Anaerobic metabolic patterns related to stress responses in hypoxia exposed mussels Mytilus galloprovincialis

作者：Anestis Andreas; Poertner Hans O; Michaelidis Basile^*

来源：Journal of Experimental Marine Biology and Ecology, 2010, 394(1-2): 123-133.

DOI：10.1016/j.jembe.2010.08.008

• Bivalves
• Exposure to air
• Hsps
• Mortality
• PK
• Thermal limits

Air exposure in mussels during summer coincides with the concomitant exposure of the organism to hypoxia and ambient heat. The present study examined the metabolic and molecular stress responses of M. galloprovincialis during exposure to air at different temperatures. Mussel mortality did not rise upon 48 h of air exposure at 18 degrees but increased significantly within the first 20 h of exposure to 32 degrees C. Thermal responses and limits were determined by integrating information from various levels of biological organization. Metabolic impacts were assessed by examining the activity of the key glycolytic enzyme pyruvate kinase (PK). Molecular responses were addressed through the expression of heat shock proteins Hsp70 and Hsp90 and the phosphorylation of stress-activated protein kinases, p38 mitogen-activated protein kinase (p38 MAPK) and cJun-N-terminal kinases (JNKs). PK activity decreased during exposure in a temperature dependent manner indicating a marked reduction of metabolic rate especially when M. galloprovincialis was exposed to 32 degrees C. The heat shock response (HSR) was stimulated in all cases of exposure indicating that hypoxia by itself may induce the expression of Hsp70 and Hsp90 in the tissues of M. galloprovincialis. Increased phosphorylation of p38 MAPK and JNKs indicate activation of MAPK signaling cascades. The potential involvement of MAPKs in the induction of Hsp genes in tissues of M. galloprovincialis during hypoxia is discussed.

• 出版日期2010-10-30