Prolonged thermotolerance in the flesh fly, Sarcophaga crassipalpis, does not require continuous expression or persistence of the 72 kDa heat-shock protein

Abstract

A brief exposure to a supraoptimal temperature (35–45°C) induced thermotolerance in pharate adults of the flesh fly Sarcophaga crassipalpis. While a 90 min exposure to 45°C was normally lethal to flies reared at 25°C, a brief pretreatment at high temperature generated protection from heat-shock injury. The induction of thermotolerance was dependent upon both the temperature and duration of the pretreatment, and in this study maximal thermotolerance was induced by a 2 h exposure to 40°C. Thermotolerance induced by a 2 h exposure to 40°C decayed slowly over a 72 h period. This prolonged thermotolerance appears to be independent of the continuous synthesis and persistence of heat-shock proteins.