Meeting Abstract

62.4  Jan. 7  Variation in gene expression among the brains of behaviorally distinct zebrafish strains: no evidence for parallel transcriptome evolution during domestication. ROBISON, B.D.*; DREW, R.E.; SETTLES, M.; CHURCHILL, E.; MORETZ, J.; MARTINS, E.P.; University of Idaho; University of Idaho; University of Idaho; University of Idaho; Indiana University; Indiana University brobison@uidaho.edu

Fearfulness and anxiety are often reduced in animals that have undergone prolonged bouts of captivity. This pattern is repeatedly observed across vertebrate taxa, strongly suggesting that the evolution of reduced fearfulness during domestication is an example of parallel evolution. However, it remains unclear whether these parallel patterns of behavioral evolution at the phenotypic level reflect common patterns of molecular evolution. We examined four behaviorally distinct zebrafish strains, two recently derived from wild populations and two from highly domesticated laboratory populations. The strains showed a dichotomy of behavior for several measures of fearfulness, with the wild strains exhibiting more fear-like behavior than the domesticated strains. In contrast, aggressive behaviors did not show patterns of parallel evolution during domestication, although there were significant differences among the strains. We then used Affymetrix microarrays to examine the patterns of brain gene expression in the four strains to test the hypothesis that convergent patterns of gene expression underlie convergent patterns of fear-like behaviors. Overall, 1316 genes showed significant variation in expression among strains (i.e. showed a significant main effect of strain), and many differentially expressed genes were candidate genes influencing behavior in other model species. However, only a small fraction of the genes (37) were differentially expressed between wild and domesticated strains, indicating the potential for different molecular mechanisms underlying parallel evolution of behavioral phenotypes.