Association of HSF1 Genetic Variation with Heat Tolerance in Chinese Cattle

SIMPLE SUMMARY: China harbors two lineages of cattle (Bos taurus and Bos indicus). North China bears Bos taurus. Bos indicus predominantly belong to south China, whereas in central China there is an admixture of Bos taurus and Bos indicus, representing a discontinuity with north and south China. It has been reported that Bos indicus are more heat resistant than Bos taurus and heat stress can damage the structure of protein. Heat shock factor1 (HSF1) is a candidate heat tolerance gene which works by increasing expression of nascent heat shock proteins (HSPs), promoting the refolding of denatured proteins. Conversely, despite its importance, the effects of the bovine HSF1 gene on heat tolerance traits in Chinese cattle remain unknown. Our results suggest that a missense mutation of the HSF1 gene is associated with the heat tolerance capability of Chinese cattle. ABSTRACT: The heat shock factor 1 (HSF1) gene is a regulator of the heat stress response, maximizing HSP protein expression survival. In this research, we explored the frequency distribution of a missense mutation (NC_037341.1 g.616087A > G, rs135258919) in the HSF1 gene in Chinese cattle with amino acid substitution, valine to alanine. This mutation could be related to the heat tolerance in Bos indicus. A total of 941 individuals representing 35 Chinese native cattle breeds, combining pure taurine (Angus) and indicine cattle, were used to determine the genotypes of the mutation through PCR and partial DNA sequencing. The results showed significant differences in allele frequencies and their genotypes amongst Chinese cattle from different regions. Allele G or indicine-specific allele frequency diminished from south to north China, while allele A (genotype AA) or the taurine-specific allele had a contrary pattern, which agreed with the distribution of taurine and indicine cattle. According to the association analysis, the NC_037341.1 g.616087A > G (rs135258919) of the bovine HSF1 gene, annual temperature (T), relative humidity (RH), and the temperature humidity index (THI) (p < 0.01) were interrelated closely, which indicated that the NC_037341.1 g.616087A > G of the HSF1 gene is associated with heat tolerance in indicine cattle.