Highly Conserved Keratin-Associated Protein 7-1 Gene in Yak, Taurine, and Zebu Cattle

In a 2017 study, researchers investigated the genetic polymorphisms of the bovine Keratin-associated protein 7-1 (KRTAP7-1) gene in 108 domestic yak, taurine, and zebu cattle from China and Indonesia. They found only two single-nucleotide polymorphisms and three haplotypes within the KRTAP7-1 gene across all animals. No polymorphism was observed in three Chinese yak breeds and one Indonesian zebu cattle population, which all shared the same haplotype (BOVIN-KRTAP7-1*A). This haplotype was also the most common among four taurine cattle populations, with a frequency of 0.80. The novel haplotype BOVIN-KRTAP7-1*B was rare, found in only one heterozygous animal in each taurine population, while BOVIN-KRTAP7-1*C was found in Simmental and Chinese Yellow cattle populations with frequencies of 0.17 and 0.36, respectively. The study concluded that the yak KRTAP7-1 gene is monomorphic and, along with the highly conserved KRTAP7-1 genes in bovine, sheep, and goat, is likely important for the mechanical strength and shape of hair due to its unique structural properties, such as a high glycine content.