中文摘要：

催乳素基因 （ＰＲＬ）第 ３外显子 （ｅｘｏｎ３）对奶牛产奶量、乳脂产量和乳蛋白产量有显著影响，但在水牛中该基因的遗传特征及其与产奶性状是否有遗传关联目前还不清楚。本研究采用 ＰＣＲ ＳＳＣＰ并结合 ＰＣＲ产物直接测序技术，分析了沼泽型水牛和河流型水牛共 １２个群体 ２７５个个体 ＰＲＬｅｘｏｎ３的遗传变异，结果表明：水牛 ＰＲＬｅｘｏｎ３由 １０８个核苷酸组成，编码 ３６个氨基酸，在水牛群体中未检测到单核苷酸多态性位点（ＳＮＰｓ），ＰＲＬｅｘｏｎ３与水牛产奶量之间没有直接相关性。通过序列比对发现在不同物种中 ＰＲＬｅｘｏｎ３具有高度保守性。但在 ＰＲＬ第 ２内含子 （ｉｎｔｒｏｎ２）的 ２２６５ｎｔ和 ２３３５ｎｔ分别检测到 Ｇ＞Ａ突变和 Ｃ＞Ｔ突变，其中２３３５ｎｔ位点突变仅在 ２头槟榔江水牛中检测到。

英文摘要：

The exon 3 of prolactin gene had significant effect on yield of milk, milk fat and milk protein in cow, but the genetic characteristics and the relevance between milk production traits and gene mutation on the exon 3 of prolaetin gene in water buffalo are unclear. In the present study, the sequence features of the exon 3 in prolactin gene were examined in 275 individuals which came from 12 river and swamp type buffalo populations using PCR-SSCP and PCR production direct sequencing methods. The results showed that the sequence of exon 3 in prolactin gene was consists of 108 nucleotides, and the sequence coding for 36 amino acid residues, the SNPs loci wasn＇t detected in water buffalo, so there was irrelevance between milk yield traits and the exon 3 of prolactin gene in water buffalo. The fragment had high conservative character in different species by sequences alignment. Two substitution was detected in intron 2 of prolactin gene, one is G 〉 A substitution at the 2 265 th nucleo- tide and another is C 〉 T substitution at the 2 335 th nucleotide. Moreover, the C 〉 T substitution at the 2 335 th nucleotide was only detected in 2 Binlangjiang water buffaloes.