Heat shock protein 70 gene expression in intact salamanders (<i>Eurycea bislineata</i>) in response to calibrated heat shocks and to high temperatures encountered in the field

Abstract

Abstract Synthesis of heat shock proteins (hsps) is a universal response of cells to heat shock. Recent evidence suggests that hsps are involved in the repair of damage caused by heat or other protein‐denaturing insults. We have determined kinetics of induction for the 70 kD heat shock protein (hsp 70) and hsp 70 mRNA in adult salamanders, Eyrycea bislineata . We demonstrate that the extent of expression of the hsp protein and mRNA is proportional to the heat dose but differs with respect to tissue. Hsp 70 synthesis was shown to be controlled primarily at the level of mRNA transcription. Hsp 70 mRNA accumulation is prolonged in the adult animal when compared to cultured cells from other vertebrate ectotherms given similar heat shocks. Additionally, we show that the hottest of four animals captured in the field on a hot summer day had synthesized hsp 70 mRNA in its tissues. These findings are discussed relative to the thermal biology of vertebrate ectotherms.