YBX1 Regulates Cell Proliferation in Developing Neural Tubes

Abstract

Cell proliferation in the developing neural tube is essential to the development of the nervous system. The balance of stem cell proliferation and differentiation requires the coordination of molecular processes including epigenetic mechanisms, which regulate gene expression profiles. One epigenetic mechanism involves the PRC2 complex, a histone methylase that has been shown to play a role in cellular differentiation, perpetuation of cellular identity, proliferation, and stem cell plasticity. Our studies of the PRC2 complex led to the identification of a new PRC2-binding protein called YBX1, which is a proliferation regulatory factor highly expressed in the brain. Quantification of cell division in the neural tubes of mice using immunofluorescent sections of both Ybx1 +/- and Ybx1 -/- shows that Ybx1 knockout results in increased cell division. A separate experiment using fluorescence activated cell sorting (FACS) confirmed our findings from immunofluorescence quantification. Altogether, our findings suggest that YBX1 modulates cell proliferation in the developing neural tube.