Cloning Of Four Fowls' Sox8 Gene Partial CDNA Sequence And Polymorphism Analysis By PCR-SSCP

The Sox gene family constitutes a group of transcription factors. All family members are characterized by possession of a specific type of DNA-binding domain-HMG box. Sox proteins have important functions both during development and in adult. One of thewell-characterized groups of Sox proteins is subgroup E. Sox8 gene is a member of the subgroop. Sox8 gene, which contains three exons and two introns, is a recently identified gene (Schepers,G.E., et al.2000) . Mutated Sox8 gene will result in some developmental defects. The deficient mice of Sox8 gene were viable and fertile. But a substantial reduction in weight was observed in these mice, especially in adipose tissue. Its reduction is likely due to changes in energy homeostasis and its regulation, such as reduced efficacy of food utilization and disproportionate energy allocation. So the study on it will have theoretical and practical significance in animal breeding.In the study, Sox8 partial cDNA sequences of four species were cloned by RT-PCR and compared the nucleotide and amino acid sequences homology of several species. The result shows that nucleotide and amino acid sequences surpasse identity of 96% and 97%, respectively. Homology analysis shows: Sox8 gene is high conservation in fowls.In addition, the seven pairs of primers for Sox8 gene were designed basing on the cDNA sequence of chiken and applied to analyze the polymorphism of chicken Sox8 cDNA among different breeds by PCR-SSCP. Two SNPs were identified in the chicken Sox8 gene and sequenced. The result shows that there are two mutations in exon 3 (786C→T 和 1350G →A) , but the two mutant sites didn't result in change of amino acid. Statistical analysis indicates that frequency of allele A is higher in broilers than layers. There is a trend that distribution of allele A is positively relative to fat character.