Natural selection and origin of a melanistic allele in North American Gray Wolves
Pigmentation is often used to understand hownatural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In graywolves, theKlocus, aβ-defensin gen...
Published in: | Molecular Biology and Evolution |
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Main Authors: | , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2018
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Subjects: | |
Online Access: | https://vbn.aau.dk/da/publications/6e9949b1-91a2-4ae4-a10f-ce32031cf1be https://doi.org/10.1093/molbev/msy031 http://www.scopus.com/inward/record.url?scp=85052589692&partnerID=8YFLogxK https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6455901/pdf/msy031.pdf |
Summary: | Pigmentation is often used to understand hownatural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In graywolves, theKlocus, aβ-defensin gene, causes black coat color via a dominantly inherited K B allele.The allele is derived from dog-Wolf hybridization and is at high frequency in North American Wolf populations.We designed a DNA capture array to probe the geographic origin, age, andnumberof introgressionevents of the K B allele inapanel of 331wolves and20dogs.Wefound lowdiversity in K B , butnot ancestral ky,Wolfhaplotypes consistentwith a selective sweep of the black haplotype across North America. Further, North American Wolf K B haplotypes are monophyletic, suggesting that a single adaptive introgression from dogs to wolves most likely occurred in the Northwest Territories or Yukon. We use a new analytical approach to date the origin of the K B allele in Yukonwolves to between 1,598 and 7,248 years ago, suggesting that introgression with early Native American dogs was the source. Using population genetic simulations, we show that the K locus is undergoing natural selection in four Wolf populations. We find evidence for balancing selection, specifically in Yellowstonewolves, which could be a result of selection for enhanced immunity in response to distemper.With these data, we demonstrate how the spread of an adaptive variant may have occurred across a species' geographic range. |
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