A Study On The Homology Of The 5' Regulatory Region Of Lactoglobulin Gene In Yak At Different Areas In China

Genetic polymorphism is an important part of biological diversity, and is the basis of the diversity of ecosystem, speices diversity and maintenance the species to survive over a long period. In this study a pair of primers for PCR were designed according to references published, the oligonucleotides were as follow: the upstream primer, 5′-gCg, AAT, TCA, TCC, CAC, gTg, CCT, gC-3′, downstream primer, 5′ -gAg, AAT, TCC, Tgg, ggA, ggg, ACC, TT-3′, after 30 cycles of PCR procedures with annealing temperature at 68℃, a fragment of 1447bp was amplified and was collected from agarose gel. Then the fragment was cloned into pMD18-T vector and sequenced. The sequencing results indicated that there were 34 nucleotides mutation in the 5′regulatory region of lactoglobulin gene between dairy cow and Qinghai yak, and the homologous sequences was 97.65%, the eminent differences were that there was a continuous delete mutation of three nucleotides at one site and one insert mutation of a single nucleotide at another site in Qinghai yak′s genome. There were 38 nucleotides mutation in the 5′ regulatory region of lactoglobulin gene between dairy cow and Yunnan yak, the homology was 97.3%. The eminent differences were also a continuous delete mutation of three nucleotides at one site and one insert mutation of a single nucleotide at another site in Yunnan yak′s genome. There were 8 nucleotides mutation in the 5′ regulatory region of lactoglobulin gene between Qinghai and Yunnan yak, the homology was 99.4%.