Studies On The Sox And DMRT Gene Of Alligator Sinensis

This paper consists of two parts,which are as follows:PART ONE: reviews1. The discovery,characteristic and function of Sox genes were discussed. Sox genes encode a group of proteins that carry a DNA-binding HMG domain. In various phages of embryonic development, Sox genes play a key role in sex-determining and in organism formation.2. The findings and function of DMRT gene were reviewed. DMRT genes are a kind of transcription factor which possesses a common motif called the DM domain. DMRT genes are considered to be involved in sex determination and sex differentiation.3. The interaction between Sox genes and DMRT genes in sex determining and sex differentiation was discussed.PART TWO: studies1. After a pair of degenerate primers based on the conservative region, HMG-box,of Human SRY gene were used, eight different fragments were amplified from both female and male Alligator sinensis whose length were all 216bp, then they were cloned by pUCm-T Vector and sequenced.The result indicated that they showed high homology to Human SOX genes, the identities to Human SOX genes in the DNA sequence and the amino acid sequence were 88%,88%,88%,89%,87%,93%,87%,93% and 91%,91%,91%,96%,100%,98%,94%,96%, respectively, which may be concluded that Sox genes were highly conservative in phylogenesis.2. The DMRT1 gene of Alligator sinensis was amplified by using a pair of special primers which can amplify the conservative motif (DM domain) of human DMRT1 gene,and then it was sequenced. The length of amplification was 140bp in both male and female, which was consistent with that of human DMRT1 gene.The result of SSCP analysis showed that there were many differences in the DMRT1 gene sequence between Alligator sinensis and human,but no differences between male and female Alligator sinensis. The sequence analysis showed that the identities of Alligator sinensis DMRT1 gene to Human DMRT1 gene in the DNA sequence and the amino acid sequence were 87% and 95%, respectively. The results indicated that DMRT genes were highly conservative in phylogeny.Our work provides molecular data for the study of sex-determining mechanism, the function of Sox genes and DMRT genes ,and the conservation of Sox genes' and DMRT genes' evolution.