Genomics, environment and balancing selection in behaviorally bimodal populations : the caribou case

Cavedon, M, Goubili, C, Heppenheimer, E, vonHoldt, B, Mariani, S ORCID:, Hebblewhite, M, Hegel, T, Hervieux, D, Serrouya, R, Steenweg, R, Weckworth, BV and Musiani, M 2019, 'Genomics, environment and balancing selection in behaviorally bimodal populations : the caribou case' , Molecular Ecology, 28 (8) , pp. 1946-1963.

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Selection forces that favor different phenotypes in different environments can change frequencies of genes between populations along environmental clines. Clines are also compatible with balancing forces, such as negative frequency‐dependent selection (NFDS), which maintains phenotypic polymorphisms within populations. For example, NFDS is hypothesized to maintain partial migration, a dimorphic behavioral trait prominent in species where only a fraction of the population seasonally migrates. Overall, NFDS is believed to be a common phenomenon in nature, yet, a scarcity of studies were published linking naturally occurring allelic variation with bimodal or multimodal phenotypes and balancing selection. We applied a Pool‐seq approach and detected selection on alleles associated with environmental variables along a North‐South gradient in western North American caribou, a species displaying partially migratory behavior. On 51 loci, we found a signature of balancing selection, which could be related to NFDS and ultimately the maintenance of the phenotypic polymorphisms known within these populations. Yet, remarkably, we detected directional selection on a locus when our sample was divided in two behaviorally distinctive groups regardless of geographic provenance (a subset of GPS‐collared migratory or sedentary individuals), indicating that, within populations, phenotypically homogeneous groups were genetically distinctive. Loci under selection were linked to functional genes involved in oxidative stress response, body development and taste perception. Overall, results indicated genetic differentiation along an environmental gradient of caribou populations, which we found characterized by genes potentially undergoing balancing selection. We suggest that the underlining balancing force, NFDS plays a strong role within populations harboring multiple haplotypes and phenotypes, as it is the norm in animals, plants and humans too.

Item Type: Article
Schools: Schools > School of Environment and Life Sciences > Ecosystems and Environment Research Centre
Journal or Publication Title: Molecular Ecology
Publisher: Wiley
ISSN: 0962-1083
Related URLs:
Funders: Alberta Upstream Petroleum Research Fund (AUPRF), PTAC Petroleum Technology Alliance Canada, Canadian Association of Petroleum Producers, Parks Canada, Shell, Governments of BC, Alberta and Yukon, Conoco-Phillips, Alberta Conservation Association, NSERC, Yukon Fish and Wildlife Enhancement Trust
Depositing User: Prof Stefano Mariani
Date Deposited: 20 Feb 2019 12:00
Last Modified: 16 Feb 2022 00:52

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