title: Estrogens disrupt serotonin receptor and cyclooxygenase mRNA expression in the gonads of mussels (Mytilus edulis).
abstract: Estrogenic contaminants in the aquatic environment are associated with feminisation of male fish, however their effects on some invertebrate species, such as bivalve molluscs, have yet to be characterised. Gametogenesis represents a critical step in the reproductive process and is subjected to hormonal control by serotonin (5-HT), prostaglandins (synthesised by cyclooxygenases-COX) and steroids such as 17beta-estradiol (E2). Here, we examine the responses of 5-HT receptor and COX mRNA expression in mussels, Mytilus edulis, exposed to estrogenic compounds during different stages of their reproductive cycle. In mature mussels, 5-HT receptor mRNA expression decreased following E2 exposure. The opposite trend was observed in mussels at early gametogenesis stages. COX mRNA expression levels at both stages were generally decreased by E2 exposure. Mussels at early gametogenesis stages were also exposed to ethynylestradiol (EE2) and estradiol benzoate (EB) and a significant increase in 5-HT receptor mRNA expression was observed with both xeno-estrogens. COX expression levels were increased with EB exposure but no significant effects were found with EE2 exposure. These results show that the natural estrogen, E2, as well as the synthetic estrogen, EE2, induce alterations, dependent on reproductive stage, in the mRNA expression levels of 5-HT receptor and/or COX in the marine bivalve M. edulis.
authors.affiliation: Department of Biology and Environmental Science, University of Sussex, BN1 9QJ Falmer, Brighton, UK.
authors.forename: Elena
authors.initials: E
authors.lastname: Cubero-Leon
authors.forename: Corina M
authors.initials: CM
authors.lastname: Ciocan
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Hill
authors.forename: Makoto
authors.initials: M
authors.lastname: Osada
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Kishida
authors.forename: Naoki
authors.initials: N
authors.lastname: Itoh
authors.forename: Reki
authors.initials: R
authors.lastname: Kondo
authors.forename: Christophe
authors.initials: C
authors.lastname: Minier
authors.forename: Jeanette M
authors.initials: JM
authors.lastname: Rotchell
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D052244:Endocrine Disruptors / Q000633:toxicity*; D004958:Estradiol / Q000031:analogs & derivatives / Q000633:toxicity; D004967:Estrogens / Q000633:toxicity*; D004997:Ethinyl Estradiol / Q000633:toxicity; D005260:Female; D005718:Gametogenesis / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D006066:Gonads / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D049880:Mytilus edulis / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011985:Receptors, Serotonin / Q000235:genetics*; D016415:Sequence Alignment; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D052244:Endocrine Disruptors; D004967:Estrogens; D012333:RNA, Messenger; D011985:Receptors, Serotonin; D014874:Water Pollutants, Chemical; C074283:estradiol 3-benzoate; D004997:Ethinyl Estradiol; D004958:Estradiol; D011451:Prostaglandin-Endoperoxide Synthases