title: Long-Term Acclimation to Different Thermal Regimes Affects Molecular Responses to Heat Stress in a Freshwater Clam Corbicula Fluminea.
abstract: Global climate change (GCC) can negatively affect freshwater ecosystems. However, the degree to which freshwater populations can acclimate to long-term warming and the underlying molecular mechanisms are not yet fully understood. We used the cooling water discharge (CWD) area of a power plant as a model for long-term warming. Survival and molecular stress responses (expression of molecular chaperones, antioxidants, bioenergetic and protein synthesis biomarkers) to experimental warming (20-41 °C, +1.5 °C per day) were assessed in invasive clams Corbicula fluminea from two pristine populations and a CWD population. CWD clams had considerably higher (by ~8-12 °C) lethal temperature thresholds than clams from the pristine areas. High thermal tolerance of CWD clams was associated with overexpression of heat shock proteins HSP70, HSP90 and HSP60 and activation of protein synthesis at 38 °C. Heat shock response was prioritized over the oxidative stress response resulting in accumulation of oxidative lesions and ubiquitinated proteins during heat stress in CWD clams. Future studies should determine whether the increase in thermal tolerance in CWD clams are due to genetic adaptation and/or phenotypic plasticity. Overall, our findings indicate that C. fluminea has potential to survive and increase its invasive range during warming such as expected during GCC.
authors.affiliation: Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC, USA.|I.Ya. Horbachevsky Ternopil State Medical University, Ternopil, Ukraine.
authors.forename: Halina I
authors.initials: HI
authors.lastname: Falfushynska
authors.affiliation: Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC, USA.
authors.forename: Tuan
authors.initials: T
authors.lastname: Phan
authors.affiliation: Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC, USA.|Department of Marine Biology, Institute of Biological Sciences, University of Rostock, Rostock, Germany.
authors.forename: Inna M
authors.initials: IM
authors.lastname: Sokolova
mesh_terms: D000064:Acclimatization; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D018834:Chaperonin 60 / Q000378:metabolism; D057231:Climate Change; D049874:Corbicula / Q000502:physiology*; D005618:Fresh Water; D005978:Glutathione / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology*; D018832:Molecular Chaperones; D018384:Oxidative Stress; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D013696:Temperature; D014874:Water Pollutants, Chemical
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D018834:Chaperonin 60; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D005978:Glutathione