Transcriptomic heterogeneity of quiescent neural stem cells underlies distinct reactivation routes and potential upon Notch signaling blockade
Adult Neural Stem Cells (NSCs) are glial cells that remain mostly quiescent but periodically activate to support neurogenesis throughout life in many species. It has progressively become clear that NSCs are heterogeneous and that the stem cell pool is in fact made up of distinct subpopulations. In zebrafish these subpopulations were recently characterized, identifying sets of molecular markers that can reliably identify subpopulations. Based on in sillico analysis and in particular the relative expression of gene sets associated either with deep quiescence or activation these subpopulations were predicted to possess distinct quiescence depths, however this prediction has not been challenged experimentally. The Notch pathway is known as a major regulator opromoting NSC quiescence in several species. Here, we used LY-411575, a potent Notch Pathway inhibitor, and treated zebrafish for 24h to push NSCs towards activation before sacrifing the fish and collecting the telencephalon, with the goal of comparing the transcriptomes of NSCs and their immediate progeny with or without LY treatment and determine whether predicted quiescence depth of NSC subpopulations does correlate with distinct responses to a pro-activation stimulus. Overall design: Cells from the telencephalon of 12wpf Tg(sox2:gfp/+) fish bathed in LY-411575 for 48 hours were isolated by Fluorescence-Activated Cell Sorting (FACS). GFP positive cells were enriched to increase the relative proportion of radial glial cells and the resulting samples were processed for scRNA-seq.