title: β-Catenin/Tcf signaling in murine oocytes identifies nonovulatory follicles.
abstract: WNTS are secreted glycoprotein molecules that signal through one of three signaling pathways. The best-characterized pathway involves stabilization of the multifunctional protein β-catenin, which in concert with members of the T-cell factor (Tcf) family activates specific gene transcription. We have examined putative Wnt/β-catenin in the murine ovary using transgenic mice harboring a reporter construct that activates β-galactosidase (lacZ) expression in response to β-catenin/Tcf binding (TopGal mice). Primordial and primary follicles did not stain for lacZ, and the proportion of β-catenin/Tcf signaling oocytes was lower than that of nonsignaling oocytes throughout estrous cycle. β-Catenin/Tcf signaling oocytes were observed in follicles from the secondary stage of development and their proportion increased with follicular maturation (secondary follicles, 20%; early antral and antral follicles, 70%). In contrast, the majority (>90%) of ovulated oocytes did not stain for lacZ. As the oocyte possesses components for WNT signal transduction, our data suggest that β-catenin/Tcf signaling is involved in the development of follicular ovulatory capability and identifies nonovulatory follicles.
authors.affiliation: Department of Experimental Medicine, McGill University, Montreal, Quebec, Canada. macalister.usongo@mail.mcgill.ca
authors.forename: Macalister
authors.initials: M
authors.lastname: Usongo
authors.forename: Aida
authors.initials: A
authors.lastname: Rizk
authors.forename: Riaz
authors.initials: R
authors.lastname: Farookhi
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D030762:Estrous Cycle; D005260:Female; D006062:Gonadotropins / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009865:Oocytes / Q000378:metabolism*; D006080:Ovarian Follicle / Q000378:metabolism*; D010060:Ovulation / Q000378:metabolism*; D051820:TCF Transcription Factors / Q000378:metabolism*; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000378:metabolism*; D001616:beta-Galactosidase
chemical_list: D015415:Biomarkers; C495267:CTNNB1 protein, mouse; D006062:Gonadotropins; D051820:TCF Transcription Factors; D051176:beta Catenin; D001616:beta-Galactosidase