Project description:Since the discovery of radial glia as the source of neurons, their heterogeneity in regard to neurogenesis has been described by clonal and time-lapse analysis in vitro. However, the molecular determinants specifying neurogenic radial glia differently from radial glia that mostly self-renew remain ill-defined. Here, we isolated two radial glial subsets that co-exist at mid-neurogenesis in the developing cerebral cortex and their immediate progeny. While one subset generates neurons directly, the other is largely non-neurogenic but also gives rise to Tbr2-positive basal precursors, thereby contributing indirectly to neurogenesis. Isolation of ; these distinct radial glia subtypes allowed determining interesting differences in their transcriptome. These transcriptomes were also strikingly different from the transcriptome of radial glia isolated at the end of neurogenesis. This analysis therefore identifies, for the first time, the lineage origin of basal progenitors and the molecular differences of this lineage in comparison to directly neurogenic and gliogenic radial glia. Experiment Overall Design: Comparison of radial glial subtypes
Project description:Since the discovery of radial glia as the source of neurons, their heterogeneity in regard to neurogenesis has been described by clonal and time-lapse analysis in vitro. However, the molecular determinants specifying neurogenic radial glia differently from radial glia that mostly self-renew remain ill-defined. Here, we isolated two radial glial subsets that co-exist at mid-neurogenesis in the developing cerebral cortex and their immediate progeny. While one subset generates neurons directly, the other is largely non-neurogenic but also gives rise to Tbr2-positive basal precursors, thereby contributing indirectly to neurogenesis. Isolation of these distinct radial glia subtypes allowed determining interesting differences in their transcriptome. These transcriptomes were also strikingly different from the transcriptome of radial glia isolated at the end of neurogenesis. This analysis therefore identifies, for the first time, the lineage origin of basal progenitors and the molecular differences of this lineage in comparison to directly neurogenic and gliogenic radial glia.
Project description:The African turquoise killifish combines a short lifespan with age-dependent loss of neuroregenerative capacity, making it a well-suited model for studying brain repair mechanisms in the context of aging. To investigate the extent of cellular diversity that shapes neuro- and gliogenesis, we performed single cell sequencing of the adult telencephalon. Our analysis identifies seventeen cell types including neuronal cells, and progenitors of glial and non-glial nature. Further subclustering unveils four radial glia (RG) types, one atypical non-glial progenitor (NGP) and two intermediate subtypes. Validation of our data in situ reveals a distinct spatial setting for defined RG subtypes, reflecting the distribution of morphologically and physiologically distinct populations. Lineage inference analysis suggests neuroepithelial-like radial glia and NGP to be the start point and intercessor of neural development, respectively. Neuronal sub-clustering uncovers immature and mature excitatory or inhibitory sub-clusters. This complete catalogue of killifish telencephalon cell types is accessible via an online tool, providing a resource to understand neurogenesis in healthy brains and upon injury or disease.
