猪乳脂肪球表面因子8的克隆与表达分布

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1296bp，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。

Cloning and Sequence Analysis of Sus scrofa MFGE8

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.