Proteomic Analysis of the Reproductive Organs of the Hermaphroditic Gastropod Lymnea stagnalis Exposed to Different Endocrine Disrupting Chemicals

Many studies have reported perturbations of mollusc reproduction following exposure to low concentrations (ng/L
range) of endocrine disrupting chemicals (EDCs). However, the mechanisms of action of these molecules on
molluscs are still poorly understood. Investigation of the modifications of protein expression in organisms exposed to
chemicals using proteomic methods can provide a broader and more comprehensive understanding of adverse
impacts of pollution on organisms than conventional biochemical biomarkers (e.g., heat-shock proteins,
metallothioneins, GST, EROD). In this study we have investigated the impacts of four chemicals, which exhibit
different endocrine disrupting properties in vertebrates, on the proteome of the hermaphroditic freshwater pulmonate
gastropod Lymnaea stagnalis after 21 days of exposure. Testosterone, tributyltin, chlordecone and cyproterone
acetate were chosen as tested compounds as they can induce adverse effects on the reproduction of this snail. The
2D-DIGE method was used to identify proteins whose expression was affected by these compounds. In addition to
modifying the expression of proteins involved in the structure and function of the cytoskeleton, chemicals had impacts
on the expression of proteins involved in the reproduction of L. stagnalis. Exposure to 19.2 μg/L of chlordecone
increased the abundance of ovipostatin, a peptide transmitted during mating through seminal fluid, which reduces
oviposition in this species. The expression of yolk ferritin, the vitellogenin equivalent in L. stagnalis, was reduced after
exposure to 94.2 ng Sn/L of tributyltin. The identification of yolk ferritin and the modification of its expression in snails
exposed to chemicals were refined using western blot analysis. Our results showed that the tested compounds
influenced the abundance of yolk ferritin in the reproductive organs. Alteration in proteins involved in reproductive
pathways (e.g., ovipostatin and yolk ferritin) could constitute relevant evidence of interaction of EDCs with
reproductive pathways that are under the control of the endocrine system of L. stagnalis.