference genome, and developmental genetics tools have led to insights into the genomic basis of adaptation and the identification of genomic changes controlling traits in vertebrates. Recently, threespine sticklebacks have been used as a model system to identify the genomic basis of highly complex traits, such as behavior and host-microbiome and host-parasite interactions. We review the latest findings and new avenues of research that have led the threespine stickleback to be considered a supermodel of evolutionary genomics.
Collapse
Affiliation(s)
- Kerry Reid
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794, USA;
| | - Michael A Bell
- University of California Museum of Paleontology, Berkeley, California 94720, USA
| | - Krishna R Veeramah
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York 11794, USA;
| |
Collapse
|
7
|
Kess T, Dempson JB, Lehnert SJ, Layton KKS, Einfeldt A, Bentzen P, Salisbury SJ, Messmer AM, Duffy S, Ruzzante DE, Nugent CM, Ferguson MM, Leong JS, Koop BF, O'Connell MF, Bradbury IR. Genomic basis of deep-water adaptation in Arctic Charr (Salvelinus alpinus) morphs. Mol Ecol 2021; 30:4415-4432. [PMID: 34152667 DOI: 10.1111/mec.16033] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/28/2021] [Accepted: 06/03/2021] [Indexed: 12/30/2022]
Abstract
The post-glacial colonization of Gander Lake in Newfoundland, Canada, by Arctic Charr (Salvelinus alpinus) provides the opportunity to study the genomic basis of adaptation to extreme deep-water environments. Colonization of deep-water (>50 m) habitats often requires extensive adaptation to cope with novel environmental challenges from high hydrostatic pressure, low temperature, and low light, but the genomic mechanisms underlying evolution in these environments are rarely known. Here, we compare genomic divergence between a deep-water morph adapted to depths of up to 288 m and a larger, piscivorous pelagic morph occupying shallower depths. Using both a SNP array and resequencing of whole nuclear and mitochondrial genomes, we find clear genetic divergence (FST = 0.11-0.15) between deep and shallow water morphs, despite an absence of morph divergence across the mitochondrial genome. Outlier analyses identified many diverged genomic regions containing genes enriched for processes such as gene expression and DNA repair, cardiac function, and membrane transport. Detection of putative copy number variants (CNVs) uncovered 385 genes with CNVs distinct to piscivorous morphs, and 275 genes with CNVs distinct to deep-water morphs, enriched for processes associated with synapse assembly. Demographic analyses identified evidence for recent and local morph divergence, and ongoing reductions in diversity consistent with postglacial colonization. Together, these results show that Arctic Charr morph divergence has occurred through genome-wide differentiation and elevated divergence of genes underlying multiple cellular and physiological processes, providing insight into the genomic basis of adaptation in a deep-water habitat following postglacial recolonization.
Collapse
Affiliation(s)
- Tony Kess
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - J Brian Dempson
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Sarah J Lehnert
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Kara K S Layton
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Anthony Einfeldt
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Paul Bentzen
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | | | - Amber M Messmer
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Steven Duffy
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | | | - Cameron M Nugent
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Moira M Ferguson
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - Jong S Leong
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Ben F Koop
- Department of Biology, University of Victoria, Victoria, BC, Canada
| | - Michael F O'Connell
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | - Ian R Bradbury
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| |
Collapse
|
8
|
Archambeault SL, Bärtschi LR, Merminod AD, Peichel CL. Adaptation via pleiotropy and linkage: Association mapping reveals a complex genetic architecture within the stickleback Eda locus. Evol Lett 2020; 4:282-301. [PMID: 32774879 PMCID: PMC7403726 DOI: 10.1002/evl3.175] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/04/2020] [Accepted: 04/29/2020] [Indexed: 11/26/2022] Open
Abstract
Genomic mapping of the loci associated with phenotypic evolution has revealed genomic "hotspots," or regions of the genome that control multiple phenotypic traits. This clustering of loci has important implications for the speed and maintenance of adaptation and could be due to pleiotropic effects of a single mutation or tight genetic linkage of multiple causative mutations affecting different traits. The threespine stickleback (Gasterosteus aculeatus) is a powerful model for the study of adaptive evolution because the marine ecotype has repeatedly adapted to freshwater environments across the northern hemisphere in the last 12,000 years. Freshwater ecotypes have repeatedly fixed a 16 kilobase haplotype on chromosome IV that contains Ectodysplasin (Eda), a gene known to affect multiple traits, including defensive armor plates, lateral line sensory hair cells, and schooling behavior. Many additional traits have previously been mapped to a larger region of chromosome IV that encompasses the Eda freshwater haplotype. To identify which of these traits specifically map to this adaptive haplotype, we made crosses of rare marine fish heterozygous for the freshwater haplotype in an otherwise marine genetic background. Further, we performed fine-scale association mapping in a fully interbreeding, polymorphic population of freshwater stickleback to disentangle the effects of pleiotropy and linkage on the phenotypes affected by this haplotype. Although we find evidence that linked mutations have small effects on a few phenotypes, a small 1.4-kb region within the first intron of Eda has large effects on three phenotypic traits: lateral plate count, and both the number and patterning of the posterior lateral line neuromasts. Thus, the Eda haplotype is a hotspot of adaptation in stickleback due to both a small, pleiotropic region affecting multiple traits as well as multiple linked mutations affecting additional traits.
Collapse
Affiliation(s)
- Sophie L. Archambeault
- Institute of Ecology and EvolutionUniversity of BernBern3012Switzerland
- Graduate Program in Molecular and Cellular BiologyUniversity of WashingtonSeattleWashington98195
- Divisions of Basic Sciences and Human BiologyFred Hutchinson Cancer Research CenterSeattleWashington98109
| | - Luis R. Bärtschi
- Institute of Ecology and EvolutionUniversity of BernBern3012Switzerland
| | | | - Catherine L. Peichel
- Institute of Ecology and EvolutionUniversity of BernBern3012Switzerland
- Graduate Program in Molecular and Cellular BiologyUniversity of WashingtonSeattleWashington98195
- Divisions of Basic Sciences and Human BiologyFred Hutchinson Cancer Research CenterSeattleWashington98109
| |
Collapse
|
9
|
Xie KT, Wang G, Thompson AC, Wucherpfennig JI, Reimchen TE, MacColl ADC, Schluter D, Bell MA, Vasquez KM, Kingsley DM. DNA fragility in the parallel evolution of pelvic reduction in stickleback fish. Science 2019; 363:81-84. [PMID: 30606845 PMCID: PMC6677656 DOI: 10.1126/science.aan1425] [Citation(s) in RCA: 124] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/18/2018] [Accepted: 11/28/2018] [Indexed: 01/22/2023]
Abstract
Evolution generates a remarkable breadth of living forms, but many traits evolve repeatedly, by mechanisms that are still poorly understood. A classic example of repeated evolution is the loss of pelvic hindfins in stickleback fish (Gasterosteus aculeatus). Repeated pelvic loss maps to recurrent deletions of a pelvic enhancer of the Pitx1 gene. Here, we identify molecular features contributing to these recurrent deletions. Pitx1 enhancer sequences form alternative DNA structures in vitro and increase double-strand breaks and deletions in vivo. Enhancer mutability depends on DNA replication direction and is caused by TG-dinucleotide repeats. Modeling shows that elevated mutation rates can influence evolution under demographic conditions relevant for sticklebacks and humans. DNA fragility may thus help explain why the same loci are often used repeatedly during parallel adaptive evolution.
Collapse
Affiliation(s)
- Kathleen T Xie
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Guliang Wang
- Division of Pharmacology and Toxicology, University of Texas at Austin, Austin, TX, USA
| | - Abbey C Thompson
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Julia I Wucherpfennig
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | - Dolph Schluter
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Michael A Bell
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, USA.
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, University of Texas at Austin, Austin, TX, USA
| | - David M Kingsley
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, USA.
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|