Identification of expressed HSP's in blacklip abalone (Haliotis rubra Leach) during heat and salinity stresses

Both prokaryotes and eukaryotes express a set of highly conserved proteins in response to external and internal stress. The stressors include tissue trauma, anoxia, heavy metal toxicity, infection, changed salinity, and the most characterized, heat shock. The result is an expression of stress proteins or heat shock proteins (HSP's) which lead to protection of protein integrity, and also to tolerance under continued heat stress conditions. The Australian blacklip abalone Haliotis rubra is found principally in southern coastal waters and also in estuarine/bay environments. Estuarine/bay environments have greater fluctuations in environmental conditions, especially those of salinity and water temperature, than are found along oceanic coasts. Abalone from estuarine/bay and oceanic coastal environments were subjected to either increased temperature (2 degrees C/day for a total of 10 degrees C) or hyposalinity (80% seawater). Estuarine/bay abalone were less affected than the oceanic animals by temperature increase and also demonstrated the ability to volume regulate 3 h after the initial salinity shock. SDS-PAGE and Western blotting techniques, together with dot blots of total protein, using HSP70 specific antibodies, were used to detect HSP70s in the foot muscle of the animals and indicated an expression of HSP70 in response to heat shock in abalone, but not following hyposalinity shock. RT-PCR yielded a partial cDNA clone of HSP70 from the foot muscle..