Brugia pahangi: characterisation of a small heat shock protein cDNA clone

Microfilariae of Brugia pahangi undergo a transition in their life cycle from the homeothermic mammalian host to the poikilothermic mosquito vector. Coincident with this switch, the developmental cycle of the microfilaria is reinitiated. When cultured at mammalian temperatures (37 degrees C), microfilariae express a complex of small heat shock proteins. In order to further characterise this group of proteins a cDNA library was constructed from heat-shocked microfilariae by reverse-transcriptase PCR and then screened with a heterologous probe. A clone which codes for a small heat shock protein was isolated and characterised in detail. Southern blot analysis identified a putative small heat shock protein multigene family. The expression of the small heat shock protein cDNA appears to be controlled at the level of RNA synthesis and is highly stage specific and temperature dependent.