title: Crustacean intersexuality is feminization without demasculinization: implications for environmental toxicology.
abstract: The dysfunction associated with intersexuality in vertebrates and molluscs is often a serious threat to ecosystems. Although poorly understood, crustacean intersexuality is associated with contamination and includes forms linked to increased sex-ratio distorting parasites at polluted sites. Despite the importance of crustaceans for monitoring vulnerable aquatic habitats, little is known about the molecular basis of this abnormal sexual differentiation and any associated sexual dysfunction. To increase the relevance of crustaceans to environmental toxicologists, we comprehensively analyzed gene expression in amphipods presenting parasite- and nonparasite-associated intersexuality. Our findings reveal existing vertebrate biomarkers of feminization should not be applied to crustaceans, as orthologous genes are not induced in feminized amphipods. Furthermore, in contrast to vertebrates, where feminization and intersexuality is often associated with deleterious demasculinization, we find males maintain masculinity even when unambiguously feminized. This reveals a considerable regulatory separation of the gene pathways responsible for male and female characteristics and demonstrates that evidence of feminization (even if detected with appropriate biomarkers) is not a proxy for demasculinization in crustaceans. This study has also produced a comprehensive spectrum of potential molecular biomarkers that, when combined with our new molecular understanding, will greatly facilitate the use of crustaceans to monitor aquatic habitats.
authors.affiliation: Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth , Ferry Road, Portsmouth, Hampshire PO4 9LY, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Short
authors.forename: Gongda
authors.initials: G
authors.lastname: Yang
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Guler
authors.forename: Amaia
authors.initials: A
authors.lastname: Green Etxabe
authors.forename: Peter
authors.initials: P
authors.lastname: Kille
authors.forename: Alex T
authors.initials: AT
authors.lastname: Ford
mesh_terms: D033304:Amphipoda; D000818:Animals; D015415:Biomarkers; D003445:Crustacea / Q000187:drug effects*; D012734:Disorders of Sex Development / Q000150:complications*; D054750:Ecotoxicology; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D005262:Feminization; D008297:Male; D010052:Ovariectomy; D012727:Sex Characteristics; D019849:Sex Determination Processes; D012733:Sex Differentiation / Q000187:drug effects* / Q000502:physiology; D012744:Sex Ratio; D013045:Species Specificity
chemical_list: D015415:Biomarkers; D052244:Endocrine Disruptors