title: Novel SNPs in the ATP1B2 gene and their associations with milk yield, milk composition and heat-resistance traits in Chinese Holstein cows.
abstract: Genetic association analysis was applied to examine the effect of the Na(+)/K(+)-ATPase beta 2 subunit (ATP1B2) gene on rectal temperature, milk traits, K(+) levels and Na(+)/K(+)-ATPase (NKA) activity in the red blood cells of 1001 Chinese Holstein cows under normal and heat-stress conditions. We detected two novel single nucleotide polymorphisms, G2258A and C2833T, in the second and fourth introns, respectively, of ATP1B2. G2258A significantly affected milk fat content (P < 0.05) and 305-day milk yield (P < 0.01), but not milk protein content. C2833T significantly affected milk protein content (P < 0.01) and 305-day milk yield (P < 0.05), but not milk fat content. Calculated gene substitution effects suggested that A to G substitution in G2258A, and T to C substitution in C2833T, positively affected milk fat content, 305-day milk yield and somatic cell score, but negatively affected milk protein content. We also detected significant variation in milk fat content, milk protein content, 305-day milk yield and somatic cell scores (P < 0.05 or P < 0.01) among the nine ATP1B2 haplotypes. Under heat-stress, the C2833T polymorphism was significantly related to rectal temperature (P < 0.01), red blood cell K(+) levels, NKA activity and milk yield (P < 0.05). Cows with the TT genotype showed the desirable characteristics of low rectal temperature and red blood cell K(+), low decline rate in milk yield and red blood cell NKA activity. This study suggests that the ATP1B2 single nucleotide polymorphism C2833T is a genetic marker of heat-resistance traits in Chinese Holstein cows.
authors.affiliation: College of Animal Science and Technology, Nanjing Agricultural University, No 1 Weigang, Nanjing City, 210095 Jiangsu Province, China.
authors.forename: Zeying
authors.initials: Z
authors.lastname: Wang
authors.forename: Genlin
authors.initials: G
authors.lastname: Wang
authors.forename: Jingmin
authors.initials: J
authors.lastname: Huang
authors.forename: Qiuling
authors.initials: Q
authors.lastname: Li
authors.forename: Changfa
authors.initials: C
authors.lastname: Wang
authors.forename: Jifeng
authors.initials: J
authors.lastname: Zhong
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000483:Alleles; D000818:Animals; D001483:Base Sequence; D001831:Body Temperature; D002417:Cattle / Q000235:genetics*; D002681:China; D003612:Dairying; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D056726:Genetic Association Studies; D005838:Genotype; D006358:Hot Temperature; D008892:Milk / Q000737:chemistry*; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D017422:Sequence Analysis, DNA; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
chemical_list: D000251:Adenosine Triphosphatases; D000254:Sodium-Potassium-Exchanging ATPase