绦虫催乳素基因cDNA克隆及序列分析

根据文献报道的脊椎动物催乳素基因 c DNA序列的保守区 ,设计 1对引物。提取绦虫总 RNA,采用 RT- PCR扩增绦虫催乳素基因 ,琼脂糖凝胶电泳分析 PCR产物 ,将回收产物连接到 p MD- 18T克隆载体 ,对待选克隆进行 PCR和酶切鉴定。阳性克隆进行序列测定 ,获得全长 893bp的 c DNA序列 ,共编码 2 2 2个氨基酸 ,其中前 2 2个氨基酸为信号肽 ,成熟蛋白共编码 2 0 0个氨基酸。将测序结果与 Gen Bank中已知序列比较 ,推导氨基酸序列并进行活性位点分析 ,所得序列与脊椎动物催乳素同源性最高 ,含有催乳素的 2个活性区域 ,证明所得到的序列就是催乳素序列。

Cloning and Sequence Analysis of the Prolactin cDNA of Cestode

According to conservative domain of the published sequence of prolactin(PRL) gene of vertebrate,a pair of primers that can amplify cestode PRL gene was designed and synthesized.By RT-PCR ,a single DNA fragment of about 800 bp was obtained.After recovery from agarose gel the target DNA fragment was cloned into pMD-18T vector and sequenced,The complete nucleotide sequence is 893 bp,encoding 222 aa.OF the complete amino acid sequence,the first 22 aa is signal peptide,and mature protein has 200 aa,By comparing with published prolactin gene sequence with BLAST,the sequence showed hightest identity with PRL gene.The amino sequence has two motif which belongs to prolactin gene. These proved that the sequence we cloned is PRL gene of cestode.