Project description:RNA-based regulatory mechanisms play important roles in the development and plasticity of neural circuits and neurologic disease. Developing axons provide a well suited model to study RNA-based regulation, and contain specific subsets of mRNAs that are locally translated and have roles in axon pathfinding. However, the RNA-binding proteins involved in axon pathfinding, and their corresponding mRNA targets, are still largely unknown. Here we find that the RNA-binding protein IMP2 (Igf2bp2) is strikingly enriched in developing axon tracts, including in spinal commissural axons. We used the HITS-CLIP approach to perform a genome-wide identification of RNAs that interact directly with IMP2 in the native context of developing brain. This IMP2 interactome was highly enriched for mRNA targets related to axon guidance. Accordingly, IMP2 knockdown in the developing spinal cord led to strong defects in commissural axon trajectories at the midline intermediate target. These results reveal a highly distinctive axonal enrichment of IMP2, show that it interacts with a network of axon guidance-related mRNAs, and reveal its requirement for normal axon pathfinding during vertebrate development. CLIP-seq
Project description:The double-stranded RNA binding protein Staufen2 (Stau2) is asymmetrically localized and segregated during asymmetric cell divisions in the developing mouse cortex and promotes intermediate progenitor cell fate. We carry out RNA immunoprecipitation with a Stau2 specific antibody, followed by microarray analysis to identify Stau2 assoicated RNAs that may be shuttled asymmetrically into one daughter cell thus affecting cell fate. Cortex was dissected from E13-14 timed-pregnant Swiss Webster Mice (Taconic) and RNA immunoprecipitation followed by microarray analysis was carried out to identy Stau2 associated RNA cargos.
Project description:Genetic investigations of X-linked intellectual disabilities have implicated the ARX (Aristaless-related homeobox) gene in a wide spectrum of disorders extending from phenotypes characterised by severe neuronal migration defects such as lissencephaly, to mild or moderate forms of mental retardation without apparent brain abnormalities but with associated features of dystonia and epilepsy. Analysis of Arx spatio-temporal localisation profile in mouse revealed expression in telencephalic structures, mainly restricted to populations of GABAergic neurons at all stages of development. Furthermore, studies of the effects of ARX loss of function in humans and animal models revealed varying defects, suggesting multiple roles of this gene during brain development. However, to date, little is known about how ARX functions as a transcription factor and the nature of its targets. To better understand its role, we combined chromatin immunoprecipitation and mRNA expression with microarray analysis and identified a total of 1006 gene promoters bound by Arx in transfected neuroblastoma (N2a) cells and in mouse embryonic brain. Some of these promoters were enriched for a sequence very similar to a motif previously identified as Arx-binding motif and approximately 24% of Arx-bound genes were found to show expression changes following Arx overexpression or knock-down. Several of the Arx target genes we identified are known to be important for a variety of functions in brain development, including axonal guidance and synaptic plasticity and some of them suggest new functions for Arx. Overall, these results identified multiple new candidate targets for Arx and should help to better understand the pathophysiological mechanisms of intellectual disability and epilepsy associated with ARX mutations. ChIP-Chip experiments were performed with either Arx transfected N2a cells or mouse embryonic brains (E15.5). Three replicates were performed for each condition.
Project description:We deep-sequenced small RNAs after immunoprecipitation of Mili or Miwi, as well as total small RNA from adult mouse testis. The goal of this experiment is to more deeply characterize the piRNA pool from adult mouse testes, using the Illumina platform. Comparison of 2 IP libraries with a non-IP library
Project description:This SuperSeries is composed of the following subset Series: GSE29985: Identification by ChIP-on-Chip of ARX target genes, a transcription factor implicated in mental retardation and epilepsy GSE30190: Comparison of gene expression between Arx-transfected N2a cells and cells transfected by the corresponding empty vector Refer to individual Series
Project description:iCLIP experiments tomap the RNA binding sites of the RNA-binding protein Unkempt across the transcriptome in SH-SY5Y cells, HeLa cells with ectopic Unk expression and mouse E15 embryonic brain samples. Expression of Unk is normally largely restricted to the nervous system. We therefore mapped the binding sites in human SH-SY5Y and mouse E15 brain to detect its physiological binding sites (in SH-SY5Y, we also performed the RNAseq experiment upon Unk knockdown). HeLa cells on the other hand normally don't express Unk, but convert to neuron-like shape when the protein is ectopically expressed. So, here we hoped to identify those binding events (and hence target transcripts) that are critical for this morphological transformation.
Project description:Acquisition of the intestinal microbiota begins at birth, and a stable microbial community develops from a succession of key organisms. Disruption of the microbiota during maturation by low-dose antibiotic exposure can alter host metabolism and adiposity. We now show that low-dose penicillin (LDP), delivered from birth, induces metabolic alterations and affects ileal expression of genes involved in immunity. LDP that is limited to early life transiently perturbs the microbiota, which is sufficient to induce sustained effects on body composition, indicating that microbiota interactions in infancy may be critical determinants of long-term host metabolic effects. In addition, LDP enhances the effect of high-fat diet induced obesity. The growth promotion phenotype is transferrable to germ-free hosts by LDP-selected microbiota, showing that the altered microbiota, not antibiotics per se, play a causal role. These studies characterize important variables in early-life microbe-host metabolic interaction and identify several taxa consistently linked with metabolic alterations. Male and female mice were exposed to low-dose penicillin from birth. In a second experiment, microbiota from female control and LDP mice was transferred to 3-week old female germ-free mice. Livers were collected at 8 weeks of age, RNA was extracted, and transcriptional differences were measured by RNAseq.
Project description:To identify genes heretofore undiscovered as critical players in the biogenesis of teeth, we have used microarray gene expression analysis of the developing mouse molar tooth (DMT) between 1 and 10 days postnatal to identify genes differentially expressed when compared to 16 control tissues (GEO accession # GSE1986). Of the top 100 genes exhibiting increased expression in the DMT, 29 were found to have been previously associated with tooth development. Differential expression of the remaining 71 genes not previously associated with tooth development was confirmed by qRT-PCR analysis. Further analysis of seven of the latter genes by mRNA in situ hybridization found that five were specific to the developing tooth in the craniofacial region (Rspo4, Papln, Amtn, Gja1, Maf). Of the remaining two, one was found to be more widely expressed (Sp7) and the other was found to be specific to the nasal serous gland, which is close to, but distinct from, the developing tooth (Vrm). Experiment Overall Design: mRNA from molar teeth extracted from Swiss Webster mouse pups between 1 and 10 days post-natal was pooled, labeled, and hybridized in quadruplicate to Affymetrix Mouse Genome Expression 430 2.0 microarrays. This data was compared to that of 16 control tissues (GEO accession # GSE1986) to identify genes differentially expressed in the DMT mRNA.
Project description:Developmental regulation of gliogenesis in the mammalian CNS is incompletely understood, in part due to a limited repertoire of lineage-specific genes. We used Aldh1l1-GFP as a marker for gliogenic radial glia and later-stage precursors of developing astrocytes and performed gene expression profiling of these cells. We then used this dataset to identify candidate transcription factors that may serve as glial markers or regulators of glial fate. Our analysis generated a database of developmental stage-related markers of Aldh1l1+ cells between murine embryonic day 13.5-18.5. Using these data we identify the bZIP transcription factor Nfe2l1 and demonstrate that it promotes glial fate under direct Sox9 regulatory control. Thus, this dataset represents a resource for identifying novel regulators of glial development. 18 total samples consisting of three biological replicates each of flow sorted embryonic spinal cord Aldh1l1-GFP positive cells and whole cord, spanning the radial glial to astrocyte transition
Project description:We developed a ChIP protocol for the analysis of histone marks using less than 10,000 cells per IP, and used it to investigate the chromatin state of E11.5 mouse primordial germ cells (PGCs). A genome-wide ChIP-Seq analysis of E11.5 PGCs revealed a distribution of H3K4me3/H3K27me3 bivalent domains highly enriched for developmental regulatory genes. H3K4me3 and H3K27me3 ChIP-Seq from mouse E11.5 primordial germ cells.