Study On Genetic Diversity In Tibet Yaks By RAPD Technique And Several Functional Genes In Maiwa Yak

Study on the use of RAPD analysis in11groups including Baqin yak, Dingqin yak, Sibu yak,Sangri yak, Kangbu yak, Jiali yak, Sangsang yak, Pali yak, Jiangda yak, Leiwuqi yak,Gongbujiangdayak in genetic diversity, and clustering analysis and identification of genetic relationship. H-FABP,HSL and MC4R were analyzed by PCR-SSCP, and the correlation between SNPs and prolificay wasassessed. Clone and sequence analysis of candidate genes about influencing meat quality traits.(1)Study on genetic variation in Tibetan Yak by RAPD technique.The result showed that Tibet yak breeds or groups of genetic diversity index varied between0.1857and0.4053. Among them Pali Yak minimum was0.1857, indicated that Pali Yak wasrelatively pure, group was neat. And Gongbujiangda Yak biggest was0.4053, display that groupinternal have more variations. In11breeds or group, its genetic diversity index size respectivelywere: Gongbujiangda Yak(0.4053)＞Jiangda Yak (0.3536)＞Sibu Yak(0.3448)＞Kangbu Yak(0.3428)＞Jiali Yak(0.3323)＞Sangri Yak(0.2823)＞Baqin Yak(0.2793)＞Sangsang(0.2698)＞DingqinYak(0.2597)＞Leiwuqi Yak(0.2241)＞Pali(0.1857). With eastern Tibet yak breeds or groups ofgenetic diversity was relative taller, and the western yak was relatively low trend, adumbrativeeastern Tibet may be yak origin. According to molecular clustering relationship chart shows thatTibet11yak breeds or groups could be divided into two forms. Pali Yak (PL) was a group, with therest was another group.(2) SNP analysis of H-FABP, HSL and MC4R genes in Maiwa yak.SNP analysis of H-FABP, HSL and MC4R genes in Maiwa yak.With the PCR-SSCP method,SNP information was analyzed in candidate genes of exon region after PCR amplified.â‘ Theresult indicated that there were polymorphisms in amplified region and three genotypes (CC, CD andDD) were detected in exon4in H-FABP gene. In exon4has single mutation（Tâ†'C）at7339bp. Thismutation did not make the amino acid changed.â‘¡There were two genotypes (EE and EF) in MC4Rgene. The EE and EF genotypes have conversion (Câ†'T) mutation in1172bp.â‘¢Sequencingrevealed on single nucleotide mutation (Aâ†'G) at6818bp,(Gâ†'C) at6883, and (Gâ†'A) at6950bpof the amplified region in primer7. In primer8(1), single nucleotide mutation (Aâ†'G) was at10183 bp of the amplified region. This mutation made the amino acid changed(Cysâ†'Gly).(3)Cloning and sequence analysis of Maiwa yak in several candidate genes.Cloning and sequence analysis of Maiwa yak in several candidate genes. The size of cloningH-FABP in Maiwa yak was440bp and CDS was401bp, it encoded133aminoacids. The size ofcloning MC4R in yak was1434bp and CDS was999bp, it encoded332aminoacids. The homologyof nucleotide sequence of yak H-FABP and MC4R gene was83%～99%,85%～99%, respectively,compared with that of ordinary cattle, sheep, swine, human and mouse. The homology of ordinarycattle was highest with yak(99%,99%), followed by sheep(96%,95%)and mouse which is lowest.The results indicate that they were orthologous genes in different species. This study also found thatthe H-FABP and MC4R protein were hydrophobic protein belonging to a structural protein.As mentioned above, The results of the study of the11Tibet yak groups which is first showsthat Tibet yak has rich genetic diversity and groups of genetic differentation in significant thatprovides important genetic resources for cultivating new varieties of Maiwa yak in the future; Theresearch of H-FABP, MC4R gene and related production performance of Yak laid the foundation forrevealing a candidate gene function and then discussing the relationship between the gene and thetraits.