Project description:Bergmann glial cells of the vertebrate cerebellum play essential roles in the development and maintenance of cerebellar structure and function. During development, Bergmann glia provide structural support to the expanding cerebellar anlage and also serve as guides for migrating neurons (granule cells). As the cerebellum matures, Bergmann glia become important in dendritic arborization, synapse maintenance and synaptic function. The molecular mechanisms underlying these diverse and important functions of Bergmann glia remain largely unknown. We used microarray analysis to examine global gene expression in individual Bergmann glial cells derived at P6 (a time of extensive neuronal migration and cerebellar growth) and at P30 (when cerebellar development is complete and Bergmann glia play important roles at synapses). After gentle dissociation of cerebellar tissue derived from mice expressing GFP under the GFAP gene promoter (GFAP-GFP mice) (Zhuo, L., et al., 1997, Developmental biology), single GFP-positive Bergmann glial cells were aspirated into microcapillary tubes. Amplified cDNAs were prepared from single cells using RT-PCR and hybridized to Affymetrix GeneChip Mouse Genome 430 2.0 expression arrays (one array per cell). Five P6 cells and five P30 cells were used to generate the data presented in this study.
Project description:Bergmann glial cells of the vertebrate cerebellum play essential roles in the development and maintenance of cerebellar structure and function. During development, Bergmann glia provide structural support to the expanding cerebellar anlage and also serve as guides for migrating neurons (granule cells). As the cerebellum matures, Bergmann glia become important in dendritic arborization, synapse maintenance and synaptic function. The molecular mechanisms underlying these diverse and important functions of Bergmann glia remain largely unknown. We used microarray analysis to examine global gene expression in individual Bergmann glial cells derived at P6 (a time of extensive neuronal migration and cerebellar growth) and at P30 (when cerebellar development is complete and Bergmann glia play important roles at synapses).
Project description:Cerebellar circuitry is critical for balance and motor control among a wide array of functions and largely consists of granule and Purkinje neurons. Bergmann glia in the cerebellum form distinct morphological structures that facilitate granule neuron migration during development and that maintain the cerebellar organization and functional integrity. At present, molecular control of the formation and morphogenesis of Bergmann glia remains obscure. In this study, we found that Zeb2 (a.k.a. Sip1 or Zfhx1b), a Mowat-Wilson syndrome-associated transcriptional regulator, is highly restricted to Bergmann glia and is essential for their development and maturation. The mice with Zeb2 ablation in the cerebellar neural progenitor exhibit dysgenesis of cerebellar cortical lamination and locomotion defects. Deletion of Zeb2 markedly reduced Bergmann glial proliferation, differentiation and the establishment of the normal radial scaffold, disrupting migration of granule cell progenitors from external to internal granular layers. Transcriptome profiling indicated that Zeb2 regulates multiple pathways including FGF and Notch signaling as well as axonal guidance cues including Netrin G2 and Gdf10 to control Bergmann glial development. Our data reveal that Zeb2 acts as a transcriptional integrator of diverse signaling pathways to regulate the formation and morphogenesis of Bergmann glia ensuring maintenance of cerebellar integrity, suggesting that Zeb2 dysfunction in Bergmann glia might contribute to motor deficits in Mowat-Wilson syndrome.
Project description:Neurogenic astroglia-like cells of the prospective white matter (PWM) generate interneurons and astroglia during cerebellar development. However, the characterization of PWM subpopulations is still insufficient. Here we show that ACSA-2 (Astrocyte Cell Surface Antigen-2) is an intrinsic marker of astrocyte-committed precursors. In the developing cerebellum, the ontogeny of ACSA-2+ astrocytes revealed this epitope to be exclusively expressed by PWM cells. By contrast, in the adult brain, ACSA-2 is observed on parenchymal astrocytes, fibrous astrocytes of the white matter and at low level on Bergmann glia. In combination with GLAST, a marker for astroglia-like progenitors, we addressed the characteristics of neurogenic (ACSA-2-/GLAST+) and astrocyte-committed (ACSA-2+/GLAST+) precursors using transcriptomics and cell transplantation assays. Gene expression analyses identified major differences in genes related to the maturation status of astrocytes, their potential to generate interneurons and genes required for Bergmann glia specification. Transplantation assays further confirmed a divergent differentiation potential: ACSA-2+/GLAST+ cells, on the one side, differentiate into astrocytes and oligodendrocytes but not into Bergmann glia or neurons when transplanted into the neonatal cerebellum. On the other side, ACSA-2-/GLAST+ progenitors were able to generate interneurons and all the glial phenotypes. Moreover, ACSA-2-/GLAST+ progenitors even maintained the neurogenic potential when transplanted into the adult cerebellum. In conclusion, this work reports about ACSA-2, a marker for glial-restricted precursors of the PWM that in combination with GLAST enables for the discrimination and isolation of neurogenic and astrocyte-committed progenitors of the neonatal cerebellum.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:Single-nucleus RNA sequencing (snRNA-seq) was used to profile the transcriptome of 5,264 nuclei in mouse adult testis. This dataset includes two samples from two different individuals. This dataset is part of a larger evolutionary study of adult testis at the single-nucleus level (97,521 single-nuclei in total) across mammals including 10 representatives of the three main mammalian lineages: human, chimpanzee, bonobo, gorilla, gibbon, rhesus macaque, marmoset, mouse (placental mammals); grey short-tailed opossum (marsupials); and platypus (egg-laying monotremes). Corresponding data were generated for a bird (red junglefowl, the progenitor of domestic chicken), to be used as an evolutionary outgroup.