LANZHOU -- A recent research conducted by Chinese scientists has found that approximately 90 percent of domestic yaks exhibit fixed genetic introgression of allelic structural variations derived from cattle.

This hybridized introgression has led to the emergence of a new phenotype known as the white yak, which is characterized by novel genetic mutations from such an introgression.

"Approximately 7,300 years ago, the inhabitants of the Qinghai-Tibet Plateau successfully domesticated wild yaks, marking the origins of domestic yaks," said Liu Jianquan, a professor at the College of Ecology, Lanzhou University.

According to the expert, around 4,000 years ago, humans domesticated wild aurochs in India and the Fertile Crescent, which subsequently gave rise to cattle. These cattle were later introduced to the Qinghai-Tibet Plateau.

Liu's research team, in collaboration with experts such as Yan Ping, a researcher at the Lanzhou Institute of Husbandry and Pharmaceutical Sciences of the Chinese Academy of Agricultural Sciences, collected materials from various yak breeds, as well as wild yaks and other related species, over a span of three decades. This extensive collection facilitated their comprehensive study.

The study revealed that nearly 90 percent of domestic yaks possess genomic structural variations that are specific to cattle. The introduction of cattle to the Qinghai-Tibet Plateau by humans resulted in hybridization between domestic yaks and cattle. The color-sided yaks acquired corresponding variants from color-sided cattle, leading to the development of new mutations responsible for the emergence of white yaks.

The research findings were published on Sept 19 in Nature Communications, an international academic journal.