番鸭催乳素基因的克隆与序列分析

为探明番鸭的遗传分化,以番鸭脑垂体的总RNA为模板,用反转录—聚合酶链式反应(RT-PCR)方法扩增了含有催乳素(PRL)基因的DNA片段,将其克隆到pMD18-T载体上并进行了序列分析.结果表明,番鸭PRL基因由765 bp组成,编码229个氨基酸;与已报道的北京鸭、马岗鹅、皖西白鹅、莱茵鹅、家鸡、火鸡、鹌鹑等禽类PRL基因相比,PRL基因的核苷酸和氨基酸序列同源性为91.0%-99.0%和98.3%-99.1%.说明PRL基因在进化过程中相当保守.番鸭PRL基因氨基酸序列与北京鸭比较两者并没有太大差别,仅在第9(K/E)、176(V/I)、194位(K/I)各有一个突变,可以推测这两者之间就巢性的差异可能与PRL的结构关系不大;但与家鸡的氨基酸序列差异则较大.

Cloning and sequence analysis of prolactin gene from muscovy duck

The prolactin(PRL) coding region of muscovy duck was amplified from the extracted total RNA of anterior pituitary gland by using RT-PCR,cloned into the pMD18-T vector,and sequenced.The results indicated that the PRL coding region comprised 765 nucleotides and encoded a putative protein of 229 amino acids.The nucleotide and the putative amino acid of PRL gene were compared with other birds,such as Peking duck,Magang goose,Wanxi white goose,Rhine goose,chicken,turkey and quail,it shares 91.0%-99.0% and 98.3%-99.1% homology in nucleotide and putative amino acid sequence respectively.It is proved that PRL gene in birds was considerably conserved in the process of evolution;the amino acid sequence of PRL gene in muscovy duck had insignificant or no difference from that in Peking duck;and it is inferred that the variation in broodiness of these two kinds of ducks has little relation to the structure of PRL,but the difference is relatively significant as compared to chicken.