Meeting Abstract

11.1  Friday, Jan. 4  Genetic accommodation and behavioral evolution: insights from genomic studies RENN, S.C.P.; Reed College, Portland renns@reed.edu

We know that gene expression level, a first order phenotype, underlies much behavioral variation. Using a genomic approach we can ask “how many and which genes show expression level variation related to plastic behaviors?” and “how many and which genes show expression level variation related to evolved changes in behavior?”. Our model system includes two closely related species of African cichlid fishes. Jullidocromis transcriptus, exhibits “conventional” sex-biases in behavior such that the larger male provides territory defense while the smaller female provides nest care whereas J. marlieri naturally pair in the reverse size ratio, and exhibits a reversal of behavioral roles. In both species, there is plasticity, such that behavioral patterns can be experimentally manipulated by controlling the relative size of the male and female in the pair. By examining gene expression in this system and borrowing terminology from the field of phenotypic plasticity, we characterize changes in gene expression level according to the concept of a norm of reaction and describe the various patterns of gene regulation evolution that accompany the evolution of behavioral plasticity. It is interesting to see the extent to which norms of reaction for evolved gene expression parallel the norms of reaction for the behavioral phenotypes they orchestrate.