Characterization of Alleles Associated with White Spotting in North American Domestic Yaks (Bos grunniens)

Domestic yaks (Bos grunniens) have been present in North America for over 100 years and are thought to descend from an importation of six yaks of Chinese origin from England to Canada in 1909 and from additional individuals imported as zoo exhibits. There has been essentially no gene flow between this population (currently around 5000 head) and the much larger population in China and India (numbering over 14 million animals). Their popularity as farmed animals for meat, fiber, milk, and trekking is increasing in the United States and Canada, where multiple coat color phenotypes exist, including “royal”, which is black and white piebald. Serial translocations generating copy number variation involving the KIT locus found to be associated with color sidedness in cattle have been documented in (Chinese) yaks. These translocation alleles are thought to have been introduced into the yak via historic hybridization events with cattle. This study explores these translocation alleles (on chromosomes 6 and 29) in North American yaks using whole genome sequence data from royal and solid-colored yaks and targeted PCR analysis. North American yaks may have a different history with cattle than Chinese yaks, which may be reflected in their genomes.