title: Brain aromatase (Cyp19A2) and estrogen receptors, in larvae and adult pejerrey fish Odontesthes bonariensis: Neuroanatomical and functional relations.
abstract: Although estrogens exert many functions on vertebrate brains, there is little information on the relationship between brain aromatase and estrogen receptors. Here, we report the cloning and characterization of two estrogen receptors, alpha and beta, in pejerrey. Both receptors' mRNAs largely overlap and were predominantly expressed in the brain, pituitary, liver, and gonads. Also brain aromatase and estrogen receptors were up-regulated in the brain of estradiol-treated males. In situ hybridization was performed to study in more detail, the distribution of the two receptors in comparison with brain aromatase mRNA in the brain of adult pejerrey. The estrogen receptors' mRNAs exhibited distinct but partially overlapping patterns of expression in the preoptic area and the mediobasal hypothalamus, as well as in the pituitary gland. Moreover, the estrogen receptor alpha, but not beta, were found to be expressed in cells lining the preoptic recess, similarly as observed for brain aromatase. Finally, it was shown that the onset expression of brain aromatase and both estrogen receptors in the head of larvae preceded the morphological differentiation of the gonads. Because pejerrey sex differentiation is strongly influenced by temperature, brain aromatase expression was measured during the temperature-sensitive window and was found to be significantly higher at male-promoting temperature. Taken together these results suggest close neuroanatomical and functional relationships between brain aromatase and estrogen receptors, probably involved in the sexual differentiation of the brain and raising interesting questions on the origin (central or peripheral) of the brain aromatase substrate.
authors.affiliation: Laboratorio de Ictiofisiología y Acuicultura, Instituto Tecnologico de Chascomus (IIB-INTECH) (CONICET-UNSAM), Camino de Circunvalacion Laguna, B7130IWA Chascomus, Buenos Aires, Argentina.
authors.forename: Pablo H
authors.initials: PH
authors.lastname: Strobl-Mazzulla
authors.forename: Christèle
authors.initials: C
authors.lastname: Lethimonier
authors.forename: Marie Madeleine
authors.initials: MM
authors.lastname: Gueguen
authors.forename: Makiko
authors.initials: M
authors.lastname: Karube
authors.forename: Juan I
authors.initials: JI
authors.lastname: Fernandino
authors.forename: Goro
authors.initials: G
authors.lastname: Yoshizaki
authors.forename: Reynaldo
authors.initials: R
authors.lastname: Patiño
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Strüssmann
authors.forename: Olivier
authors.initials: O
authors.lastname: Kah
authors.forename: Gustavo M
authors.initials: GM
authors.lastname: Somoza
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology / Q000502:physiology*; D003001:Cloning, Molecular; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D010473:Perciformes / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D012333:RNA, Messenger; D011960:Receptors, Estrogen; D004958:Estradiol; D001141:Aromatase