Identification of SNP inHSP90AB1and its Association with the Relative Thermotolerance and Milk Production Traits in Indian Dairy Cattle

Abstract

Heat shock proteins (Hsp) play crucial role in cellular thermotolerance and heat stress response. In the present work, Allele specific PCR (AS-PCR) was standardized to detect the nucleotide polymorphism within the HSP90AB1 gene (SNP g.4338T>C) in Indian breeds of dairy cattle. The identified genotypes were associated with relative thermotolerance in terms of physiological parameters and milk production traits. The results of the experiments revealed that the genotype frequency of CC, CT, and TT for Sahiwal were 0.05, 0.78, and 0.17, respectively, and in Frieswal, the frequencies were 0.20, 0.70, and 0.10, respectively. The average rectal temperature (ART) and average respiration rates (ARR) were recorded during peak summer stress and heat tolerance coefficient (HTC) was calculated. The association studies indicated that TT genotypes had significantly (P < 0.01) higher HTC and lower ARR values than CT and CC in both the breeds. The TT genotype animals also had better production parameter in terms of total milk yield (TMY) (P < 0.01). These findings may partly suggest the role of HSP90AB1 polymorphisms in the regulation of heat stress response and consequent effect on production traits. Nevertheless, involvement of other regulatory mechanisms cannot be overruled.

Polymorphisms in Hsp90ab1 gene and their association with heattolerance in Sahiwal and Karan Fries cows

“…The present study inferred that cows of genotype CT has the least rectal temperature and are able to maintain their body temperature under stress condition compared to other cows. In other studies, it was found that allele T at SNP locus T4338C was found to be associated with lower RT in Thai indigenous, Frieswal and Sahiwal cattle in India (Charoensook et al, 2012, Sajjanar et al, 2015. It is well described that RT of Bos taurus is higher than Bos indicus cattle and, as a result Bos taurus cattle are more sensitive to heat stress than Bos indicus (Mayengbam, 2008;Singh and Upadhyay, 2009).…”

“…The present study inferred that Karan Fries cows of genotype AA recorded least respiration rate per minute and is better thermo-tolerant under stress condition than other cows. Previous studies reported that allele T at SNP locus T4338C was associated with lower RR in Thai indigenous, Sahiwal and Frieswal cattle in India (Charoensook et al, 2012;Sajjanar et al, 2015). Increased respiration is an important thermoregulatory response to heat stress.…”

“…Several studies have shown significant association of SNPs with physiological parameters (RR, PCV, RT and HTC) to evaluate the heat tolerance/stress in cattle (Liu et al, 2010;Liu et al, 2011;Charoensook et al, 2012;Sajjanar et al, 2015). Heat tolerance traits such as RR, RT and HTC of both Sahiwal and Karan Fries cows differed significantly (p<0.01) in all three THI subclasses of different seasons.…”

“…Recently, novel single nucleotide polymorphisms (SNP) were identified at different positions of the bovine Hsp90ab1 gene in Bos taurus, crossbred and Bos indicus cattle. High prevalence of this gene in zebu cattle enable them to survive and perform better to crossbred cattle due to better heat tolerance (Deb et al, 2013;McManus et al, 2014;Sajjanar et al, 2015) The objective of this study was to identify SNPs in the targeted regions of Hsp90ab1 gene in Sahiwal and Karan Fries cows and to analyze the association of genetic variants with thermal stress related physiological parameters, viz. respiration rate, rectal temperature and HTC.…”

Single nucleotide polymorphisms in Heat Shock Protein (HSP) 90AA1 gene and their association with heat tolerance traits in Sahiwal cows

“…Effects of the SNP g.1524G>A, g.3494T>C and g.6601G>A within HSP70A1A affect thermo-tolerance in Chinese Holstein cattle . In contrast allele T at SNP g.4338>C of HSP90AB1 gene was found to be associated with heat tolerance coefficient in Thai native cattle (Charoensook et al, 2013), Sahiwal and Frieswal cattle in India (Deb et al, 2013;Sajjanar et al, 2015). Recently in Jersey crossbred cows found that of CC genotype had better thermo-tolerance capacity at (T17872112C) locus of HSP90AB1 gene .…”