Shell protein characteristics and vitellogenin-like proteins in brine shrimp Artemia franciscana exposed to municipal effluent and 20-hydroxyecdysone.
We developed biomarkers to monitor the endocrine-disrupting potential of contaminants and municipal effluents in aquatic arthropods. Artemia fransciscana shrimp were cultured and exposed to increasing concentrations of 20-hydroxyecdysone (20HE) and solid phase (C-8) municipal effluent extract (MEE) for 48 h at 20 degrees C. The levels of vitellogenin (Vtg)-like proteins, alkali-labile phosphates in total proteins and acetylcholinesterase (AChE) activity were determined in soft tissues. The levels of acid-soluble, alkali-soluble (sclerotin), neutral-soluble (arthropodin) proteins and chitin were determined to characterize the maturation state of shells. Both 20HE and the municipal effluent extract readily increased the total activity of acetylcholinesterase, alkali-labile phosphates in proteins and vitellogenin-like proteins in brine shrimp. In shells, 20HE and the effluent extract increased the proportion of chitin in shells and acid-soluble proteins but were not statistically significant for the latter. The proportion of sclerotin was increased by 20HE but was not changed by the effluent extract. The proportion of arthropodin was decreased by both 20HE and the effluent extract. Correlation analysis revealed that, as expected, the proportion of acid-soluble protein for biomineralisation and chitin levels were positively correlated and the proportion of arthropodin and sclerotin were negatively correlated in shells exposed to 20HE. Principal component analysis revealed that the proportion of chitin, arthropodin, sclerotin and acid-soluble proteins explained 63% of the responses. Shell protein and carbohydrate contents, controlled by the molting hormone 20HE, could be used as efficient markers for ecdysial properties of various contaminants. The municipal effluent appears to contain ecdysial-like chemicals that are capable of producing changes in shell protein composition that are similar to 20HE.
Gagné
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St. Lawrence Centre, Environment Canada, 105 McGill St., Montréal, Québec, Canada H2Y 2E7. francois.gagne@ec.gc.ca
Blaise
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D000110:Acetylcholinesterase / Q000032:analysis / Q000378:metabolism; D000818:Animals; D001156:Artemia / Q000187:drug effects* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D002686:Chitin / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004441:Ecdysterone / Q000633:toxicity*; D006727:Hormone Antagonists / Q000633:toxicity*; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D012722:Sewage / Q000009:adverse effects*; D014819:Vitellogenins / Q000378:metabolism*
D015415:Biomarkers; D006727:Hormone Antagonists; D011506:Proteins; D012722:Sewage; D014819:Vitellogenins; C013247:sclerotin; D002686:Chitin; D004441:Ecdysterone; D000110:Acetylcholinesterase