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Lanata CM, Blazer A, Criswell LA. The Contribution of Genetics and Epigenetics to Our Understanding of Health Disparities in Rheumatic Diseases. Rheum Dis Clin North Am 2020; 47:65-81. [PMID: 34042055 DOI: 10.1016/j.rdc.2020.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Socioeconomic determinants of health are associated with worse outcomes in the rheumatic diseases and contribute significantly to health disparities. However, genetic and epigenetic risk factors may affect different populations disproportionally and further exacerbate health disparities. We discuss the role of genetics and epigenetics to the health disparities observed in rheumatic diseases. We review concepts of population genetics and natural selection, current genome-wide genetic and epigenetic studies of several autoimmune diseases, and environmental exposures associated with disease risk in different populations. To understand how genomics influence health disparities in the rheumatic diseases, further studies in different populations worldwide are needed.
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Affiliation(s)
- Cristina M Lanata
- Russell/Engleman Rheumatology Research Center, University of California, San Francisco, 513 Parnassus Avenue, MSB S865, San Francisco, CA, USA
| | - Ashira Blazer
- Department of Medicine, Division of Rheumatology, NYU Langone Health, 550 1st Avenue, MSB 606, New York, NY 10029, USA
| | - Lindsey A Criswell
- Russell/Engleman Rheumatology Research Center, University of California, San Francisco, 513 Parnassus Avenue, MSB S864, San Francisco, CA, USA.
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52
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Marchi N, Excoffier L. Gene flow as a simple cause for an excess of high-frequency-derived alleles. Evol Appl 2020; 13:2254-2263. [PMID: 33005222 PMCID: PMC7513730 DOI: 10.1111/eva.12998] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 01/19/2023] Open
Abstract
Most human populations exhibit an excess of high-frequency variants, leading to a U-shaped site-frequency spectrum (uSFS). This pattern has been generally interpreted as a signature of ongoing episodes of positive selection, or as evidence for a mis-assignment of ancestral/derived allelic states, but uSFS has also been observed in populations receiving gene flow from a ghost population, in structured populations, or after range expansions. In order to better explain the prevalence of high-frequency variants in humans and other populations, we describe here which patterns of gene flow and population demography can lead to uSFS by using extensive coalescent simulations. We find that uSFS can often be observed in a population if gene flow brings a few ancestral alleles from a well-differentiated population. Gene flow can either consist in single pulses of admixture or continuous immigration, but different demographic conditions are necessary to observe uSFS in these two scenarios. Indeed, an extremely low and recent gene flow is required in the case of single admixture events, while with continuous immigration, uSFS occurs only if gene flow started recently at a high rate or if it lasted for a long time at a low rate. Overall, we find that a neutral uSFS occurs under more restrictive conditions in populations having received single pulses of gene flow than in populations exposed to continuous gene flow. We also show that the uSFS observed in human populations from the 1000 Genomes Project can easily be explained by gene flow from surrounding populations without requiring past episodes of positive selection. These results imply that uSFS should be common in non-isolated populations, such as most wild or domesticated plants and animals.
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Affiliation(s)
- Nina Marchi
- CMPGInstitute of Ecology and EvolutionUniversity of BerneBerneSwitzerland
- Swiss Institute of BioinformaticsLausanneSwitzerland
| | - Laurent Excoffier
- CMPGInstitute of Ecology and EvolutionUniversity of BerneBerneSwitzerland
- Swiss Institute of BioinformaticsLausanneSwitzerland
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53
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Ruzicka F, Dutoit L, Czuppon P, Jordan CY, Li X, Olito C, Runemark A, Svensson EI, Yazdi HP, Connallon T. The search for sexually antagonistic genes: Practical insights from studies of local adaptation and statistical genomics. Evol Lett 2020; 4:398-415. [PMID: 33014417 PMCID: PMC7523564 DOI: 10.1002/evl3.192] [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: 04/28/2020] [Revised: 07/13/2020] [Accepted: 07/28/2020] [Indexed: 12/16/2022] Open
Abstract
Sexually antagonistic (SA) genetic variation-in which alleles favored in one sex are disfavored in the other-is predicted to be common and has been documented in several animal and plant populations, yet we currently know little about its pervasiveness among species or its population genetic basis. Recent applications of genomics in studies of SA genetic variation have highlighted considerable methodological challenges to the identification and characterization of SA genes, raising questions about the feasibility of genomic approaches for inferring SA selection. The related fields of local adaptation and statistical genomics have previously dealt with similar challenges, and lessons from these disciplines can therefore help overcome current difficulties in applying genomics to study SA genetic variation. Here, we integrate theoretical and analytical concepts from local adaptation and statistical genomics research-including F ST and F IS statistics, genome-wide association studies, pedigree analyses, reciprocal transplant studies, and evolve-and-resequence experiments-to evaluate methods for identifying SA genes and genome-wide signals of SA genetic variation. We begin by developing theoretical models for between-sex F ST and F IS, including explicit null distributions for each statistic, and using them to critically evaluate putative multilocus signals of sex-specific selection in previously published datasets. We then highlight new statistics that address some of the limitations of F ST and F IS, along with applications of more direct approaches for characterizing SA genetic variation, which incorporate explicit fitness measurements. We finish by presenting practical guidelines for the validation and evolutionary analysis of candidate SA genes and discussing promising empirical systems for future work.
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Affiliation(s)
- Filip Ruzicka
- School of Biological SciencesMonash UniversityClaytonVIC 3800Australia
| | - Ludovic Dutoit
- Department of ZoologyUniversity of OtagoDunedin9054New Zealand
| | - Peter Czuppon
- Institute of Ecology and Environmental Sciences, UPEC, CNRS, IRD, INRASorbonne UniversitéParis75252France
- Center for Interdisciplinary Research in Biology, CNRS, Collège de FrancePSL Research UniversityParis75231France
| | - Crispin Y. Jordan
- School of Biomedical SciencesUniversity of EdinburghEdinburghEH8 9XDUnited Kingdom
| | - Xiang‐Yi Li
- Institute of BiologyUniversity of NeuchâtelNeuchatelCH‐2000Switzerland
| | - Colin Olito
- Department of BiologyLund UniversityLundSE‐22362Sweden
| | - Anna Runemark
- Department of BiologyLund UniversityLundSE‐22362Sweden
| | | | | | - Tim Connallon
- School of Biological SciencesMonash UniversityClaytonVIC 3800Australia
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54
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Ebert D, Fields PD. Host-parasite co-evolution and its genomic signature. Nat Rev Genet 2020; 21:754-768. [PMID: 32860017 DOI: 10.1038/s41576-020-0269-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2020] [Indexed: 01/14/2023]
Abstract
Studies in diverse biological systems have indicated that host-parasite co-evolution is responsible for the extraordinary genetic diversity seen in some genomic regions, such as major histocompatibility (MHC) genes in jawed vertebrates and resistance genes in plants. This diversity is believed to evolve under balancing selection on hosts by parasites. However, the mechanisms that link the genomic signatures in these regions to the underlying co-evolutionary process are only slowly emerging. We still lack a clear picture of the co-evolutionary concepts and of the genetic basis of the co-evolving phenotypic traits in the interacting antagonists. Emerging genomic tools that provide new options for identifying underlying genes will contribute to a fuller understanding of the co-evolutionary process.
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Affiliation(s)
- Dieter Ebert
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland. .,Wissenschaftskolleg zu Berlin, Berlin, Germany.
| | - Peter D Fields
- Department of Environmental Sciences, Zoology, University of Basel, Basel, Switzerland
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55
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Mughal MR, Koch H, Huang J, Chiaromonte F, DeGiorgio M. Learning the properties of adaptive regions with functional data analysis. PLoS Genet 2020; 16:e1008896. [PMID: 32853200 PMCID: PMC7480868 DOI: 10.1371/journal.pgen.1008896] [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: 12/13/2019] [Revised: 09/09/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022] Open
Abstract
Identifying regions of positive selection in genomic data remains a challenge in population genetics. Most current approaches rely on comparing values of summary statistics calculated in windows. We present an approach termed SURFDAWave, which translates measures of genetic diversity calculated in genomic windows to functional data. By transforming our discrete data points to be outputs of continuous functions defined over genomic space, we are able to learn the features of these functions that signify selection. This enables us to confidently identify complex modes of natural selection, including adaptive introgression. We are also able to predict important selection parameters that are responsible for shaping the inferred selection events. By applying our model to human population-genomic data, we recapitulate previously identified regions of selective sweeps, such as OCA2 in Europeans, and predict that its beneficial mutation reached a frequency of 0.02 before it swept 1,802 generations ago, a time when humans were relatively new to Europe. In addition, we identify BNC2 in Europeans as a target of adaptive introgression, and predict that it harbors a beneficial mutation that arose in an archaic human population that split from modern humans within the hypothesized modern human-Neanderthal divergence range.
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Affiliation(s)
- Mehreen R. Mughal
- Bioinformatics and Genomics at the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Hillary Koch
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Jinguo Huang
- Bioinformatics and Genomics at the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Francesca Chiaromonte
- Department of Statistics, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Michael DeGiorgio
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida, United States of America
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56
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Evolutionary origins of genomic adaptations in an invasive copepod. Nat Ecol Evol 2020; 4:1084-1094. [DOI: 10.1038/s41559-020-1201-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 04/14/2020] [Indexed: 12/18/2022]
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57
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Lundberg M, Zhong X, Konrad A, Olsen RA, Råberg L. Balancing selection in Pattern Recognition Receptor signalling pathways is associated with gene function and pleiotropy in a wild rodent. Mol Ecol 2020; 29:1990-2003. [PMID: 32374503 DOI: 10.1111/mec.15459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/20/2020] [Accepted: 04/28/2020] [Indexed: 12/13/2022]
Abstract
Pathogen-mediated balancing selection is commonly considered to play an important role in the maintenance of genetic diversity, in particular in immune genes. However, the factors that may influence which immune genes are the targets of such selection are largely unknown. To address this, here we focus on Pattern Recognition Receptor (PRR) signalling pathways, which play a key role in innate immunity. We used whole-genome resequencing data from a population of bank voles (Myodes glareolus) to test for associations between balancing selection, pleiotropy and gene function in a set of 123 PRR signalling pathway genes. To investigate the effect of gene function, we compared genes encoding (a) receptors for microbial ligands versus downstream signalling proteins, and (b) receptors recognizing components of microbial cell walls, flagella and capsids versus receptors recognizing features of microbial nucleic acids. Analyses based on the nucleotide diversity of full coding sequences showed that balancing selection primarily targeted receptor genes with a low degree of pleiotropy. Moreover, genes encoding receptors recognizing components of microbial cell walls etc. were more important targets of balancing selection than receptors recognizing nucleic acids. Tests for localized signatures of balancing selection in coding and noncoding sequences showed that such signatures were mostly located in introns, and more evenly distributed among different functional categories of PRR pathway genes. The finding that signatures of balancing selection in full coding sequences primarily occur in receptor genes, in particular those encoding receptors for components of microbial cell walls etc., is consistent with the idea that coevolution between hosts and pathogens is an important cause of balancing selection on immune genes.
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Affiliation(s)
- Max Lundberg
- Department of Biology, Lund University, Lund, Sweden
| | - Xiuqin Zhong
- Department of Biology, Lund University, Lund, Sweden
| | - Anna Konrad
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Remi-André Olsen
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Lars Råberg
- Department of Biology, Lund University, Lund, Sweden
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58
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Mathieson I. Human adaptation over the past 40,000 years. Curr Opin Genet Dev 2020; 62:97-104. [PMID: 32745952 PMCID: PMC7484260 DOI: 10.1016/j.gde.2020.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/10/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
Abstract
Over the past few years several methodological and data-driven advances have greatly improved our ability to robustly detect genomic signatures of selection in humans. New methods applied to large samples of present-day genomes provide increased power, while ancient DNA allows precise estimation of timing and tempo. However, despite these advances, we are still limited in our ability to translate these signatures into understanding about which traits were actually under selection, and why. Combining information from different populations and timescales may allow interpretation of selective sweeps. Other modes of selection have proved more difficult to detect. In particular, despite strong evidence of the polygenicity of most human traits, evidence for polygenic selection is weak, and its importance in recent human evolution remains unclear. Balancing selection and archaic introgression seem important for the maintenance of potentially adaptive immune diversity, but perhaps less so for other traits.
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Affiliation(s)
- Iain Mathieson
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, United States.
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59
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Berrio A, Haygood R, Wray GA. Identifying branch-specific positive selection throughout the regulatory genome using an appropriate proxy neutral. BMC Genomics 2020; 21:359. [PMID: 32404186 PMCID: PMC7222330 DOI: 10.1186/s12864-020-6752-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 04/21/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Adaptive changes in cis-regulatory elements are an essential component of evolution by natural selection. Identifying adaptive and functional noncoding DNA elements throughout the genome is therefore crucial for understanding the relationship between phenotype and genotype. RESULTS We used ENCODE annotations to identify appropriate proxy neutral sequences and demonstrate that the conservativeness of the test can be modulated during the filtration of reference alignments. We applied the method to noncoding Human Accelerated Elements as well as open chromatin elements previously identified in 125 human tissues and cell lines to demonstrate its utility. Then, we evaluated the impact of query region length, proxy neutral sequence length, and branch count on test sensitivity and specificity. We found that the length of the query alignment can vary between 150 bp and 1 kb without affecting the estimation of selection, while for the reference alignment, we found that a length of 3 kb is adequate for proper testing. We also simulated sequence alignments under different classes of evolution and validated our ability to distinguish positive selection from relaxation of constraint and neutral evolution. Finally, we re-confirmed that a quarter of all non-coding Human Accelerated Elements are evolving by positive selection. CONCLUSION Here, we introduce a method we called adaptiPhy, which adds significant improvements to our earlier method that tests for branch-specific directional selection in noncoding sequences. The motivation for these improvements is to provide a more sensitive and better targeted characterization of directional selection and neutral evolution across the genome.
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Affiliation(s)
- Alejandro Berrio
- Department of Biology, Duke University, Biological Sciences Building, 124 Science Drive, Durham, NC, 27708, USA.
| | - Ralph Haygood
- Ronin Institute for Independent Scholarship, 127 Haddon Pl., Montclair, NJ, 07043, USA
| | - Gregory A Wray
- Department of Biology, Duke University, Biological Sciences Building, 124 Science Drive, Durham, NC, 27708, USA
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60
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Rastogi A, Vieira FRJ, Deton-Cabanillas AF, Veluchamy A, Cantrel C, Wang G, Vanormelingen P, Bowler C, Piganeau G, Hu H, Tirichine L. A genomics approach reveals the global genetic polymorphism, structure, and functional diversity of ten accessions of the marine model diatom Phaeodactylum tricornutum. THE ISME JOURNAL 2020; 14:347-363. [PMID: 31624346 PMCID: PMC6976637 DOI: 10.1038/s41396-019-0528-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/24/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022]
Abstract
Diatoms emerged in the Mesozoic period and presently constitute one of the main primary producers in the world's ocean and are of a major economic importance. In the current study, using whole genome sequencing of ten accessions of the model diatom Phaeodactylum tricornutum, sampled at broad geospatial and temporal scales, we draw a comprehensive landscape of the genomic diversity within the species. We describe strong genetic subdivisions of the accessions into four genetic clades (A-D) with constituent populations of each clade possessing a conserved genetic and functional makeup, likely a consequence of the limited dispersal of P. tricornutum in the open ocean. We further suggest dominance of asexual reproduction across all the populations, as implied by high linkage disequilibrium. Finally, we show limited yet compelling signatures of genetic and functional convergence inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success and impact on aquatic ecosystems where they play a major role. Our work provides valuable resources for functional genomics and for exploiting the biotechnological potential of this model diatom species.
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Affiliation(s)
- Achal Rastogi
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Corteva Agriscience™, The V Ascendas, Atria Block, 12th Floor, Madhapur, Hyderabad, 500081, India
| | - Fabio Rocha Jimenez Vieira
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Anne-Flore Deton-Cabanillas
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Alaguraj Veluchamy
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Biological and Environmental Sciences and Engineering Division, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Catherine Cantrel
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China
| | - Pieter Vanormelingen
- Department of Biology, Research Group Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281/S8 9000, Gent, Belgium
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gwenael Piganeau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China.
| | - Leila Tirichine
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France.
- Université de Nantes, CNRS, UFIP, UMR 6286, F-44000, Nantes, France.
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61
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Gilbert KJ, Pouyet F, Excoffier L, Peischl S. Transition from Background Selection to Associative Overdominance Promotes Diversity in Regions of Low Recombination. Curr Biol 2019; 30:101-107.e3. [PMID: 31866368 DOI: 10.1016/j.cub.2019.11.063] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/16/2019] [Accepted: 11/21/2019] [Indexed: 12/16/2022]
Abstract
Linked selection is a major driver of genetic diversity. Selection against deleterious mutations removes linked neutral diversity (background selection [BGS]) [1], creating a positive correlation between recombination rates and genetic diversity. Purifying selection against recessive variants, however, can also lead to associative overdominance (AOD) [2, 3], due to an apparent heterozygote advantage at linked neutral loci that opposes the loss of neutral diversity by BGS. Zhao and Charlesworth [3] identified the conditions under which AOD should dominate over BGS in a single-locus model and suggested that the effect of AOD could become stronger if multiple linked deleterious variants co-segregate. We present a model describing how and under which conditions multi-locus dynamics can amplify the effects of AOD. We derive the conditions for a transition from BGS to AOD due to pseudo-overdominance [4], i.e., a form of balancing selection that maintains complementary deleterious haplotypes that mask the effect of recessive deleterious mutations. Simulations confirm these findings and show that multi-locus AOD can increase diversity in low-recombination regions much more strongly than previously appreciated. While BGS is known to drive genome-wide diversity in humans [5], the observation of a resurgence of genetic diversity in regions of very low recombination is indicative of AOD. We identify 22 such regions in the human genome consistent with multi-locus AOD. Our results demonstrate that AOD may play an important role in the evolution of low-recombination regions of many species.
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Affiliation(s)
- Kimberly J Gilbert
- Institute of Ecology and Evolution, Baltzerstrasse 6, University of Bern, 3012 Bern, Switzerland; Swiss Institute of Bioinformatics, Quartier Sorge-Batiment Amphipole, 1015 Lausanne, Switzerland.
| | - Fanny Pouyet
- Institute of Ecology and Evolution, Baltzerstrasse 6, University of Bern, 3012 Bern, Switzerland; Swiss Institute of Bioinformatics, Quartier Sorge-Batiment Amphipole, 1015 Lausanne, Switzerland
| | - Laurent Excoffier
- Institute of Ecology and Evolution, Baltzerstrasse 6, University of Bern, 3012 Bern, Switzerland; Swiss Institute of Bioinformatics, Quartier Sorge-Batiment Amphipole, 1015 Lausanne, Switzerland
| | - Stephan Peischl
- Swiss Institute of Bioinformatics, Quartier Sorge-Batiment Amphipole, 1015 Lausanne, Switzerland; Interfaculty Bioinformatics Unit, Baltzerstrasse 6, University of Bern, 3012 Bern, Switzerland
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62
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Giner-Delgado C, Villatoro S, Lerga-Jaso J, Gayà-Vidal M, Oliva M, Castellano D, Pantano L, Bitarello BD, Izquierdo D, Noguera I, Olalde I, Delprat A, Blancher A, Lalueza-Fox C, Esko T, O'Reilly PF, Andrés AM, Ferretti L, Puig M, Cáceres M. Evolutionary and functional impact of common polymorphic inversions in the human genome. Nat Commun 2019; 10:4222. [PMID: 31530810 PMCID: PMC6748972 DOI: 10.1038/s41467-019-12173-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 08/27/2019] [Indexed: 12/21/2022] Open
Abstract
Inversions are one type of structural variants linked to phenotypic differences and adaptation in multiple organisms. However, there is still very little information about polymorphic inversions in the human genome due to the difficulty of their detection. Here, we develop a new high-throughput genotyping method based on probe hybridization and amplification, and we perform a complete study of 45 common human inversions of 0.1–415 kb. Most inversions promoted by homologous recombination occur recurrently in humans and great apes and they are not tagged by SNPs. Furthermore, there is an enrichment of inversions showing signatures of positive or balancing selection, diverse functional effects, such as gene disruption and gene-expression changes, or association with phenotypic traits. Therefore, our results indicate that the genome is more dynamic than previously thought and that human inversions have important functional and evolutionary consequences, making possible to determine for the first time their contribution to complex traits. Inversions are a little-studied type of genomic variation that could contribute to phenotypic traits. Here the authors characterize 45 common polymorphic inversions in human populations and investigate their evolutionary and functional impact.
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Affiliation(s)
- Carla Giner-Delgado
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Sergi Villatoro
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Jon Lerga-Jaso
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Magdalena Gayà-Vidal
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain.,CIBIO/InBIO Research Center in Biodiversity and Genetic Resources, Universidade do Porto, Vairão, Distrito do Porto, 4485-661, Portugal
| | - Meritxell Oliva
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - David Castellano
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Lorena Pantano
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Bárbara D Bitarello
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Saxony, 04103, Germany
| | - David Izquierdo
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Isaac Noguera
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Iñigo Olalde
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Alejandra Delprat
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Antoine Blancher
- Laboratoire d'immunologie, CHU de Toulouse, IFB Hôpital Purpan, Toulouse, 31059, France.,Centre de Physiopathologie Toulouse-Purpan (CPTP), Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (Inserm), Université Paul Sabatier (UPS), Toulouse, 31024, France
| | - Carles Lalueza-Fox
- Institute of Evolutionary Biology, CSIC-Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Tõnu Esko
- Estonian Genome Center, Institute of Genomics, University of Tartu, Tartu, 51010, Estonia
| | - Paul F O'Reilly
- Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 8AF, UK
| | - Aida M Andrés
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Saxony, 04103, Germany.,UCL Genetics Institute, Department of Genetics, Evolution and Environment, University College London, London, WC1E 6BT, UK
| | - Luca Ferretti
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, OX3 7LF, UK
| | - Marta Puig
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - Mario Cáceres
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain. .,ICREA, Barcelona, 08010, Spain.
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63
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Connallon T, Chenoweth SF. Dominance reversals and the maintenance of genetic variation for fitness. PLoS Biol 2019; 17:e3000118. [PMID: 30695026 PMCID: PMC6368311 DOI: 10.1371/journal.pbio.3000118] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/08/2019] [Indexed: 01/01/2023] Open
Abstract
Antagonistic selection between different fitness components (e.g., survival versus fertility) or different types of individuals in a population (e.g., females versus males) can potentially maintain genetic diversity and thereby account for the high levels of fitness variation observed in natural populations. However, the degree to which antagonistic selection can maintain genetic variation critically depends on the dominance relations between antagonistically selected alleles in diploid individuals. Conditions for stable polymorphism of antagonistically selected alleles are narrow, particularly when selection is weak, unless the alleles exhibit "dominance reversals"-in which each allele is partially or completely dominant in selective contexts in which it is favored and recessive in contexts in which it is harmful. Although theory predicts that dominance reversals should emerge under biologically plausible conditions, evidence for dominance reversals is sparse. In this primer, we review theoretical arguments and data supporting a role for dominance reversals in the maintenance of genetic variation. We then highlight an illuminating new study by Grieshop and Arnqvist, which reports a genome-wide signal of dominance reversals between male and female fitness in seed beetles.
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Affiliation(s)
- Tim Connallon
- School of Biological Sciences and Centre for Geometric Biology, Monash University, Clayton, Australia
- * E-mail:
| | - Stephen F. Chenoweth
- School of Biological Sciences, University of Queensland, St. Lucia, Australia
- Swedish Collegium for Advanced Study, Uppsala, Sweden
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64
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Uhl GR, Martinez MJ. PTPRD: neurobiology, genetics, and initial pharmacology of a pleiotropic contributor to brain phenotypes. Ann N Y Acad Sci 2019; 1451:112-129. [PMID: 30648269 PMCID: PMC6629525 DOI: 10.1111/nyas.14002] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/12/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022]
Abstract
Receptor-type protein tyrosine phosphatase, receptor type D (PTPRD) has likely roles as a neuronal cell adhesion molecule and synaptic specifier. Interest in its neurobiology and genomics has been stimulated by results from human genetics and mouse models for phenotypes related to addiction, restless leg syndrome, neurofibrillary pathology in Alzheimer's disease, cognitive impairment/intellectual disability, mood lability, and obsessive-compulsive disorder. We review PTPRD's discovery, gene family, candidate homomeric and heteromeric binding partners, phosphatase activities, brain distribution, human genetic associations with nervous system phenotypes, and mouse model data relevant to these phenotypes. We discuss the recently reported discovery of the first small molecule inhibitor of PTPRD phosphatase, the identification of its addiction-related effects, and the implications of these findings for the PTPRD-associated brain phenotypes. In assembling PTPRD neurobiology, human genetics, and mouse genetic and pharmacological datasets, we provide a compelling picture of the roles played by PTPRD, its variation, and its potential as a target for novel therapeutics.
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Affiliation(s)
- George R Uhl
- Neurology and Research Services, New Mexico VA Healthcare System, Albuquerque, New Mexico.,Departments of Neurology, Neuroscience, Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico.,Biomedical Research Institute of New Mexico, Albuquerque, New Mexico.,Departments of Neurology, Neuroscience and Mental Health, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Maria J Martinez
- Neurology and Research Services, New Mexico VA Healthcare System, Albuquerque, New Mexico.,Biomedical Research Institute of New Mexico, Albuquerque, New Mexico
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65
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Reher D, Key FM, Andrés AM, Kelso J. Immune Gene Diversity in Archaic and Present-day Humans. Genome Biol Evol 2019; 11:232-241. [PMID: 30566634 PMCID: PMC6347564 DOI: 10.1093/gbe/evy271] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/14/2018] [Indexed: 12/19/2022] Open
Abstract
Genome-wide analyses of two Neandertals and a Denisovan have shown that these archaic humans had lower genetic heterozygosity than present-day people. A similar reduction in genetic diversity of protein-coding genes (gene diversity) was found in exome sequences of three Neandertals. Reduced gene diversity, particularly in genes involved in immunity, may have important functional consequences. In fact, it has been suggested that reduced diversity in immune genes may have contributed to Neandertal extinction. We therefore explored gene diversity in different human groups, and at different time points on the Neandertal lineage, with a particular focus on the diversity of genes involved in innate immunity and genes of the Major Histocompatibility Complex (MHC). We find that the two Neandertals and a Denisovan have similar gene diversity, all significantly lower than any present-day human. This is true across gene categories, with no gene set showing an excess decrease in diversity compared with the genome-wide average. Innate immune-related genes show a similar reduction in diversity to other genes, both in present-day and archaic humans. There is also no observable decrease in gene diversity over time in Neandertals, suggesting that there may have been no ongoing reduction in gene diversity in later Neandertals, although this needs confirmation with a larger sample size. In both archaic and present-day humans, genes with the highest levels of diversity are enriched for MHC-related functions. In fact, in archaic humans the MHC genes show evidence of having retained more diversity than genes involved only in the innate immune system.
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Affiliation(s)
- David Reher
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Felix M Key
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Aida M Andrés
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Department of Genetics, Evolution and Environment, UCL Genetics Institute, University College London, London, United Kingdom
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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66
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Abstract
Trans-species polymorphism has been widely used as a key sign of long-term balancing selection across multiple species. However, such sites are often rare in the genome and could result from mutational processes or technical artifacts. Few methods are yet available to specifically detect footprints of trans-species balancing selection without using trans-species polymorphic sites. In this study, we develop summary- and model-based approaches that are each specifically tailored to uncover regions of long-term balancing selection shared by a set of species by using genomic patterns of intraspecific polymorphism and interspecific fixed differences. We demonstrate that our trans-species statistics have substantially higher power than single-species approaches to detect footprints of trans-species balancing selection, and are robust to those that do not affect all tested species. We further apply our model-based methods to human and chimpanzee whole-genome sequencing data. In addition to the previously established major histocompatibility complex and malaria resistance-associated FREM3/GYPE regions, we also find outstanding genomic regions involved in barrier integrity and innate immunity, such as the GRIK1/CLDN17 intergenic region, and the SLC35F1 and ABCA13 genes. Our findings not only echo the significance of pathogen defense but also reveal novel candidates in maintaining balanced polymorphisms across human and chimpanzee lineages. Finally, we show that these trans-species statistics can be applied to and work well for an arbitrary number of species, and integrate them into open-source software packages for ease of use by the scientific community.
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Affiliation(s)
- Xiaoheng Cheng
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Michael DeGiorgio
- Department of Biology, Pennsylvania State University, University Park, PA
- Department of Statistics, Pennsylvania State University, University Park, PA
- Institute for CyberScience, Pennsylvania State University, University Park, PA
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67
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An Ancient Fecundability-Associated Polymorphism Creates a GATA2 Binding Site in a Distal Enhancer of HLA-F. Am J Hum Genet 2018; 103:509-521. [PMID: 30245028 DOI: 10.1016/j.ajhg.2018.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 08/17/2018] [Indexed: 12/20/2022] Open
Abstract
Variation in female reproductive traits, such as fertility, fecundity, and fecundability, are heritable in humans, but identifying and functionally characterizing genetic variants associated with these traits have been challenging. Here, we explore the functional significance and evolutionary history of a G/A polymorphism at SNP rs2523393, which is an eQTL for HLA-F and is significantly associated with fecundability (the probability of being pregnant within a single menstrual cycle). We replicated the association between the rs2523393 genotype and HLA-F expression by using GTEx data and demonstrate that HLA-F is upregulated in the endometrium during the window of implantation and by progesterone in decidual stromal cells. Next, we show that the rs2523393 A allele creates a GATA2 binding site in a progesterone-responsive distal enhancer that loops to the HLA-F promoter. Remarkably, we found that the A allele is derived in the human lineage and that the G/A polymorphism arose before the divergence of modern and archaic humans and segregates at intermediate to high frequencies across human populations. Remarkably, the derived A allele is has also been identified in a GWAS as a risk allele for multiple sclerosis. These data suggest that the polymorphism is maintained by antagonistic pleiotropy and a reproduction-health tradeoff in human evolution.
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68
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Brandt DYC, César J, Goudet J, Meyer D. The Effect of Balancing Selection on Population Differentiation: A Study with HLA Genes. G3 (BETHESDA, MD.) 2018; 8:2805-2815. [PMID: 29950428 PMCID: PMC6071603 DOI: 10.1534/g3.118.200367] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/21/2018] [Indexed: 01/10/2023]
Abstract
Balancing selection is defined as a class of selective regimes that maintain polymorphism above what is expected under neutrality. Theory predicts that balancing selection reduces population differentiation, as measured by FST. However, balancing selection regimes in which different sets of alleles are maintained in different populations could increase population differentiation. To tackle the connection between balancing selection and population differentiation, we investigated population differentiation at the HLA genes, which constitute the most striking example of balancing selection in humans. We found that population differentiation of single nucleotide polymorphisms (SNPs) at the HLA genes is on average lower than that of SNPs in other genomic regions. We show that these results require using a computation that accounts for the dependence of FST on allele frequencies. However, in pairs of closely related populations, where genome-wide differentiation is low, differentiation at HLA is higher than in other genomic regions. Such increased population differentiation at HLA genes for recently diverged population pairs was reproduced in simulations of overdominant selection, as long as the fitness of the homozygotes differs between the diverging populations. The results give insight into a possible "divergent overdominance" mechanism for the nature of balancing selection on HLA genes across human populations.
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Affiliation(s)
- Débora Y C Brandt
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Jônatas César
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Jérôme Goudet
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - Diogo Meyer
- Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, SP, Brazil
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69
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Tennessen JA. Gene buddies: linked balanced polymorphisms reinforce each other even in the absence of epistasis. PeerJ 2018; 6:e5110. [PMID: 29967750 PMCID: PMC6026533 DOI: 10.7717/peerj.5110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/05/2018] [Indexed: 01/16/2023] Open
Abstract
The fates of genetic polymorphisms maintained by balancing selection depend on evolutionary dynamics at linked sites. While coevolution across linked, epigenetically-interacting loci has been extensively explored, such supergenes may be relatively rare. However, genes harboring adaptive variation can occur in close physical proximity while generating independent effects on fitness. Here, I present a model in which two linked loci without epistasis are both under balancing selection for unrelated reasons. Using forward-time simulations, I show that recombination rate strongly influences the retention of adaptive polymorphism, especially for intermediate selection coefficients. A locus is more likely to retain adaptive variation if it is closely linked to another locus under balancing selection, even if the two loci have no interaction. Thus, two linked polymorphisms can both be retained indefinitely even when they would both be lost to drift if unlinked. While these results may be intuitive, they have important implications for genetic architecture: clusters of mutually reinforcing genes may underlie phenotypic variation in natural populations, and such genes cannot be assumed to be functionally associated. Future studies that measure selection coefficients and recombination rates among closely linked genes will be fruitful for characterizing the extent of this phenomenon.
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Affiliation(s)
- Jacob A. Tennessen
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
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