Study On The Phylogenetic Differentiation Of MSTN Gene Among Bovinae Livestocks

Using the method of random sampling in typical colonies of the habitat and PCR amplification techniques,the variations of structural gene—the three exons sequences of Myostatin(MSTN) gene of six Bovinae species :Bos taurus,Bos indius,Bos grunniens, Bibos frontalis ,Swamp Bubalus buffalo and River Bubalus buffalo,were examined. The six representative breeds of six species were 18 Bayingolin Mongolia cattle,18 Leiqiong cattle ,18 Bayingolin Yak, 12 Gayal,19 Haizi water buffalo and 15 Nili-Ravi water buffalo. The gained sequences were then processed and analyzed with DNAman, Mega4.1 and DNAsp4.1 software. And nucleotide composition ,genetic distince , the index of nucleotide differentiation and gene divarication were obtained. Analyzed of the genetic variations and genetic differentiations among 6 Bovinae species. Haplotypes of each Bovinae species and four MSTN gene sequences cited from GenBank were used to construct the phylogenetic trees by means of NJ, ME and MP with Ovis aries (AF019622) as the outgroup. The four selected sequences were Bos Taurus (AB076403), Bos indicus (AY794986), Bos grunniens (AY787760S series), Bubalus buffalo(River) (DQ091762). The results indicated that:1. Extensive variations were observed among Bovinae species. A high mutation rate of MSTN gene existed at the procedure of evolution.2. Genetic differentiation and genetic diversity of Leiqiong cattle were highest in 6 Bovinae species, but Haizi water buffalo were lowest. Furthermore, the level of genetic differentiation of MSTN gene among Bovinae species was different by the time.3. Genetic differentiation of MSTN gene between Bubalus and other Bovinae species was obvious; genetic differentiation between Swamp bubalus buffalo and River bubalus buffalo was at a high degree, the level of phylogenetic differentiation between Swamp buffalo and River buffalo has probably achieved the standard of species. But differentiation of MSTN gene among other four Bovinae species were low ,especially between Bos taurus and Bibos frontalis, genetic similarity of them was comparatively high, therefore the gene comunication existed at the former generation.4. Though analysis on sequences and phylogenetic relationship, the boundary of phylogenetic relationship of Bubalus and Bos was obvious; Genetic distance of Bibos frontalis and Bos taurus was comparatively close, It is logical that gayal is a kind of Bos, Therefore ,it is an independent species of Bos. Bos grunniens, Bos taurus and Bos indicus had same haplotypes, furthermore, genetic distance was close also among them . Bos grunniens is also an independent species of Bos.