title: Imposex development in Nucella lapillus--evidence for the involvement of retinoid X receptor and androgen signalling pathways in vivo.
abstract: Imposex in female gastropods is a widely documented masculinisation phenomenon in response to tributyltin (TBT) exposure. Although it is generally accepted that imposex is a case of endocrine disruption the underlying mechanisms are controversially discussed with aromatase inhibition and retinoid X receptor (RXR) signalling pathways as two conflicting hypotheses. Hence, we performed injection experiments with the marine dogwhelk Nucella lapillus. As expected TBT induced imposex in all test specimens while the natural RXR ligand 9 cis-retinoic acid did not cause significant effects. Additionally, TBT effects were suppressed if the organotin compound was simultaneously injected with an androgen receptor inhibitor (cyproterone acetate) but not if co-administered with the synthetic RXR antagonist HX531. In contrast, the injection of the RXR agonist HX630 resulted in imposex development in nearly 100% females. Therefore, the results provide evidence for the involvement of the RXR and the androgen signalling pathway. Further investigations are necessary to resolve the biochemical mechanism of imposex development.
authors: Johann Wolfgang Goethe University Frankfurt am Main, Department Aquatic Ecotoxicology, Max-von-Laue-Str. 13, 60438 Frankfurt, Germany. Stange@bio.uni-frankfurt.de
authors: Daniela
authors: D
authors: Stange
authors: Agnes
authors: A
authors: Sieratowicz
authors: Jörg
authors: J
authors: Oehlmann
mesh_terms: D000728:Androgens / Q000378:metabolism*; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D047072:Aromatase Inhibitors / Q000633:toxicity; D012734:Disorders of Sex Development / Q000139:chemically induced / Q000662:veterinary; D052244:Endocrine Disruptors / Q000633:toxicity; D004703:Endocrine System / Q000187:drug effects / Q000378:metabolism; D005260:Female; D049851:Gastropoda / Q000187:drug effects / Q000502:physiology*; D047488:Retinoid X Receptors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014220:Trialkyltin Compounds / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D000728:Androgens; D047072:Aromatase Inhibitors; D052244:Endocrine Disruptors; D047488:Retinoid X Receptors; D014220:Trialkyltin Compounds; D014874:Water Pollutants, Chemical; C011559:tributyltin; D001141:Aromatase