An international team of researchers has delved into the genomes of foxes that were bred for tameness or for aggressiveness to find more than a hundred genomic regions affected by that breeding, the Washington Post reports.
In the late 1950s, scientists in the Soviet Union started a long-term selective breeding program known as the 'farm-fox experiment,' in which friendly foxes were chosen for breeding and began to exhibit changes to their appearances, the Post adds. The scientists later also bred aggressive foxes.
As they report in Nature Ecology and Evolution, the researchers sequenced the red fox genome and then compared the genomes of those tame and aggressive foxes to those of conventional farm-bred foxes. They uncovered 103 regions with either decreased heterozygosity in one of those groups or increased divergence between them. They also highlighted the SorCS1 gene, which encodes a protein that mediates intracellular protein trafficking and sorting, as a candidate gene for tameness.
"We're interested to see what are the genes that make such a big difference in behavior. There are not so many animal models which are good to study genetics of social behavior, and in these foxes it's such a big difference between tame foxes compared to conventional foxes, and those selected for aggressive behavior," first author Anna Kukekova from the University of Illinois at Urbana-Champaign tells the Post.