Association of ATP1A1 gene polymorphism with heat tolerance traits in dairy cattle.

Heat stress produces oxidative stress and affects the alternation of plasma K(+) and Na(+). Since Na(+),K(+)-ATPase is sensitive to oxidative stress and critical for maintaining the homeostasis of these two ions, we examined the genetic polymorphism of the ATP1A1 gene in 160 Holstein cows using polymerase chain reaction low ionic strength single-strand conformation polymorphism and DNA sequencing methods. G to A at position -14103 in exon 14 and C to T at position -14242 in intron 14 of the bovine ATP1A1 gene were identified, but the former single nucleotide polymorphism was silent with respect to the amino acid sequence of the protein. However, we found significant correlations between ATP1A1 gene polymorphism and the coefficient of heat tolerance (P<0.01) and with respiratory rate (P<0.01). Genotype AC was the most favorable genotype for heat tolerance. This polymorphism site has potential as a genetic marker for heat tolerance traits in dairy cattle breeding.