Project description:During cortical development neurons are generated from basal progenitors (BPs) which specifically express the transcription factor Tbr2. We used fluorescent-activated cell sorting (FACS) to isolate BPs from Tbr2-conditional knockout mice brain at early (E13) and late (E16) stages of cortical neurogenesis and determined mRNA expression profiles using microarray (Illumina MouseWG-6 v2). Role of transcription factor Tbr2 in basal progenitors during corticogenesis.
Project description:During cortical development neurons are generated sequentially from basal progenitors (BPs) which specifically express the transcription factor Tbr2. We used fluorescent-activaed cell sorting (FACS) to isolate BPs from Tbr2GFP knockin reporter mice (Arnold SJ et al. Genesis, 2009) at early (embryonic day, E13) and late (embryonic day, E16) stages of cortical neurogenesis and determined mRNA expression profiles using mouse mRNA microarray (Illumina MouseWG-6 v2). Comparison of E13 and E16 mRNA expression profiles allowed us to identify regulatory gene networks for maintaining stage specific homeostasis of BPs throughout neurogenesis. FACS isolated BPs at E13 and E16 mouse brain cortex were used for microarray analyses. Six biological replicates (embryonic cortex from three different litters) for E13 and five biological replicates (embryonic cortex from three different litters) for E16 were analysed.
Project description:During cortical development neurons are generated sequentially from basal progenitors (BPs) which specifically express the transcription factor Tbr2. We used fluorescent-activaed cell sorting (FACS) to isolate BPs from Tbr2GFP knockin reporter mice (Arnold SJ et al. Genesis, 2009) at early (embryonic day, E13) and late (embryonic day, E16) stages of cortical neurogenesis and determined mRNA expression profiles using mouse mRNA microarray (Illumina MouseWG-6 v2). Comparison of E13 and E16 mRNA expression profiles allowed us to identify regulatory gene networks for maintaining stage specific homeostasis of BPs throughout neurogenesis.
Project description:During cortical development neurons are generated sequentially from basal progenitors (BPs) which specifically express the transcription factor Tbr2. We used fluorescent-activaed cell sorting (FACS) to isolate BPs from Tbr2GFP knockin reporter mice (Arnold SJ et al. Genesis, 2009) at early (embryonic day, E13) and late (embryonic day, E16) stages of cortical neurogenesis and determined miRNA expression profiles using mouse miRNA microarray (Agilent).Comparison of E13 and E16 microRNA expression profiles allowed us to identify regulatory mechanisms for maintaining stage specific homeostasis of BPs.
Project description:During cortical development neurons are generated sequentially from basal progenitors (BPs) which specifically express the transcription factor Tbr2. We used fluorescent-activaed cell sorting (FACS) to isolate BPs from Tbr2GFP knockin reporter mice (Arnold SJ et al. Genesis, 2009) at early (embryonic day, E13) and late (embryonic day, E16) stages of cortical neurogenesis and determined miRNA expression profiles using mouse miRNA microarray (Agilent).Comparison of E13 and E16 microRNA expression profiles allowed us to identify regulatory mechanisms for maintaining stage specific homeostasis of BPs. FACS isolated BPs at E13 and E16 mouse brain cortex were used for miRNA microarray analyses. Four biological replicates (embryonic cortex from three different litters) for each group (E13 or E16) were analysed.
Project description:The cerebral cortex contains layers of neurons sequentially generated by distinct lineage-related progenitors. At the onset of corticogenesis, the first-born progenitors are apical progenitors (APs) whose asymmetric division give birth directly to neurons. Later, they switch to indirect neurogenesis by generating intermediate progenitors (IPs), which give rise to projection neurons of all cortical layers. While a direct lineage relationship between APs and IPs has been established, the molecular mechanism that controls their transition remains elusive. Our data suggest that interfering with codon translation speed triggers endoplasmic reticulum stress and the unfolded protein response (UPR), further impairing the generation of IPs and leading to microcephaly. Moreover, we demonstrate that a progressive downregulation of UPR in cortical progenitors acts as physiological signal to amplify IPs and promotes indirect neurogenesis. Thus, our findings reveal a hitherto unrecognized contribution of UPR to cell fate acquisition during mammalian brain development. Ribosome profiling and RNA-Seq of forebrains from E14.5 mouse embryos from wild type animals and mutants carrying a conditional knockout of ELP3 in cortical progenitors
Project description:During cortical development, radial glial cells, known as neural stem cells, initially generate a large number of cortical glutamatergic pyramidal neurons through a process called neurogenesis. This is followed by the generation of a diversity of cortical astrocytes, oligodendrocytes, and olfactory bulb interneurons, known as gliogenesis. However, the molecular mechanisms underlying the switch from cortical neurogenesis to gliogenesis, and the subsequent fate determination of cortical astrocytes, oligodendrocytes, and olfactory bulb interneurons, remain unclear. Here, we report that extracellular signal-regulated kinase (ERK) signaling plays a fundamental role in promoting cortical gliogenesis and the generation of cortical glial progenitors. Additionally, SHH-SMO-GLI activator signaling has an auxiliary function to ERK during these processes. We further demonstrate that NOTCH signaling is absolutely required for the fate determination of astrocytes, while ERK signaling plays a prominent role in oligodendrocyte fate specification, and SHH signaling is crucial for the fate determination of olfactory bulb interneurons from cortical progenitors. We provide evidence suggesting that this mechanism is conserved in both mice and humans. Finally, we propose a unifying principle of mammalian cortical gliogenesis.