Genetic Architecture of Variation in Growth and Feeding-Related Traits in Rainbow Trout (Oncorhynchus mykiss) Chronically Exposed to Warmer Water Temperatures

Abstract

I characterized the genetic architecture of growth- and feeding-related traits as indicators of animal performance in rainbow trout exposed to atypical (warmer) temperatures over a chronic timescale (64 days). Most of the single nucleotide polymorphisms (SNPs) associated with variation in weight specific growth rate (adjusted for initial body weight) (WSGR-adjusted) were located on two chromosomes, Omy05 and Omy20, based on the genome wide association analysis. Candidate gene analysis identified 2125 unique rainbow trout genes located within 100kb of significant SNPs. Ontology analysis for the biological processes of these genes revealed assignments to neurotransmission, cellular processes, cell structure, signalling, and development. Analysis of feeding-related traits detected fewer significant SNPs, but the associated genes were characterized by similar biological processes as WSGR-adjusted. My results suggest that the genetic variants for growth rate identified here could be used to improve the performance of Ontario rainbow trout exposed to heightened summer temperatures.

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Keywords

GWAS, rainbow trout, genetic architecture, chronic, Oncorhynchus mykiss, thermal

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