ESTIMATION OF HEAT SHOCK PROTEIN 70 (Hsp 70) GENE EXPRESSION IN NILE TILAPIA (Oreochromis niloticus) USING QUANTITATIVE REAL-TIME PCR

Abstract

Heat shock protein 70 (Hsp70) is one of family of proteins expressed in response to a wide range of biotic and abiotic stress conditions. Quantitative real-time PCR (qRT-PCR) has been used to study the expression profiles of heat shock protein (Hsp70) gene in Nile tilapia, Oreochromis niloticus. Young fish (30 g) were exposed to different degrees of heat (10, 15, 35, 39) and control (28°C) for 2 and 4 hr., followed by qRT-PCR of Hsp70 mRNA, using Beta actin (ß-Actin) as a reference gene and flourogenic dyes. Expression of Hsp70 gene was different among fish tissues (muscles, gills and liver). In all treatments the expression level detected in male were more than female fish. The highest expression organs after 2 hr., was muscles in both fish sex but after 4 hr., liver recorded the highest expression value at cold shock where muscles recorded the highest expression at heat shock treatments in both fish sex.