Chick retinal pigment epithelium transdifferentiation assay for proneural activities.

We describe a cell culture system for assaying proneural activities of genes hypothesized to play instrumental roles in neuronal fate specification during vertebrate retinal development. The retinal pigment epithelium (RPE) is collected from embryonic day 6 (E6) chick to establish a primary RPE cell culture. The culture is then infected with a replication competent retrovirus RCAS expressing the gene of interest. The presence of retinal neurons in the otherwise nonneural, RPE cell culture is examined between 4 and 10 days after the administration of the virus. Taking advantage of the plasticity and the relative simplicity of RPE cells, this method offers an informative assay for proneural activities prior to planning for large-scale in vivo experiments.