title: Activation of AMP-activated protein kinase in response to temperature elevation shows seasonal variation in the zebra mussel, Dreissena polymorpha.
abstract: Global climate change is affecting ectothermic species, and a variety of studies are needed on thermal tolerances, especially from cellular and physiological perspectives. This study utilized AMP-activated protein kinase (AMPK), a key regulator of cellular energy levels, to examine the effects of high water temperatures on zebra mussel (Dreissena polymorpha) physiology. During heating, AMPK activity increased as water temperature increased to a point, and maximum AMPK activity was detected at high, but sublethal, water temperatures. This pattern varied with season, suggesting that cellular mechanisms of seasonal thermal acclimatization affect basic metabolic processes during sublethal heat stress. There was a greater seasonal variation in the water temperature at which maximum AMPK activity was measured than in lethal water temperature. Furthermore, baseline AMPK activity varied significantly across seasons, most likely reflecting altered metabolic states during times of growth and reproduction. In addition, when summer-collected mussels were lab-acclimated to winter and spring water temperatures, patterns of heat stress mirrored those of field-collected animals. These data suggest that water temperature is the main driver of the seasonal variation in physiology. This study concluded that AMPK activity, which reflects changes in energy supply and demand during heat stress, can serve as a sensitive and early indicator of temperature stress in mussels.
authors.affiliation: Biology Department, Bradley University, Peoria, IL 61625, USA. Electronic address: jjost@bradley.edu.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Jost
authors.affiliation: Biology Department, Bradley University, Peoria, IL 61625, USA.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Keshwani
authors.affiliation: Biology Department, Bradley University, Peoria, IL 61625, USA.
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Abou-Hanna
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000064:Acclimatization; D000220:Adaptation, Biological; D000818:Animals; D057231:Climate Change; D049875:Dreissena / Q000502:physiology*; D004789:Enzyme Activation; D012621:Seasons; D013312:Stress, Physiological; D013696:Temperature
chemical_list: D055372:AMP-Activated Protein Kinases
keywords: AMPK; Acclimation; Climate change; HSP; Heat stress; Mussel; Season; Sublethal; Temperature