Exposure of Daphnia magna to trichloroethylene (TCE) and vinyl chloride (VC): evaluation of gene transcription, cellular activity, and life-history parameters.
Trichloroethylene (TCE) is a ubiquitous contaminant classified as a human carcinogen. Vinyl chloride (VC) is primarily used to manufacture polyvinyl chloride and can also be a degradation product of TCE. Very few data exist on the toxicity of TCE and VC in aquatic organisms particularly at environmentally relevant concentrations. The aim of this study was to evaluate the sub-lethal effects (10 day exposure; 0.1; 1; 10 µg/L) of TCE and VC in Daphnia magna at the gene, cellular, and life-history levels. Results indicated impacts of VC on the regulation of genes related to glutathione-S-transferase (GST), juvenile hormone esterase (JHE), and the vitelline outer layer membrane protein (VMO1). On the cellular level, exposure to 0.1, 1, and 10 µg/L of VC significantly increased the activity of JHE in D. magna and TCE increased the activity of chitinase (at 1 and 10 µg/L). Results for life-history parameters indicated a possible tendency of TCE to affect the number of molts at the individual level in D. magna (p=0.051). Measurement of VG-like proteins using the alkali-labile phosphates (ALP) assay did not show differences between TCE treated organisms and controls. However, semi-quantitative measurement using gradient gel electrophoresis (213-218 kDa) indicated significant decrease in VG-like protein levels following exposure to TCE at all three concentrations. Overall, results indicate effects of TCE and VC on genes and proteins related to metabolism, reproduction, and growth in D. magna.
Environment Canada, Science and Technology Branch, Centre Saint-Laurent, 105 McGill Street, Montreal, QC, Canada H2Y 2E7. Electronic address: magali.houde@ec.gc.ca.
Magali
M
Houde
Environment Canada, Science and Technology Branch, Centre Saint-Laurent, 105 McGill Street, Montreal, QC, Canada H2Y 2E7. Electronic address: melanie.douville@ec.gc.ca.
Mélanie
M
Douville
Environment Canada, Science and Technology Branch, Centre Saint-Laurent, 105 McGill Street, Montreal, QC, Canada H2Y 2E7. Electronic address: pierre.gagnon@ec.gc.ca.
Pierre
P
Gagnon
Environment Canada, Science and Technology Branch, Prairie and Northern Laboratory for Environmental Testing, 5320 122 St. NW, Edmonton, AB, Canada T6H 3S5. Electronic address: jim.sproull@ec.gc.ca.
Jim
J
Sproull
Environment Canada, Environmental Protection Operations Directorate, 105 McGill Street, Montreal, QC, Canada H2Y 2E7. Electronic address: francois.cloutier@ec.gc.ca.
François
F
Cloutier
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D003621:Daphnia / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014158:Transcription, Genetic / Q000187:drug effects*; D014241:Trichloroethylene / Q000633:toxicity*; D014752:Vinyl Chloride / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D002273:Carcinogens; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D014752:Vinyl Chloride
Cellular activity; Daphnia magna; Gene transcription; Life-history parameters; Trichloroethylene; Vinyl chloride