CONICET | Buscador de Institutos y Recursos Humanos

A wide range of substances like pesticides, polychlorinated biphenyls and plasticizers cause endocrine disruption and affect many biological functions. Atrazine (ATZ) is a worldwide used herbicide to control broadleaf and grassy weeds in agricultural practices. Reports have shown that ATZ have endocrine disruptor activity, however their adverse effects on human and animal health remain controversial. The aim of this work is to assess the effects of ATZ treatment in the reproductive development of nematode Caenorhabditis elegans and to evaluate this biological model as a tool to develop protocols to screening pesticides with putative endocrine disrupting activity. C. elegans in L4 larval stage were exposed to different ATZ concentrations (0; 0.001; 0.01; 0.1; 1; 10 mg/L) for 24 hours until the control worms reached adulthood and several parameters of nematode development were measured. Both body length as offspring were decreased on ATZ-treated worms displaying a non-monotonic dose-response curve characteristic of an endocrine disruptor. The maximum effect on body length and offspring was found in 0.001 and 0.01 mg/L ATZ. When the reproductive development was analyzed, the ATZ-treated worms showed a delay in reaching gravid adult stage and a strongly decreased in the gene expression of two yolk protein, vit-2 and vit-6. Finally, the effect of ATZ treatment on body vitellogenin distribution was studied with vit-2::GFP transgene expression. The ATZ-treated worms showed an increased accumulation of enlarged vit-2::GFP containing vesicles in the body cavity and a reduced amount of fluorescence in embryos. Our results suggested that low doses of ATZ can lead to changes on normal expression and trafficking of yolk, thereby interfering with the normal reproductive development and decreasing the reproduction rates in the nematode.