Abstract

The domestication of animals has generated a set of phenotypic modifications, affecting behaviour, appearance, physiology and reproduction, which are consistent across a range of species. We hypothesized that some of these phenotypes could have evolved because of genetic correlation to tameness, an essential trait for successful domestication. Starting from an outbred population of red junglefowl, ancestor of all domestic chickens, we selected birds for either high or low fear of humans for five generations. Birds from the fifth selected generation (S-5) showed a divergent pattern of growth and reproduction, where low fear chickens grew larger and produced larger offspring. To examine underlying genetic mechanisms, we used microarrays to study gene expression in thalamus/hypothalamus, a brain region involved in fear and stress, in both the parental generation and the S-5. While parents of the selection lines did not show any differentially expressed genes, there were a total of 33 genes with adjusted p-values below 0.1 in S-5. These were mainly related to sperm-function, immunological functions, with only a few known to be relevant to behaviour. Hence, five generations of divergent selection for fear of humans produced changes in hypothalamic gene expression profiles related to pathways associated with male reproduction and to immunology. This may be linked

Keywords

artificial selection; gene expression; microarray; chicken; fearfulness

Published in

Royal Society Open Science
2016, Volume: 3, number: 8

Associated SLU-program

Centre of Excellence in Animal Welfare Science


UKÄ Subject classification

Genetics


Publication identifier

DOI: https://doi.org/10.1098/rsos.160033

Permanent link to this page (URI)

https://res.slu.se/id/publ/86701