title: The zebrafish, brain-specific, aromatase cyp19a2 is neither expressed nor distributed in a sexually dimorphic manner during sexual differentiation.
abstract: Differential cyp19 aromatase expression during development leads to sexual dimorphisms in the mammalian brain. Whether this is also true for fish is unknown. The aim of the current study has been to follow the expression of the brain-specific aromatase cyp19a2 in the brains of sexually differentiating zebrafish. To assess the role of cyp19a2 in the zebrafish brain during gonadal differentiation, we used quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry to detect differences in the transcript or protein levels and/or expression pattern in juvenile fish, histology to monitor the gonadal status, and double immunofluorescence with neuronal or radial glial markers to characterize aromatase-positive cells. Our data show that cyp19a2 expression levels during zebrafish sexual differentiation cannot be assigned to a particular sex; the expression pattern in the brain is similar in both sexes and aromatase-positive cells appear to be mostly of radial glial nature.
authors.affiliation: Centre for Fish and Wildlife Health, University of Bern, Bern, Switzerland. evangelia.kallivretaki@itpa.unibe.ch
authors.forename: Evangelia
authors.initials: E
authors.lastname: Kallivretaki
authors.forename: Rik I L
authors.initials: RI
authors.lastname: Eggen
authors.forename: Stephan C F
authors.initials: SC
authors.lastname: Neuhauss
authors.forename: Olivier
authors.initials: O
authors.lastname: Kah
authors.forename: Helmut
authors.initials: H
authors.lastname: Segner
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics* / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012727:Sex Characteristics; D012733:Sex Differentiation; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D029961:Zebrafish Proteins; D001141:Aromatase; C440729:Cyp19a1a protein, zebrafish