title: Foxo3b but not Foxo3a activates cyp19a1a in Epinephelus coioides.
abstract: FOXO3 has been shown to be a critical transcription factor for folliculogenesis in mammals, while the information on its roles in reproduction of nonmammalian vertebrates remains scarce. In this study, two foxo3 homologs, namely foxo3a and foxo3b, were identified in a teleost, the orange-spotted grouper Epinephelus coioides. foxo3a was mainly expressed in the central nervous system, ovary, and gut whereas foxo3b was expressed ubiquitously in tissues examined. In contrast to the dominant expression of mammalian FOXO3 in germ cells but barely detectable in ovarian follicular cells, immunoreactive Foxo3a and Foxo3b were identified both in the ovarian germ cells and follicular cells. The immunointensities of both Foxo3a and Foxo3b in ovarian follicular cells during vitellogenesis were significantly increased stage-dependently, and co-localized with Cyp19a1a. In the nucleus of ovarian follicular cells, both Foxo3a and Foxo3b immunostaining could be detected at the vitellogenic stages. Transient transfection and EMSA showed that Foxo3a and Foxo3b upregulated cyp19a1a promoter activities in vitro through a conserved Foxo-binding site, with the latter being a more potent activator. However, ChIP analysis showed that only Foxo3b binds to cyp19a1a proximal promoter region containing the conserved Foxo-binding site in the vitellogenic ovary. Taken together, these results suggested that Foxo3a and Foxo3b are involved in the ovarian development possibly through regulating the ovarian germ cells as well as follicular cells, and Foxo3b but not Foxo3a may activate cyp19a1a in the ovarian follicular cells during vitellogenesis in the orange-spotted grouper.
authors.affiliation: Institute of Aquatic Economic AnimalsSchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China Department of Histology and EmbryologyZunyi Medical College, Zunyi, Guizhou, People's Republic of China.
authors.forename: Qiongyou
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Institute of Aquatic Economic AnimalsSchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Institute of Aquatic Economic AnimalsSchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Boyang
authors.initials: B
authors.lastname: Shi
authors.affiliation: Institute of Aquatic Economic AnimalsSchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Huijie
authors.initials: H
authors.lastname: Lu
authors.affiliation: Department of BiologySchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Aquatic Economic AnimalsSchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China Department of BiologySchool of Life Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China lsszwm@mail.sysu.edu.cn.
authors.forename: Weimin
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D029941:Fish Proteins / Q000378:metabolism*; D051858:Forkhead Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D009928:Organ Specificity; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D021381:Protein Transport; D017422:Sequence Analysis, DNA
chemical_list: D029941:Fish Proteins; D051858:Forkhead Transcription Factors; D019363:Cytochrome P-450 CYP1A1
keywords: Cyp19a1a; Foxo3; orange-spotted grouper Epinephelus coioides; ovarian follicular cell; ovarian germ cell