Heat Shock Protein70 (HSP70) Gene Expression Pattern in Peripheral Blood Mononuclear Cells (PBMCs) during different Seasons in Sahiwal Cows (Bos Indicus)

Thermal stress alters the normal body homeostasis and causes severe detrimental effects on production and productivity of animals. Heat shock proteins (HSPs) are highly conserved family of proteins that are ubiquitously expressed in animal’s body during thermal stress. Out of all the members present in this family, HSP70 is regarded as the most significant indicator of thermal stress. The present study was therefore conducted to demonstrate the relative mRNA expression pattern of HSP70 gene in peripheral blood mononuclear cells (PBMCs) during different seasons in Sahiwal cows (Bos Indicus). Apparently healthy, non lactating and non pregnant sahiwal cows (above two years of age) were taken for study (n = 6). Blood samples were collected thrice i.e. once in December-January (THI <72), between February March (THI = 72) and June (THI > 72). Blood sample collected in thermo neutral zone (THI = 72) was taken as control. Quantitative real-time PCR (qPCR) study was undertaken to investigate the variation in relative mRNA expression profile of HSP70 gene during different seasons. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as a housekeeping gene. The relative expression values of HSP70 during summer season were found statistically significant in comparison to winter. These results suggest that HSP70 gene expression varies with THI and this variation may play an imperative role in conferring thermo tolerance against heat stress during different seasons of a year.