International audience | Amphibians are now recognized as the most endangered group. One of this decline causes is the degradation of their habitat through direct contamination of water, soil leaching, or runoff from surrounding contaminated soils and environments. In the North of France, the extensive industrial activities resulted in massive soil contamination by metal compounds. Mineral amendments were added to soils to decrease trace metal mobility. Because of the large areas to be treated, the use of inexpensive industrial by-products was favored. Two types of fly ashes were both tested in an experimental site with the plantation of trees in 2000. Aim of the present work was to investigate the effects of extracts from metal-contaminated soils treated or not for 10 years with fly ashes on Xenopus laevis oocyte using cell biology approaches. Indeed, our previous studies have shown that the Xenopus oocyte is a relevant model to study the metal ion toxicity. Survival and maturation of oocyte exposed to the soil extracts were evaluated by phenotypic approaches and electrophysiological recordings. An extract derived from a metal-contaminated soil treated for 10 years with sulfo-calcic ashes induced the largest effects. Membrane integrity appeared affected and ion fluxes in exposed oocytes were changed. Thus, it appeared that extracted elements from certain mineral amendments used to prevent the mobility of metals in the case of highly metal-contaminated soils could have a negative impact on X. laevis oocytes.

International audience | Amphibians are now recognized as the most endangered group. One of this decline causes is the degradation of their habitat through direct contamination of water, soil leaching, or runoff from surrounding contaminated soils and environments. In the North of France, the extensive industrial activities resulted in massive soil contamination by metal compounds. Mineral amendments were added to soils to decrease trace metal mobility. Because of the large areas to be treated, the use of inexpensive industrial by-products was favored. Two types of fly ashes were both tested in an experimental site with the plantation of trees in 2000. Aim of the present work was to investigate the effects of extracts from metal-contaminated soils treated or not for 10 years with fly ashes on Xenopus laevis oocyte using cell biology approaches. Indeed, our previous studies have shown that the Xenopus oocyte is a relevant model to study the metal ion toxicity. Survival and maturation of oocyte exposed to the soil extracts were evaluated by phenotypic approaches and electrophysiological recordings. An extract derived from a metal-contaminated soil treated for 10 years with sulfo-calcic ashes induced the largest effects. Membrane integrity appeared affected and ion fluxes in exposed oocytes were changed. Thus, it appeared that extracted elements from certain mineral amendments used to prevent the mobility of metals in the case of highly metal-contaminated soils could have a negative impact on X. laevis oocytes.

International audience | Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup® GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination.

International audience | Pesticides are often found at high concentrations in small ponds near agricultural field where amphibians are used to live and reproduce. Even if there are many studies on the impacts of phytopharmaceutical active ingredients in amphibian toxicology, only a few are interested in the earlier steps of their life cycle. While their populations are highly threatened with extinction. The aim of this work is to characterize the effects of glyphosate and its commercial formulation Roundup® GT Max on the Xenopus laevis oocyte maturation which is an essential preparation for the laying and the fertilization. Glyphosate is an extensively used herbicide, not only known for its effectiveness but also for its indirect impacts on non-target organisms. Our results showed that exposures to both forms of glyphosate delayed this hormone-dependent process and were responsible for spontaneous maturation. Severe and particular morphogenesis abnormalities of the meiotic spindle were also observed. The MAPK pathway and the MPF did not seem to be affected by exposures. The xenopus oocyte is particularly affected by the exposures and appears as a relevant model for assessing the effects of environmental contamination.

Members of the catadromous eel live in various fresh, brackish and marine habitats. Therefore, these eels can accumulate organic pollutants and are a suitable bioindicator species for determining the levels of organic contaminants within different water bodies. The ecological risk for organochlorine compounds (OCs) in Anguilla japonica with various migration patterns, such as freshwater, estuarine and marine residences, was examined to understand the specific accumulation patterns. The concentrations of HCB, ∑HCHs, ∑CHLs and ∑DDTs in the silver stage (maturing) eel were significantly higher than those in the yellow stage (immature) eel, in accordance with the higher lipid contents in the former versus the latter. The OC accumulations were clearly different among migratory types in the eel. The ecological risk of OCs increased as the freshwater residence period in the eel lengthened. The migratory histories and the lipid contents directly affected the OC accumulation in the catadromous eel species.