SD大鼠EGF基因cDNA序列的分子克隆

参考大鼠EGF基因序列,用PCR方法对SD大鼠EGF基因cDNA序列进行了克隆,获得了SD大鼠EGF基因的3 522bp的cDNA序列（GenBank登录号：JX149564）,其中CDS长度为3 186bp,编码了1 061个氨基酸。SD大鼠与国外报道的大鼠、小鼠、原鸡、猕猴、人等5个物种的EGF基因cDNA序列的同源性分别为97.6%、83.4%、59.7%、76.4%、73.5%,其编码蛋白的氨基酸序列同源性分别为99.2%、80.1%、52.6%、69.7%、69.4%。这一结果表明了EGF基因在进化过程中具有一定的保守性,但不同物种之间也具有特异性。通过比较SD大鼠EGF基因与GenBank数据库中发布的EGF基因的cDNA序列,本试验发现了22个SNP位点,其中9个没有改变氨基酸残基的性质,这一研究结果为EGF基因的SNPs数据库提供了新的信息。

Molecular cloning of cDNA sequences encoding EGF gene in the SD rats

This study was designed to clone and analyze the cDNA encoding EGF from SD rats.The PCR method was developed to clone the EGF cDNA.A full-length cDNA and CDS sequences of SD rat were 3522bp and 3186 bp,which have been accepted by GenBank（Accession Number：JX149564）.EGF protein encoded by this gene was composed of 1 061 amino acid residues.The identities of cDNA sequences of EGF gene were 97.6%,83.4%,59.7%,76.4% and 73.5% by homologous comparison among SD rat and other species,and in amino acid sequences were 99.2%,80.1%,52.6%,69.7% and 69.4%,respectively.The result suggested a certain degree of conservation of the EGF gene among different mammalian taxons,but there were some specificity among different mammalian taxons.The results derived from information searching by Blast program revealed there were 22 SNP sites in the sequences of EGF gene cDNA between SD rats and that collected in GenBank.Nine of 22 SNP sites did not alter the related amino acids encoded.The results provided new data for SNPs in EGF gene.