锯缘青蟹Sox基因的PCR扩增(英文)

SRY基因(sex-determining region of the Y chromosome)是人类及哺乳动物睾丸决定因子TDF(testisdetermining factor)的最佳候选基因。SRY蛋白含有204个氨基酸,其中1个约79个氨基酸区域即HMG盒(high mobility group box)是SRY基因编码蛋白质的唯一功能区。由于SRY的发现,人们进而发现了1个庞大的与性别决定有关的SRY盒-Sox(SRY-related HMG box gene)基因家族。锯缘青蟹是我国重要的海洋经济蟹类之一,其性染色体和性别决定机制仍处于进化的早期阶段,在分子水平上探讨其性别决定机制尚不多见。通过采用PCR技术,以特异扩增人SRY基因HMG盒保守区的1对兼并引物,扩增了锯缘青蟹基因组的Sox基因。结果表明锯缘青蟹雌雄个体与人一样,均能扩增出1条大小约为216bp左右的基因片段,显示出该基因在进化上的高度保守性,为探索锯缘青蟹的性别决定机制及Sox基因的进化提供了分子资料。

PCR amplification of Sox gene in the mud crab Scylla serrata

Sox genes are a family of genes that encode proteins which are characterized by the presence of a HMG-box related to that of the mammalian sex-determining gene SRY. By definition, the DNA binding domain of Sox genes is at least 50% identical to the 79 amino acids HMG-box of the SRY gene. Sox genes are highly conserved throughout evolution, from human to Drosophila . In the present study, using degenerate primers which specially amplify the conservative motif of human SRY gene, the PCR amplification of Sox gene in genomic DNA of the mud crab Scylla serrata was studied. The result showed that only one band was present in the PCR products of Scylla serrata, and the length was 216bp, equal to that of human SRY gene, but no difference between male and female. These may be concluded that Sox genes are highly conservative in phylogenetics. The present paper provides molecular data for the study of sex-determining mechanism of Scylla serrata or other shrimps and crabs, and for the evolution of Sox genes.