title: Canonical Wnt/β-catenin signalling is essential for optic cup formation.
abstract: A multitude of signalling pathways are involved in the process of forming an eye. Here we demonstrate that β-catenin is essential for eye development as inactivation of β-catenin prior to cellular specification in the optic vesicle caused anophthalmia in mice. By achieving this early and tissue-specific β-catenin inactivation we find that retinal pigment epithelium (RPE) commitment was blocked and eye development was arrested prior to optic cup formation due to a loss of canonical Wnt signalling in the dorsal optic vesicle. Thus, these results show that Wnt/β-catenin signalling is required earlier and play a more central role in eye development than previous studies have indicated. In our genetic model system a few RPE cells could escape β-catenin inactivation leading to the formation of a small optic rudiment. The optic rudiment contained several neural retinal cell classes surrounded by an RPE. Unlike the RPE cells, the neural retinal cells could be β-catenin-negative revealing that differentiation of the neural retinal cell classes is β-catenin-independent. Moreover, although dorsoventral patterning is initiated in the mutant optic vesicle, the neural retinal cells in the optic rudiment displayed almost exclusively ventral identity. Thus, β-catenin is required for optic cup formation, commitment to RPE cells and maintenance of dorsal identity of the retina.
authors: Umeå Center for Molecular Medicine, Umeå University, Umeå, Sweden.
authors: Anna-Carin
authors: AC
authors: Hägglund
authors: Anna
authors: A
authors: Berghard
authors: Leif
authors: L
authors: Carlsson
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000853:Anophthalmos / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D019521:Body Patterning; D015820:Cadherins / Q000378:metabolism; D019070:Cell Lineage; D016764:Cell Polarity; D049109:Cell Proliferation; D004622:Embryo, Mammalian / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005123:Eye / Q000196:embryology* / Q000378:metabolism*; D051379:Mice; D009154:Mutation / Q000235:genetics; D009928:Organ Specificity; D055213:Retinal Pigment Epithelium / Q000196:embryology / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000378:metabolism; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000378:metabolism
chemical_list: D000199:Actins; D015820:Cadherins; D014157:Transcription Factors; D051176:beta Catenin