TY - JOUR T1 - Genotoxicity of diuron and glyphosate in oyster spermatozoa and embryos A1 - Akcha,Farida A1 - Spagnol,Charlene A1 - Rouxel,Julien AD - IFREMER, Lab Ecotoxicol, Dept Biogeochem & Ecotoxicol, F-44311 Nantes 03, France. UR - https://doi.org/10.1016/j.aquatox.2011.10.018 DO - 10.1016/j.aquatox.2011.10.018 KW - Genotoxicity KW - Embryotoxicity KW - Oyster KW - Gametes KW - Pesticides KW - Diuron KW - Glyphosate N2 - We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with the surrounding waters and are hence particularly exposed to these potentially dangerous substances. In the course of this study, differences in genotoxic and embryotoxic responses were observed in the various experiments, possibly due to differences in pollutant sensitivity between the tested genitor lots. Glyphosate and Roundup had no effect on oyster development at the concentrations tested, whereas diuron significantly affected embryo-larval development from the lowest tested concentration of 0.05 mu g L-1, i.e. an environmentally realistic concentration. Diuron may therefore have a significant impact on oyster recruitment rates in the natural environment. Our spermiotoxicity study revealed none of the tested herbicides to be cytotoxic for oyster spermatozoa. However, the alkaline comet assay showed diuron to have a significant genotoxic effect on oyster spermatozoa at concentrations of 0.05 mu g L-1 upwards. Conversely, no effects due to diuron exposure were observed on sperm mitochondrial function or acrosomal membrane integrity. Although our initial results showed no negative effect on sperm function, the possible impact on fertilization rate and the consequences of the transmission of damaged DNA for oyster development and physiological performances, requires further investigation. A likely hypothesis to explain the embryotoxic and genotoxic effects of diuron is that it may act via causing oxidative stress. (C) 2011 Elsevier B.V. All rights reserved. Y1 - 2012/01 PB - Elsevier Science Bv JF - Aquatic Toxicology SN - 0166-445X VL - 106 SP - 104 EP - 113 ID - 18128 ER -