Mammalian Scratch participates in neuronal differentiation in P19 embryonal carcinoma cells.

Mammalian Scratch (Scrt) is a Snail family zinc finger transcription factor that is specifically expressed in newly differentiating, post-mitotic central nervous system neurons. While Scrt-related genes appear essential for invertebrate neurogenesis, the role of Scrt in mammalian neural development is unknown. In this study, we found that neural differentiation of multipotent mouse P19 embryonal carcinoma cells by retinoic acid led to the appearance of Scrt together with neuron-specific class III beta-tubulin (Tuj1), following the earlier elaboration of Mash1. Transient co-transfection in P19 cells with either Mash1 or NeuroD2 plus E12 also induced Scrt gene expression. Moreover, overexpression of Scrt alone was sufficient to confer Tuj1 immunoreactivity and neuronal morphology in a subset of P19 cells. Scrt thus appears to function downstream of proneural bHLH proteins in promoting mammalian neural differentiation in this model system.