Mutations Of Genes And Their Effects On Milk Performance Traits And Establish A Detection Method Of CVM

The milk yield and quality,one of the most important economic traits in the dairy industry,are directly impact on production efficiency.In this study,the four candidate genes(prolactin,PRL;pituitary-specific transcription factor 1,POU1F1;estrogen receptorα,ERαand Cytokines signal inhibiting protein-2,SOCS-2),which related to breast development or regulate the growth and development of body,have been identifyed for single nucleotide polymorphisms(SNPs) and analysed association with milk yield and qulity.12 pairs of primers from the exons of the four candidates Gene have been designed searching for SNP and six SNPs have been identified using DNA sequencing;the five of six SNPs variation in 270 Holstein cows have been detect by PCR-RFLP and the introduction of restriction sites assays;three of the five SNPs were significantly correlated with milk yield,while one SNP significantly associated with the milk fat percentage,and other SNP with milk protein.The method to test genotype of SLC35A3,a recessive genetic gene that leads to complex vertebral malform(CVM) in cows,which also influences milk production,has been established,verified by the method of gene sequencing,and applied 150 Holstein cows to find carring harmful allelic gene.The results were as follows:1.Six SNPs in four candidate genes have been identified.There were two SNPs in PRL, one SNP in POU1F1,one SNP in ERa gene,two SNPs in SOCS-2 gene.2.Four new SNPs have been found out by DNA sequencing,one SNP was in PRL,two SNPs in ERα,one SNP in SOCS-2 gene.3.Genotyping methods of PCR-RFLPs for SNPs in the exon3 and exon5 of PRL (PRL-PCR-Rsa I-RFLP,PRL-PCR-Aci I-RFLP),in the exon6 of POU1F1 (POU1F1-PCR-Hinf I-RFLP),in the exon2 of ER(ERα-PCR-Dra I-RFLP),in the exon4 of SOCS-2(SOCS-2-PCR-BsiY I-RFLP,SOCS-2-PCR-Hinf I-RFLP) have been established in this study.4.There were polymorphisms of the five SNPs from 4 candidate gene in Holstein cows.5.There were three SNPs significant associated with milk yield,including POU1F1-Hinf I-RFLP,ERα-Dra I-RFLP,SOCS-2-BsiY I-RFLP polymorphism. 6.One significant association of POU1F1-Hinf I-RFLP polymorphism with milk fat percentage has been identified.7.Molecular biology methods testing CVM has been successfully established,verified and application.