Search results for "differentiation"
showing 10 items of 1605 documents
Comm Sorts Robo to Control Axon Guidance at the Drosophila Midline
2002
AbstractAxon growth across the Drosophila midline requires Comm to downregulate Robo, the receptor for the midline repellent Slit. We show here that comm is required in neurons, not in midline cells as previously thought, and that it is expressed specifically and transiently in commissural neurons. Comm acts as a sorting receptor for Robo, diverting it from the synthetic to the late endocytic pathway. A conserved cytoplasmic LPSY motif is required for endosomal sorting of Comm in vitro and for Comm to downregulate Robo and promote midline crossing in vivo. Axon traffic at the CNS midline is thus controlled by the intracellular trafficking of the Robo guidance receptor, which in turn depends…
Analysis of Drosophila salivary gland, epidermis and CNS development suggests an additional function of brinker in anterior-posterior cell fate speci…
2000
Salivary glands are simple structured organs which can serve as a model system in the study of organogenesis. Following a large EMS mutagenesis we have identified a number of genes required for normal salivary gland development. Mutations in the locus small salivary glands-1 (ssg-1) lead to a drastic reduction in the size of the salivary glands. The gene ssg-1 was cloned and subsequent sequence and genetic analysis showed identity to the recently published gene brinker. The salivary gland placode in brinker mutants appears reduced along both the anterior-posterior and dorso-ventral axis. Analysis of the brinker cuticle phenotype revealed a similar loss of anterior-posterior as well as later…
Abdominal-A mediated repression of Cyclin E expression during cell-fate specification in the Drosophila central nervous system
2009
Homeotic/Hox genes are known to specify a given developmental pathway by regulating the expression of downstream effector genes. During embryonic CNS development of Drosophila, the Hox protein Abdominal-A (AbdA) is required for the specification of the abdominal NB6-4 lineage. It does so by down regulating the expression of the cell cycle regulator gene Dcyclin E (CycE). CycE is normally expressed in the thoracic NB6-4 lineage to give rise to mixed lineage of neurons and glia, while only glial cells are produced from the abdominal NB6-4 lineage due to the repression of CycE by AbdA. Here we investigate how AbdA represses the expression of CycE to define the abdominal fate of a single NB6-4 …
Cytosolic RIG-I–like helicases act as negative regulators of sterile inflammation in the CNS
2011
The action of cytosolic RIG-I-like helicases (RLHs) in the CNS during autoimmunity is largely unknown. Using a mouse model of multiple sclerosis, we found that mice lacking the RLH adaptor IPS-1 developed exacerbated disease that was accompanied by markedly higher inflammation, increased axonal damage and elevated demyelination with increased encephalitogenic immune responses. Furthermore, activation of RLH ligands such as 5'-triphosphate RNA oligonucleotides decreased CNS inflammation and improved clinical signs of disease. RLH stimulation repressed the maintenance and expansion of committed T(H)1 and T(H)17 cells, whereas T-cell differentiation was not altered. Notably, T(H)1 and T(H)17 s…
Multiple roles forHoxgenes in segment-specific shaping of CNS lineages
2008
In this article we highlight some of the recently accumulating evidence showing that Hox genes are involved at different steps during the development of neural cell lineages to control segmental patterning of the CNS. In addition to their well-known early role in establishing segmental identities, Hox genes act on neural stem cells and their progeny at various stages during embryonic and postembryonic development to control proliferation, cell fate and/or apoptosis in a segment-specific manner. This leads to differential shaping of serially homologous lineages and thus to structural diversification of segmental CNS units (neuromeres) in adaptation to their specific functional tasks in proce…
Mutations in spalt cause a severe but reversible neurodegenerative phenotype in the embryonic central nervous system ofDrosophila melanogaster
2002
The gene spalt is expressed in the embryonic central nervous system of Drosophila melanogaster but its function in this tissue is still unknown. To investigate this question, we used a combination of techniques to analyse spalt mutant embryos. Electron microscopy showed that in the absence of Spalt, the central nervous system cells are separated by enlarged extracellular spaces populated by membranous material at 60% of embryonic development. Surprisingly, the central nervous system from slightly older embryos (80% of development) exhibited almost wild-type morphology. An extensive survey by laser confocal microscopy revealed that thespalt mutant central nervous system has abnormal levels o…
Oligodendrogliogenic and neurogenic adult subependymal zone neural stem cells constitute distinct lineages and exhibit differential responsiveness to…
2012
The adult mouse subependymal zone (SEZ) harbours adult neural stem cells (aNSCs) that give rise to neuronal and oligodendroglial progeny. However it is not known whether the same aNSC can give rise to neuronal and oligodendroglial progeny or whether these distinct progenies constitute entirely separate lineages. Continuous live imaging and single-cell tracking of aNSCs and their progeny isolated from the mouse SEZ revealed that aNSCs exclusively generate oligodendroglia or neurons, but never both within a single lineage. Moreover, activation of canonical Wnt signalling selectively stimulated proliferation within the oligodendrogliogenic lineage, resulting in a massive increase in oligodendr…
A common precursor for glia and neurons in the embryonic CNS of Drosophila gives rise to segment-specific lineage variants
1993
ABSTRACT The nervous system consists of two classes of cells, neurons and glia, which differ in morphology and function. They derive from precursors located in the neurogenic region of the ectoderm. In this study, we present the complete embryonic lineage of a neuroectodermal precursor in Drosophila that gives rise to neurons as well as glia in the abdominal CNS. This lineage is conserved among different Drosophila species. We show that neuronal and glial cell types in this clone derive from one segregating precursor, previously described as NB1-1. Thus, in addition to neuroblasts and glioblasts, there exists a third class of CNS precursors in Drosophila, which we call neuroglioblasts. We f…
IL-17 and related cytokines involved in the pathology and immunotherapy of multiple sclerosis: Current and future developments.
2014
Multiple sclerosis (MS), an autoimmune neurological disorder, is driven by self-reactive T helper (Th) cells. Research on the role of Th17 lymphocytes in MS pathogenesis has made significant progress in identifying various immunological as well as environmental factors that induce the differentiation and expansion of these cells, different subsets of Th17 cells with varying degrees of pathogenicity, and the role of the secreted effector cytokines. While approved therapies for MS offer significant benefit to patients, there remain unmet needs. Ongoing clinical trials aim to translate the advanced knowledge of Th17 cytokines to improved therapies. This review discusses the current status and …
Identification of an Antigen Related to the Sea Urchin RNA-Binding Protein LP54 in Mammalian Central Nervous System
2001
LP54 is an RNA-binding protein involved in localization of maternal messengers in sea urchin egg and embryos. Using a polyclonal antibody directed against Paracentrotus lividus LP54 we detected a 66-kDa cross-reacting antigen in undifferentiated and differentiated SH-SY5Y human neuroblastoma cells. After treatment of undifferentiated cells with detergent, the 66-kDa antigen was found to be enriched in the cytoskeletal fraction. By Western blot the expression of this antigen was also analyzed in regions of the CNS and in tissues of the adult rat and its exclusive presence in the hippocampus and thalamus was revealed. The immunoreactivity with P. lividus antibody against LP54 in hippocampal l…