猪乳脂肪球表面因子8的克隆与表达分布

Cloning and Sequence Analysis of Sus scrofa MFGE8

基于电子延伸序列,本试验成功克隆了猪乳脂肪球表面因子8(MFGE8)基因(GenBank登录号:EU559724)并进行了序列分析,同时利用RT-PCR方法分析了MFGE8基因的组织分布规律。序列分析结果表明MFGE8开放读码框全长为1296 bp,编码431个氨基酸残基的多肽链,克隆的MFGE8基因与人、大鼠、小鼠、牛的同源性分别为71.9%、78.7%、79.1%、87.7%,推测的氨基酸序列的同源性分别为65.7%、74.0%、74.0%、84.5%。氨基酸序列N端含有Notch样"EGF"结构,C端含有FA58C结构域。构建的系统发育树显示猪与牛的亲缘关系最近。组织表达分析结果表明MFGE8在乳腺中表达最高,在大脑中表达量最低。

The coding sequence of Sus scrofa MFGE8 （GenBank accession No： EU559724） is amplified based on the in silico sequence information and its expression profile is researched with semi - quantitative RT - PCR method. Sequence analyses show that the full ORF is 1296 bp, encoding a polypeptide of 431 amino acids. Identity analysis shows that the Sus scrofa MFGE8 nucleotide sequence shares 71.9%, 78.7%, 79.1% and 87.7%, the deduced protein sequence shares 65.7%, 74.0%, 74.0% and 84.5% homology with that of human, rat, mouse and cattle, respectively. The deduced peptide contains N - terminal Notch - like EGF domain and the EGF - like domains are followed by two discoidinlike Factor 5/Factor 8 domains. The phylogenetic tree demonstrates that pig is the closest to cattle. Semi - quantitative RT - PCR analyses show that the expression level of MFGE8 is the highest in mammary and the lowest in cerebrum.