title: Transcriptional and cellular responses of the green alga Chlamydomonas reinhardtii to perfluoroalkyl phosphonic acids.
abstract: Perfluoroalkyl phosphonic acids (PFPAs), a new class of perfluoroalkyl substances used primarily in the industrial sector as surfactants, were recently detected in surface water and wastewater treatment plant effluents. Toxicological effects of PFPAs have as yet not been investigated in aquatic organisms. The objective of the present study was to evaluate the effects of perfluorooctylphosphonic acid (C8-PFPA) and perfluorodecylphosphonic acid (C10-PFPA) exposure (31-250μg/L) on Chlamydomonas reinhardtii using genomic (qRT-PCR), biochemical (reactive oxygen species production (ROS) and lipid peroxidation), and physiological (cellular viability) indicators. After 72h of exposure, no differences were observed in cellular viability for any of the two perfluorochemicals. However, increase in ROS concentrations (36% and 25.6% at 125 and 250μg/L, respectively) and lipid peroxidation (35.5% and 35.7% at 125 and 250μg/L, respectively) was observed following exposure to C10-PFPA. C8-PFPA exposure did not impact ROS production and lipid peroxidation in algae. To get insights into the molecular response and modes of action of PFPA toxicity, qRT-PCR-based assays were performed to analyze the transcription of genes related to antioxidant responses including superoxide dismutase (SOD-1), glutathione peroxidase (GPX), catalase (CAT), glutathione S-transferase (GST), and ascorbate peroxidase (APX I). Genomic analyses revealed that the transcription of CAT and APX I was up-regulated for all the C10-PFPA concentrations. In addition, PFPAs were quantified in St. Lawrence River surface water samples and detected at concentrations ranging from 250 to 850pg/L for C8-PFPA and 380 to 650pg/L for C10-PFPA. This study supports the prevalence of PFPAs in the aquatic environment and suggests potential impacts of PFPA exposure on the antioxidant defensive system in C. reinhardtii.
authors.affiliation: Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montreal, Canada H3C 3P8.
authors.forename: David
authors.initials: D
authors.lastname: Sanchez
authors.affiliation: Environment Canada, Centre Saint-Laurent, 105 McGill Street, Montreal, Québec, Canada H2Y 2E7. Electronic address: magali.houde@ec.gc.ca.
authors.forename: Magali
authors.initials: M
authors.lastname: Houde
authors.affiliation: Environment Canada, Centre Saint-Laurent, 105 McGill Street, Montreal, Québec, Canada H2Y 2E7.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Douville
authors.affiliation: Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, Canada L7S 1A1.
authors.forename: Amila O
authors.initials: AO
authors.lastname: De Silva
authors.affiliation: Canada Centre for Inland Waters, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, Canada L7S 1A1.
authors.forename: Christine
authors.initials: C
authors.lastname: Spencer
authors.affiliation: Centre de recherche en toxicologie de l'environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-ville, Montreal, Canada H3C 3P8.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Verreault
mesh_terms: D016825:Chlamydomonas reinhardtii / Q000187:drug effects* / Q000235:genetics; D004789:Enzyme Activation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010088:Oxidoreductases / Q000378:metabolism; D010757:Phosphorous Acids / Q000633:toxicity*; D011792:Quebec; D017382:Reactive Oxygen Species / Q000378:metabolism; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010757:Phosphorous Acids; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases
keywords: Chlamydomonas reinhardtii; Gene transcription; Lipid peroxidation.; Perfluoroalkyl phosphonic acids; Reactive oxygen species