title: Steroidogenesis and phase II conjugation during the gametogenesis of thicklip grey mullet (Chelon labrosus) from a population showing intersex condition.
abstract: Steroidogenesis, the process by which steroid hormones are synthesized, involves a vast number of enzymes and biochemical pathways that are susceptible to chemical modulation. Endocrine disrupting compounds (EDCs) are of special concern since they can alter hormone homeostasis by interfering with synthesis, transport and elimination of hormones. It is important to understand gender differences and the natural variation in steroid balance through gamete development in fish exposed to EDCs. The aim of this study was to determine mRNA levels of genes encoding for Steroidogenic Acute Regulatory (star) protein; the steroidogenic enzymes P450 11β hydroxylase (cyp11b1) and P450 aromatase (cyp19a1a); as well as the phase II conjugation enzymes sulfotransferase (sult) and UDP-glucuronosyltransferase (ugt), together with the activity of P450 aromatase and plasma levels of 17β-estradiol (E2) and 11-ketotestosterone (11-KT), at different gametogenic stages and in intersex individuals of the thicklip grey mullet Chelon labrosus. Results demonstrated that the transcription levels of star, sult and ugt and levels of E2 and 11-KT in plasma significantly changed with the interaction between gender and reproductive stage. Cyp11b1 and cyp19a1a transcription levels were significantly different between genders while the activity of P450 aromatase varied significantly between genders and reproductive stages. Results from a multivariate assessment demonstrated that measured endpoints distinguished male, female and intersex mullets at immature gametogenic stage. Intersex distinction was based on sult, ugt and cyp19a1a transcript levels and P450 aromatase activity. The present work provides data to be used in future experimental designs with C. labrosus species, and gives new clues about the molecular events that lead to intersex occurrence in mullets.
authors.affiliation: CBET Research group, Dept. of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Sarriena z/g, E-48940 Leioa, Basque Country, Spain.
authors.forename: Adriana E
authors.initials: AE
authors.lastname: Sardi
authors.affiliation: CBET Research group, Dept. of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Sarriena z/g, E-48940 Leioa, Basque Country, Spain; Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Areatza z/q, E-48620 Plentzia, Basque Country, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bizarro
authors.affiliation: CBET Research group, Dept. of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Sarriena z/g, E-48940 Leioa, Basque Country, Spain; Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Areatza z/q, E-48620 Plentzia, Basque Country, Spain.
authors.forename: Miren P
authors.initials: MP
authors.lastname: Cajaraville
authors.affiliation: CBET Research group, Dept. of Zoology and Animal Cell Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Sarriena z/g, E-48940 Leioa, Basque Country, Spain; Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Areatza z/q, E-48620 Plentzia, Basque Country, Spain. Electronic address: maren.ortiz@ehu.es.
authors.forename: Maren
authors.initials: M
authors.lastname: Ortiz-Zarragoitia
mesh_terms: D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D012734:Disorders of Sex Development / Q000503:physiopathology*; D052244:Endocrine Disruptors / Q000494:pharmacology; D005260:Female; D005718:Gametogenesis / Q000187:drug effects / Q000502:physiology*; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D023701:Smegmamorpha / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013252:Steroid 11-beta-Hydroxylase / Q000378:metabolism*; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D052244:Endocrine Disruptors; D012739:Gonadal Steroid Hormones; D012333:RNA, Messenger; D013739:Testosterone; D001141:Aromatase; D013252:Steroid 11-beta-Hydroxylase; C003600:11-ketotestosterone
keywords: Chelon labrosus; Intersex; Pasaia harbor; Phase II conjugation; Sex steroids; Steroidogenesis