Yao, H.H. The pathway to femaleness: current knowledge on embryonic development of the ovary. Mol. Cell. Endocrinol. 230, 87-93
Department of Veterinary Biosciences, University of Illinois at Urbana-Champaign, IL 61802, USA.Molecular and Cellular Endocrinology (Impact Factor: 4.41). 02/2005; 230(1-2):87-93. DOI: 10.1016/j.mce.2004.11.003
Increasing evidence indicates that organogenesis of the ovary is not a passive process arising by default in the absence of the testis pathway. A coordinated interaction is actually in force between somatic cells and female germ cells in embryonic ovaries, thus creating a unique microenvironment that facilitates the formation of follicles. Identification of the functional roles of several novel regulatory elements such as Figalpha, Foxl2, follistatin, and Wnt4 reveals the complexity of early ovarian organization. Challenges await us to establish the molecular connections of these molecules as well as to discover new candidates in the pathway of early ovarian development.
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- "FOXL2 suppresses expression of Dmrt1 and vice versa for maintaining female or male gonadal fate, respectively (Uhlenhaut et al. 2009; Matson et al. 2011). Additionally it has been reported that FOXL2 and WNT4 (Yao 2005; Ottolenghi et al. 2007; Garcia-Ortiz et al. 2009) cooperate in regulating FST expression during ovarian development. Interestingly in the ovary the expression profiles of Foxl2 highly correlate with that of Aromatase (Cyp19), suggesting that Foxl2 is involved in the regulation of estrogen synthesis via direct transcriptional upregulation of Aromatase (Pannetier et al. 2006). "
ABSTRACT: Genetic control of male or female gonad development displays between different groups of organisms a remarkable diversity of “master sex-determining genes” at the top of the genetic hierarchies, whereas downstream components surprisingly appear to be evolutionarily more conserved. Without much further studies, conservation of sequence has been equalized to conservation of function. We have used the medaka fish to investigate the generality of this paradigm. In medaka, the master male sex-determining gene is dmrt1bY, a highly conserved downstream regulator of sex determination in vertebrates. To understand its function in orchestrating the complex gene regulatory network, we have identified targets genes and regulated pathways of Dmrt1bY. Monitoring gene expression and interactions by transgenic fluorescent reporter fish lines, in vivo tissue-chromatin immunoprecipitation and in vitro gene regulation assays revealed concordance but also major discrepancies between mammals and medaka, notably amongst spatial, temporal expression patterns and regulations of the canonical Hedgehog and R-spondin/Wnt/Follistatin signaling pathways. Examination of Foxl2 protein distribution in the medaka ovary defined a new subpopulation of theca cells, where ovarian-type aromatase transcriptional regulation appears to be independent of Foxl2. In summary, these data show that the regulation of the downstream regulatory network of sex determination is less conserved than previously thought.
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- "Sex determination and differentiation are complex processes that are better understood in mammals than in other taxa. The mammalian Y-chromosome specific gene, SRY, activates an early gene cascade that inhibits the female pathway and diverts cell fate toward the formation of testes, whereas without SRY present on X chromosomes, the gonads are driven toward ovarian differentiation (Yao, 2005; Wilhelm et al., 2007). Recently several different master sex-determining genes have been identified in fish species, including DMY/dmrt1bY and Gsdf Y in medaka (Oryzias latipes and O. luzonensis, respectively), amhy in pejerrey (Odontesthes hatcheri), Amhr2 in pufferfish (Takifugu rubripes), and sdY in rainbow trout (Oncorhynchus mykiss) (Matsuda et al., 2002; Hattori et al., 2012; Kamiya et al., 2012; Myosho et al., 2012; Yano et al., 2012). "
ABSTRACT: Regardless of how sex is determined, the gonadal genes expressed downstream that regulate sex differentiation are relatively conserved among vertebrates. The goal of this study was to clone and characterize five key sex differentiation-related genes in a Scorpaeniform fish, sablefish (Anoplopoma fimbria). Complete mRNA sequences of foxl2, cyp19a1a, dmrt1, sox9a and amh were cloned, sequenced, and phylogenetically analyzed. The sablefish mRNA sequences exhibited the characteristic domains of each gene. The deduced amino sequences were highly conserved in some cases, such as Foxl2, whereas others, such as Amh, exhibited lower homology to corresponding sequences in other vertebrates. Using quantitative PCRs developed for each gene, we found that foxl2 and cyp19a1a mRNA levels were significantly elevated in juvenile sablefish ovaries compared to testes, whereas dmrt1, sox9a and amh mRNA levels were significantly elevated in testes relative to ovaries. These patterns were upheld in our tissue distribution analyses of adult fish, but overall four of the genes, foxl2, cyp19a1a, dmrt1 and amh, were robust markers of sex in sablefish. This study provides important molecular tools for ongoing work related to sex control in sablefish and exploration of the earliest period of molecular sex differentiation and its regulation.
- "U ssaków płcią podstawową jest płeć żeńska. Jeśli nie zadziała sygnał wywoławczy prowadzący do powstania płci męskiej, samorzutnie realizowany zostaje podstawowy wzorzec ekspresji genów prowadzący do powstania płci żeńskiej . Uważa się, że sygnałem wywoławczym jest ekspresja genu Sry, zlokalizowanego na krótkim ramieniu chromosomu Y, w komórkach somatycznych zawiązka gonady. "
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