Adverse effect of antifouling compounds on the reproductive mechanisms of the ascidian Ciona intestinalis.
Fertilization and embryo development that occur in sea water are sensitive to xenobiotics from anthropogenic sources. In this work, we evaluated the influence of two antifouling biocides, tributyltin (TBT) and diuron, on the reproductive mechanisms of the marine invertebrate Ciona intestinalis. By using electrophysiological techniques, we examined the impact of these compounds on the electrical properties of the mature oocytes and of events occurring at fertilization. With different toxicity assays, we studied the effect of the two biocides on the gametes by evaluating fertilization rate and embryo development. Results show that sodium (Na⁺) currents were significantly reduced by either of the two biocides, whereas conductance was significantly increased. The fertilization current frequency and amplitude, fertilization rate and larval development were affected only by TBT. This study suggests that: (i) the two biocides affect either the electrical properties of the oocyte plasma membrane and the reproductive success representing a risk factor for the survival of the species exposed to environmental pollution; (ii) the ascidian Ciona intestinalis may represent a good model organism to test toxicity of marine pollutants. Possible mechanisms of action of the two biocides are discussed.
Laboratory of Animal Physiology and Evolution, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples 80121, Italy.
Alessandra
A
Gallo
Elisabetta
E
Tosti
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002938:Ciona intestinalis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D004202:Disinfectants / Q000009:adverse effects*; D004237:Diuron / Q000009:adverse effects; D047108:Embryonic Development / Q000187:drug effects; D005306:Fertilization / Q000187:drug effects; D007448:Invertebrates / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development; D012098:Reproduction / Q000187:drug effects*; D012964:Sodium / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism; D014220:Trialkyltin Compounds / Q000009:adverse effects; D014561:Urochordata / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
D004202:Disinfectants; D015222:Sodium Channels; D014220:Trialkyltin Compounds; C011559:tributyltin; D004237:Diuron; D012964:Sodium