中国荷斯坦奶牛NDUFAF4基因多态性及其与乳品质性状的相关分析OA

This experiment selected Chinese Holstein dairy cows as the research object,aiming to identify potential genetic markers affect-ing the milk quality traits of these cows by screening the mutation sites in the NADH dehydrogenase[ubiquinone]1 alpha subcomplex as-sembly factor 4(NDUFAF4)gene.The fragment of the NDUFAF4 gene was amplified by PCR,and the single nucleotide polymorphism of the target gene fragment was detected by direct sequencing.Then,the correlation between this single nucleotide polymorphism and milk qual-ity traits of the Chinese Holstein dairy cows was analyzed using the SPSS 27.0 software.The results showed that there were 8 mutation sites in intron 2 of the NDUFAF4 gene.Among them,the I2-6501A＞G site had three genotypes of AA,AG,and GG,and the milk yield and urea nitrogen content of the GG genotype were significantly higher than those of the AA and AG genotypes(P＜0.05);theI2-6620A＞Gsite had two genotypes of AA and AG,and the milk yield and corrected milk yield of AG were significantly higher than those of AA(P＜0.05).Using the HaploView 4.2 software to carry out linkage analysis on 8 SNPs sites of the NDUFAF4 gene,it was found that the I2-6502C＞T and I2-6525A＞G sites showed strong linkage,forming a haplotype domains structures.The I2-6613T＞G,I2-6620A＞G,and I2-6622A＞T sites showed strong linkage,forming a haplotype domains structures.Among them,the H5H7 haplotype in block2 can be considered the optimal haplotype for screening dairy cattle individuals with high milk yield,high lactose content,and high corrected milk yield.The NDUFAF4 gene plays a crucial role in the metabolic regulation of lactation performance and milk quality traits in dairy cows,which may form a molecular the-oretical basis for selection and breeding of dairy cows with excellent milk quality traits in the future.