ABSTRACT
The superposition of male sexual characteristics in female marine gastropods (imposex) represents one of the clearest ecological examples of organotin-mediated endocrine disruption. Recent evidences suggest that signaling pathways mediated by members of the nuclear receptor superfamily, RXR and PPARγ, are involved in the development of this pseudohermaphroditic condition. Here, we identified significant differences in RXR expression in two caenogastropod species from Nuevo Gulf, Argentina, Buccinanops globulosus and Trophon geversianus, which present clear contrast in imposex incidence. In addition, B. globulosus males from a polluted and an unpolluted area showed differences in RXR expression. Conversely, PPARγ levels were similar between both analyzed species. These findings indicate specie-specific RXR and PPARγ expression, suggesting a major role of RXR in the induction of imposex.
Subject(s)
Disorders of Sex Development/metabolism , Gastropoda , Gene Expression Regulation, Developmental , Retinoid X Receptors/metabolism , Animals , Disease Susceptibility , Disorders of Sex Development/pathology , Female , Male , PPAR gamma/metabolismABSTRACT
The imposex incidence and TBT pollution were investigated along 4,700km of Argentinean coast, including city harbors and proximal zones without marine traffic. We analyzed 1805 individuals from 12 gastropod species, including families Volutidae, Muricidae, Nassariidea, Calyptraidae, Marginellidae, and Buccinidae, and found the imposex phenomenon for the first time in six species. In high marine traffic zones, TBT pollution was registered and the percentage of imposex was high, while these occurrences were null in areas without boat traffic. The species that best reflect the degree of imposex were those inhabiting sandy/muddy or mixed bottoms. TBT determination and imposex incidence indicate that pollution was focused only in ports with high marine traffic or in areas where ship hulls are painted. This is the first report of an imposex-sediment approach to evaluate organotin contamination along the coast of a South American country.
