香猪SRY基因的克隆及序列分析

试验参照猪SRY基因保守序列设计了1对引物，对香猪基因组DNA进行PCR扩增。将扩增产物通过T—A互补法克隆到质粒pGEM—T载体中，筛选阳性克隆进行DNA测序。测序结果显示，香猪SRY基因开放阅读框全长627bp，编码227个氨基酸。其中核心区域HMG—box长237bp，并且编码79个氨基酸。与白鲸、人、牛、绵羊4种哺乳动物的SRY基因序列相比较，香猪和白鲸的SRY序列具有较高的相似性，相似度达82．1％。序列相似性和邻接法聚类树的结果均显示，在SRY基因中香猪和白鲸有着较近的亲缘关系，表明以白鲸为代表的鲸目和以香猪为代表的偶蹄目有较近的亲缘关系。

Cloning and Sequence Analysis of SRY Gene from Xiang-pig

SRY gene is the sex determining region in mammalian animal. In this study, the SRY gene of Xiang pig was determined by using PCR with a pair of primers according to the conserved SRY sequence of other reported pig breeds. The PCR product was cloned into the pGEM - T vector using T - A clone method and positive clone was sequenced. The sequenced result showed the ORF of SRY gene of Xaing - pig breed was 627 bp which encoded 272 amino acids and the HMG - box was 237 bp which encoded 79 amino acids. Comparing with Beluga whale, Bos Taunts, Homo, Ovis aries four mammals, the SRY gene sequence of Xiang - pig breed had a high similarity with Beluga whale （ 82.1% ）. Both of the sequence similarity and NJ phylogenic tree revealed Xiang - pig breed had a close relationship with Beluga whale, which consistent with the viewpoint that artiodactyla had a closer relationship with cetacean.