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Association study of single nucleotide polymorphisms in JAK 2 and STAT 5B genes and their differential mRNA expression with mastitis susceptibility in Chinese Holstein cattle
Author(s) -
Usman T.,
Wang Y.,
Liu C.,
Wang X.,
Zhang Y.,
Yu Y.
Publication year - 2015
Publication title -
animal genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0268-9146
DOI - 10.1111/age.12306
Subject(s) - biology , single nucleotide polymorphism , genotype , genetics , snp , population , microbiology and biotechnology , gene , demography , sociology
Summary The JAK – STAT pathway plays a key role in mediating immune responses. The genetic effects of single nucleotide polymorphisms ( SNP s) in JAK 2 and STAT 5B were investigated for serum cytokines, mastitis indicators and productions traits in a population of 468 Chinese Holstein cattle. Pooled DNA sequencing revealed one SNP ( BTA 8:g.39645396A>G) in JAK 2 and two SNP s ( BTA 19:g.43673888A>G and BTA 19:g.43660093T>C) in STAT 5B . A fixed effect model considering the effects of SNP s, parity, herd, season and year of calving was used by way of the general linear model procedure of sas . Genotype frequencies of these SNP s in the population were in Hardy–Weinberg equilibrium ( P > 0.05). A novel SNP (g.39645396A>G) in JAK 2 was predicted to change the amino acid from lysine to asparagine and was significantly associated with the somatic cell count ( SCC ) and somatic cell score ( SCS ), whereas g.43673888A>G in STAT 5B was significantly associated with SCC , SCS and interleukin‐4 ( IL ‐4) ( P < 0.05). The dominant effect of g.39645396A>G in JAK 2 was significant for SCS , and its additive effect was significant for SCC , whereas the dominant effect of g.43673888A>G in STAT 5B was significant for SCS and IL ‐4 ( P < 0.05). The combination of g.39645396A>G in JAK 2 and g.43673888A>G in STAT 5B showed a significant effect on SCC , SCS , IL ‐4 and TNF ‐ α ( P < 0.05). As for mRNA expression analysis, the AA genotype g.39645396A>G and GG genotype g.43673888A>G indicated higher mRNA expression level and were significantly different from other genotypes ( P < 0.05). The results imply that JAK 2 and STAT 5B genes could be useful candidate genes, and the identified polymorphisms might potentially be strong genetic markers for selection of dairy cattle against mastitis development.