RT Journal Article SR Electronic T1 Differential chromatin accessibility in developing projection neurons is correlated with transcriptional regulation of cell fate JF bioRxiv FD Cold Spring Harbor Laboratory SP 645572 DO 10.1101/645572 A1 Whitney E. Heavner A1 Shaoyi Ji A1 James H. Notwell A1 Ethan S. Dyer A1 Alex M. Tseng A1 Johannes Birgmeier A1 Boyoung Yoo A1 Gill Bejerano A1 Susan K. McConnell YR 2019 UL http://biorxiv.org/content/early/2019/05/21/645572.abstract AB We are only just beginning to catalog the vast diversity of cell types in the cerebral cortex. Such categorization is a first step toward understanding how diversification relates to function. All cortical projection neurons arise from a uniform pool of progenitor cells that lines the ventricles of the forebrain. It is still unclear how these progenitor cells generate the more than fifty unique types of mature cortical projection neurons defined by their distinct gene expression profiles. Here we compare gene expression and chromatin accessibility of two subclasses of projection neurons with divergent morphological and functional features as they develop in the mouse brain between embryonic day 13 and postnatal day 5 in order to identify transcriptional networks that diversity neuron cell fate. We find groups of transcription factors whose expression is correlated with chromatin accessibility, transcription factor binding motifs, and lncRNAs that define each subclass and validate the function of a family of novel candidate genes in vitro. Our multidimensional approach reveals that subclass-specific chromatin accessibility is significantly correlated with gene expression, providing a resource for generating new specific genetic drivers and revealing regions of the genome that are particularly susceptible to harmful genetic mutations by virtue of their correlation with important developmental genes.