Abstract
Abstract: :
Purpose: Wnt proteins are secreted signaling molecules that have been implicated in embryonic patterning, cell polarity, cell fate determination and proliferation. The best characterized signaling pathway, the Wnt/ß–catenin pathway, appears to be largely conserved from flies to vertebrates. Upon Wnt binding to Frizzled receptors, ß–catenin accumulates in the cytoplasm and translocates to the nucleus where it can bind to HMG transcription factors TCF/LEF–1 and activate gene expression. Since little is known about the function of Wnt/ß–catenin during eye development, the purpose of our study is to define exactly when and where during eye development the Wnt/ß–catenin pathway is active. Methods: Mice transgenic for a Wnt/ß–catenin responsive reporter (TOPGAL; DasGupta and Fuchs, 1999) are used to analyze the expression of ß–galactosidase at different embryonic and postnatal stages of eye development. Results: The initial analysis shows that the reporter is expressed in the dorsal optic vesicle. At later embryonic stages, Wnt/ß–catenin signaling is observed in a subset of retinal progenitor cells and in RPE cells. Conclusions: The expression of the TOPGAL reporter strongly suggests a role for Wnt/ß–catenin signaling during mouse eye development.
Keywords: retinal development • cell–cell communication • transgenics/knock–outs