Effects Of Polymorphisms Of SERPINA1 Gene And POU1F1 Gene On Milk Traits Of Chinese Holstein Cows

With the higher requirement of modern production of dairy cows,it needs to assure the genetic effects of quantitative traits genes on milk traits of cows, aiming to fasten the progeny test program.These experiments chosed SERPINAl and POU1F1 genes as the functional candidate genes to find Marker-Assisted Selection for Chinese Holstein cows by SNP analysis and statistical modelling.blood sampling of 220 Chinese Holstein cows with good production records were tested for polymorphisms of SERPINAl gene using PCR-RFLP,CRS-PCR,MAMA-PCR and PCR-SSCP technique,and exon 6 of POU1F1 gene using PCR-RFLP technique,and then analysed the association of RFLP with milk traits(including milk production, milk protein content,milk fat content,and Somatic Cell Scores).The results showed that five sites(5504,5609,5624 and 5747 in exon 2 and site 8178 in exon 4 ) of SERPINAI gene existed polymorphisms.No polymorphism was found in exon 5 of SERPINAl gene.Observed genotype frequencies of five sites are consistent with Hardy-Weinberg equilibrium except for site 5624,and each polymorphism information content was medium.GLM(General Linear Model) analysis was applied to evaluate associations of five SNP with milk performance traits (305d milk,fat content,protein content and Somatic Cell Scores).It concluded that the value of association of genotypes of five sites with milk traits(305d milk,fat content,protein content) were at non-significant levels(P>0.05).Only SCS (Somatic Cell Score) in site 5747 was at a significant level(P<0.05).Thus,locus 5747 of the bovine SERPINAl gene may be used as an indicator to choose lower SCS cows.The results showed that observed genotype frequencies of exon 6 of POU1F1 gene are consistent with Hardy-Weinberg equilibrium,polymorphism information content was medium.GLM(General Linear Model) analysis was applied to evaluate associations of POU1F1 gene polymorphisms with milk performance traits(305d milk,fat content,protein content and SCS).It concluded that cows with GG genotypes were associated with the higher milk protein contents(P<0.05),the value of other milk traits(305d milk,fat content and SCS) were at non-significant levels(P >0.05).Thus,this SNP of the bovine POU1F1 gene can be used as an indicator to choose the higher protein percentage and can be proved further by larger population.