The complement component 4 binding protein alpha(C4BPA)gene is the alpha chain of complement binding protein 4.As a plasma protein involved in the complement and coagulation systems,it can influence immune responses and lipid metabolism.In order to study the polymor-phism of C4BPA gene and its correlation with milk quality traits in Chinese Holstein cows,genom-ic DNA was extracted from blood samples of 92 Chinese Holstein cows,and the target fragment of C4BPA gene was amplified by PCR,and the association analysis was performed by using direct se-quencing to obtain the SNP loci and milk quality traits.The results showed that among the four SNPs found at the third intron of the C4BPA gene,I3-11 G＞A was highly significantly correlated with milk protein and urea nitrogen(P＜0.05),I3-291 T＞G was significantly correlated with lac-tose(P＜0.05),I3-374 C＞T was highly significantly correlated with lactose and urea nitrogen(P＜0.05),and I3-375 T＞G was highly significantly correlated with lactose(P＜0.05),milk pro-tein and urea nitrogen.The chi-square test values for each point indicated that the population was in genetic equilibrium.Individuals of haplotype combination H1 H1 had the highest lactose content,and haplotype combination H1H2 can be used as the best haplotype combination in the molecular selection work of dairy cows.

The complement component 4 binding protein alpha(C4BPA)gene is the alpha chain of complement binding protein 4.As a plasma protein involved in the complement and coagulation systems,it can influence immune responses and lipid metabolism.In order to study the polymor-phism of C4BPA gene and its correlation with milk quality traits in Chinese Holstein cows,genom-ic DNA was extracted from blood samples of 92 Chinese Holstein cows,and the target fragment of C4BPA gene was amplified by PCR,and the association analysis was performed by using direct se-quencing to obtain the SNP loci and milk quality traits.The results showed that among the four SNPs found at the third intron of the C4BPA gene,I3-11 G＞A was highly significantly correlated with milk protein and urea nitrogen(P＜0.05),I3-291 T＞G was significantly correlated with lac-tose(P＜0.05),I3-374 C＞T was highly significantly correlated with lactose and urea nitrogen(P＜0.05),and I3-375 T＞G was highly significantly correlated with lactose(P＜0.05),milk pro-tein and urea nitrogen.The chi-square test values for each point indicated that the population was in genetic equilibrium.Individuals of haplotype combination H1 H1 had the highest lactose content,and haplotype combination H1H2 can be used as the best haplotype combination in the molecular selection work of dairy cows.

The peroxisome proliferator-activated receptor gamma(peroxisome proliferator-activated receptor gamma,coactivator 1 beta,PPARGC1B)gene is an intranuclear receptor transcription fac-tor responsible for regulating the expression of target genes.To comprehend the characteristics and mutations of the PPARGC1B gene within the Sichuan yak population,the SNP loci of the PPARGC1B gene were identified through direct sequencing of PCR products.Additionally,the cod-ing region of the PPARGC1B gene was obtained via PCR amplification and sequencing.Bioinforma-tics analyses were conducted to predict protein-coding and mRNA secondary structure.This study identified four exon SNP mutation sites(E9-189A→C,E9-387G→A,E9-542C→T,and E9-554T→C)based on the single nucleotide polymorphism analysis of the PPARGC1B gene in Sichuan yaks.Notably,the E9-387G→A and E9-554T→C loci exhibited significant correlations with shear force and backfat thickness in Sichuan yaks.Subsequently,bioinformatics analysis of the four mutation sites revealed that the PPARGC1B protein is an acidic,unstable,non-transmembrane,and non-secretory hydrophilic protein with a coiled helix structure.It lacks a signal peptide and transmembrane region,predominantly functions in the nucleus,and features 106 phosphorylation sites,one glycosylation site,and one conserved RRM structure.The secondary structure comprises mainly α-helix and random coils.Although the protein structure of the PPARGC1B gene remained unchanged post-mutation,there were significant differences in mRNA secondary structure.These findings suggest that the polymorphic loci of the PPARGC1B gene in Sichuan yaks could serve as a theoretical basis for enhancing meat quality traits through molecular biological methods,presen-ting practical applications in breeding.