Burns Carole J, Zhang Jianmin, Brown Erinn C, Van Bibber Alyssa M, Van Es Johan, Clevers Hans, Ishikawa Tomo-o, Taketo M Mark, Vetter Monica L, Fuhrmann Sabine
Department of Neurobiology and Anatomy, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132, USA.
Dev Dyn. 2008 Jun;237(6):1614-26. doi: 10.1002/dvdy.21565.
Recent studies revealed that the Wnt receptor Frizzled-5 (Fzd5) is required for eye and retina development in zebrafish and Xenopus, however, its role during mammalian eye development is unknown. In the mouse embryo, Fzd5 is prominently expressed in the pituitary, distal optic vesicle, and optic stalk, then later in the progenitor zone of the developing retina. To elucidate the role of Fzd5 during eye development, we analyzed embryos with a germline disruption of the Fzd5 gene at E10.25, just before embryos die due to defects in yolk sac angiogenesis. We observed severe defects in optic cup morphogenesis and lens development. However, in embryos with conditional inactivation of Fzd5 using Six3-Cre, we observed no obvious early eye defects. Analysis of Axin2 mRNA expression and TCF/LEF-responsive reporter activation demonstrate that Fzd5 does not regulate the Wnt/beta-catenin pathway in the eye. Thus, the function of Fzd5 during eye development appears to be species-dependent.
最近的研究表明，Wnt受体卷曲蛋白5（Fzd5）是斑马鱼和非洲爪蟾眼睛及视网膜发育所必需的，然而，其在哺乳动物眼睛发育过程中的作用尚不清楚。在小鼠胚胎中，Fzd5在垂体、远端视泡和视柄中显著表达，随后在发育中的视网膜祖细胞区表达。为了阐明Fzd5在眼睛发育过程中的作用，我们分析了在E10.25时Fzd5基因种系破坏的胚胎，此时胚胎因卵黄囊血管生成缺陷而死亡。我们观察到视杯形态发生和晶状体发育存在严重缺陷。然而，在使用Six3-Cre对Fzd5进行条件性失活的胚胎中，我们未观察到明显的早期眼睛缺陷。对Axin2 mRNA表达和TCF/LEF反应性报告基因激活的分析表明，Fzd5在眼睛中不调节Wnt/β-连环蛋白信号通路。因此，Fzd5在眼睛发育过程中的功能似乎具有物种依赖性。
