Cloning And Sequence Analysis Of The CDNA Of Bcl-2/Bax Gene In Mongolia Sheep

Bcl-2(b-cell lymphoma/leukemia-2gene) is a proto-onco gene, the function of which has been proved to inhibit apoptosis in recent years. According to the protein function, Bcl-2 is classified into 2 classes that one like Bcl-2 of inhibiting apoptosis and the other like Bax of promoting apoptosis.Firstly, four pairs of primers were designed according to Bcl-2 and Bax conserved sequence of ruminants in the gene pool. Total RNA was extracted from the spleen of Mongolia sheep and the cDNA middle fragment of Bcl-2 and Bax in Mongolia sheep was amplified by the way of reverse transcription PCR(RT-PCR), and then the full-length sequence of Bcl-2 in Mongolia sheep was amplified successfully using the method of RACE(Rapid Amplification of cDNA Ends). The length of midregion sequence of Bax cDNA was 134 bp, and the full-length of Bcl-2cDNA was 806 bp, which containing a ORF of 693 bp, an 3′UTR of 109 bp and ploy(A)15 and the ORF encoding 229 amino acid residues. The results of the nucleic acid and amino acid sequences of Bcl-2 showed that Mongolia sheep had the highest homology with the cow Bcl-2, secondary with cat, dog, human and rat, and the lowest with chick. This indicated that Bcl-2 in Mongolia sheep had a closer evolutionalary relationship with the ruminant than chick either in nucleic acid sequence, or in amino acid sequence.