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Zambrano-Tipan D, Narváez-Padilla V, Reynaud E. Escargot a Snail superfamily member and its multiple roles in Drosophila melanogaster development. J Cell Physiol 2024. [PMID: 38572978 DOI: 10.1002/jcp.31269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 03/21/2024] [Accepted: 03/27/2024] [Indexed: 04/05/2024]
Abstract
The Snail superfamily of transcription factors plays a crucial role in metazoan development; one of the most important vertebrate members of this family is Snai1 which is orthologous to the Drosophila melanogaster esg gene. This review offers a comprehensive examination of the roles of the esg gene in Drosophila development, covering its expression pattern and downstream targets, and draws parallels between the vertebrate Snai1 family proteins on controlling the epithelial-to-mesenchymal transition and esg. This gene regulates stemness, ploidy, and pluripontency. esg is expressed in various tissues during development, including the gut, imaginal discs, and neuroblasts. The functions of the esg include the suppression of differentiation in intestinal stem cells and the preservation of diploidy in imaginal cells. In the nervous system development, esg expression also inhibits neuroblast differentiation, thus regulating the number of neurons and the moment in development of neuronal differentiation. Loss of esg function results in diverse developmental defects, including defects in intestinal stem cell maintenance and differentiation, and alters imaginal disc and nervous system development. Expression levels of esg also play a role in regulating longevity and metabolism in adult stages. This review provides an overview of the current understanding of esg's developmental role, emphasizing cellular and tissue effects that arise from its loss of function. The insights gained may contribute to a better understanding of evolutionary conserved developmental mechanisms and certain metabolic diseases.
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Affiliation(s)
- Diego Zambrano-Tipan
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Verónica Narváez-Padilla
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México
| | - Enrique Reynaud
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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2
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Medina-Jiménez BI, Budd GE, Janssen R. Single-cell RNA sequencing of mid-to-late stage spider embryos: new insights into spider development. BMC Genomics 2024; 25:150. [PMID: 38326752 PMCID: PMC10848406 DOI: 10.1186/s12864-023-09898-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/12/2023] [Indexed: 02/09/2024] Open
Abstract
BACKGROUND The common house spider Parasteatoda tepidariorum represents an emerging new model organism of arthropod evolutionary and developmental (EvoDevo) studies. Recent technical advances have resulted in the first single-cell sequencing (SCS) data on this species allowing deeper insights to be gained into its early development, but mid-to-late stage embryos were not included in these pioneering studies. RESULTS Therefore, we performed SCS on mid-to-late stage embryos of Parasteatoda and characterized resulting cell clusters by means of in-silico analysis (comparison of key markers of each cluster with previously published information on these genes). In-silico prediction of the nature of each cluster was then tested/verified by means of additional in-situ hybridization experiments with additional markers of each cluster. CONCLUSIONS Our data show that SCS data reliably group cells with similar genetic fingerprints into more or less distinct clusters, and thus allows identification of developing cell types on a broader level, such as the distinction of ectodermal, mesodermal and endodermal cell lineages, as well as the identification of distinct developing tissues such as subtypes of nervous tissue cells, the developing heart, or the ventral sulcus (VS). In comparison with recent other SCS studies on the same species, our data represent later developmental stages, and thus provide insights into different stages of developing cell types and tissues such as differentiating neurons and the VS that are only present at these later stages.
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Affiliation(s)
- Brenda I Medina-Jiménez
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden.
| | - Graham E Budd
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden
| | - Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Villavägen 16, 75236, Uppsala, Sweden.
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3
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Differences in Immunohistochemical and Ultrastructural Features between Podocytes and Parietal Epithelial Cells (PECs) Are Observed in Developing, Healthy Postnatal, and Pathologically Changed Human Kidneys. Int J Mol Sci 2022; 23:ijms23147501. [PMID: 35886848 PMCID: PMC9322852 DOI: 10.3390/ijms23147501] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 02/06/2023] Open
Abstract
During human kidney development, cells of the proximal nephron gradually differentiate into podocytes and parietal epithelial cells (PECs). Podocytes are terminally differentiated cells that play a key role in both normal and pathological kidney function. Therefore, the potential of podocytes to regenerate or be replaced by other cell populations (PECs) is of great interest for the possible treatment of kidney diseases. In the present study, we analyzed the proliferation and differentiation capabilities of podocytes and PECs, changes in the expression pattern of nestin, and several early proteins including WNT4, Notch2, and Snail, as well as Ki-67, in tissues of developing, postnatal, and pathologically changed human kidneys by using immunohistochemistry and electron microscopy. Developing PECs showed a higher proliferation rate than podocytes, whereas nestin expression characterized only podocytes and pathologically changed kidneys. In the developing kidneys, WNT4 and Notch2 expression increased moderately in podocytes and strongly in PECs, whereas Snail increased only in PECs in the later fetal period. During human kidney development, WNT4, Notch2, and Snail are involved in early nephrogenesis control. In kidneys affected by congenital nephrotic syndrome of the Finnish type (CNF) and focal segmental glomerulosclerosis (FSGS), WNT4 decreased in both cell populations, whereas Notch2 decreased in FSGS. In contrast, Snail increased both in CNF and FSGS, whereas Notch2 increased only in CNF. Electron microscopy revealed cytoplasmic processes spanning the urinary space between the podocytes and PECs in developing and healthy postnatal kidneys, whereas the CNF and FSGS kidneys were characterized by numerous cellular bridges containing cells with strong expression of nestin and all analyzed proteins. Our results indicate that the mechanisms of gene control in nephrogenesis are reactivated under pathological conditions. These mechanisms could have a role in restoring glomerular integrity by potentially inducing the regeneration of podocytes from PECs.
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ASC proneural factors are necessary for chromatin remodeling during neuroectodermal to neuroblast fate transition to ensure the timely initiation of the neural stem cell program. BMC Biol 2022; 20:107. [PMID: 35549704 PMCID: PMC9102361 DOI: 10.1186/s12915-022-01300-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 04/20/2022] [Indexed: 11/11/2022] Open
Abstract
Background In both Drosophila and mammals, the achaete-scute (ASC/ASCL) proneural bHLH transcription factors are expressed in the developing central and peripheral nervous systems, where they function during specification and maintenance of the neural stem cells in opposition to Notch signaling. In addition to their role in nervous system development, ASC transcription factors are oncogenic and exhibit chromatin reprogramming activity; however, the impact of ASC on chromatin dynamics during neural stem cell generation remains elusive. Here, we investigate the chromatin changes accompanying neural commitment using an integrative genetics and genomics methodology. Results We found that ASC factors bind equally strongly to two distinct classes of cis-regulatory elements: open regions remodeled earlier during maternal to zygotic transition by Zelda and less accessible, Zelda-independent regions. Both classes of cis-elements exhibit enhanced chromatin accessibility during neural specification and correlate with transcriptional regulation of genes involved in a variety of biological processes necessary for neuroblast function/homeostasis. We identified an ASC-Notch regulated TF network that includes likely prime regulators of neuroblast function. Using a cohort of ASC target genes, we report that ASC null neuroblasts are defectively specified, remaining initially stalled, unable to divide, and lacking expression of many proneural targets. When mutant neuroblasts eventually start proliferating, they produce compromised progeny. Reporter lines driven by proneural-bound enhancers display ASC dependency, suggesting that the partial neuroblast identity seen in the absence of ASC genes is likely driven by other, proneural-independent, cis-elements. Neuroblast impairment and the late differentiation defects of ASC mutants are corrected by ectodermal induction of individual ASC genes but not by individual members of the TF network downstream of ASC. However, in wild-type embryos, the induction of individual members of this network induces CNS hyperplasia, suggesting that they synergize with the activating function of ASC to consolidate the chromatin dynamics that promote neural specification. Conclusions We demonstrate that ASC proneural transcription factors are indispensable for the timely initiation of the neural stem cell program at the chromatin level by regulating a large number of enhancers in the vicinity of neural genes. This early chromatin remodeling is crucial for both neuroblast homeostasis as well as future progeny fidelity. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01300-8.
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Rust K, Wodarz A. Transcriptional Control of Apical-Basal Polarity Regulators. Int J Mol Sci 2021; 22:ijms222212340. [PMID: 34830224 PMCID: PMC8624420 DOI: 10.3390/ijms222212340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/06/2021] [Accepted: 11/10/2021] [Indexed: 12/17/2022] Open
Abstract
Cell polarity is essential for many functions of cells and tissues including the initial establishment and subsequent maintenance of epithelial tissues, asymmetric cell division, and morphogenetic movements. Cell polarity along the apical-basal axis is controlled by three protein complexes that interact with and co-regulate each other: The Par-, Crumbs-, and Scrib-complexes. The localization and activity of the components of these complexes is predominantly controlled by protein-protein interactions and protein phosphorylation status. Increasing evidence accumulates that, besides the regulation at the protein level, the precise expression control of polarity determinants contributes substantially to cell polarity regulation. Here we review how gene expression regulation influences processes that depend on the induction, maintenance, or abolishment of cell polarity with a special focus on epithelial to mesenchymal transition and asymmetric stem cell division. We conclude that gene expression control is an important and often neglected mechanism in the control of cell polarity.
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Affiliation(s)
- Katja Rust
- Department of Molecular Cell Physiology, Institute of Physiology and Pathophysiology, Philipps-University, 35037 Marburg, Germany
- Correspondence: (K.R.); (A.W.)
| | - Andreas Wodarz
- Department of Molecular Cell Biology, Institute I for Anatomy, Faculty of Medicine and University Hospital Cologne, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany
- Cluster of Excellence—Cellular Stress Response in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
- Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Str. 21, 50931 Cologne, Germany
- Correspondence: (K.R.); (A.W.)
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6
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Brenneis G, Schwentner M, Giribet G, Beltz BS. Insights into the genetic regulatory network underlying neurogenesis in the parthenogenetic marbled crayfish Procambarus virginalis. Dev Neurobiol 2021; 81:939-974. [PMID: 34554654 DOI: 10.1002/dneu.22852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/26/2021] [Accepted: 09/20/2021] [Indexed: 11/09/2022]
Abstract
Nervous system development has been intensely studied in insects (especially Drosophila melanogaster), providing detailed insights into the genetic regulatory network governing the formation and maintenance of the neural stem cells (neuroblasts) and the differentiation of their progeny. Despite notable advances over the last two decades, neurogenesis in other arthropod groups remains by comparison less well understood, hampering finer resolution of evolutionary cell type transformations and changes in the genetic regulatory network in some branches of the arthropod tree of life. Although the neurogenic cellular machinery in malacostracan crustaceans is well described morphologically, its genetic molecular characterization is pending. To address this, we established an in situ hybridization protocol for the crayfish Procambarus virginalis and studied embryonic expression patterns of a suite of key genes, encompassing three SoxB group transcription factors, two achaete-scute homologs, a Snail family member, the differentiation determinants Prospero and Brain tumor, and the neuron marker Elav. We document cell type expression patterns with notable similarities to insects and branchiopod crustaceans, lending further support to the homology of hexapod-crustacean neuroblasts and their cell lineages. Remarkably, in the crayfish head region, cell emigration from the neuroectoderm coupled with gene expression data points to a neuroblast-independent initial phase of brain neurogenesis. Further, SoxB group expression patterns suggest an involvement of Dichaete in segmentation, in concordance with insects. Our target gene set is a promising starting point for further embryonic studies, as well as for the molecular genetic characterization of subregions and cell types in the neurogenic systems in the adult crayfish brain.
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Affiliation(s)
- Georg Brenneis
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts, USA.,Zoologisches Institut und Museum, Universität Greifswald, Greifswald, Germany
| | - Martin Schwentner
- Naturhistorisches Museum Wien, Vienna, Austria.,Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Gonzalo Giribet
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA
| | - Barbara S Beltz
- Neuroscience Program, Wellesley College, Wellesley, Massachusetts, USA
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7
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Shard C, Luna-Escalante J, Schweisguth F. Tissue-wide coordination of epithelium-to-neural stem cell transition in the Drosophila optic lobe requires Neuralized. J Cell Biol 2021; 219:152101. [PMID: 32946560 PMCID: PMC7594497 DOI: 10.1083/jcb.202005035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/06/2020] [Accepted: 08/17/2020] [Indexed: 12/15/2022] Open
Abstract
Many tissues are produced by specialized progenitor cells emanating from epithelia via epithelial-to-mesenchymal transition (EMT). Most studies have so far focused on EMT involving single or isolated groups of cells. Here we describe an EMT-like process that requires tissue-level coordination. This EMT-like process occurs along a continuous front in the Drosophila optic lobe neuroepithelium to produce neural stem cells (NSCs). We find that emerging NSCs remain epithelial and apically constrict before dividing asymmetrically to produce neurons. Apical constriction is associated with contractile myosin pulses and involves RhoGEF3 and down-regulation of the Crumbs complex by the E3 ubiquitin ligase Neuralized. Anisotropy in Crumbs complex levels also results in accumulation of junctional myosin. Disrupting the regulation of Crumbs by Neuralized lowered junctional myosin and led to imprecision in the integration of emerging NSCs into the front. Thus, Neuralized promotes smooth progression of the differentiation front by coupling epithelium remodeling at the tissue level with NSC fate acquisition.
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Affiliation(s)
- Chloé Shard
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France
| | - Juan Luna-Escalante
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France.,Laboratoire de Physique, Ecole Normale Supérieure, Centre National de la Recherche Scientifique, Sorbonne Université, Université Paris Diderot, Paris, France
| | - François Schweisguth
- Institut Pasteur, Paris, France.,UMR3738, Centre National de la Recherche Scientifique, Paris, France
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8
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Park L, Luth ES, Jones K, Hofer J, Nguyen I, Watters KE, Juo P. The Snail transcription factor CES-1 regulates glutamatergic behavior in C. elegans. PLoS One 2021; 16:e0245587. [PMID: 33529210 PMCID: PMC7853468 DOI: 10.1371/journal.pone.0245587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/04/2021] [Indexed: 11/18/2022] Open
Abstract
Regulation of AMPA-type glutamate receptor (AMPAR) expression and function alters synaptic strength and is a major mechanism underlying synaptic plasticity. Although transcription is required for some forms of synaptic plasticity, the transcription factors that regulate AMPA receptor expression and signaling are incompletely understood. Here, we identify the Snail family transcription factor ces-1 in an RNAi screen for conserved transcription factors that regulate glutamatergic behavior in C. elegans. ces-1 was originally discovered as a selective cell death regulator of neuro-secretory motor neuron (NSM) and I2 interneuron sister cells in C. elegans, and has almost exclusively been studied in the NSM cell lineage. We found that ces-1 loss-of-function mutants have defects in two glutamatergic behaviors dependent on the C. elegans AMPA receptor GLR-1, the mechanosensory nose-touch response and spontaneous locomotion reversals. In contrast, ces-1 gain-of-function mutants exhibit increased spontaneous reversals, and these are dependent on glr-1 consistent with these genes acting in the same pathway. ces-1 mutants have wild type cholinergic neuromuscular junction function, suggesting that they do not have a general defect in synaptic transmission or muscle function. The effect of ces-1 mutation on glutamatergic behaviors is not due to ectopic cell death of ASH sensory neurons or GLR-1-expressing neurons that mediate one or both of these behaviors, nor due to an indirect effect on NSM sister cell deaths. Rescue experiments suggest that ces-1 may act, in part, in GLR-1-expressing neurons to regulate glutamatergic behaviors. Interestingly, ces-1 mutants suppress the increased reversal frequencies stimulated by a constitutively-active form of GLR-1. However, expression of glr-1 mRNA or GFP-tagged GLR-1 was not decreased in ces-1 mutants suggesting that ces-1 likely promotes GLR-1 function. This study identifies a novel role for ces-1 in regulating glutamatergic behavior that appears to be independent of its canonical role in regulating cell death in the NSM cell lineage.
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Affiliation(s)
- Lidia Park
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Cell, Developmental and Molecular Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Eric S. Luth
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Kelsey Jones
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Julia Hofer
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Irene Nguyen
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Katherine E. Watters
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Peter Juo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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9
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Arefin B, Parvin F, Bahrampour S, Stadler CB, Thor S. Drosophila Neuroblast Selection Is Gated by Notch, Snail, SoxB, and EMT Gene Interplay. Cell Rep 2020; 29:3636-3651.e3. [PMID: 31825841 DOI: 10.1016/j.celrep.2019.11.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/20/2019] [Accepted: 11/08/2019] [Indexed: 12/14/2022] Open
Abstract
In the developing Drosophila central nervous system (CNS), neural progenitor (neuroblast [NB]) selection is gated by lateral inhibition, controlled by Notch signaling and proneural genes. However, proneural mutants still generate many NBs, indicating the existence of additional proneural genes. Moreover, recent studies reveal involvement of key epithelial-mesenchymal transition (EMT) genes in NB selection, but the regulatory interplay between Notch signaling and the EMT machinery is unclear. We find that SoxNeuro (SoxB family) and worniu (Snail family) are integrated with the Notch pathway, and constitute the missing proneural genes. Notch signaling, the proneural, SoxNeuro, and worniu genes regulate key EMT genes to orchestrate the NB selection process. Hence, we uncover an expanded lateral inhibition network for NB selection and demonstrate its link to key players in the EMT machinery. The evolutionary conservation of the genes involved suggests that the Notch-SoxB-Snail-EMT network may control neural progenitor selection in many other systems.
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Affiliation(s)
- Badrul Arefin
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Farjana Parvin
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Shahrzad Bahrampour
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Caroline Bivik Stadler
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden; School of Biomedical Sciences, University of Queensland, St. Lucia, QLD 4072, Australia.
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10
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The Integrator Complex Prevents Dedifferentiation of Intermediate Neural Progenitors back into Neural Stem Cells. Cell Rep 2020; 27:987-996.e3. [PMID: 31018143 DOI: 10.1016/j.celrep.2019.03.089] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/31/2019] [Accepted: 03/24/2019] [Indexed: 01/08/2023] Open
Abstract
Mutations of the Integrator subunits are associated with neurodevelopmental disorders and cancers. However, their role during neural development is poorly understood. Here, we demonstrate that the Drosophila Integrator complex prevents dedifferentiation of intermediate neural progenitors (INPs) during neural stem cell (neuroblast) lineage development. Loss of intS5, intS8, and intS1 generated ectopic type II neuroblasts. INP-specific knockdown of intS8, intS1, and intS2 resulted in the formation of excess type II neuroblasts, indicating that Integrator prevents INP dedifferentiation. Cell-type-specific DamID analysis identified 1413 IntS5-binding sites in INPs, including zinc-finger transcription factor earmuff (erm). Furthermore, erm expression is lost in intS5 and intS8 mutant neuroblast lineages, and intS8 genetically interacts with erm to suppress the formation of ectopic neuroblasts. Taken together, our data demonstrate that the Drosophila Integrator complex plays a critical role in preventing INP dedifferentiation primarily by regulating a key transcription factor Erm that also suppresses INP dedifferentiation.
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11
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An Optogenetic Method to Study Signal Transduction in Intestinal Stem Cell Homeostasis. J Mol Biol 2020; 432:3159-3176. [DOI: 10.1016/j.jmb.2020.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/09/2020] [Accepted: 03/12/2020] [Indexed: 02/07/2023]
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12
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Lough KJ, Byrd KM, Descovich CP, Spitzer DC, Bergman AJ, Beaudoin GM, Reichardt LF, Williams SE. Telophase correction refines division orientation in stratified epithelia. eLife 2019; 8:49249. [PMID: 31833472 PMCID: PMC6959978 DOI: 10.7554/elife.49249] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
During organogenesis, precise control of spindle orientation balances proliferation and differentiation. In the developing murine epidermis, planar and perpendicular divisions yield symmetric and asymmetric fate outcomes, respectively. Classically, division axis specification involves centrosome migration and spindle rotation, events occurring early in mitosis. Here, we identify a novel orientation mechanism which corrects erroneous anaphase orientations during telophase. The directionality of reorientation correlates with the maintenance or loss of basal contact by the apical daughter. While the scaffolding protein LGN is known to determine initial spindle positioning, we show that LGN also functions during telophase to reorient oblique divisions toward perpendicular. The fidelity of telophase correction also relies on the tension-sensitive adherens junction proteins vinculin, α-E-catenin, and afadin. Failure of this corrective mechanism impacts tissue architecture, as persistent oblique divisions induce precocious, sustained differentiation. The division orientation plasticity provided by telophase correction may enable progenitors to adapt to local tissue needs.
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Affiliation(s)
- Kendall J Lough
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States
| | - Kevin M Byrd
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States.,Department of Oral & Craniofacial Health Sciences, The University of North Carolina School of Dentistry, Chapel Hill, United States
| | - Carlos P Descovich
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States
| | - Danielle C Spitzer
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States
| | - Abby J Bergman
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States
| | - Gerard Mj Beaudoin
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, United States.,Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Louis F Reichardt
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, United States.,Department of Physiology, University of California, San Francisco, San Francisco, United States
| | - Scott E Williams
- Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer Center, The University of North Carolina, Chapel Hill, United States.,Department of Biology, Lineberger Comprehensive Cancer Centre, The University of North Carolina, Chapel Hill, United States
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13
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Wu C, Li Z, Ding X, Guo X, Sun Y, Wang X, Hu Y, Li T, La X, Li J, Li JA, Li W, Xue L. Snail modulates JNK-mediated cell death in Drosophila. Cell Death Dis 2019; 10:893. [PMID: 31772150 PMCID: PMC6879600 DOI: 10.1038/s41419-019-2135-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 11/05/2019] [Accepted: 11/11/2019] [Indexed: 02/07/2023]
Abstract
Cell death plays a pivotal role in animal development and tissue homeostasis. Dysregulation of this process is associated with a wide variety of human diseases, including developmental and immunological disorders, neurodegenerative diseases and tumors. While the fundamental role of JNK pathway in cell death has been extensively studied, its down-stream regulators and the underlying mechanisms remain largely elusive. From a Drosophila genetic screen, we identified Snail (Sna), a Zinc-finger transcription factor, as a novel modulator of ectopic Egr-induced JNK-mediated cell death. In addition, sna is essential for the physiological function of JNK signaling in development. Our genetic epistasis data suggest that Sna acts downstream of JNK to promote cell death. Mechanistically, JNK signaling triggers dFoxO-dependent transcriptional activation of sna. Thus, our findings not only reveal a novel function and the underlying mechanism of Sna in modulating JNK-mediated cell death, but also provide a potential drug target and therapeutic strategies for JNK signaling-related diseases.
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Affiliation(s)
- Chenxi Wu
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China.,College of Traditional Chinese Medicine, North China University of Science and Technology, 21 Bohai Road, Tangshan, 063210, China
| | - Zhuojie Li
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiang Ding
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xiaowei Guo
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Ying Sun
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Xingjun Wang
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China.,Department of Neuroscience, Scripps Research Institute, 130 Scripps Way, Jupiter, Fl, 33458, USA
| | - Yujia Hu
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China.,Life Sciences Institute, Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Tongtong Li
- College of Traditional Chinese Medicine, North China University of Science and Technology, 21 Bohai Road, Tangshan, 063210, China
| | - Xiaojin La
- College of Traditional Chinese Medicine, North China University of Science and Technology, 21 Bohai Road, Tangshan, 063210, China
| | - Jianing Li
- College of Traditional Chinese Medicine, North China University of Science and Technology, 21 Bohai Road, Tangshan, 063210, China
| | - Ji-An Li
- College of Traditional Chinese Medicine, North China University of Science and Technology, 21 Bohai Road, Tangshan, 063210, China
| | - Wenzhe Li
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China
| | - Lei Xue
- Institute of Intervention Vessel, Shanghai 10th People's Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, 200092, China. .,Center of Intervention Radiology, Zhuhai People's Hospital, Zhuhai, 519000, China.
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14
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Liu Y, Bao H, Wang W, Lim HY. Cardiac Snail family of transcription factors directs systemic lipid metabolism in Drosophila. PLoS Genet 2019; 15:e1008487. [PMID: 31725726 PMCID: PMC6879157 DOI: 10.1371/journal.pgen.1008487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 11/26/2019] [Accepted: 10/21/2019] [Indexed: 12/30/2022] Open
Abstract
Maintenance of normal lipid homeostasis is crucial to heart function. On the other hand, the heart is now recognized to serve an important role in regulating systemic lipid metabolism; however, the molecular basis remains unclear. In this study, we identify the Drosophila Snail family of transcription factors (herein termed Sna TFs) as new mediators of the heart control of systemic lipid metabolism. Overexpression of Sna TF genes specifically in the heart promotes whole-body leanness whereas their knockdown in the heart promotes obesity. In addition, flies that are heterozygous for a snail deficiency chromosome also exhibit systemic obesity, and that cardiac-specific overexpression of Sna substantially reverses systemic obesity in these flies. We further show that genetically manipulating Sna TF levels in the fat body and intestine do not affect systemic lipid levels. Mechanistically, we find that flies bearing the overexpression or inhibition of Sna TFs in the postnatal heart only exhibit systemic lipid metabolic defects but not heart abnormalities. Cardiac-specific alterations of Sna TF levels also do not perturb cardiac morphology, viability, lipid metabolism or fly food intake. On the other hand, cardiac-specific manipulations of Sna TF levels alter lipogenesis and lipolysis gene expression, mitochondrial biogenesis and respiration, and lipid storage droplet 1 and 2 (Lsd-1 and Lsd-2) levels in the fat body. Together, our results reveal a novel and specific role of Sna TFs in the heart on systemic lipid homeostasis maintenance that is independent of cardiac development and function and involves the governance of triglyceride synthesis and breakdown, energy utilization, and lipid droplet dynamics in the fat body.
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Affiliation(s)
- Ying Liu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Hong Bao
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Weidong Wang
- Department of Medicine, Section of Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail: (WW); (H-YL)
| | - Hui-Ying Lim
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail: (WW); (H-YL)
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15
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Tzortzopoulos A, Thomaidou D, Gaitanou M, Matsas R, Skoulakis E. Expression of Mammalian BM88/CEND1 in Drosophila Affects Nervous System Development by Interfering with Precursor Cell Formation. Neurosci Bull 2019; 35:979-995. [PMID: 31079319 DOI: 10.1007/s12264-019-00386-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 12/27/2018] [Indexed: 12/31/2022] Open
Abstract
We used Drosophila melanogaster as an experimental model to express mouse and pig BM88/CEND1 (cell cycle exit and neuronal differentiation 1) in order to investigate its potential functional effects on Drosophila neurogenesis. BM88/CEND1 is a neuron-specific protein whose function is implicated in triggering cells to exit from the cell cycle and differentiate towards a neuronal phenotype. Transgenic flies expressing either mouse or pig BM88/CEND1 in the nervous system had severe neuronal phenotypes with variable expressivity at various stages of embryonic development. In early embryonic stage 10, BM88/CEND1 expression led to an increase in the neural-specific antigenicity of neuroectoderm at the expense of precursor cells [neuroblasts (Nbs) and ganglion mother cells (GMCs)] including the defective formation and differentiation of the MP2 precursors, whereas at later stages (12-15), protein accumulation induced gross morphological defects primarily in the CNS accompanied by a reduction of Nb and GMC markers. Furthermore, the neuronal precursor cells of embryos expressing BM88/CEND1 failed to carry out proper cell-cycle progression as revealed by the disorganized expression patterns of specific cell-cycle markers. BM88/CEND1 accumulation in the Drosophila eye affected normal eye disc development by disrupting the ommatidia. Finally, we demonstrated that expression of BM88/CEND1 modified/reduced the levels of activated MAP kinase indicating a functional effect of BM88/CEND1 on the MAPK signaling pathway. Our findings suggest that the expression of mammalian BM88/CEND1 in Drosophila exerts specific functional effects associated with neuronal precursor cell formation during embryonic neurogenesis and proper eye disc development. This study also validates the use of Drosophila as a powerful model system in which to investigate gene function and the underlying molecular mechanisms.
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Affiliation(s)
| | - Dimitra Thomaidou
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521, Athens, Greece
| | - Maria Gaitanou
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521, Athens, Greece
| | - Rebecca Matsas
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, 11521, Athens, Greece
| | - Efthimios Skoulakis
- "Alexander Fleming" Biomedical Sciences Research Centre, 16672, Athens, Greece
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16
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Bahrampour S, Jonsson C, Thor S. Brain expansion promoted by polycomb-mediated anterior enhancement of a neural stem cell proliferation program. PLoS Biol 2019; 17:e3000163. [PMID: 30807568 PMCID: PMC6407790 DOI: 10.1371/journal.pbio.3000163] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 03/08/2019] [Accepted: 02/08/2019] [Indexed: 12/31/2022] Open
Abstract
During central nervous system (CNS) development, genetic programs establish neural stem cells and drive both stem and daughter cell proliferation. However, the prominent anterior expansion of the CNS implies anterior–posterior (A–P) modulation of these programs. In Drosophila, a set of neural stem cell factors acts along the entire A–P axis to establish neural stem cells. Brain expansion results from enhanced stem and daughter cell proliferation, promoted by a Polycomb Group (PcG)->Homeobox (Hox) homeotic network. But how does PcG->Hox modulate neural-stem-cell–factor activity along the A–P axis? We find that the PcG->Hox network creates an A–P expression gradient of neural stem cell factors, thereby driving a gradient of proliferation. PcG mutants can be rescued by misexpression of the neural stem cell factors or by mutation of one single Hox gene. Hence, brain expansion results from anterior enhancement of core neural-stem-cell–factor expression, mediated by PcG repression of brain Hox expression. A study in fruit flies shows that the anterior expansion of the central nervous system, to form the brain, is driven by Polycomb-mediated repression of Hox genes, resulting in anterior enhancement of a neural stem cell program. The central nervous system displays a pronounced anterior expansion that forms the brain. In the fruit fly Drosophila melanogaster, this expansion is driven by enhanced anterior cell proliferation. Recent studies reveal that cell proliferation in the brain is promoted by the Polycomb Group Complex, a key epigenetic complex. During development of the central nervous system, the Polycomb Group Complex acts to exclude Hox homeotic gene expression from the brain, thereby rendering the brain a Hox-free zone. Hox genes act in an antiproliferative manner, which explains the hyperproliferation observed in the brain, as well as the gradient of proliferation along the anterior–posterior axis of the central nervous system. Here, we find that Hox genes act by repressing a common neural stem cell proliferation program in more posterior regions, resulting in an anterior–posterior gradient of “stemness.” Hence, elevated anterior proliferation is promoted by the Polycomb Group Complex acting to keep the brain free of negative Hox input, thereby ensuring elevated expression of neural stem cell factors in the brain. Strikingly, mutants of the Polycomb Group Complex can be rescued by mutation of one single Hox gene, demonstrating that the primary role of the Polycomb Group Complex is indeed Hox repression. This study advances our understanding of how neural stem cell programs operate at different axial levels of the central nervous system and may have implications also for stem cell and organoid biology.
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Affiliation(s)
- Shahrzad Bahrampour
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| | - Carolin Jonsson
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
- School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, Australia
- * E-mail:
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17
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Harding K, White K. Drosophila as a Model for Developmental Biology: Stem Cell-Fate Decisions in the Developing Nervous System. J Dev Biol 2018; 6:E25. [PMID: 30347666 PMCID: PMC6315890 DOI: 10.3390/jdb6040025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/16/2018] [Accepted: 10/17/2018] [Indexed: 12/25/2022] Open
Abstract
Stem cells face a diversity of choices throughout their lives. At specific times, they may decide to initiate cell division, terminal differentiation, or apoptosis, or they may enter a quiescent non-proliferative state. Neural stem cells in the Drosophila central nervous system do all of these, at stereotypical times and anatomical positions during development. Distinct populations of neural stem cells offer a unique system to investigate the regulation of a particular stem cell behavior, while comparisons between populations can lead us to a broader understanding of stem cell identity. Drosophila is a well-described and genetically tractable model for studying fundamental stem cell behavior and the mechanisms that underlie cell-fate decisions. This review will focus on recent advances in our understanding of the factors that contribute to distinct stem cell-fate decisions within the context of the Drosophila nervous system.
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Affiliation(s)
- Katherine Harding
- Massachusetts General Hospital Cutaneous Biology Research Center, Harvard Medical School, Boston, MA 02129, USA
| | - Kristin White
- Massachusetts General Hospital Cutaneous Biology Research Center, Harvard Medical School, Boston, MA 02129, USA.
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18
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Symonenko AV, Roshina NV, Krementsova AV, Pasyukova EG. Reduced Neuronal Transcription of Escargot, the Drosophila Gene Encoding a Snail-Type Transcription Factor, Promotes Longevity. Front Genet 2018; 9:151. [PMID: 29760717 PMCID: PMC5936762 DOI: 10.3389/fgene.2018.00151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 04/12/2018] [Indexed: 12/11/2022] Open
Abstract
In recent years, several genes involved in complex neuron specification networks have been shown to control life span. However, information on these genes is scattered, and studies to discover new neuronal genes and gene cascades contributing to life span control are needed, especially because of the recognized role of the nervous system in governing homeostasis, aging, and longevity. Previously, we demonstrated that several genes that encode RNA polymerase II transcription factors and that are involved in the development of the nervous system affect life span in Drosophila melanogaster. Among other genes, escargot (esg) was demonstrated to be causally associated with an increase in the life span of male flies. Here, we present new data on the role of esg in life span control. We show that esg affects the life spans of both mated and unmated males and females to varying degrees. By analyzing the survival and locomotion of the esg mutants, we demonstrate that esg is involved in the control of aging. We show that increased longevity is caused by decreased esg transcription. In particular, we demonstrate that esg knockdown in the nervous system increased life span, directly establishing the involvement of the neuronal esg function in life span control. Our data invite attention to the mechanisms regulating the esg transcription rate, which is changed by insertions of DNA fragments of different sizes downstream of the structural part of the gene, indicating the direction of further research. Our data agree with the previously made suggestion that alterations in gene expression during development might affect adult lifespan, due to epigenetic patterns inherited in cell lineages or predetermined during the development of the structural and functional properties of the nervous system.
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Affiliation(s)
- Alexander V Symonenko
- Laboratory of Genome Variation, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Natalia V Roshina
- Laboratory of Genome Variation, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia.,Laboratory of Genetic Basis of Biodiversity, N. I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Anna V Krementsova
- Laboratory of Genome Variation, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia.,Laboratory of Kinetics and Mechanisms of Enzymatic and Catalytic Reactions, N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Elena G Pasyukova
- Laboratory of Genome Variation, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
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19
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Bahrampour S, Gunnar E, Jonsson C, Ekman H, Thor S. Neural Lineage Progression Controlled by a Temporal Proliferation Program. Dev Cell 2017; 43:332-348.e4. [PMID: 29112852 DOI: 10.1016/j.devcel.2017.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 08/09/2017] [Accepted: 10/05/2017] [Indexed: 10/18/2022]
Abstract
Great progress has been made in identifying transcriptional programs that establish stem cell identity. In contrast, we have limited insight into how these programs are down-graded in a timely manner to halt proliferation and allow for cellular differentiation. Drosophila embryonic neuroblasts undergo such a temporal progression, initially dividing to bud off daughters that divide once (type I), then switching to generating non-dividing daughters (type 0), and finally exiting the cell cycle. We identify six early transcription factors that drive neuroblast and type I daughter proliferation. Early factors are gradually replaced by three late factors, acting to trigger the type I→0 daughter proliferation switch and eventually to stop neuroblasts. Early and late factors regulate each other and four key cell-cycle genes, providing a logical genetic pathway for these transitions. The identification of this extensive driver-stopper temporal program controlling neuroblast lineage progression may have implications for studies in many other systems.
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Affiliation(s)
- Shahrzad Bahrampour
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Erika Gunnar
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Carolin Jonsson
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Helen Ekman
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, 58185 Linkoping, Sweden.
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20
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Roubinet C, Tsankova A, Pham TT, Monnard A, Caussinus E, Affolter M, Cabernard C. Spatio-temporally separated cortical flows and spindle geometry establish physical asymmetry in fly neural stem cells. Nat Commun 2017; 8:1383. [PMID: 29123099 PMCID: PMC5680339 DOI: 10.1038/s41467-017-01391-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 09/04/2017] [Indexed: 01/09/2023] Open
Abstract
Asymmetric cell division, creating sibling cells with distinct developmental potentials, can be manifested in sibling cell size asymmetry. This form of physical asymmetry occurs in several metazoan cells, but the underlying mechanisms and function are incompletely understood. Here we use Drosophila neural stem cells to elucidate the mechanisms involved in physical asymmetry establishment. We show that Myosin relocalizes to the cleavage furrow via two distinct cortical Myosin flows: at anaphase onset, a polarity induced, basally directed Myosin flow clears Myosin from the apical cortex. Subsequently, mitotic spindle cues establish a Myosin gradient at the lateral neuroblast cortex, necessary to trigger an apically directed flow, removing Actomyosin from the basal cortex. On the basis of the data presented here, we propose that spatiotemporally controlled Myosin flows in conjunction with spindle positioning and spindle asymmetry are key determinants for correct cleavage furrow placement and cortical expansion, thereby establishing physical asymmetry.
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Affiliation(s)
- Chantal Roubinet
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Anna Tsankova
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
- Streuli Pharma AG, Bahnhofstrasse 7, CH-8730, Uznach, Switzerland
| | - Tri Thanh Pham
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA, 98195, USA
| | - Arnaud Monnard
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA, 98195, USA
| | - Emmanuel Caussinus
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
- Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Markus Affolter
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland
| | - Clemens Cabernard
- Biozentrum, University of Basel, Klingelbergstrasse 50-70, CH-4056, Basel, Switzerland.
- Department of Biology, University of Washington, 24 Kincaid Hall, Seattle, WA, 98195, USA.
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21
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Inscuteable maintains type I neuroblast lineage identity via Numb/Notch signaling in the Drosophila larval brain. J Genet Genomics 2017; 44:151-162. [DOI: 10.1016/j.jgg.2017.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/23/2017] [Accepted: 02/27/2017] [Indexed: 01/11/2023]
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22
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Drosophila melanogaster Neuroblasts: A Model for Asymmetric Stem Cell Divisions. Results Probl Cell Differ 2017; 61:183-210. [PMID: 28409305 DOI: 10.1007/978-3-319-53150-2_8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Asymmetric cell division (ACD) is a fundamental mechanism to generate cell diversity, giving rise to daughter cells with different developmental potentials. ACD is manifested in the asymmetric segregation of proteins or mRNAs, when the two daughter cells differ in size or are endowed with different potentials to differentiate into a particular cell type (Horvitz and Herskowitz, Cell 68:237-255, 1992). Drosophila neuroblasts, the neural stem cells of the developing fly brain, are an ideal system to study ACD since this system encompasses all of these characteristics. Neuroblasts are intrinsically polarized cells, utilizing polarity cues to orient the mitotic spindle, segregate cell fate determinants asymmetrically, and regulate spindle geometry and physical asymmetry. The neuroblast system has contributed significantly to the elucidation of the basic molecular mechanisms underlying ACD. Recent findings also highlight its usefulness to study basic aspects of stem cell biology and tumor formation. In this review, we will focus on what has been learned about the basic mechanisms underlying ACD in fly neuroblasts.
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23
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Stollewerk A. A flexible genetic toolkit for arthropod neurogenesis. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150044. [PMID: 26598727 DOI: 10.1098/rstb.2015.0044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Arthropods show considerable variations in early neurogenesis. This includes the pattern of specification, division and movement of neural precursors and progenitors. In all metazoans with nervous systems, including arthropods, conserved genes regulate neurogenesis, which raises the question of how the various morphological mechanisms have emerged and how the same genetic toolkit might generate different morphological outcomes. Here I address this question by comparing neurogenesis across arthropods and show how variations in the regulation and function of the neural genes might explain this phenomenon and how they might have facilitated the evolution of the diverse morphological mechanisms of neurogenesis.
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Affiliation(s)
- Angelika Stollewerk
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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24
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Ramat A, Audibert A, Louvet-Vallée S, Simon F, Fichelson P, Gho M. Escargot and Scratch regulate neural commitment by antagonizing Notch activity in Drosophila sensory organs. Development 2016; 143:3024-34. [PMID: 27471258 DOI: 10.1242/dev.134387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 07/12/2016] [Indexed: 12/15/2022]
Abstract
During Notch (N)-mediated binary cell fate decisions, cells adopt two different fates according to the levels of N pathway activation: an Noff-dependent or an Non-dependent fate. How cells maintain these N activity levels over time remains largely unknown. We address this question in the cell lineage that gives rise to the Drosophila mechanosensory organs. In this lineage a primary precursor cell undergoes a stereotyped sequence of oriented asymmetric cell divisions and transits through two neural precursor states before acquiring a neuron identity. Using a combination of genetic and cell biology strategies, we show that Escargot and Scratch, two transcription factors belonging to the Snail superfamily, maintain Noff neural commitment by directly blocking the transcription of N target genes. We propose that Snail factors act by displacing proneural transcription activators from DNA binding sites. As such, Snail factors maintain the Noff state in neural precursor cells by buffering any ectopic variation in the level of N activity. Since Escargot and Scratch orthologs are present in other precursor cells, our findings are fundamental for understanding precursor cell fate acquisition in other systems.
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Affiliation(s)
- Anne Ramat
- CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France
| | - Agnès Audibert
- Sorbonne Universités, UPMC Université Paris 06, UMR7622, Laboratoire de Biologie du Développement, Paris F-75005, France
| | - Sophie Louvet-Vallée
- Sorbonne Universités, UPMC Université Paris 06, UMR7622, Laboratoire de Biologie du Développement, Paris F-75005, France
| | - Françoise Simon
- CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France
| | - Pierre Fichelson
- CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France
| | - Michel Gho
- CNRS, UMR 7622, Laboratoire de Biologie du Développement, IBPS, Paris F-75005, France
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25
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Ou Q, Zeng J, Yamanaka N, Brakken-Thal C, O'Connor MB, King-Jones K. The Insect Prothoracic Gland as a Model for Steroid Hormone Biosynthesis and Regulation. Cell Rep 2016; 16:247-262. [PMID: 27320926 DOI: 10.1016/j.celrep.2016.05.053] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/01/2016] [Accepted: 05/12/2016] [Indexed: 11/17/2022] Open
Abstract
Steroid hormones are ancient signaling molecules found in vertebrates and insects alike. Both taxa show intriguing parallels with respect to how steroids function and how their synthesis is regulated. As such, insects are excellent models for studying universal aspects of steroid physiology. Here, we present a comprehensive genomic and genetic analysis of the principal steroid hormone-producing organs in two popular insect models, Drosophila and Bombyx. We identified 173 genes with previously unknown specific expression in steroid-producing cells, 15 of which had critical roles in development. The insect neuropeptide PTTH and its vertebrate counterpart ACTH both regulate steroid production, but molecular targets of these pathways remain poorly characterized. Identification of PTTH-dependent gene sets identified the nuclear receptor HR4 as a highly conserved target in both Drosophila and Bombyx. We consider this study to be a critical step toward understanding how steroid hormone production and release are regulated in all animal models.
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Affiliation(s)
- Qiuxiang Ou
- Department of Biological Sciences, University of Alberta, G-504 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada
| | - Jie Zeng
- Department of Biological Sciences, University of Alberta, G-504 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada
| | - Naoki Yamanaka
- Institute for Integrative Genome Biology, Center for Disease Vector Research, and Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA
| | - Christina Brakken-Thal
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Michael B O'Connor
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kirst King-Jones
- Department of Biological Sciences, University of Alberta, G-504 Biological Sciences Building, Edmonton, AB T6G 2E9, Canada.
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26
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Tseng CY, Kao SH, Hsu HJ. Snail controls proliferation of Drosophila ovarian epithelial follicle stem cells, independently of E-cadherin. Dev Biol 2016; 414:142-8. [DOI: 10.1016/j.ydbio.2016.04.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 01/11/2023]
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27
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Zhang Y, Rai M, Wang C, Gonzalez C, Wang H. Prefoldin and Pins synergistically regulate asymmetric division and suppress dedifferentiation. Sci Rep 2016; 6:23735. [PMID: 27025979 PMCID: PMC4812327 DOI: 10.1038/srep23735] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 03/14/2016] [Indexed: 01/14/2023] Open
Abstract
Prefoldin is a molecular chaperone complex that regulates tubulin function in mitosis. Here, we show that Prefoldin depletion results in disruption of neuroblast polarity, leading to neuroblast overgrowth in Drosophila larval brains. Interestingly, co-depletion of Prefoldin and Partner of Inscuteable (Pins) leads to the formation of gigantic brains with severe neuroblast overgrowth, despite that Pins depletion alone results in smaller brains with partially disrupted neuroblast polarity. We show that Prefoldin acts synergistically with Pins to regulate asymmetric division of both neuroblasts and Intermediate Neural Progenitors (INPs). Surprisingly, co-depletion of Prefoldin and Pins also induces dedifferentiation of INPs back into neuroblasts, while depletion either Prefoldin or Pins alone is insufficient to do so. Furthermore, knocking down either α-tubulin or β-tubulin in pins- mutant background results in INP dedifferentiation back into neuroblasts, leading to the formation of ectopic neuroblasts. Overexpression of α-tubulin suppresses neuroblast overgrowth observed in prefoldin pins double mutant brains. Our data elucidate an unexpected function of Prefoldin and Pins in synergistically suppressing dedifferentiation of INPs back into neural stem cells.
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Affiliation(s)
- Yingjie Zhang
- Neuroscience &Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456
| | - Madhulika Rai
- Institute for Research in Biomedicine (IRB-Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Cheng Wang
- Neuroscience &Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857
| | - Cayetano Gonzalez
- Institute for Research in Biomedicine (IRB-Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA). Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Hongyan Wang
- Neuroscience &Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore 169857.,NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 28 Medical Drive, Singapore 117456.,Dept. of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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Chen K, Koe CT, Xing ZB, Tian X, Rossi F, Wang C, Tang Q, Zong W, Hong WJ, Taneja R, Yu F, Gonzalez C, Wu C, Endow S, Wang H. Arl2- and Msps-dependent microtubule growth governs asymmetric division. J Cell Biol 2016; 212:661-76. [PMID: 26953351 PMCID: PMC4792071 DOI: 10.1083/jcb.201503047] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 02/10/2016] [Indexed: 12/18/2022] Open
Abstract
Drosophila Arl2 governs neuroblast asymmetric cell division through regulation of microtubule growth and localization of Msps to centrosomes. Asymmetric division of neural stem cells is a fundamental strategy to balance their self-renewal and differentiation. It is long thought that microtubules are not essential for cell polarity in asymmetrically dividing Drosophila melanogaster neuroblasts (NBs; neural stem cells). Here, we show that Drosophila ADP ribosylation factor like-2 (Arl2) and Msps, a known microtubule-binding protein, control cell polarity and spindle orientation of NBs. Upon arl2 RNA intereference, Arl2-GDP expression, or arl2 deletions, microtubule abnormalities and asymmetric division defects were observed. Conversely, overactivation of Arl2 leads to microtubule overgrowth and depletion of NBs. Arl2 regulates microtubule growth and asymmetric division through localizing Msps to the centrosomes in NBs. Moreover, Arl2 regulates dynein function and in turn centrosomal localization of D-TACC and Msps. Arl2 physically associates with tubulin cofactors C, D, and E. Arl2 functions together with tubulin-binding cofactor D to control microtubule growth, Msps localization, and NB self-renewal. Therefore, Arl2- and Msps-dependent microtubule growth is a new paradigm regulating asymmetric division of neural stem cells.
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Affiliation(s)
- Keng Chen
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857 National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456
| | - Chwee Tat Koe
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857 National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456
| | - Zhanyuan Benny Xing
- Department of Cell Biology, Duke University, Duke University Medical Center, Durham, NC 27710
| | - Xiaolin Tian
- Neuroscience Center of Excellence, Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Fabrizio Rossi
- Institute for Research in Biomedicine Barcelona, 08028 Barcelona, Spain
| | - Cheng Wang
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857
| | - Quan Tang
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117604
| | - Wenhui Zong
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117604
| | - Wan Jin Hong
- Institute of Molecular and Cell Biology, Singapore 138673
| | - Reshma Taneja
- National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Fengwei Yu
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857 National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604 Department of Biological Sciences, National University of Singapore, Singapore 117604
| | - Cayetano Gonzalez
- Institute for Research in Biomedicine Barcelona, 08028 Barcelona, Spain Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Chunlai Wu
- Neuroscience Center of Excellence, Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, LA 70112
| | - Sharyn Endow
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857 Department of Cell Biology, Duke University, Duke University Medical Center, Durham, NC 27710
| | - Hongyan Wang
- Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore 169857 National University of Singapore Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456 Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
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Yang CP, Fu CC, Sugino K, Liu Z, Ren Q, Liu LY, Yao X, Lee LP, Lee T. Transcriptomes of lineage-specific Drosophila neuroblasts profiled by genetic targeting and robotic sorting. Development 2015; 143:411-21. [PMID: 26700685 DOI: 10.1242/dev.129163] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/11/2015] [Indexed: 12/21/2022]
Abstract
A brain consists of numerous distinct neurons arising from a limited number of progenitors, called neuroblasts in Drosophila. Each neuroblast produces a specific neuronal lineage. To unravel the transcriptional networks that underlie the development of distinct neuroblast lineages, we marked and isolated lineage-specific neuroblasts for RNA sequencing. We labeled particular neuroblasts throughout neurogenesis by activating a conditional neuroblast driver in specific lineages using various intersection strategies. The targeted neuroblasts were efficiently recovered using a custom-built device for robotic single-cell picking. Transcriptome analysis of mushroom body, antennal lobe and type II neuroblasts compared with non-selective neuroblasts, neurons and glia revealed a rich repertoire of transcription factors expressed among neuroblasts in diverse patterns. Besides transcription factors that are likely to be pan-neuroblast, many transcription factors exist that are selectively enriched or repressed in certain neuroblasts. The unique combinations of transcription factors present in different neuroblasts may govern the diverse lineage-specific neuron fates.
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Affiliation(s)
- Ching-Po Yang
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Chi-Cheng Fu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Graduate Program, University of California, Berkeley, CA 94720, USA
| | - Ken Sugino
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Zhiyong Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Qingzhong Ren
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Ling-Yu Liu
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xiaohao Yao
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Luke P Lee
- Departments of Bioengineering, Electrical Engineering and Computer Science, and Biophysics Graduate Program, University of California, Berkeley, CA 94720, USA
| | - Tzumin Lee
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
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Ballard MS, Zhu A, Iwai N, Stensrud M, Mapps A, Postiglione MP, Knoblich JA, Hinck L. Mammary Stem Cell Self-Renewal Is Regulated by Slit2/Robo1 Signaling through SNAI1 and mINSC. Cell Rep 2015; 13:290-301. [PMID: 26440891 PMCID: PMC4606466 DOI: 10.1016/j.celrep.2015.09.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/03/2015] [Accepted: 09/01/2015] [Indexed: 01/12/2023] Open
Abstract
Tissue homeostasis requires somatic stem cell maintenance; however, mechanisms regulating this process during organogenesis are not well understood. Here, we identify asymmetrically renewing basal and luminal stem cells in the mammary end bud. We demonstrate that SLIT2/ROBO1 signaling regulates the choice between self-renewing asymmetric cell divisions (ACDs) and expansive symmetric cell divisions (SCDs) by governing Inscuteable (mInsc), a key member of the spindle orientation machinery, through the transcription factor Snail (SNAI1). Loss of SLIT2/ROBO1 signaling increases SNAI1 in the nucleus. Overexpression of SNAI1 increases mInsc expression, an effect that is inhibited by SLIT2 treatment. Increased mInsc does not change cell proliferation in the mammary gland (MG) but instead causes more basal cap cells to divide via SCD, at the expense of ACD, leading to more stem cells and larger outgrowths. Together, our studies provide insight into how the number of mammary stem cells is regulated by the extracellular cue SLIT2.
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Affiliation(s)
- Mimmi S Ballard
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Anna Zhu
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Naomi Iwai
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Michael Stensrud
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA; Department of Biology, California State University Channel Islands, Camarillo, CA 93012, USA
| | - Aurelia Mapps
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Maira Pia Postiglione
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Juergen A Knoblich
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, 1030 Vienna, Austria
| | - Lindsay Hinck
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
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31
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Kim HJ, Ahn HJ, Lee S, Kim JH, Park J, Jeon SH, Kim SH. Intrinsic dorsoventral patterning and extrinsic EGFR signaling genes control glial cell development in the Drosophila nervous system. Neuroscience 2015; 307:242-52. [PMID: 26318336 DOI: 10.1016/j.neuroscience.2015.08.049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 08/08/2015] [Accepted: 08/20/2015] [Indexed: 11/26/2022]
Abstract
Dorsoventral patterning and epidermal growth factor receptor (EGFR) signaling genes are essential for determining neural identity and differentiation of the Drosophila nervous system. Their role in glial cell development in the Drosophila nervous system is not clearly established. Our study demonstrated that the dorsoventral patterning genes, vnd, ind, and msh, are intrinsically essential for the proper expression of a master glial cell regulator, gcm, and a differentiation gene, repo, in the lateral glia. In addition, we showed that esg is particularly required for their expression in the peripheral glia. These results indicate that the dorsoventral patterning and EGFR signaling genes are essential for identity determination and differentiation of the lateral glia by regulating proper expression of gcm and repo in the lateral glia from the early glial development. In contrast, overexpression of vnd, msh, spi, and Egfr genes repressed the expression of Repo in the ventral neuroectoderm, indicating that maintenance of correct columnar identity along the dorsoventral axis by proper expression of these genes is essential for restrictive formation of glial precursor cells in the lateral neuroectoderm. Therefore, the dorsoventral patterning and EGFR signaling genes play essential roles in correct identity determination and differentiation of lateral glia in the Drosophila nervous system.
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Affiliation(s)
- H J Kim
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea
| | - H J Ahn
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea
| | - S Lee
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea
| | - J H Kim
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea
| | - J Park
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea
| | - S-H Jeon
- Department of Biology Education, Seoul National University, Seoul 151-742, Republic of Korea
| | - S H Kim
- Department of Chemistry, Konkuk University, Seoul 143-701, Republic of Korea.
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Sanchez-Díaz I, Rosales-Bravo F, Reyes-Taboada JL, Covarrubias AA, Narvaez-Padilla V, Reynaud E. The Esg Gene Is Involved in Nicotine Sensitivity in Drosophila melanogaster. PLoS One 2015; 10:e0133956. [PMID: 26222315 PMCID: PMC4519288 DOI: 10.1371/journal.pone.0133956] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 07/03/2015] [Indexed: 12/04/2022] Open
Abstract
In humans, there is a strong correlation between sensitivity to substances of abuse and addiction risk. This differential tolerance to drugs has a strong genetic component. The identification of human genetic factors that alter drug tolerance has been a difficult task. For this reason and taking advantage of the fact that Drosophila responds similarly to humans to many drugs, and that genetically it has a high degree of homology (sharing at least 70% of genes known to be involved in human genetic diseases), we looked for genes in Drosophila that altered their nicotine sensitivity. We developed an instantaneous nicotine vaporization technique that exposed flies in a reproducible way. The amount of nicotine sufficient to "knock out" half of control flies for 30 minutes was determined and this parameter was defined as Half Recovery Time (HRT). Two fly lines, L4 and L70, whose HRT was significantly longer than control´s were identified. The L4 insertion is a loss of function allele of the transcriptional factor escargot (esg), whereas L70 insertion causes miss-expression of the microRNA cluster miR-310-311-312-313 (miR-310c). In this work, we demonstrate that esg loss of function induces nicotine sensitivity possibly by altering development of sensory organs and neurons in the medial section of the thoracoabdominal ganglion. The ectopic expression of the miR-310c also induces nicotine sensitivity by lowering Esg levels thus disrupting sensory organs and possibly to the modulation of other miR-310c targets.
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Affiliation(s)
- Iván Sanchez-Díaz
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal, 510–3, Cuernavaca 62210, México
| | - Fernando Rosales-Bravo
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, México
| | - José Luis Reyes-Taboada
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal, 510–3, Cuernavaca 62210, Mexico
| | - Alejandra A Covarrubias
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal, 510–3, Cuernavaca 62210, Mexico
| | - Verónica Narvaez-Padilla
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos 62209, México
| | - Enrique Reynaud
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal, 510–3, Cuernavaca 62210, México
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Novel Genes Involved in Controlling Specification of Drosophila FMRFamide Neuropeptide Cells. Genetics 2015; 200:1229-44. [PMID: 26092715 DOI: 10.1534/genetics.115.178483] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/16/2015] [Indexed: 01/28/2023] Open
Abstract
The expression of neuropeptides is often extremely restricted in the nervous system, making them powerful markers for addressing cell specification . In the developing Drosophila ventral nerve cord, only six cells, the Ap4 neurons, of some 10,000 neurons, express the neuropeptide FMRFamide (FMRFa). Each Ap4/FMRFa neuron is the last-born cell generated by an identifiable and well-studied progenitor cell, neuroblast 5-6 (NB5-6T). The restricted expression of FMRFa and the wealth of information regarding its gene regulation and Ap4 neuron specification makes FMRFa a valuable readout for addressing many aspects of neural development, i.e., spatial and temporal patterning cues, cell cycle control, cell specification, axon transport, and retrograde signaling. To this end, we have conducted a forward genetic screen utilizing an Ap4-specific FMRFa-eGFP transgenic reporter as our readout. A total of 9781 EMS-mutated chromosomes were screened for perturbations in FMRFa-eGFP expression, and 611 mutants were identified. Seventy-nine of the strongest mutants were mapped down to the affected gene by deficiency mapping or whole-genome sequencing. We isolated novel alleles for previously known FMRFa regulators, confirming the validity of the screen. In addition, we identified novel essential genes, including several with previously undefined functions in neural development. Our identification of genes affecting most major steps required for successful terminal differentiation of Ap4 neurons provides a comprehensive view of the genetic flow controlling the generation of highly unique neuronal cell types in the developing nervous system.
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Abstract
The foundation of the diverse metazoan nervous systems is laid by embryonic patterning mechanisms, involving the generation and movement of neural progenitors and their progeny. Here we divide early neurogenesis into discrete elements, including origin, pattern, proliferation, and movement of neuronal progenitors, which are controlled by conserved gene cassettes. We review these neurogenetic mechanisms in representatives of the different metazoan clades, with the goal to build a conceptual framework in which one can ask specific questions, such as which of these mechanisms potentially formed part of the developmental "toolkit" of the bilaterian ancestor and which evolved later.
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Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Angelika Stollewerk
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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Loza-Coll MA, Southall TD, Sandall SL, Brand AH, Jones DL. Regulation of Drosophila intestinal stem cell maintenance and differentiation by the transcription factor Escargot. EMBO J 2014; 33:2983-96. [PMID: 25433031 DOI: 10.15252/embj.201489050] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Tissue stem cells divide to self-renew and generate differentiated cells to maintain homeostasis. Although influenced by both intrinsic and extrinsic factors, the genetic mechanisms coordinating the decision between self-renewal and initiation of differentiation remain poorly understood. The escargot (esg) gene encodes a transcription factor that is expressed in stem cells in multiple tissues in Drosophila melanogaster, including intestinal stem cells (ISCs). Here, we demonstrate that Esg plays a pivotal role in intestinal homeostasis, maintaining the stem cell pool while influencing fate decisions through modulation of Notch activity. Loss of esg induced ISC differentiation, a decline in Notch activity in daughter enteroblasts (EB), and an increase in differentiated enteroendocrine (EE) cells. Amun, an inhibitor of Notch in other systems, was identified as a target of Esg in the intestine. Decreased expression of esg resulted in upregulation of Amun, while downregulation of Amun rescued the ectopic EE cell phenotype resulting from loss of esg. Thus, our findings provide a framework for further comparative studies addressing the conserved roles of Snail factors in coordinating self-renewal and differentiation of stem cells across tissues and species.
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Affiliation(s)
- Mariano A Loza-Coll
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Sharsti L Sandall
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Andrea H Brand
- The Gurdon Institute University of Cambridge, Cambridge, UK
| | - D Leanne Jones
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA Department of Molecular, Cell, and Developmental Biology, University of California Los Angeles, Los Angeles, CA, USA Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California Los Angeles, Los Angeles, CA, USA
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Zander MA, Cancino GI, Gridley T, Kaplan DR, Miller FD. The Snail transcription factor regulates the numbers of neural precursor cells and newborn neurons throughout mammalian life. PLoS One 2014; 9:e104767. [PMID: 25136812 PMCID: PMC4138084 DOI: 10.1371/journal.pone.0104767] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/17/2014] [Indexed: 11/20/2022] Open
Abstract
The Snail transcription factor regulates diverse aspects of stem cell biology in organisms ranging from Drosophila to mammals. Here we have asked whether it regulates the biology of neural precursor cells (NPCs) in the forebrain of postnatal and adult mice, taking advantage of a mouse containing a floxed Snail allele (Snailfl/fl mice). We show that when Snail is inducibly ablated in the embryonic cortex, this has long-term consequences for cortical organization. In particular, when Snailfl/fl mice are crossed to Nestin-cre mice that express Cre recombinase in embryonic neural precursors, this causes inducible ablation of Snail expression throughout the postnatal cortex. This loss of Snail causes a decrease in proliferation of neonatal cortical neural precursors and mislocalization and misspecification of cortical neurons. Moreover, these precursor phenotypes persist into adulthood. Adult neural precursor cell proliferation is decreased in the forebrain subventricular zone and in the hippocampal dentate gyrus, and this is coincident with a decrease in the number of adult-born olfactory and hippocampal neurons. Thus, Snail is a key regulator of the numbers of neural precursors and newborn neurons throughout life.
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Affiliation(s)
- Mark A. Zander
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute for Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Gonzalo I. Cancino
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Thomas Gridley
- Maine Medical Center Research Institute, University of Maine, Scarborough, Maine, United States of America
| | - David R. Kaplan
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute for Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Freda D. Miller
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada
- Institute for Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Snail coordinately regulates downstream pathways to control multiple aspects of mammalian neural precursor development. J Neurosci 2014; 34:5164-75. [PMID: 24719096 DOI: 10.1523/jneurosci.0370-14.2014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The Snail transcription factor plays a key role in regulating diverse developmental processes but is not thought to play a role in mammalian neural precursors. Here, we have examined radial glial precursor cells of the embryonic murine cortex and demonstrate that Snail regulates their survival, self-renewal, and differentiation into intermediate progenitors and neurons via two distinct and separable target pathways. First, Snail promotes cell survival by antagonizing a p53-dependent death pathway because coincident p53 knockdown rescues survival deficits caused by Snail knockdown. Second, we show that the cell cycle phosphatase Cdc25b is regulated by Snail in radial precursors and that Cdc25b coexpression is sufficient to rescue the decreased radial precursor proliferation and differentiation observed upon Snail knockdown. Thus, Snail acts via p53 and Cdc25b to coordinately regulate multiple aspects of mammalian embryonic neural precursor biology.
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Ferrero E, Fischer B, Russell S. SoxNeuro orchestrates central nervous system specification and differentiation in Drosophila and is only partially redundant with Dichaete. Genome Biol 2014; 15:R74. [PMID: 24886562 PMCID: PMC4072944 DOI: 10.1186/gb-2014-15-5-r74] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 05/30/2014] [Indexed: 12/31/2022] Open
Abstract
Background Sox proteins encompass an evolutionarily conserved family of transcription factors with critical roles in animal development and stem cell biology. In common with vertebrates, the Drosophila group B proteins SoxNeuro and Dichaete are involved in central nervous system development, where they play both similar and unique roles in gene regulation. Sox genes show extensive functional redundancy across metazoans, but the molecular basis underpinning functional compensation mechanisms at the genomic level are currently unknown. Results Using a combination of genome-wide binding analysis and gene expression profiling, we show that SoxNeuro directs embryonic neural development from the early specification of neuroblasts through to the terminal differentiation of neurons and glia. To address the issue of functional redundancy and compensation at a genomic level, we compare SoxNeuro and Dichaete binding, identifying common and independent binding events in wild-type conditions, as well as instances of compensation and loss of binding in mutant backgrounds. Conclusions We find that early aspects of group B Sox functions in the central nervous system, such as stem cell maintenance and dorsoventral patterning, are highly conserved. However, in contrast to vertebrates, we find that Drosophila group B1 proteins also play prominent roles during later aspects of neural morphogenesis. Our analysis of the functional relationship between SoxNeuro and Dichaete uncovers evidence for redundant and independent functions for each protein, along with unexpected examples of compensation and interdependency, thus providing new insights into the general issue of transcription factor functional redundancy.
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39
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He H, Kise Y, Izadifar A, Urwyler O, Ayaz D, Parthasarthy A, Yan B, Erfurth ML, Dascenco D, Schmucker D. Cell-intrinsic requirement of Dscam1 isoform diversity for axon collateral formation. Science 2014; 344:1182-6. [DOI: 10.1126/science.1251852] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Voog J, Sandall SL, Hime GR, Resende LPF, Loza-Coll M, Aslanian A, Yates JR, Hunter T, Fuller MT, Jones DL. Escargot restricts niche cell to stem cell conversion in the Drosophila testis. Cell Rep 2014; 7:722-34. [PMID: 24794442 DOI: 10.1016/j.celrep.2014.04.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 02/05/2013] [Accepted: 04/17/2014] [Indexed: 01/08/2023] Open
Abstract
Stem cells reside within specialized microenvironments, or niches, that control many aspects of stem cell behavior. Somatic hub cells in the Drosophila testis regulate the behavior of cyst stem cells (CySCs) and germline stem cells (GSCs) and are a primary component of the testis stem cell niche. The shutoff (shof) mutation, characterized by premature loss of GSCs and CySCs, was mapped to a locus encoding the evolutionarily conserved transcription factor Escargot (Esg). Hub cells depleted of Esg acquire CySC characteristics and differentiate as cyst cells, resulting in complete loss of hub cells and eventually CySCs and GSCs, similar to the shof mutant phenotype. We identified Esg-interacting proteins and demonstrate an interaction between Esg and the corepressor C-terminal binding protein (CtBP), which was also required for maintenance of hub cell fate. Our results indicate that niche cells can acquire stem cell properties upon removal of a single transcription factor in vivo.
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Affiliation(s)
- Justin Voog
- Department of Biomedical Sciences, University of California, San Diego, La Jolla, CA, 92037, USA; Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sharsti L Sandall
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Gary R Hime
- ARC Centre of Excellence in Biotechnology and Development, University of Melbourne, VIC 3010, Australia; Department of Anatomy and Neuroscience, University of Melbourne, VIC 3010, Australia
| | - Luís Pedro F Resende
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; GABBA, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Portugal
| | - Mariano Loza-Coll
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Aaron Aslanian
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Margaret T Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - D Leanne Jones
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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41
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Yan B, Memar N, Gallinger J, Conradt B. Coordination of cell proliferation and cell fate determination by CES-1 snail. PLoS Genet 2013; 9:e1003884. [PMID: 24204299 PMCID: PMC3814331 DOI: 10.1371/journal.pgen.1003884] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 09/03/2013] [Indexed: 12/17/2022] Open
Abstract
The coordination of cell proliferation and cell fate determination is critical during development but the mechanisms through which this is accomplished are unclear. We present evidence that the Snail-related transcription factor CES-1 of Caenorhabditis elegans coordinates these processes in a specific cell lineage. CES-1 can cause loss of cell polarity in the NSM neuroblast. By repressing the transcription of the BH3-only gene egl-1, CES-1 can also suppress apoptosis in the daughters of the NSM neuroblasts. We now demonstrate that CES-1 also affects cell cycle progression in this lineage. Specifically, we found that CES-1 can repress the transcription of the cdc-25.2 gene, which encodes a Cdc25-like phosphatase, thereby enhancing the block in NSM neuroblast division caused by the partial loss of cya-1, which encodes Cyclin A. Our results indicate that CDC-25.2 and CYA-1 control specific cell divisions and that the over-expression of the ces-1 gene leads to incorrect regulation of this functional ‘module’. Finally, we provide evidence that dnj-11 MIDA1 not only regulate CES-1 activity in the context of cell polarity and apoptosis but also in the context of cell cycle progression. In mammals, the over-expression of Snail-related genes has been implicated in tumorigenesis. Our findings support the notion that the oncogenic potential of Snail-related transcription factors lies in their capability to, simultaneously, affect cell cycle progression, cell polarity and apoptosis and, hence, the coordination of cell proliferation and cell fate determination. Animal development is a complex process and requires the coordination in space and time of various processes. These processes include the controlled production of cells, also referred to as ‘cell proliferation’, and the adoption by cells of specific fates, also referred to as ‘cell fate determination’. The observation that uncontrolled cell proliferation and cell fate determination contribute to conditions such as cancer, demonstrates that a precise coordination of these processes is not only important for development but for the prevention of disease throughout life. Snail-related transcription factors have previously been shown to be involved in the regulation of cell proliferation and cell fate determination. For example, the Caenorhabditis elegans Snail-related protein CES-1 affects cell fate determination in a specific cell lineage, the NSM (neurosecretory motorneuron) lineage. We now present evidence that CES-1 also controls cell proliferation in this lineage. Within a short period of time, CES-1 therefore coordinates cell proliferation and cell fate determination in one and the same lineage. Based on this finding, we propose that CES-1 is an important coordinator that is involved in the precise control - in space (NSM lineage) and time (<150 min) - of processes that are critical for animal development.
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Affiliation(s)
- Bo Yan
- Center for Integrated Protein Science, Department of Biology II, Ludwig-Maximilians-University, Munich, Planegg-Martinsried, Germany
- Department of Genetics, MCB Graduate Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Nadin Memar
- Center for Integrated Protein Science, Department of Biology II, Ludwig-Maximilians-University, Munich, Planegg-Martinsried, Germany
| | - Julia Gallinger
- Department of Genetics, MCB Graduate Program, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, United States of America
| | - Barbara Conradt
- Center for Integrated Protein Science, Department of Biology II, Ludwig-Maximilians-University, Munich, Planegg-Martinsried, Germany
- * E-mail:
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42
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Lai SL, Miller MR, Robinson KJ, Doe CQ. The Snail family member Worniu is continuously required in neuroblasts to prevent Elav-induced premature differentiation. Dev Cell 2013; 23:849-57. [PMID: 23079601 DOI: 10.1016/j.devcel.2012.09.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/17/2012] [Accepted: 09/12/2012] [Indexed: 11/17/2022]
Abstract
Snail family transcription factors are best known for regulating epithelial-mesenchymal transition (EMT). The Drosophila Snail family member Worniu is specifically transcribed in neural progenitors (neuroblasts) throughout their lifespan, and worniu mutants show defects in neuroblast delamination (a form of EMT). However, the role of Worniu in neuroblasts beyond their formation is unknown. We performed RNA-seq on worniu mutant larval neuroblasts and observed reduced cell-cycle transcripts and increased neural differentiation transcripts. Consistent with these genomic data, worniu mutant neuroblasts showed a striking delay in prophase/metaphase transition by live imaging and increased levels of the conserved neuronal differentiation splicing factor Elav. Reducing Elav levels significantly suppressed the worniu mutant phenotype. We conclude that Worniu is continuously required in neuroblasts to maintain self-renewal by promoting cell-cycle progression and inhibiting premature differentiation.
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Affiliation(s)
- Sen-Lin Lai
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
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43
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Sousa-Nunes R, Somers WG. Mechanisms of asymmetric progenitor divisions in the Drosophila central nervous system. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 786:79-102. [PMID: 23696353 DOI: 10.1007/978-94-007-6621-1_6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Drosophila central nervous system develops from polarised asymmetric divisions of precursor cells, called neuroblasts. Decades of research on neuroblasts have resulted in a substantial understanding of the factors and molecular events responsible for fate decisions of neuroblasts and their progeny. Furthermore, the cell-cycle dependent mechanisms responsible for asymmetric cortical protein localisation, resulting in the unequal partitioning between daughters, are beginning to be exposed. Disruption to the appropriate partitioning of proteins between neuroblasts and differentiation-committed daughters can lead to supernumerary neuroblast-like cells and the formation of tumours. Many of the factors responsible for regulating asymmetric division of Drosophila neuroblasts are evolutionarily conserved and, in many cases, have been shown to play a functionally conserved role in mammalian neurogenesis. Recent genome-wide studies coupled with advancements in live-imaging technologies have opened further avenues of research into neuroblast biology. We review our current understanding of the molecular mechanisms regulating neuroblast divisions, a powerful system to model mammalian neurogenesis and tumourigenesis.
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Affiliation(s)
- Rita Sousa-Nunes
- MRC Centre for Developmental Neurobiology, King's College London, New Hunt's House, London, SE1 1UL, UK.
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Haenfler JM, Kuang C, Lee CY. Cortical aPKC kinase activity distinguishes neural stem cells from progenitor cells by ensuring asymmetric segregation of Numb. Dev Biol 2012; 365:219-28. [PMID: 22394487 DOI: 10.1016/j.ydbio.2012.02.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/16/2012] [Accepted: 02/20/2012] [Indexed: 12/23/2022]
Abstract
During asymmetric stem cell division, polarization of the cell cortex targets fate determinants unequally into the sibling daughters, leading to regeneration of a stem cell and production of a progenitor cell with restricted developmental potential. In mitotic neural stem cells (neuroblasts) in fly larval brains, the antagonistic interaction between the polarity proteins Lethal (2) giant larvae (Lgl) and atypical Protein Kinase C (aPKC) ensures self-renewal of a daughter neuroblast and generation of a progenitor cell by regulating asymmetric segregation of fate determinants. In the absence of lgl function, elevated cortical aPKC kinase activity perturbs unequal partitioning of the fate determinants including Numb and induces supernumerary neuroblasts in larval brains. However, whether increased aPKC function triggers formation of excess neuroblasts by inactivating Numb remains controversial. To investigate how increased cortical aPKC function induces formation of excess neuroblasts, we analyzed the fate of cells in neuroblast lineage clones in lgl mutant brains. Surprisingly, our analyses revealed that neuroblasts in lgl mutant brains undergo asymmetric division to produce progenitor cells, which then revert back into neuroblasts. In lgl mutant brains, Numb remained localized in the cortex of mitotic neuroblasts and failed to segregate exclusively into the progenitor cell following completion of asymmetric division. These results led us to propose that elevated aPKC function in the cortex of mitotic neuroblasts reduces the function of Numb in the future progenitor cells. We identified that the acyl-CoA binding domain containing 3 protein (ACBD3) binding region is essential for asymmetric segregation of Numb in mitotic neuroblasts and suppression of the supernumerary neuroblast phenotype induced by increased aPKC function. The ACBD3 binding region of Numb harbors two aPKC phosphorylation sites, serines 48 and 52. Surprisingly, while the phosphorylation status at these two sites directly impinged on asymmetric segregation of Numb in mitotic neuroblasts, both the phosphomimetic and non-phosphorylatable forms of Numb suppressed formation of excess neuroblasts triggered by increased cortical aPKC function. Thus, we propose that precise regulation of cortical aPKC kinase activity distinguishes the sibling cell identity in part by ensuring asymmetric partitioning of Numb into the future progenitor cell where Numb maintains restricted potential independently of regulation by aPKC.
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Affiliation(s)
- Jill M Haenfler
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
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45
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Abstract
In the Drosophila embryonic central nervous system, the neural precursor cells called neuroblasts undergo a number of asymmetric divisions along the apical-basal axis to give rise to different daughter cells of distinct fates. This review summarizes recent progress in understanding the mechanisms of these asymmetric cell divisions. We discuss proteins that are localized at distinct domains of cortex in the neuroblasts and their role in generating asymmetry. We also review uniformly cortical localized factors and actin cytoskeleton-associated motor proteins with regard to their potential role to serve as a link between distinct cortical domains in the neuroblasts. In this review, asymmetric divisions of sensory organ precursor and larval neuroblasts are also briefly discussed.
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Affiliation(s)
- Hongyan Wang
- Temasek Life Sciences Laboratory, 1 Research Link, The National University of Singapore, Singapore 117604
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46
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Wang C, Li S, Januschke J, Rossi F, Izumi Y, Garcia-Alvarez G, Gwee SSL, Soon SB, Sidhu HK, Yu F, Matsuzaki F, Gonzalez C, Wang H. An ana2/ctp/mud complex regulates spindle orientation in Drosophila neuroblasts. Dev Cell 2011; 21:520-33. [PMID: 21920316 DOI: 10.1016/j.devcel.2011.08.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 05/26/2011] [Accepted: 08/01/2011] [Indexed: 12/11/2022]
Abstract
Drosophila neural stem cells, larval brain neuroblasts (NBs), align their mitotic spindles along the apical/basal axis during asymmetric cell division (ACD) to maintain the balance of self-renewal and differentiation. Here, we identified a protein complex composed of the tumor suppressor anastral spindle 2 (Ana2), a dynein light-chain protein Cut up (Ctp), and Mushroom body defect (Mud), which regulates mitotic spindle orientation. We isolated two ana2 alleles that displayed spindle misorientation and NB overgrowth phenotypes in larval brains. The centriolar protein Ana2 anchors Ctp to centrioles during ACD. The centriolar localization of Ctp is important for spindle orientation. Ana2 and Ctp localize Mud to the centrosomes and cell cortex and facilitate/maintain the association of Mud with Pins at the apical cortex. Our findings reveal that the centrosomal proteins Ana2 and Ctp regulate Mud function to orient the mitotic spindle during NB asymmetric division.
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Affiliation(s)
- Cheng Wang
- Neuroscience & Behavioral Disorder Program, Duke-National University of Singapore Graduate Medical School Singapore, Singapore, Singapore
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Stagg SB, Guardiola AR, Crews ST. Dual role for Drosophila lethal of scute in CNS midline precursor formation and dopaminergic neuron and motoneuron cell fate. Development 2011; 138:2171-83. [PMID: 21558367 DOI: 10.1242/dev.056507] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Dopaminergic neurons play important behavioral roles in locomotion, reward and aggression. The Drosophila H-cell is a dopaminergic neuron that resides at the midline of the ventral nerve cord. Both the H-cell and the glutamatergic H-cell sib are the asymmetric progeny of the MP3 midline precursor cell. H-cell sib cell fate is dependent on Notch signaling, whereas H-cell fate is Notch independent. Genetic analysis of genes that could potentially regulate H-cell fate revealed that the lethal of scute [l(1)sc], tailup and SoxNeuro transcription factor genes act together to control H-cell gene expression. The l(1)sc bHLH gene is required for all H-cell-specific gene transcription, whereas tailup acts in parallel to l(1)sc and controls genes involved in dopamine metabolism. SoxNeuro functions downstream of l(1)sc and controls expression of a peptide neurotransmitter receptor gene. The role of l(1)sc may be more widespread, as a l(1)sc mutant shows reductions in gene expression in non-midline dopaminergic neurons. In addition, l(1)sc mutant embryos possess defects in the formation of MP4-6 midline precursor and the median neuroblast stem cell, revealing a proneural role for l(1)sc in midline cells. The Notch-dependent progeny of MP4-6 are the mVUM motoneurons, and these cells also require l(1)sc for mVUM-specific gene expression. Thus, l(1)sc plays an important regulatory role in both neurogenesis and specifying dopaminergic neuron and motoneuron identities.
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Affiliation(s)
- Stephanie B Stagg
- Curriculum in Neurobiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA
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48
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Rybina OY, Zaitsev AA, Roschina NV, Pasyukova EG. Neuroendocrine system in lifespan control of Drosophila melanogaster. ADVANCES IN GERONTOLOGY 2011. [DOI: 10.1134/s207905701103012x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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49
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Ungerer P, Eriksson BJ, Stollewerk A. Neurogenesis in the water flea Daphnia magna (Crustacea, Branchiopoda) suggests different mechanisms of neuroblast formation in insects and crustaceans. Dev Biol 2011; 357:42-52. [PMID: 21624360 DOI: 10.1016/j.ydbio.2011.05.662] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/10/2011] [Accepted: 05/15/2011] [Indexed: 11/29/2022]
Abstract
Within euarthropods, the morphological and molecular mechanisms of early nervous system development have been analysed in insects and several representatives of chelicerates and myriapods, while data on crustaceans are fragmentary. Neural stem cells (neuroblasts) generate the nervous system in insects and in higher crustaceans (malacostracans); in the remaining euarthropod groups, the chelicerates (e.g. spiders) and myriapods (e.g. millipedes), neuroblasts are missing. In the latter taxa, groups of neural precursors segregate from the neuroectoderm and directly differentiate into neurons and glial cells. In all euarthropod groups, achaete-scute homologues are required for neuroblast/neural precursor group formation. In the insects Drosophila melanogaster and Tribolium castaneum achaete-scute homologues are initially expressed in clusters of cells (proneural clusters) in the neuroepithelium but expression becomes restricted to the future neuroblast. Subsequently genes such as snail and prospero are expressed in the neuroblasts which are required for asymmetric division and differentiation. In contrast to insects, malacostracan neuroblasts do not segregate into the embryo but remain in the outer neuroepithelium, similar to vertebrate neural stem cells. It has been suggested that neuroblasts are present in another crustacean group, the branchiopods, and that they also remain in the neuroepithelium. This raises the questions how the molecular mechanisms of neuroblast selection have been modified during crustacean and insect evolution and if the segregation or the maintenance of neuroblasts in the neuroepithelium represents the ancestral state. Here we take advantage of the recently published Daphnia pulex (branchiopod) genome and identify genes in Daphnia magna that are known to be required for the selection and asymmetric division of neuroblasts in the fruit fly D. melanogaster. We unambiguously identify neuroblasts in D. magna by molecular marker gene expression and division pattern. We show for the first time that branchiopod neuroblasts divide in the same pattern as insect and malacostracan neuroblasts. Furthermore, in contrast to D. melanogaster, neuroblasts are not selected from proneural clusters in the branchiopod. Snail rather than ASH is the first gene to be expressed in the nascent neuroblasts suggesting that ASH is not required for the selection of neuroblasts as in D. melanogaster. The prolonged expression of ASH in D. magna furthermore suggests that it is involved in the maintenance of the neuroblasts in the neuroepithelium. Based on these and additional data from various representatives of arthropods we conclude that the selection of neural precursors from proneural clusters as well as the segregation of neural precursors represents the ancestral state of neurogenesis in arthropods. We discuss that the derived characters of malacostracans and branchiopods - the absence of neuroblast segregation and proneural clusters - might be used to support or reject the possible groupings of paraphyletic crustaceans.
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Affiliation(s)
- Petra Ungerer
- School of Biological and Chemical Sciences, Queen Mary, University of London, UK.
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50
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Sabino D, Brown NH, Basto R. Drosophila Ajuba is not an Aurora-A activator but is required to maintain Aurora-A at the centrosome. J Cell Sci 2011; 124:1156-66. [PMID: 21402878 PMCID: PMC3056608 DOI: 10.1242/jcs.076711] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2010] [Indexed: 11/20/2022] Open
Abstract
The LIM-domain protein Ajuba localizes at sites of epithelial cell-cell adhesion and has also been implicated in the activation of Aurora-A (Aur-A). Despite the expected importance of Ajuba, Ajuba-deficient mice are viable, which has been attributed to functional redundancy with the related LIM-domain protein LIMD1. To gain insights into the function of Ajuba, we investigated its role in Drosophila, where a single gene (jub) encodes a protein closely related to Ajuba and LIMD1. We identified a key function in neural stem cells, where Jub localizes to the centrosome. In these cells, mutation in jub leads to centrosome separation defects and aberrant mitotic spindles, which is a phenotype similar to that of aur-A mutants. We show that in jub mutants Aur-A activity is not perturbed, but that Aur-A recruitment and maintenance at the centrosome is affected. As a consequence the active kinase is displaced from the centrosome. On the basis of our studies in Drosophila neuroblasts, we propose that a key function of Ajuba, in these cells, is to maintain active Aur-A at the centrosome during mitosis.
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Affiliation(s)
- Dora Sabino
- Compartimentation et Dynamique Cellulaires, CNRS, UMR144 Paris F-75248, France
- Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Nicholas H. Brown
- Gurdon Institute and Department of Physiology, Development and Neuroscience, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Renata Basto
- Compartimentation et Dynamique Cellulaires, CNRS, UMR144 Paris F-75248, France
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