Date of Award

2013

Degree Type

Thesis

Degree Name

M.Sc.

Department

Great Lakes Institute for Environmental Research

Keywords

Biological sciences, Common garden, Genetic architecture, Maternal effects, Outbreeding depression, Transcription, Oncorhynchus tshawytscha

Rights

CC BY-NC-ND 4.0

Abstract

Chinook salmon ( Oncorhynchus tshawytscha ) life history provides an excellent opportunity to study the molecular mechanisms of selective divergence. I analyzed gene transcription in Chinook salmon that were created in a replicated North Carolina II breeding design to estimate quantitative genetic parameters that contributed to among-population variation in gene expression. Following Fischer's fundamental theorem, transcriptional variation of many genes was due to additive effects. However, a surprising number of genes exhibited non-additive genetic and maternal effects on transcription, and these effects may explain the high potential for rapid population-level evolution in salmon. Indeed, populations differed substantially in gene transcription. Pervasive non-additive gene expression raises concerns for conservation strategies that result in intraspecific hybridization. I document extensive amounts of reciprocal hybrid disagreement in gene transcription, indicative of breakdown of gene expression regulation complexes that are likely co-adapted. Anomalous hybrid gene transcription warrants caution for conservation strategies that employ mixing natural stocks.

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