| In this experiment a total of138individuals of three horse breeds like new Kirgiz horse, Yili horse andRussian trotter as material, using PCR-SSCP,bioinformatics and sequencing analyse technology, analysisthe characterics of PRLR and CSN1S2gene, to investigate the correlation of population genetic structure,genetic polymorphism and milk traits, in order to choose the candidate gene that effect horse milk traits,and accelerate to explore in molecular level to deliver previous research base and technical support for milktraits genetic mechanism of XINJIANG horse breeds, and will use marker assisted breeding technology todeliver scientific basis for breeding a horse milk traits. The main research results of this experiment asfollows:1. the correlation between genetic variation of PRLR gene flanking SNP and milk yieldthe experiment of three horse groups, found a5SNP loci.among them c.30048470T>G(SNP1),c.26005568G>C(SNP2), c.25704972G>A(SNP3) were missense mutation, caused the amino acid changerespectively: p.74Val>Gly, p.89Arg>Thr and p.33His> Arg; c.30068107T>C (SNP4), c.30106738T>C(SNP5) were synonymous mutation, without causing amino acid changes.The result indicate that the PRLR gene flanking SNPs exist the groups of in new Kyrgyz horse, Yilihorse and Russia trotter, and genetic variation of each SNP in three groups were different, except to theSNP1and SNP4were not found homozygotic type, and among other SNP in three experiment groupsdetected three genotype, explain three groups genetic variation were rich that mey be related with thecrossbreeding work. Chi square test of independence of the distribution of allele and genotype show that inthis gene difference between in three horse groups were significant（P<0.05）.according to the previousexperiment results,the different breeds in PRLR gene variation was grate, has sum of these variation causedby diversity of milk trait in different breeds.Correlation analysis showed: SNP2was a negative effect for YILI horse milk yield, SNP5was apositive effect for YILI horse milk yield, thus SNP2and SNP5were may be an important loci for effectmilk yields of Yili horse; SNP3was a positive effect for new Kirgiz horse milk yield, thus SNP3was maybe an important loci for effect milk yields of new Kirgiz horse.2. the analyse of CSN1S2gene genetic variation and population genetic structurein this experiment, detected polymorphism of CSN1S2gene exon1and exon3in new Kyrgyzhorse,Yili horse and Russia trotter, results shows that CSN1S2gene exon1exit one polymorphism loci, wasc.1082T>C caused base transition, and accelerate to discover that it was belong to samesense mutation.CSN1S2gene exon1in new kirqiz horse was non Hardy-Weinberg equilibrium state, Yili horse and Russiatrotter were Hardy-Weinberg equilibrium state. the polymorphism information of CSN1S2gene exon1inthree horse breeds: new Kirgiz horse (PIC=0.298), Russian trotter (PIC=0.175), Yili horse (PIC=0.038). Bycomparison, the new Kirgiz horse was rich, the Russian trotter was second, Yili horse was poor.Chi squaretest of independence of the distribution of allele and genotype show that in this gene difference between inthree horse groups were significant（P<0.05）.CSN1S2gene exon3do not exit polymorphism. |
