绵羊Lin28基因编码区克隆与序列分析

为研究绵羊Lin28基因的功能,探讨其在绵羊体细胞重编程中的作用,本研究参照GenBank上小鼠、猪、牛和人的Lin28基因mRNA序列的保守区设计简并引物,Trizol法提取100 d左右胎绵羊肠组织总RNA,RT-PCR扩增Lin28基因编码区(CDS)序列,利用生物信息学软件DNAMAN、BioEdit和在线软件NCBI BLASTn、PlantsP和ScanProsite等分别进行核苷酸和推导的氨基酸序列比对,构建进化树,分析蛋白功能结构域并推测氨基酸序列的三维结构。结果显示,绵羊CDS区为包括终止密码子在内的630 bp,编码209个氨基酸。同源性分析结果表明,其与爪蟾、斑马鱼、鸡、牛、马、猫、猪、人、大鼠和小鼠的核苷酸序列同源性分别为53.8%、55.2%、70.2%、88.3%、88.7%、89.2%、89.5%、90.5%、95.9%和98.9%;氨基酸序列同源性分别为76.5%、67.9%、93.2%、99.3%、97.7%、99.3%、99.3%、98.5%、99.3%和100.0%。生物信息学分析显示,绵羊Lin28蛋白含有2个CCHC型的锌指结构和1个冷休克结构域。结果表明,本试验成功克隆Lin28基因的编码区,为进一步研究Lin28基因的功能及探讨其在绵羊体细胞重编程中的作用奠定基础。

Cloning and Sequence Analysis of Lin28 Gene Coding Region from Sheep

The assay was aimed to study the function of Lin28 gene of sheep,in this study,according to the Lin28 gene mRNA sequence of mice,pigs,cattles and human in GenBank,the degenerate primer was designed.Total RNA was extracted by Trizol from intestine of 100 d sheep embro,and CDS sequence of the gene was amplified by RT-PCR using the primer.Using a series of bio-software such as DNAMAN,BioEdit and NCBI BLASTn,PlantsP,ScanProsite online and so on,we analyzed the homologies between nucleotide and deduced amino acid sequences,constructed phylogenetic tree,analyzed protein functional domains and deduced three-dimensional structure of amino acid sequence.The results showed that the sequence of sheep Lin28's CDS including stop codon,was in a length of 630 bp,encoded 209 amino acids.Analysis of homology showed that sheep Lin28 gene also shared 53.8%,55.2%,70.2%,88.3%,88.7%,89.2%,89.5%,90.5%,95.9% and 98.9% nucleotide homologies and 76.5%,67.9%,93.2%,99.3%,97.7%,99.3%,99.3%,98.5%,99.3% and 100.0% amino acid identities with Xenopus laevis,Danio rerio,Gallus gallus,Bos taurus,Equus caballus,Felis catus,Sus scrofa,Homo sapiens,Rattus norvegicus and Mus musculus,respectively.Two zinc finger domains and one cold shock domain could be found by bioinformatics analyzing.The successful cloning of Lin28 revealed that the gene in the structure and function was very conservative and helpful to study gene function and its role in somatic reprogramming in future.