Desiccation elicits heat shock protein transcription in the flesh fly, Sarcophaga crassipalpis, but does not enhance tolerance to high or low temperatures.

Although heat shock protein (hsp) production has been noted in response to multiple environmental stresses, no link has been previously established between desiccation and hsps. Following a nonlethal desiccation at 0% relative humidity (R.H.) for up to 48 h, two heat shock protein transcripts, hsp23 and hsp70, were upregulated in pupae of the flesh fly, Sarcophaga crassipalpis. The transcripts were nearly undetectable in control pupae, but within 24 h after being placed at 0% R.H. high transcript expression was observed. This suggests that protection against desiccation may be linked to the general stress response employed by flesh flies against other environmental stressors such as low or high temperature. Adaptive cross-tolerance to cold shock and heat shock following an hsp-inducing desiccation pretreatment was also tested. Although the two hsp transcripts were upregulated in response to desiccation, the upregulation was less dramatic than the upregulation elicited by heat shock, and desiccation failed to generate tolerance to high or low temperatures.