Project description:We profiled retinal progenitor cells by integrating next generation sequencing methods and interrogating changes in chromatin accessibility at embryonic and post-natal murine stages. We identified putative factors involved in the developmental progression of the retinal progenitors epigenome and we report Lhx2 role in the regulation of chromatin accessibility by coordinated action of developmentally regulated pioneer factors
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:In mammals, retinal damage is followed by Müller glia cell activation and proliferation. While retinal gliosis persists in adult mammals after an insult or disease, some vertebrates, including zebrafish, have the capacity to regenerate. We believe we are the first group to show that gliosis is a fibrotic-like process in mammals’ eyes caused by differential activation of canonical and non-canonical TGFβ signaling pathways.
Project description:Lhx2 is a retinal progenitor cell transcription factor critical for eye development. We previously reported that conditional inactivation of Lhx2 at the start of mouse retinal neurogenesis disrupted retinal progenitor cell (RPC) proliferation, greatly reduced the RPC pool and altered neurogenic output as indicated by changes in the production of multiple fated precursor populations. To identify genes whose expression levels are dependent on Lhx2 at this stage of development, Lhx2 conditional inactivation was initiated at E11.5 in RPCs with the progenitor Cre driver Hes1CreERT2 and retinal tissue was collected at E15.5 for RNA sequencing. The gene expression profiles of Lhx2 CKO retinas were compared to control (Lhx2 conditional heterozygotes) were compared. Downregulated and upregulated gene expression was observed, with some likely due to direct and indirect regulation by Lhx2 within RPCs and others due to changes in differentiation and the altered neurogenic output.
