Genome Wide Association Mapping of Quantitative Genetic Variation in a Pedigreed Wild Population of Coho Salmon

Researchers have increasingly relied on molecular based pedigrees of wild individuals in effort to understand the relationship between population productivity and evolutionary processes. For example, measures of inbreeding can be related to survivorship, or fitness to recruitment success. Many evolutionary based approaches depend on estimates of the genetic diversity underlying fitness related traits, but this task is complicated by the fact they are typically encoded by several loci that interact with each other and the environment. Next-generation sequencing technologies provide a means of typing a large number of genetic markers, thus permitting population level surveys of the genome in an effort to identify the quantitative trait loci involved in fitness traits. Their identification allows, in turn, an evaluation of their relative contribution to trait variation in a wild population, and an examination of locus-specific responses to evolutionary processes. We have been studying selection, quantitative genetic variation and response to selection in a pedigreed wild population of coho salmon Oncorhynchus kisutch in Puget Sound in the Pacific Northwest of the USA. Here, we describe the results of association mapping of quantitative trait loci in this population, provide details on key parameters used to study evolution at such loci, and examine estimates of the effect of selection on these loci.  Studies such as this have significant potential to contribute to an understanding of the links between ecological and evolutionary processes in wild populations, and thus the importance of monitoring genetic diversity in the long term.