The distribution of a missense mutation in SDK1 gene across native Chinese breeds

Sidekick cell adhesion molecule 1 (SDK1) gene belonging to the immunoglobulin superfamily (IgSF) is reported to be associated with disease resistance. A novel missense mutation (XM_015469413.1: c.2678 A > G: p. Asp893Gly) in bovine SDK1 gene was observed in the Bovine Genome Variation Database (BGVD). The purpose of the current study was to determine the allelic frequency distribution of XM_015469413.1: c.2678 A > G: p. Asp893Gly and analyze its association with disease resistance in native Chinese cattle. Here, we explored the allele frequency of the missense mutation (M_015469413.1: c.2678 A > G: p. Asp893Gly) in 542 individuals from 27 Chinese indigenous cattle breeds using PCR and DNA sequencing methods. The frequency of the mutant allele (G) gradually decreased from the southern cattle groups to the northern cattle groups, whereas the frequency of the wild-type allele A showed an opposite pattern, consistent with the distribution of indicine and taurine cattle in China. Thus, our results proved that the bovine SDK1 gene might be candidate genes associated with disease resistance in Chinese cattle.