• Ohkawara B, Okuno M, Ishii T, Horiuchi M and Tomooka Y (2003). Characterization of a multipotent neural progenitor cell line cloned from an adult p53(-/-) mouse cerebellum. Brain Res 959:11-9. Summary: Here we report developmental characteristics of clonal cell line 2Y6f1, which was established from an adult p53(-/-) mouse cerebellum. 2Y6f1 began as a homogeneous population of small polygonal epithelial cells, but during passages it gradually became heterogeneous, containing cells of varying size and shape that expressed either neuron- or astrocyte-specific proteins. Supplements to the culture medium altered the levels of some of the cell type markers. For example, addition of insulin increased expression of neurofilaments, while cholera toxin increased that of glial fibrillary acidic protein. In a colony assay, 2Y6f1 cells gave rise to both homogeneous and heterogeneous colonies, consistent with the idea that they contained multipotent neural progenitor cells. Establishment of subclones that were exclusively neuronal or astroglial in differentiation further supported the conclusion that 2Y6f1 cells have many features that may qualify them as bona fide stem cells and make them a useful new model in neural stem cell biology. Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, City, Chiba 278-8510, Noda, Japan