Single nucleotide polymorphisms in HSP70–1 gene associated with cellular heat tolerance in Chinese Holstein cows

Abstract

Polymorphisms in the 5′ regulatory and translated regions of a heat shock protein 70 kDa protein –A1 (HSP70A1A) are observed as the responsible for cellular protection against heat stress and associated with heat tolerance in dairy cows. The present study was conducted to determine the genetic variation in the inducible heat shock protein 70–1 gene and its association with heat resistance in Chinese Holstein cattle. Three single nucleotide polymorphisms (SNPs) were newly identified in 149 multiparous lactating cows, using direct sequencing. Luciferase reporter assay method was conducted and showed that GG genotype in g.-133 (mutant) increased the promoter activity than did CC (wildtype). We performed DNAStar Protean Software to detect the hydrophilicity and secondary structure of the HSP70–1 protein. The results revealed the SNP in the coding region (g. 462 G/T) was found to bring changes to the amino acid sequence at 154 Gln → His. These results suggested that the genetic polymorphisms in the HSP70–1 gene may influence the heat resistance, and it can be used as a molecular marker in thermoregulation. Therefore, this study may prove beneficial of these markers in genetic selections for heat tolerance in Chinese Holstein.