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Pinheiro AS, Tsarouhas V, Senti KA, Arefin B, Samakovlis C. Scavenger receptor endocytosis controls apical membrane morphogenesis in the Drosophila airways. eLife 2023; 12:e84974. [PMID: 37706489 PMCID: PMC10564452 DOI: 10.7554/elife.84974] [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: 11/17/2022] [Accepted: 09/13/2023] [Indexed: 09/15/2023] Open
Abstract
The acquisition of distinct branch sizes and shapes is a central aspect in tubular organ morphogenesis and function. In the Drosophila airway tree, the interplay of apical extracellular matrix (ECM) components with the underlying membrane and cytoskeleton controls tube elongation, but the link between ECM composition with apical membrane morphogenesis and tube size regulation is elusive. Here, we characterized Emp (epithelial membrane protein), a Drosophila CD36 homolog belonging to the scavenger receptor class B protein family. emp mutant embryos fail to internalize the luminal chitin deacetylases Serp and Verm at the final stages of airway maturation and die at hatching with liquid filled airways. Emp localizes in apical epithelial membranes and shows cargo selectivity for LDLr-domain containing proteins. emp mutants also display over elongated tracheal tubes with increased levels of the apical proteins Crb, DE-cad, and phosphorylated Src (p-Src). We show that Emp associates with and organizes the βH-Spectrin cytoskeleton and is itself confined by apical F-actin bundles. Overexpression or loss of its cargo protein Serp lead to abnormal apical accumulations of Emp and perturbations in p-Src levels. We propose that during morphogenesis, Emp senses and responds to luminal cargo levels by initiating apical membrane endocytosis along the longitudinal tube axis and thereby restricts airway elongation.
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Affiliation(s)
- Ana Sofia Pinheiro
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
| | - Vasilios Tsarouhas
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
| | - Kirsten André Senti
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
- IMBA – Institute of Molecular Biotechnology, Austrian Academy of SciencesViennaAustria
| | - Badrul Arefin
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
- Sahlgrenska Academy, Gothenburg UniversityGothenburgSweden
| | - Christos Samakovlis
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm UniversityStockholmSweden
- Cardiopulmonary Institute, Justus Liebig University of GiessenGiessenGermany
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2
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Levo M, Raimundo J, Bing XY, Sisco Z, Batut PJ, Ryabichko S, Gregor T, Levine MS. Transcriptional coupling of distant regulatory genes in living embryos. Nature 2022; 605:754-760. [PMID: 35508662 PMCID: PMC9886134 DOI: 10.1038/s41586-022-04680-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 03/23/2022] [Indexed: 02/01/2023]
Abstract
The prevailing view of metazoan gene regulation is that individual genes are independently regulated by their own dedicated sets of transcriptional enhancers. Past studies have reported long-range gene-gene associations1-3, but their functional importance in regulating transcription remains unclear. Here we used quantitative single-cell live imaging methods to provide a demonstration of co-dependent transcriptional dynamics of genes separated by large genomic distances in living Drosophila embryos. We find extensive physical and functional associations of distant paralogous genes, including co-regulation by shared enhancers and co-transcriptional initiation over distances of nearly 250 kilobases. Regulatory interconnectivity depends on promoter-proximal tethering elements, and perturbations in these elements uncouple transcription and alter the bursting dynamics of distant genes, suggesting a role of genome topology in the formation and stability of co-transcriptional hubs. Transcriptional coupling is detected throughout the fly genome and encompasses a broad spectrum of conserved developmental processes, suggesting a general strategy for long-range integration of gene activity.
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Affiliation(s)
- Michal Levo
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - João Raimundo
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Xin Yang Bing
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Zachary Sisco
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Philippe J. Batut
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Sergey Ryabichko
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Thomas Gregor
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA,Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ, USA,Department of Developmental and Stem Cell Biology, UMR3738, Institut Pasteur, Paris, France,Corresponding authors
| | - Michael S. Levine
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA,Corresponding authors
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3
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Folkendt L, Lohmann I, Domsch K. An Evolutionary Perspective on Hox Binding Site Preferences in Two Different Tissues. J Dev Biol 2021; 9:jdb9040057. [PMID: 34940504 PMCID: PMC8705983 DOI: 10.3390/jdb9040057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/23/2021] [Accepted: 12/07/2021] [Indexed: 01/04/2023] Open
Abstract
Transcription factor (TF) networks define the precise development of multicellular organisms. While many studies focused on TFs expressed in specific cell types to elucidate their contribution to cell specification and differentiation, it is less understood how broadly expressed TFs perform their precise functions in the different cellular contexts. To uncover differences that could explain tissue-specific functions of such TFs, we analyzed here genomic chromatin interactions of the broadly expressed Drosophila Hox TF Ultrabithorax (Ubx) in the mesodermal and neuronal tissues using bioinformatics. Our investigations showed that Ubx preferentially interacts with multiple yet tissue-specific chromatin sites in putative regulatory regions of genes in both tissues. Importantly, we found the classical Hox/Ubx DNA binding motif to be enriched only among the neuronal Ubx chromatin interactions, whereas a novel Ubx-like motif with rather low predicted Hox affinities was identified among the regions bound by Ubx in the mesoderm. Finally, our analysis revealed that tissues-specific Ubx chromatin sites are also different with regards to the distribution of active and repressive histone marks. Based on our data, we propose that the tissue-related differences in Ubx binding behavior could be a result of the emergence of the mesoderm as a new germ layer in triploblastic animals, which might have required the Hox TFs to relax their binding specificity.
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Affiliation(s)
- Laura Folkendt
- Developmental Biology, Erlangen-Nürnberg University, 91058 Erlangen, Germany;
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
- Correspondence: (I.L.); (K.D.)
| | - Katrin Domsch
- Developmental Biology, Erlangen-Nürnberg University, 91058 Erlangen, Germany;
- Centre for Organismal Studies (COS) Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
- Correspondence: (I.L.); (K.D.)
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4
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Ramirez Moreno M, Stempor PA, Bulgakova NA. Interactions and Feedbacks in E-Cadherin Transcriptional Regulation. Front Cell Dev Biol 2021; 9:701175. [PMID: 34262912 PMCID: PMC8273600 DOI: 10.3389/fcell.2021.701175] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/04/2021] [Indexed: 01/07/2023] Open
Abstract
Epithelial tissues rely on the adhesion between participating cells to retain their integrity. The transmembrane protein E-cadherin is the major protein that mediates homophilic adhesion between neighbouring cells and is, therefore, one of the critical components for epithelial integrity. E-cadherin downregulation has been described extensively as a prerequisite for epithelial-to-mesenchymal transition and is a hallmark in many types of cancer. Due to this clinical importance, research has been mostly focused on understanding the mechanisms leading to transcriptional repression of this adhesion molecule. However, in recent years it has become apparent that re-expression of E-cadherin is a major step in the progression of many cancers during metastasis. Here, we review the currently known molecular mechanisms of E-cadherin transcriptional activation and inhibition and highlight complex interactions between individual mechanisms. We then propose an additional mechanism, whereby the competition between adhesion complexes and heterochromatin protein-1 for binding to STAT92E fine-tunes the levels of E-cadherin expression in Drosophila but also regulates other genes promoting epithelial robustness. We base our hypothesis on both existing literature and our experimental evidence and suggest that such feedback between the cell surface and the nucleus presents a powerful paradigm for epithelial resilience.
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Affiliation(s)
- Miguel Ramirez Moreno
- Department of Biomedical Science and Bateson Centre, The University of Sheffield, Sheffield, England
| | | | - Natalia A Bulgakova
- Department of Biomedical Science and Bateson Centre, The University of Sheffield, Sheffield, England
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5
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Rice C, Macdonald SJ, Wang X, Ward RE. The Broad Transcription Factor Links Hormonal Signaling, Gene Expression, and Cellular Morphogenesis Events During Drosophila Imaginal Disc Development. Genetics 2020; 216:1137-1152. [PMID: 33115752 PMCID: PMC7768262 DOI: 10.1534/genetics.120.303717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 10/05/2020] [Indexed: 11/18/2022] Open
Abstract
Imaginal disc morphogenesis during metamorphosis in Drosophila melanogaster provides an excellent model to uncover molecular mechanisms by which hormonal signals effect physical changes during development. The broad (br) Z2 isoform encodes a transcription factor required for disc morphogenesis in response to 20-hydroxyecdysone, yet how it accomplishes this remains largely unknown. Here, we use functional studies of amorphic br5 mutants and a transcriptional target approach to identify processes driven by br and its regulatory targets in leg imaginal discs. br5 mutants fail to properly remodel their basal extracellular matrix (ECM) between 4 and 7 hr after puparium formation. Additionally, br5 mutant discs do not undergo the cell shape changes necessary for leg elongation and fail to elongate normally when exposed to the protease trypsin. RNA-sequencing of wild-type and br5 mutant leg discs identified 717 genes differentially regulated by br, including a large number of genes involved in glycolysis, and genes that encode proteins that interact with the ECM. RNA interference-based functional studies reveal that several of these genes are required for adult leg formation, particularly those involved in remodeling the ECM. Additionally, brZ2 expression is abruptly shut down at the onset of metamorphosis, and expressing it beyond this time results in failure of leg development during the late prepupal and pupal stages. Taken together, our results suggest that brZ2 is required to drive ECM remodeling, change cell shape, and maintain metabolic activity through the midprepupal stage, but must be switched off to allow expression of pupation genes.
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Affiliation(s)
- Clinton Rice
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Stuart J Macdonald
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Xiaochen Wang
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Robert E Ward
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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6
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Nevil M, Gibson TJ, Bartolutti C, Iyengar A, Harrison MM. Establishment of chromatin accessibility by the conserved transcription factor Grainy head is developmentally regulated. Development 2020; 147:dev185009. [PMID: 32098765 PMCID: PMC10624965 DOI: 10.1242/dev.185009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 02/07/2020] [Indexed: 12/18/2022]
Abstract
The dramatic changes in gene expression required for development necessitate the establishment of cis-regulatory modules defined by regions of accessible chromatin. Pioneer transcription factors have the unique property of binding closed chromatin and facilitating the establishment of these accessible regions. Nonetheless, much of how pioneer transcription factors coordinate changes in chromatin accessibility during development remains unknown. To determine whether pioneer-factor function is intrinsic to the protein or whether pioneering activity is developmentally modulated, we studied the highly conserved, essential transcription factor Grainy head (Grh). Prior work established that Grh is expressed throughout Drosophila development and is a pioneer factor in the larva. We demonstrated that Grh remains bound to mitotic chromosomes, a property shared with other pioneer factors. By assaying chromatin accessibility in embryos lacking maternal and/or zygotic Grh at three stages of development, we discovered that Grh is not required for chromatin accessibility in early embryogenesis, in contrast to its essential functions later in development. Our data reveal that the pioneering activity of Grh is temporally regulated and likely influenced by additional factors expressed at a given developmental stage.
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Affiliation(s)
- Markus Nevil
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Constantine Bartolutti
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Anusha Iyengar
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
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7
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Co-option of wing-patterning genes underlies the evolution of the treehopper helmet. Nat Ecol Evol 2019; 4:250-260. [DOI: 10.1038/s41559-019-1054-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/25/2019] [Indexed: 12/18/2022]
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8
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Skouloudaki K, Christodoulou I, Khalili D, Tsarouhas V, Samakovlis C, Tomancak P, Knust E, Papadopoulos DK. Yorkie controls tube length and apical barrier integrity during airway development. J Cell Biol 2019; 218:2762-2781. [PMID: 31315941 PMCID: PMC6683733 DOI: 10.1083/jcb.201809121] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 05/02/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022] Open
Abstract
Skouloudaki et al. identify an alternative role of the transcriptional coactivator Yorkie (Yki) in controlling water impermeability and tube size of developing Drosophila airways. Tracheal impermeability is triggered by Yki-mediated transcriptional regulation of δ-aminolevulinate synthase (Alas), whereas tube elongation is controlled by binding of Yki to the actin-severing factor Twinstar. Epithelial organ size and shape depend on cell shape changes, cell–matrix communication, and apical membrane growth. The Drosophila melanogaster embryonic tracheal network is an excellent model to study these processes. Here, we show that the transcriptional coactivator of the Hippo pathway, Yorkie (YAP/TAZ in vertebrates), plays distinct roles in the developing Drosophila airways. Yorkie exerts a cytoplasmic function by binding Drosophila Twinstar, the orthologue of the vertebrate actin-severing protein Cofilin, to regulate F-actin levels and apical cell membrane size, which are required for proper tracheal tube elongation. Second, Yorkie controls water tightness of tracheal tubes by transcriptional regulation of the δ-aminolevulinate synthase gene (Alas). We conclude that Yorkie has a dual role in tracheal development to ensure proper tracheal growth and functionality.
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Affiliation(s)
| | - Ioannis Christodoulou
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Dilan Khalili
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Vasilios Tsarouhas
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Christos Samakovlis
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.,Excellence Cluster Cardio-Pulmonary System, University of Giessen, Giessen, Germany
| | - Pavel Tomancak
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Elisabeth Knust
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany
| | - Dimitrios K Papadopoulos
- Max-Planck Institute for Molecular Cell Biology and Genetics, Dresden, Germany .,Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
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9
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Best BT. Single-cell branching morphogenesis in the Drosophila trachea. Dev Biol 2018; 451:5-15. [PMID: 30529233 DOI: 10.1016/j.ydbio.2018.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/23/2018] [Accepted: 12/01/2018] [Indexed: 12/20/2022]
Abstract
The terminal cells of the tracheal epithelium in Drosophila melanogaster are one of the few known cell types that undergo subcellular morphogenesis to achieve a stable, branched shape. During the animal's larval stages, the cells repeatedly sprout new cytoplasmic processes. These grow very long, wrapping around target tissues to which the terminal cells adhere, and are hollowed by a gas-filled subcellular tube for oxygen delivery. Our understanding of this ramification process remains rudimentary. This review aims to provide a comprehensive summary of studies on terminal cells to date, and attempts to extrapolate how terminal branches might be formed based on the known genetic and molecular components. Next to this cell-intrinsic branching mechanism, we examine the extrinsic regulation of terminal branching by the target tissue and the animal's environment. Finally, we assess the degree of similarity between the patterns established by the branching programs of terminal cells and other branched cells and tissues from a mathematical and conceptual point of view.
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Affiliation(s)
- Benedikt T Best
- Director's Research Unit, European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany; Collaboration for Joint PhD degree from EMBL and Heidelberg University, Faculty of Biosciences, Germany
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10
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Bakshi A, Joshi R. Understanding the regulation of neural stem cell proliferation in Drosophila central nervous system. J Neurosci Res 2018; 96:1119-1120. [PMID: 29577373 DOI: 10.1002/jnr.24234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 02/28/2018] [Indexed: 11/07/2022]
Affiliation(s)
- Asif Bakshi
- Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.,Manipal Academy of Higher Education, Manipal, India
| | - Rohit Joshi
- Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
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11
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12
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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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