DNA Polymorphism and Genetic Differentiation of MyoG Gene in Three Chinese Domestic Bovine Species

Variations of the partial sequence of MyoG gene in Bos Taurus(Luxi cattle,Bohai cattle),Tianzhou yak and Chinese Guangxi water buffalo are analyzed to explore their nucleotide polymorphisms and genetic differentiations.The partial DNA sequence of MyoG's exon 1 and 5' flanking region of the 4 bovine populations are obtained with PCR and DNA directly sequencing.The sequences are compared with the homologous MyoG gene retrieved from GenBank.Results show that there is no mutation in Bohai and Yak.In Luxi cattle,one polymorphism site is found,which defines two hyplotypes.In water buffalo,six mutation sites are found but there is only one polymorphism site.The nucleotide diversity(Pi)is between 0.000 00-0.001 35,which indicates a low genetic polymorphism within the populations.The intrapopulation nucleotide divergence(Dxy) between GX and LX reaches 0.01397,which is the highest among all paired comparisons.The results indicate an obvious genetic differentiation of water buffalo from cattle and yak.Phylogenic tree constructed show that the Bos taurus(cattle)and Poёphagus grunniens(Yak) are more closer related,which supports the viewpoint of previous research of classifying the yak into a subgenus or a species of Bos.