THERMOTOLERANCE IDENTIFICATION IN WATER BUFFALO USING HEAT SHOCK PROTEIN 70 (HSP70) AND ITS EFFECT TO SEMEN QUALITY IN VARYING ENVIRONMENTAL CONDITIONS

Abstract

The synthesis of Heat Shock Proteins (HSPs) acts as a countermeasure for cel­lular protection when certain environmental parameters exceeded tolerable ranges and threatened cell survival. HSP70, one of the major HSPs is com­monly induced in sperm of livestock animals and found to be associated with semen quality and fertility. This study aimed to determine and evaluate the role of HSP70 in semen quality and thermotolerance of water buffalo as affected by seasonal variations. Total RNA was isolated from the ejaculates of twenty regular semen donor bulls during four seasons and was subjected to Real-time PCR for the analysis of the HSP70 expression. The relative expression value of HSP70 was found to be significantly (P<0.05) highest (1.12) during the hottest season while significantly (P<0.05) least (0.55) on the coldest season. A moder­ately positive correlation was observed between HSP70 expression and semen quality (r=0.26-0.30). It was also found that individual bulls are capable of ex­pressing significantly (P<0.05) different HSP70 levels from 0.156-1.79. In con­clusion, the expression of HSP70 in semen can be a good indicator of thermo­tolerance and thermoresistance in water buffaloes as well as its semen quality, allowing it to be a potential biomarker for heat stress of an animal.