Polymorphisms Of MASPs Gene And Its Relationship With Milk Performance Traits And Complement Activity In Chinese Holstein Cattle

Mannose-binding lectin (MBL)-associated serine protease (MASP) is enzyme molecules in the innate immune system, having biological functions of antibacterial and anti-inflammatory activities. In this report, we scaned the entire exons of MASP1 and MASP2 gene with DNA sequencing to identify single nucleotide polymorphisms (SNPs) in MASP gene. Two novel single nucleotide polymorphisms (SNPs) (g.5766C>T, g.51228A>C) were detected in the MASP1 gene and three novel single nucleotide polymorphisms (SNPs) (g.14247A>C, g.14248T>C, g.14391C>T) were found in the MASP2 gene. Furthermore, g.14248T>C and g.14391C>T were found linkage in 648 Holstein cows by PCR-restriction fragment length polymorphism (PCR-RFLP), Created Restriction Site PCR (CRS-PCR)and DNA sequencing methods. The SNP g.14047 A>C(GAA(Glu)>GAC(Asp)at the position 608th aa) correlated with CH50 (P<0.05) and Protein percentage (P<0.05). The SNP g.14248 T>C(ATT(Ile)>ATC(Ile) at the position 675th aa) showed only two genotypes and correlate with CH50, total Protein volume, total fat and total milk weights (P<0.05).The polymorphism at g.5766C>T correlated with Protein percentage(P<0.05). In this study, the polymorphism g.51228A>C only have two genotypes, and this SNP have no significant correlation with CH50,ACH50, fat content, protein content and 305 d milk yields and SCS scores. In this study, among six combined haplotypes of MASP2, the individuals with haplotype combination H1H4 showed highher CH50 and lower total fat than the ones with haplotype combinations H2H2 (P<0.05) and H2H4 (P<0.05). In addition, lower total fat than H4H4 (P<0.05). The individuals with haplotype combination H1H2 showed highher SCS, lower 305 d milk yield, total fat, total Protein and total milk weights than the ones with haplotype combinations H2H2 and H2H4,and some what H3H4 and H4H4(P<0.05). These results suggest that MASP2 be a candidate gene that influences mastitis of cows and it could be implemented in breeding programmes to improve the production performance of Chinese Holstein cattle.