Detection of β-casein variants in yak ( Bos grunniens) by PCR-SSCP.

The aim of this study was to investigate diversity of the β-casein gene in Maiwa yak. A polymorphism of β-casein gene exon VII has been identified in Chinese Maiwa yak by PCR-single-strand conformation polymorphism protocol. Two new variants have been identified in Maiwa yak by resequencing analysis and entered into GenBank with accession numbers JN655524 and JN655525. Comparing the X14711 sequence, the new variant JN655524 consists of 4 single nucleotide mutations at position 66, 74, 234 and 385 of the exon VII of CSN2 gene, resulting in three synonymous mutations and a non-synonymous mutation (codon 67 His/Pro). Compared with JN655524, the new variant JN655525 showed a nucleotide difference in position number 193 in exon VII of CSN2 gene. The new variants may be helpful for future studies on genetic variation within and between yak populations or on associated traits. [ABSTRACT FROM AUTHOR]