Identification And Functional Analysis Of Candidate Gene SCARA5 For Milk Production Traits In Holstein Cow

Collect the production data of 1280 Holstein cows in Ningxia,using Illumina cow 150K Bovine genome-wide SNP genotyping chip,the use of statistcal methods for Farm CPU 5 lactation traits(milk production,milk fat fraction,milk fat fraction,milk protein fraction,and milk protein fraction)and somatic cell scores,and the genes related to milk production traits were screened out.The candidate genes for milk production traits were further determined by qRT-PCR technology,and then overexpression vectors were constructed and transfected into Holstein cow mammary epithelial cell lines to detect the expression of milk fat metabolism-related genes and determine the main components of milk fat,namely the intracellular triglyceride content.Perform functional verification at the cellular level.The main findings are as follows:1 In this study,a large population of GWAS was used to screen a total of 7 genes related to milk production traits in dairy cows.Among them,DOCK2 and GRPR genes are related to milk fat content,SCARA5 andDGAT1 genes are related to milk fat rate,FGFR2 gene is related to somatic cell number,SLCO1A2 gene is related to protein content,and ZNF38 and DGAT1are related to milk protein rate.2 Through fluorescence quantitative analysis of different tissues(liver,ovary,breast,heart and uterus),FGFR2 and SCARA5 genes are highly expressed in the breast and can be used as candidate genes for milk production traits.3 SCARA5 overexpression can significantly up-regulate the expression of VLDLR,GPAM,LPL and ACACAgenes(P<0.05),but the effect of up-regulation of FASN gene is not obvious.4 When the SCARA5 gene was overexpressed,the triglyceride content in the mammary epithelial cells of dairy cows increased significantly(P<0.05).In summary,Holstein dairy cow SCARA5 gene may play a certain regulatory role in the milk fat metabolism pathway,and it can be used as a gene that affects milk production in dairy cows to continue in-depth research.On the one hand,the results of this study expanded the candidate gene pool of milk production traits in dairy cows,and on the other hand,provided certain molecular materials for the breeding of dairy cows.