Department of Experimental Medicine, McGill University, Montreal, Quebec, Canada.
Reproduction. 2012 Dec;144(6):669-76. doi: 10.1530/REP-12-0291. Epub 2012 Sep 24.
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.
WNTS 是分泌的糖蛋白分子，通过三种信号通路之一进行信号传递。研究最充分的途径涉及多功能蛋白 β-catenin 的稳定，β-catenin 与 T 细胞因子 (Tcf) 家族成员协同激活特定基因转录。我们使用携带报告基因构建体的转基因小鼠检查了小鼠卵巢中的推定 Wnt/β-catenin，该报告基因构建体在响应 β-catenin/Tcf 结合时激活β-半乳糖苷酶 (lacZ) 表达（TopGal 小鼠）。原始卵泡和初级卵泡未染色为 lacZ，β-catenin/Tcf 信号卵母细胞的比例在整个发情周期中均低于非信号卵母细胞。在从次级发育阶段的卵泡中观察到 β-catenin/Tcf 信号卵母细胞，并且随着卵泡成熟，其比例增加（次级卵泡，20%；早期和腔前卵泡，70%）。相比之下，大多数（>90%）排卵卵母细胞未染色为 lacZ。由于卵母细胞具有 WNT 信号转导的成分，我们的数据表明 β-catenin/Tcf 信号参与了卵泡排卵能力的发育，并确定了非排卵卵泡。
