Heat pretreatment induces thermotolerance in the Jinjiang oyster (Crassostrea ariakensis Gould)
ZHANG qi-zhong1,2, QIU ma-yin3, WU xin-zhong1, PAN Jin-pei1
1. South China Sea Institute of Oceanology, The Chinese Academy of Sciences, Guangzhou 510301, China; 2. Institute of Hydrobiology, Jinan University, Guangzhou 510632; 3. Marine and Fishery Bureau of Yangxi County, Yangxi County 529800, Guangdong, China
Jinjiang oysters, Crassostrea ariakensis, were subjected to heat shock at various temperatures (38℃、39℃、40℃、 41℃、42℃、43℃) for 1.5h, and then transferred to the ambient temperature seawater for 3 days. The results showed the 50% mortality (LT50) temperature for Jinjiang oyster was 40℃, sublethal temperature was 36℃ and lethal temperature was 42℃.The experiments also indicated that exposure to sublethal temperature dramatically enhances thermotolerance. Oysters both exposed to a single nonlethal heat shock (36℃ for 1.5 h) and subsequently recovered for 6 h in ambient temperature seawater acquired a tolerance to a subsequent exposure previously determined to be lethal (42℃ for 1.5h), i.e., the oysters pretreated with nonlethal heat shock were in a survival rate of 96.7% which was significantly higher than that the control treatment.
[1] Beattie J H, Davis S L, Downing S L & Chew K K. 1988.Summer mortality in oysters[A]. In: W. S. Fisher (ed).American Fisheries Society Special Publication 18: 265-268.
[2] Littlewood DT J & Ford S E. 1990. Physiological responses to acute temperature elevation in oysters. Crassostrea virginica, parasitized by Haplosporidium nelsoni (MSX)[J]. J Shellfish Res, 9: 159-163.
[3] Shamseldin A A, Clegg J, Friedman C S, et al. 1997. lnduced thermotolerance in the pacific oyster, Crassostrea gigas[J]. J shellfish Res, 16 (2): 487-491.
[4] Clegg J S, Uhlinger K R, Jackson S A, et a. 1998. Induced thermotolerance and the heat shock protein-70 family in the Pacific oyster Crassostrea gigas[J]. Mol Mar Biol Biot,7: 21-30.
[5] Dubeau S F, Pan F, Tremblay G C, et al. 1998. Thermal shock of salmon in vivo induces the heat shock protein hsp 70 and confers protection against osmotic shock[J]. Aquaculture, 168:311-323.
[6] Tedengren M, Olsson B, Reimer O, et al. 1999. Heat pretreatment increases cadmium resistance and HSP70 levels in Baltic Sea mussels[J]. Aquat Toxicol, 48: 1-12.
[7] Kiang J G, Ding X Z & McClain D E. 1996. Thermotolerance attenuates heat-induced increases in [Ca2+] i and HSP72synthesis but not heat-induced intracellular acidification in human A-431 cell [J]. JInvestig Med, 44: 53-63.
[8] Riabowol K T, Mizzen L A & Welch W J. 1988. Heat shock is lethal to fibroblasts microinjected with antibodies against hsp70[J]. Science, 242: 433-436.
