中文摘要：

为了初步探讨牦牛RGs2基因的结构和功能，试验采用RT—PCR方法及TA克隆法得到麦洼牦牛RGS2基因，并运用不同的生物信息学软件对序列进行分析。结果表明：牦牛RGS2基因系列含1个540bp的开放阅读框，共编码178个氨基酸，GenBank数据库中登录号为FJ786041。编码Phe的密码子UUU、编码Leu的密码子UUG、编码IIe的密码子AUU等20种密码子为该基因的偏好性密码子，确定的27种最优密码子均以G或c结尾。RGS2氨基酸序列与普通牛、绵羊、山羊相似性分别为99．5％、96．3％、96．1％。系统发育树上，牦牛与普通牛聚在一起，亲缘关系最近。

英文摘要：

To preliminarily study the structure and function of yak RGS2 gene, the RGS2 gene in Maiwa yak was obtained by the methods of RT - PCR and TA cloning. The RGS2 gene sequence was analyzed with various bioinformatics softwares. The results showed that the RGS2 gene sequence in Maiwa yak contained an open reading frame （ORF） of 540 bp, encoding for a protein of 178 amino acids. Its accession num- ber in GenBank database was FJ786041. Codon preference analysis showed that the codon UUU in the encoding Phe, codon UUG in the enco- ding Leu, eodon AUU in the encoding He, and other 20 kinds of codons were the preference codons for the RGS2 gene. The endings of 27 kinds of the determined optimal codons were in C or G. The similarities of RGS2 amino sequence in the Maiwa yak with Bos taurus, Ovis aries, and Capra hireus were determined as 99.5%, 96.3%, and 96.1%, respectively. Phylogenetic analysis indicated that Bos grunniens gathered to- gether with Bos taurus, ：there was a closest genetic relationship between them.