Genetic Effect Analysis Of Candidate Gene Of Milk Production Traits In Chinese Holstein Cattle

In this study, Holstein cattle in Hutubi cattle farm, Urumqi cattle farm and TianShan animal husbandry bio-engineering CO.,LTD were subjects. Using the DHI data for cattle during 2011-2014, measurement records of production performance and calving records; Screened SNPs by using whole genome re-sequencing technology of DNA mixed pool and conducted SNPs type by using MassArray technology,genetic effects analysis of milk production traits were made by using software SAS8.1. All studies in this paper were hoping to find molecular markers which related to milk production traits of Chinese Holstein cattle and validating molecular markers those latest discovered, providing a theoretical basis to the molecular marker assisted selection of milk production traits for Chinese Holstein cattle. The results were as follows:1.A large number of SNPs were obtained by the whole genome re-sequencing technology of DNA mixed pool, screened SNPs and finally selected 6 SNPs which were met the requirements of MassArray technology, after further typing test we found that 6 SNPs were nonsynonymous and first be found.2.Genotyped of 15 SNPs sites by using MassArray technology(6 SNPs were obtained by DNA mixed pool re-sequencing, 9 SNPs were obtained from the literature),genotyping results and genetic effects analysis of milk production traits showed that there are 8 sites(G73896754A,C79894591 T,C43045807T,C107216562 T,A38899763G,T41947097 G,A16234934G and A80965296G)had a significant effects on C79894591 T,C107216562T,A38899763 G and T41947097 G had a significant effect on milk protein percentage, in which T41947097 G had a very significant effect on milk protein percentage C43045807 T had a very significant effect on Lactose rate; A16234934 G had a significant effect on fat yield, lactose rate and SCS respectively; A80965296G8 had a significant effect on milk production of 305 days.3.Linkage and haplotype analysis for SNPs were conducted by using Haploview software,3 haplotype blocks were found. Haplotypen block consisted by A16234934 G and C16233476 T was a haplotype,which significantly affected the lactose rate. Haplotype block consisted by C79894591 T and G73896754 A was a haplotype,had a sigenifcantly affected on the milk fat percentage.Haplotype block consisted by G98736141 A and T98741711 C was a haplotype, which had an bvious influence on the lactose rate.In this paper, 15 SNPs sites and genetic effect of milk production traits in Chinese Holstein cattle were studied, T41947097 G, C43045807 T and TTGG,CCGG,AACC haplotype may have great genetic effect on milk production traits of Chinese Holstein cattle. For the further study and providing theoretical basis of genetic breeding improvement, animal groups should be expanded, the correlation between T41947097 G 、C43045807T and haplotype(TTGG,CCGG,AACC) sites with genetic effect of milk production traits should be validated in order to determine the SNPs which are related with genetic effects of milk production traits.