Non-lethal heat shock induces Hsp70 synthesis and promotes tolerance against heat, ammonia and metals in post-larvae of the white leg shrimp Penaeus vannamei (Boone, 1931)

Exposure to temperatures above ambient compromises normal physiological processes and adversely affects aquatic organisms. Nonetheless, non-lethal heat shock (NLHS) protects aquatic organisms against abiotic and biotic stress, perhaps due in part to the accumulation of heat shock protein 70 (Hsp70), a well conserved molecular chaperone. Hsp70 protects cells against stress-induced damage by assisting in the recovery of misfolded proteins, facilitating the folding of nascent proteins and promoting protein degradation. In this study, the immunoprobing of western blots containing protein extracts from the caudal muscle of heated and non-heated postlarvae (PL) of the shrimp, Penaeus vannamei with an antibody specific to Hsp70 revealed that NLHS enhanced Hsp70 build-up in the caudal tissues of shrimp PL. Moreover, exposure to NLHS protected P. vannamei PL against heat, ammonia and heavy metals. The findings in this paper indicate that Hsp70 synthesized in response to NLHS contributed to the protection of P. vannamei PL against several different abiotic stressors. Such findings are potentially useful in the formulation of strategies to protect Penaeid shrimps against environmental stresses during aquaculture.