Meeting Abstract

P3.208  Sunday, Jan. 6  AMPK activity as an indicator of seasonal temperature acclimation in the zebra mussel, Dreissena polymorpha JOST, JA*; ABOU-HANNA, JJ; Bradley University jjost@bradley.edu

Invertebrate temperature stress has been widely examined in the context of climate change and there is a strong interest in measuring thermal stress for invertebrate species. Previous work on crustaceans shows that AMP-activated protein kinase (AMPK) activity can indicate high temperature stress and detect sublethal temperature ranges where survival is possible but growth and reproduction may be limited. The freshwater zebra mussel, Dreissena polymorpha, is an invasive aquatic species capable of biofouling hard substrates, including organisms, boat ramps and industrial equipment. Previous work indicates zebra mussels are capable of thermal acclimation depending on incubation temperature. However, little is known about the cellular mechanism of temperature stress, thermal acclimation or sublethal temperature range for this species. In this study, we investigated the potential for AMPK activity to indicate (a) sublethal temperature stress in the zebra mussel and (b) thermal acclimation relative to seasonal variation in river temperature. Mussels were collected every 30 days for 1 year, exposed to progressive temperature increases and harvested every 2°C until lethal temperature was reached. Results indicate that AMPK activity increases as temperature stress occurs and that maximum AMPK activity levels vary with river temperature. Mussels collected in winter show dramatic increases in AMPK activity at low temperatures while AMPK activity increases in summer mussels only near the lethal temperature. Our results suggest that zebra mussels are acclimating seasonally and that this response is detectable using a cellular stress marker. This research is the first step in determining sublethal temperatures and the abiotic factors that may limit future invasions.