Our laboratory is interested in understanding the coordination of cell proliferation with cell fate determination and differentiation in development, stem cells and reprogramming, focusing particularly on the nervous system (as well as in endocrine gut and pancreas). Recently, we have been investigating cell cycle regulation of basic helix-loop-helix proneural transcription factors in a variety of systems. By combining work in the experimentally tractable Xenopus frog embryo with genetically modified mouse models, we study developmental effects of cell cycle modulation in simple and complex nervous systems. These varied approaches allow us to gain a deeper mechanistic understanding of the many ways that cell cycle and differentiation machineries are linked in the nervous system. Moreover, we are using our finding to enhance neuron generation in vitro from ES cells and after reprogramming of fibroblasts, and to investigate potential therapies for cancers of the nervous system.