Polymorphisms in MX2 Gene Are Related with SCS in Chinese Dairy Cows.

Viral infections can play direct or indirect roles in the etiology of the bovine mastitis. Mx dynamin-like GTPase 2 (MX2) gene is a main effector of the antiviral innate immune defense mediated by type I interferon (IFN I), which was demonstrated to confer positive antiviral responses to many viruses. Given the importance of the MX2 in modulating the host immune response, MX2 gene may be a suitable candidate gene for studying disease resistance in dairy cattle. Here, we scanned the sequence variation of the MX2 gene in Chinese indigenous cattle breeds. Twenty-three previously reported SNPs were identified. To further analyze the effects of SNPs detected on mastitis disease, analysis of two SNPs (g.787527 C > T and g.787610 T > C) from 297 Chinese Holstein cows revealed a significant association with somatic cell score (SCS). Although functional studies are necessary to ascertain whether these two SNPs are causal polymorphisms or merely in linkage with the true causal SNPs, implementation of these two SNPs as genetic markers in the dairy industry may be beneficial in selecting individuals with lower SCS.