Project description:DOT1L as methyltransferase of H3K79 is implicated in brian development. Here, we further defined DOT1L function within the granular neurons during cerebellar development using ChIP-seq of H3K79 dimethylation of isolated cerebellar granular neurons and progenitors. Thereby we compared samples treated with a DOT1L inhibitor versus DMSO treated cells. The data sets reveals new important targets of DOT1L, which ensure a correct development of the cerebellum.
Project description:DOT1L as methyltransferase of H3K79 is implicated in brian development. Here, we further defined DOT1L function in gene expression during cerebellar development using Microarrays. For that we generated Dot1l knockout mice using a Atoh-Cre driver line resulting in a Dot1l knockout within the cerebellum. The RNA of cerebellar tissue of the Dot1l knockout animals was thereby compared to controls. Additionally we compared the RNA levels of cultured CGNP and CGN samples treated with a DOT1L inhibitor versus DMSO treated cells. The data sets reveals potential new gene expression targets of DOT1L in vivo and in vitro, which ensure a correct development of the cerebellum.
Project description:Interferon-b (IFN-b) belongs to the type I interferon family of cytokines and via binding to its receptor, interferon-a/b-receptor (IFNAR), it exerts immunoregulatory effects such as anti-viral and anti-inflammatory properties, and clinical benefits for patients with the CNS disease multiple sclerosis. To compare differentially regulated genes in neurons of interferon-beta knock out mice (Ifnb–/–), we conducted a microarray analysis on cerebellar granular neurons (CGNs) from wt (Ifnb+/+) and Ifnb-/- mice with or without treatment with recombinant IFN-b.
Project description:Internal granular progenitors (IGPs) in the developing cerebellar cortex of ferrets differentiate towards neural and glial lineages. The present study tracked IGPs that proliferated in response to valproic acid (VPA) to determine their fate during cerebellar cortical histogenesis. Ferret kits were used to administer VPA (200 μg/g body weight) on postnatal days 6 and 7. EdU and BrdU were injected on postnatal days 5 and 7, respectively, to label the post-proliferative and proliferating cells when exposed to VPA. At postnatal day 20, when the external granule layer was most expanded, EdU- and BrdU-single-labeled cells were significantly denser in the inner granular layer of VPA-exposed ferrets than in controls. No EdU- or BrdU-labeling was found in Purkinje cells and molecular layer interneurons. Significantly higher percentages of NeuN and Pax6 immunostaining in VPA-exposed ferrets revealed VPA-induced differentiation of IGPs towards granular neurons in BrdU-single-labeled cells. In contrast, both EdU- and BrdU-single-labeled cells exhibited significantly greater percentages of PCNA immunostaining, which appeared in immature Bergman glia, in the internal granular layer of VPA-exposed ferrets. These findings suggest that VPA affects the proliferation of IGPs to induce differentiative division towards granular neurons as well as post-proliferative IGPs toward differentiation into Bergmann glia.
Project description:It is well established that cerebellar granule cell precursors (GCPs) initially derive from progenitors in the rhombic lip of the embryonic cerebellar primordium. GCPs proliferate and migrate tangentially across the cerebellum to form the external granule cell layer (EGL) in late embryogenesis and early postnatal development. It is unclear whether GCPs are specified exclusively in the embryonic rhombic lip or whether their precursor persists in the neonate. Using transgenic mice expressing DsRed under the human glial fibrillary acidic protein (hGFAP) promoter, we found 2 populations of DsRed(+) cells in the EGL in the first postnatal week defined by bright and faint DsRed-fluorescent signal. Bright DsRed(+) cells have a protein expression profile and electrophysiological characteristics typical of astrocytes, but faint DsRed(+) cells in the EGL and internal granule cell layer (IGL) express markers and physiological properties of immature neurons. To determine if these astroglial cells gave rise to GCPs, we genetically tagged them with EGFP or betagal reporter genes at postnatal day (P)3-P5 using a hGFAP promoter driven inducible Cre recombinase. We found that GFAP promoter(+) cells in the EGL are proliferative and express glial and neural stem cell markers. In addition, immature granule cells (GCs) en route to the IGL at P12 as well as GCs in the mature cerebellum, 30days after recombination, express the reporter protein, suggesting that GFAP promoter(+) cells in the EGL generate a subset of granule cells. The identification of glial cells which function as neuronal progenitor cells profoundly impacts our understanding of cellular plasticity in the developing cerebellum.
