SRA

Domestication leads to a spectrum of striking behavioral changes whose genetic basis remains largely unknown. Silver foxes have been selectively bred for tame and aggressive behaviors for over 50 years at the Institute for Cytology and Genetics in Novosibirsk, Russia. To further understand the genetic basis and molecular mechanisms underlying tame and aggressive behavioral phenotypes segregating in selected strains of the silver fox, we quantified genome-wide gene expression levels using RNA-seq in two selected brain tissues, right prefrontal cortex and basal forebrain, from 12 aggressive and 12 tame individuals. Expression analysis reveals 146 differentially expressed genes in prefrontal cortex between tame and aggressive individuals at a 5% FDR, and 33 hits were found in basal forebrain. These candidates include genes in key pathways known to be critical to neurological processing, such as serotonin and glutamate receptor pathways. The data relate in interesting ways to neurological and pharmacological effects that are actively being studied to understand human aggression. In addition, we identified 31,000 high quality exonic SNPs, 295 of which show significant allele frequency differences between tame and aggressive individuals at an adjust P-value < 0.05 level from gene dropping simulation based on the entire pedigrees. A non-synonymous change in a glutamate receptor, GRM3, is among these significant SNPs, indicating that expression and allele-frequency changes are hitting the same pathways. These changes in expression level and allele frequency might be the direct response to the artificial selection and will help understand the genetic basis of mammalian domestication process. Overall design: Profile of transcriptome-wide gene expression levels in 1.5-year old tame and aggressive fox brain