The Polymorphism Analysis Of α_s1-Casein And α_s2-Casein Gene In Yak

The nutritional value of yak milk casein is high, αs1-casein and αs2.casein is the main component of casein. There is widespread genetic polymorphism about CSNIS1 and CSN1S2 gene in mammals. There is a close relationship with population differentiation and regional distribution. So far, there have been more CSN1S1 geneand CSN1S2 gene polymorphism studies in Holstein cows and Cattle. However, there have been less reports on CSN1S1 gene and CSN1S2 gene polymorphism in yak. In order to reveal the yak CSNISI and CSN1S2 gene polymorphism in yak. In this paper, four breeds of yak as the research objects, respectively, Datong yak, Ganan yak, Tianzhu white yak and Pali yak. The SNPs were tested by using the method of DNA pools sequencing. HRM method was used for genotyping, in order to explore CSNISI and CSN1S2 genetic diversity in yak breeds. It provided the theory basis for the development and utilization of yak milk.1. The genetic diversity of yak CSNISI geneThere were three SNPs, respectively, T14962C, C19638T and C26201A. T14962C was in the exon 4, C19638T was in the exon 9, C26201A was in the exon 17.Chi-square test indicated that the four breeds of yak were in Hardy-Winberg imbalance in T14962C and C26201A sites, except for C19638T. Pali yak was not in Hardy-Winberg imbalance in C19638T site. Genetic polymorphism indicators showed three SNPs sites of CSN1S1 gene were under low polymorphism in most of the yak breeds. Three SNPs constructed 7 kinds of haploid type, and the frequency of CTA was the highest in four breeds of yak.2. Genetic diversity of CSN1S2 gene in YakThere were two SNPs, respectively, T6150C and G10912A. T6150C was in the exon 3, and G10912A was in the intron 11.Chi-square test indicated that the four breeds of yak were in Hardy-Winberg imbalance in G10912A site, Tianzhu white yak was not in Hardy-Winberg imbalance in T6150C site. Genetic polymorphism indicators showed two SNPs sites of CSN1S2 gene were under low polymorphism in most of the yak breeds. Two SNPs constructed 4 kinds of haploid type, and the frequency of CG was the highest in four breeds of yak.