Abstract: 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.

Key words: sheep; Lin28; sequence analysis