Project description:Neocortical projection neurons of mammalian brains are largely direct daughters of intermediate progenitors (IP), which are progenies of radial glial cells (RG). The maintenance of the RG pool, production and expansion of IPs are essential for neocortical formation during development, as well as neocortical expansion during evolution. Here we characterized an epigenetic circuit that controls precise neurogenic programming of the neocortex. The circuit comprises a long non-coding RNA – LncBAR and the SWI/SNF (BAF) chromatin-remodeling complex, which transcriptionally maintains the expression of Zbtb20. LncBAR knockout neocortex contains fewer upper-layer projection neurons. Intriguingly, loss of LncBAR promotes IP production of RGCs, but hampers neurogenic division and lengthens the cell-cycle durations of IPs during mid-later cortical neurogenesis. Moreover, in LncBAR knockout mice, depletion of the neural progenitor pool at embryonic stage causes fewer adult neural stem cells at the subventricular zone, leading to compromised adult neurogenesis to replenish the olfactory bulb. LncBAR binds to BRG1, the core enzymatic component of the SWI/SNF (BAF) chromatin-remodeling complex. LncBAR depletion enhances association of BRG1 with and the genomic locus of, and suppresses the expression of Zbtb20, a transcription factor gene known to regulate both embryonic and adult neurogenesis. ZBTB20 re-expression in LncBAR-knockout neural precursors reversed compromised neurogenic divisions of IPCs. Together, we revealed a previously unidentified epigenetic machinery to control neurogenesis of neural precursors.
Project description:Neocortical projection neurons of mammalian brains are largely direct daughters of intermediate progenitors (IP), which are progenies of radial glial cells (RG). The maintenance of the RG pool, production and expansion of IPs are essential for neocortical formation during development, as well as neocortical expansion during evolution. Here we characterized an epigenetic circuit that controls precise neurogenic programming of the neocortex. The circuit comprises a long non-coding RNA – LncBAR and the SWI/SNF (BAF) chromatin-remodeling complex, which transcriptionally maintains the expression of Zbtb20. LncBAR knockout neocortex contains fewer upper-layer projection neurons. Intriguingly, loss of LncBAR promotes IP production of RGCs, but hampers neurogenic division and lengthens the cell-cycle durations of IPs during mid-later cortical neurogenesis. Moreover, in LncBAR knockout mice, depletion of the neural progenitor pool at embryonic stage causes fewer adult neural stem cells at the subventricular zone, leading to compromised adult neurogenesis to replenish the olfactory bulb. LncBAR binds to BRG1, the core enzymatic component of the SWI/SNF (BAF) chromatin-remodeling complex. LncBAR depletion enhances association of BRG1 with and the genomic locus of, and suppresses the expression of Zbtb20, a transcription factor gene known to regulate both embryonic and adult neurogenesis. ZBTB20 re-expression in LncBAR-knockout neural precursors reversed compromised neurogenic divisions of IPCs. Together, we revealed a previously unidentified epigenetic machinery to control neurogenesis of neural precursors.
