Cluster And Genetic Diversity Analysis Of Six Yak Populations In Gansu Province Using Mitochondrial D-loop Sequence And Microsatellite Marker

This research was carried out to study the genetic diversity of6yak popultions(Maqu yak, Luqu yak, Xiahe yak, Tianzhu yak, Tianzhu white yak and Sunan yak)by using the methods of microsatellite DNA makers and mitochondrial DNAmolecular markers from two level of intra-nuclear and extra-nuclear genetic material,and to analyze the phylogeny, network relation, principal component, geneticstructure and other information in yak. The results were as follows.1.146alleles were measured at15microsatellite loci, the mean allele numberwas9.73at the15loci in240individual for6yak groups in Gansu Province. Thediversity of MGTG7was highest in15loci. The allele number at15loci in6groupswas different, the range was from74to106, in them, the allele number in Maqu yakwas most, which was106, ordinal, Luqu yak was99, Xiahe yak was96, Tianzhu yakwas91, Sunan yak was87, Tianzhu white yak was74.2. As to heterozygosity and polymorphism information content in6yak groups,the genetic diversity in Maqu yak and Luqu yak and Xiahe yak was rich, while, thegenetic diversity in Tianzhu white yak and Tianzhu yak and Sunan yak was low.3. Da and DSgenetic distance values show that the genetic relationship amongMaqu yak and Luqu yak and Xiahe yak was close, the genetic relationship amongTianzhu yak and Tianzhu white yak and Sunan yak was close in the study of the sixyak populations.4.6yak groups in this study can be divided into two branches obviously byconstructing the NJ tree based on genetic distance for Da and DS, namely, Maqu yakand Luqu yak and Xiahe yak were clustered in the same class, Tianzhu white yak andTianzhu yak and Sunan yak were clustered in the same class.5. Three-dimensional space analysis of principal component PC1-PC2-PC3showthat the major constituent in Maqu yak and Luqu yak and Xiahe yak was similar, inaddition, the major constituent in Tianzhu white yak and Tianzhu yak and Sunan yakwas similar.6. By analyzing genetic structure based allele at15microsatellite loci in6yak groups, the result show that: when K=2, the genetic structure of Tianzhu white yakand Tianzhu yak and Sunan yak was similar, which can be the same kind, the geneticstructure of Maqu yak and Luqu yak and Xiahe yak was similar, which can be thesame another kind.7. Research show that the variation to the general sequence length of mtDNAD-loop was from891to895bp, in them, the content of (G+C) was38.80%, thecontent of (A+T) was61.20%, therefore, the content of (A+T) in mtDNA D-loopwas rich in240individual for6yak groups in Gansu Province.8. There were60variant loci on mtDNA D-loop in240individual for6yakgroups in Gansu Province, the variation centered between200bp to400bp, where thevariant loci were29, accounted for48.33%in all variant loci, therefore, this regionwas more variant on mtDNA D-loop in yak.9.41kinds of haplotype were found by analyzing mtDNA D-loop sequence in240individual for6yak groups in Gansu Province, in them, the haplotype number inMaqu yak and Luqu yak was most, which were all21, the haplotype number in Xiaheyak was the next, which was18. However, the haplotype number in Tianzhu whiteyak was least, which was only11. The haplotype diversity in Maqu yak and Luqu yakwas higher, the mean value was above0.900, while, the haplotype diversity inTianzhu white yak was lower, which was only0.662. in addition, the haplotypediversity in Sunan yak was0.754. the results of nucleotide diversity was consistentwith the results of haplotype diversity, the mean difference coefficient of nucleotide inMaqu yak was highest, which was16.47, while, the mean difference coefficient ofnucleotide in Tianzhu white yak was only8.20.10.6yak groups in Gansu Province may have2matrilinear origin throughconstructing phylogenesis tree and analyzing network relation based on41kinds ofhaplotype at mtDNA D-loop sequence in yak, this result was consistent with the resultof microsatellite DNA markers.