Polymorphism Of Chinese Holstein Cow Mastitis Gene And Its Association With Somatic Cell Score

210 Chinese Holstein cow blood samples from 4 dairy farms of Hebei Province were applied to analyze the single nucleotide polymorphisms of AHCY, TLR10, PRKDC and SLC11A1 gene. The correlation between the different genotypes and somatic cell scores (SCS) was analyzed using least-squares analysis, the results as follows:(1) Non-denatured PAGE(Polyacrylamide Gle Electorphoresis) method was used to detect the mutation of AHCY and TLR10 genes, no polymorphism was found in both two genes in these population.(2) PCR-SSCP and DNA sequencing technologies were used to detect the polymorphism of PRKDC gene in 210 Holstein cows, five polymorphic sites were found, G34126A, C77353T, T77384G, C77406T and C deletion at 77408 bp were found, and G34126A mutation caused an amino acid change Ser1071Asn. Chi-square test showed that Holstein cows were in Hardy-Weinberg equilibrium in all sites. AA(0.186), AB(0.433) and BB(0.381) genotypes were detected at G34126A site in Holstein cows using PCR-SSCP. CC(0.786), CD(0.129), DD(0.009), CE(0.067) and DE(0.009) were found at C77353T, T77384G, C77406T and C deletion of 77408 bp sites in Holstein cows by PCR-SSCP. The relationship between polymorphisms of PRKDC gene and SCS (somatic cell score) in Holstein cows was analyzed by least squares linear model. Least squares mean of SCS for AA was significantly lower than that for AB or BB (both P<0.05), and the difference of the least squares means for SCS between AB and BB was not significant (P>0.05). AA genotype is predominant genotype to mastitis. The difference of the least squares means for SCS between CC, CD, DD, CE and DE was not significant (P>0.05). (3) Polymorphisms of SLC11A1 gene in 210 Holstein cows were detected by PCR-SSCP and PCR-RFLP, five polymorphic sites of SLC11A1 gene at C723T, C1144G, A1749G, T1782G, and GT deletion of 1803-4bp were found in Holstein cows and C723T, C1144G mutations resulted in amino acid change: Ala217Val, Pro356Ala, respectively. Chi-square test showed that Holstein cows were in Hardy-Weinberg equilibrium in all sites. AA(0.791), AB(0.209) genotypes were detected at C723T site using PCR-RFLP with Bpu10 I, CC(0.628), CD(0.343) and DD(0.019) were detected at C1144G site with Pst I. LSM of SCS for AA was significantly lower than that for AB (P<0.05), AA genotype is the predominant genotype to mastitis. EE(0.686), EF(0.300) and FF(0.014) were found at A1749G, T1782G and GT deletion of 1803-4bp polymorphic sites in Holstein cows by PCR-SSCP. LSM of SCS among all genotypes was nonsignificant (P>0.05). In 210 Holstein cows, 7 haplotypes were reconstructed. The frequency of ACG was more than 70%.(4) Least square analysis showed that bull, cattle farm, parity had significant effect on SCS(P<0.05).