A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals

http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002962

When I wrote NOT A CHIMP, Frank Albert, at the Max Planck Institute for Evolutionary Anthropology, was just beginning to cross rats to produce a violently feral strain and a docile, more domesticated behavioural variant. He hoped to be able to find genes that underlie these traits and, eventually, to compare genes that seem important in, say, rat domestication, with genes important in domesticated traits in other species. Is there a universal genetic foundation for domestication throughout the animal kingdom? Here, in this open access PLoS Genetics paper, he presents his results for rats, compared with wild and domesticated representatives from a range of species. "We used mRNA sequencing to analyze genome-wide gene expression patterns in brain frontal cortex in three pairs of domesticated and wild species (dogs and wolves, pigs and wild boars, and domesticated and wild rabbits). We compared the expression differences with those between domesticated guinea pigs and a distant wild relative (Cavia aperea) as well as between two lines of rats selected for tameness or aggression towards humans."

Unfortunately there was no evidence at all for such universal genetics: "There were few gene expression differences between domesticated and wild dogs, pigs, and rabbits (30–75 genes (less than 1%) of expressed genes were differentially expressed), while guinea pigs and C. aperea differed more strongly. Almost no overlap was found between the genes with differential expression in the different domestication events. In addition, joint analyses of all domesticated and wild samples provided only suggestive evidence for the existence of a small group of genes that changed their expression in a similar fashion in different domesticated species."

He concludes: "In summary, the majority of brain gene expression changes in domesticated animals are specific to the given domestication event, suggesting that the causative variants of behavioral domestication traits may likewise be different."