Genomic responses to selection for tame/aggressive behaviors in the silver fox (Vulpes vulpes)

Animal domestications have led to a shared spectrum of striking behavioral and morphological changes. To recapitulate this process, silver foxes have been selectively bred for tame and aggressive behaviors for over 50 generations at the Institute for Cytology and Genetics in Novosibirsk, Russia. To understand the genetic basis and molecular mechanisms underlying the phenotypic changes, we profiled gene expression level and coding SNP allele frequencies in two brain tissues from 12 aggressive and 12 tame foxes. Expression analysis revealed 146 genes in prefrontal cortex and 33 genes in basal forebrain that were differentially expressed (5% FDR). These candidates include genes in key pathways known to be critical to neurological processing, including the serotonin and glutamate receptor pathways. In addition, 295 of the 31,000 exonic SNPs show significant allele frequency differences between tame and aggressive population (1% FDR), including genes with a role in neural crest cell fate determination.