Expression analyses of E12.5 embryonic brains from Nestin Cre+, Rest GTi/GTi, p53 fl/fl vs Rest GTi/GTi, p53 fl/fl littermates. Mus musculus

We use mice containing a gene trap in the first intron of the Rest gene, which effectively eliminates transcription from all coding exons, to prematurely remove REST from neural progenitors. We find catastrophic DNA damage that occurs during S-phase of the cell cycle, with consequences including abnormal chromosome separation, apoptosis, and smaller brains. Further support for persistent effects is the latent appearance of proneural glioblastomas in adult mice also lacking the tumor suppressor, p53. A Rest deficient mouse line generated previously, using a conventional gene targeting approach, does not exhibit these phenotypes, likely due to a remaining C terminal peptide that still binds chromatin and recruits REST chromatin modifiers.Our results indicate that REST-mediated chromatin remodeling is required for proper S-phase dynamics, prior to its well-established role in relieving repression of neuronal genes at terminal differentiation. Overall design: extract RNA from E12.5 brain in triplicates, compare gene expression profile between Gene Trap REST knockout mice and control littermates