Studies On The Sox Gene Of Dinodon Refozonatum

This paper consists of two parts, which are as follows: PART ONE: reviews;1.Taking reptile for example, two types of sex determining mechanisms were discussed;2.The characteristic of Sox, function in development processes of Sox, two special Sox gene, the future trends of researches on the Sox gene and further research on SRY/Sry's downstream genes were reviewed and commented.PART TWO: studies;l.The Sox gene of Dinodon refozonatum was amplified by using a pair of primers which can amplify the conservative motif (HMG-box )of human SRY gene .The amplification band was observed in both male and female Dinodon refozonatum , whose length was consistent with that of human SRY gene, which about 220bp. The result of SSCP analysis showed that there were many differences in the Sox gene sequence between Dinodon refozonatum and human, and there was a few differences between male and female Dinodon refozonatum.2.Using a pair of degenerate primers based on the conservative region, HMG-box, of Human SRY gene, six different fragments were amplified from either female or male Dinodon refozonatum, then cloned by using pMD18-T Vector and sequenced. The sequence result indicates that they show high homology to Human SOX genes, and the identities to human SOX genes in the DNA sequence and the amino acid sequence are 91%, 89%, 91%, 91%, 85%, 92%, and 96%, 96%, 98%, 100%, 100%, 96%, respectively, which may be concluded that Sox genes are highly conservative in phylogenetic.3.In the paper, the Sox gene expression analysis of different tissues from Dinodon refozonatum was studied by using RT-PCR. An expression was observed in testicle in male, ovaries in female, and brain, spleen, heart in both male and female. The Sox gene sequence of expression from the testicle and ovaries was cloned using RT-PCR products. The results of clone revealed that the Sox gene of expression in testicle are Sox3, and that is Sox22 in the ovaries. This suggests that Sox gene are important role on the sex determination.Our work provides molecular data for the study of Sex-determining mechanism of Dinodon refozonatum, and offers the proof for the conservation of Sox genes' evolution.