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Ismail JN, Mantash S, Hallal M, Jabado N, Khoueiry P, Shirinian M. Phenotypic and transcriptomic impact of expressing mammalian TET2 in the Drosophila melanogaster model. Epigenetics 2023; 18:2192375. [PMID: 36989121 PMCID: PMC10072067 DOI: 10.1080/15592294.2023.2192375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
Ten-Eleven Translocation (TET) proteins have recently come to light as important epigenetic regulators conserved in multicellular organisms. TET knockdown studies in rodents have highlighted the critical role of these proteins for proper brain development and function. Mutations in mammalian mTET proteins and mTET2 specifically are frequent and deregulated in leukaemia and glioma respectively. Accordingly, we examined the role of mTET2 in tumorigenesis in larval haemocytes and adult heads in Drosophila melanogaster. Our findings showed that expression of mutant and wild type mTET2 resulted in general phenotypic defects in adult flies and accumulation of abdominal melanotic masses. Notably, flies with mTET2-R43G mutation at the N-terminus of mTET2 exhibited locomotor and circadian behavioural deficits, as well as reduced lifespan. Flies with mTET2-R1261C mutation in the catalytic domain, a common mutation in acute myeloid leukaemia (AML), displayed alterations affecting haemocyte haemostasis. Using transcriptomic approach, we identified upregulated immune genes in fly heads that were not exclusive to TET2 mutants but also found in wild type mTET2 flies. Furthermore, inhibiting expression of genes that were found to be deregulated in mTET2 mutants, such as those involved in immune pathways, autophagy, and transcriptional regulation, led to a rescue in fly survival, behaviour, and hemocyte number. This study identifies the transcriptomic profile of wild type mTET2 versus mTET2 mutants (catalytic versus non-catalytic) with indications of TET2 role in normal central nervous system (CNS) function and innate immunity.
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Affiliation(s)
- Joy N Ismail
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Sarah Mantash
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Mohammad Hallal
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Biomedical Engineering Program, American University of Beirut, Beirut, Lebanon
| | - Nada Jabado
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Pierre Khoueiry
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Pillar Genomics Institute, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Margret Shirinian
- Department of Experimental pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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2
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He Q, Hou T, Fan X, Wang S, Wang Y, Chen S. Juvenile hormone suppresses sensory organ precursor determination to block Drosophila adult abdomen morphogenesis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 157:103957. [PMID: 37192726 DOI: 10.1016/j.ibmb.2023.103957] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 05/18/2023]
Abstract
Juvenile hormone (JH) has a classic "status quo" action at both the pupal and adult molts when administrated exogenously. In Drosophila, treatment with JH at pupariation inhibits the formation of abdominal bristles, which are derived from the histoblasts. However, the mechanism via which JH exerts this effect remains poorly understood. In this study, we analyzed the effect of JH on histoblast proliferation, migration, and differentiation. Our results indicated that whereas the proliferation and migration of histoblasts remained unaffected following treatment with a JH mimic (JHM), their differentiation, particularly the specification of sensor organ precursor (SOP) cells, was inhibited. This effect was attributable to downregulated proneural genes achaete (ac) and Scute (sc) expression levels, which prevented the specification of SOP cells in proneural clusters. Moreover, Kr-h1 was found to mediate this effect of JHM. Histoblast-specific overexpression or knockdown of Kr-h1, respectively mimicked or attenuated the effects exerted by JHM on abdominal bristle formation, SOP determination, and transcriptional regulation of ac and sc. These results indicated that the defective SOP determination was responsible for the inhibition of abdominal bristle formation by JHM, which, in turn, was mainly mediated via the transducing action of Kr-h1.
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Affiliation(s)
- Qianyu He
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China.
| | - Tianlan Hou
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Xiaochun Fan
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Shunxin Wang
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Yanhong Wang
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
| | - Shanshan Chen
- College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, China
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3
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Umetsu D. Sample Preparation and Imaging of the Pupal Drosophila Abdominal Epidermis. Methods Mol Biol 2022; 2540:335-347. [PMID: 35980587 DOI: 10.1007/978-1-0716-2541-5_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The epithelium is one of the best studied tissues for morphogenesis, pattern formation, cell polarity, cell division, cell competition, tumorigenesis, and metastatic behaviors. However, it has been challenging to analyze real-time cell interactions or cell dynamics within the epithelia under physiological conditions. The Drosophila pupal abdominal epidermis is a model system that allows to combine long-term real-time imaging under physiological conditions with the use of powerful Drosophila genetics tools. The abdominal epidermis displays a wide range of stereotypical characteristics of the epithelia and cellular behaviors including cell division, cell death, cell rearrangement, apical constriction, and apicobasal/planar polarity, making this tissue a first choice for the study of epithelial morphogenesis and relevant phenomena. In this chapter, I describe the staging and mounting of pupae and the live imaging of the abdominal epidermis. Moreover, methods to combine live imaging with mosaic analysis or drug injection will be presented. The long-term live imaging of the pupal abdominal epidermis is straightforward and opens up the possibility to analyze cell dynamics during epithelial morphogenesis at an unprecedented resolution.
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Affiliation(s)
- Daiki Umetsu
- Graduate School of Life Sciences, Tohoku University, Sendai, Japan.
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4
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Chongtham A, Bornemann DJ, Barbaro BA, Lukacsovich T, Agrawal N, Syed A, Worthge S, Purcell J, Burke J, Chin TM, Marsh JL. Effects of flanking sequences and cellular context on subcellular behavior and pathology of mutant HTT. Hum Mol Genet 2021; 29:674-688. [PMID: 31943010 DOI: 10.1093/hmg/ddaa001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/06/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022] Open
Abstract
Huntington's disease (HD) is caused by an expansion of a poly glutamine (polyQ) stretch in the huntingtin protein (HTT) that is necessary to cause pathology and formation of HTT aggregates. Here we ask whether expanded polyQ is sufficient to cause pathology and aggregate formation. By addressing the sufficiency question, one can identify cellular processes and structural parameters that influence HD pathology and HTT subcellular behavior (i.e. aggregation state and subcellular location). Using Drosophila, we compare the effects of expressing mutant full-length human HTT (fl-mHTT) to the effects of mutant human HTTexon1 and to two commonly used synthetic fragments, HTT171 and shortstop (HTT118). Expanded polyQ alone is not sufficient to cause inclusion formation since full-length HTT and HTTex1 with expanded polyQ are both toxic although full-length HTT remains diffuse while HTTex1 forms inclusions. Further, inclusions are not sufficient to cause pathology since HTT171-120Q forms inclusions but is benign and co-expression of HTT171-120Q with non-aggregating pathogenic fl-mHTT recruits fl-mHTT to aggregates and rescues its pathogenicity. Additionally, the influence of sequences outside the expanded polyQ domain is revealed by finding that small modifications to the HTT118 or HTT171 fragments can dramatically alter their subcellular behavior and pathogenicity. Finally, mutant HTT subcellular behavior is strongly modified by different cell and tissue environments (e.g. fl-mHTT appears as diffuse nuclear in one tissue and diffuse cytoplasmic in another but toxic in both). These observations underscore the importance of cellular and structural context for the interpretation and comparison of experiments using different fragments and tissues to report the effects of expanded polyQ.
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Affiliation(s)
- Anjalika Chongtham
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - Douglas J Bornemann
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Brett A Barbaro
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Tamas Lukacsovich
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Namita Agrawal
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Adeela Syed
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Shane Worthge
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Judith Purcell
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - John Burke
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Theodore M Chin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
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5
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Csordás G, Grawe F, Uhlirova M. Eater cooperates with Multiplexin to drive the formation of hematopoietic compartments. eLife 2020; 9:57297. [PMID: 33026342 PMCID: PMC7541089 DOI: 10.7554/elife.57297] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Blood development in multicellular organisms relies on specific tissue microenvironments that nurture hematopoietic precursors and promote their self-renewal, proliferation, and differentiation. The mechanisms driving blood cell homing and their interactions with hematopoietic microenvironments remain poorly understood. Here, we use the Drosophila melanogaster model to reveal a pivotal role for basement membrane composition in the formation of hematopoietic compartments. We demonstrate that by modulating extracellular matrix components, the fly blood cells known as hemocytes can be relocated to tissue surfaces where they function similarly to their natural hematopoietic environment. We establish that the Collagen XV/XVIII ortholog Multiplexin in the tissue-basement membranes and the phagocytosis receptor Eater on the hemocytes physically interact and are necessary and sufficient to induce immune cell-tissue association. These results highlight the cooperation of Multiplexin and Eater as an integral part of a homing mechanism that specifies and maintains hematopoietic sites in Drosophila.
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Affiliation(s)
- Gábor Csordás
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ferdinand Grawe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.,Molecular Cell Biology, Institute I for Anatomy, University of Cologne Medical School, Cologne, Germany
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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6
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Valanne S, Järvelä-Stölting M, Harjula SKE, Myllymäki H, Salminen TS, Rämet M. Osa-Containing Brahma Complex Regulates Innate Immunity and the Expression of Metabolic Genes in Drosophila. THE JOURNAL OF IMMUNOLOGY 2020; 204:2143-2155. [PMID: 32198143 DOI: 10.4049/jimmunol.1900571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 02/12/2020] [Indexed: 01/20/2023]
Abstract
Negative regulation of innate immunity is essential to avoid autoinflammation. In Drosophila melanogaster, NF-κB signaling-mediated immune responses are negatively regulated at multiple levels. Using a Drosophila RNA interference in vitro screen, we identified a set of genes inhibiting immune activation. Four of these genes encode members of the chromatin remodeling Osa-containing Brahma (BAP) complex. Silencing additional two genes of the BAP complex was shown to have the same phenotype, confirming its role in immune regulation in vitro. In vivo, the knockdown of osa and brahma was shown to enhance the expression of the Toll pathway-mediated antimicrobial peptides when the flies were challenged with Gram-positive bacteria Micrococcus luteus In this setting, osa knockdown had a particularly strong effect on immune effectors that are predominantly activated by the Imd pathway. Accordingly, Drosophila NF-κB Relish expression was increased by osa silencing. These transcriptional changes were associated with enhanced survival from M. luteus + E. faecalis infection. Besides regulating the expression of immune effector genes, osa RNA interference decreased the expression of a large group of genes involved in metabolism, particularly proteolysis. Of note, the expression of the recently characterized, immune-inducible gene Induced by Infection (IBIN) was diminished in osa knockdown flies. Although IBIN has been shown to modulate metabolism upon infection, the expression of selected Osa-regulated metabolism genes was not rescued by overexpressing IBIN. We conclude that the BAP complex regulates expression of genes involved in metabolism at least partially independent or downstream of IBIN Moreover, Osa affects the NF-κB-mediated immune response by regulating Drosophila NF-κB factor Relish expression.
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Affiliation(s)
- Susanna Valanne
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Mirva Järvelä-Stölting
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Sanna-Kaisa E Harjula
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Henna Myllymäki
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Tiina S Salminen
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland.,Laboratory of Mito-Immuno-Metabolism, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Mika Rämet
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland; .,PEDEGO Research Unit, Faculty of Medicine, 90014 University of Oulu, Oulu, Finland.,Medical Research Center Oulu, 90014 University of Oulu, Oulu, Finland; and.,Department of Children and Adolescents, Oulu University Hospital, 90014 University of Oulu, Oulu, Finland
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7
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Hoshika S, Sun X, Kuranaga E, Umetsu D. Reduction of endocytic activity accelerates cell elimination during tissue remodeling of the Drosophila epidermal epithelium. Development 2020; 147:dev.179648. [PMID: 32156754 DOI: 10.1242/dev.179648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 02/24/2020] [Indexed: 12/22/2022]
Abstract
Epithelial tissues undergo cell turnover both during development and for homeostatic maintenance. Cells that are no longer needed are quickly removed without compromising the barrier function of the tissue. During metamorphosis, insects undergo developmentally programmed tissue remodeling. However, the mechanisms that regulate this rapid tissue remodeling are not precisely understood. Here, we show that the temporal dynamics of endocytosis modulate physiological cell properties to prime larval epidermal cells for cell elimination. Endocytic activity gradually reduces as tissue remodeling progresses. This reduced endocytic activity accelerates cell elimination through the regulation of Myosin II subcellular reorganization, junctional E-cadherin levels, and caspase activation. Whereas the increased Myosin II dynamics accelerates cell elimination, E-cadherin plays a protective role against cell elimination. Reduced E-cadherin is involved in the amplification of caspase activation by forming a positive-feedback loop with caspase. These findings reveal the role of endocytosis in preventing cell elimination and in the cell-property switching initiated by the temporal dynamics of endocytic activity to achieve rapid cell elimination during tissue remodeling.
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Affiliation(s)
- Shinichiro Hoshika
- Laboratory for Histogenetic Dynamics, Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Xiaofei Sun
- Laboratory for Histogenetic Dynamics, Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Erina Kuranaga
- Laboratory for Histogenetic Dynamics, Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Daiki Umetsu
- Laboratory for Histogenetic Dynamics, Department of Ecological Developmental Adaptability Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
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8
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Rohini M, Arumugam B, Vairamani M, Selvamurugan N. Stimulation of ATF3 interaction with Smad4 via TGF-β1 for matrix metalloproteinase 13 gene activation in human breast cancer cells. Int J Biol Macromol 2019; 134:954-961. [PMID: 31082421 DOI: 10.1016/j.ijbiomac.2019.05.062] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 04/27/2019] [Accepted: 05/09/2019] [Indexed: 02/08/2023]
Abstract
We previously reported that transforming growth factor-β1 (TGF-β1) stimulated the sustained and prolonged expression of activating transcription factor 3 (ATF3) in highly metastatic and invasive human breast cancer cells (MDA-MB231), in contrast to normal human mammary epithelial cells. However, the mechanism behind the stability of ATF3 expression is not yet known. Based on an in silico approach with co-immunoprecipitation and mass spectrometric analyses, we identified a number of proteins, including Smad4, that interacted with ATF3 after TGF-β1 treatment in MDA-MB231 cells. The knockdown of Smad4 using the siRNA technique resulted in a significant loss of ATF3 expression in these cells. Chromatin immunoprecipitation was then used to identify the formation of an ATF3 and Smad4 complex at the matrix metalloproteinase 13 (MMP13) promoter upon TGF-β1-treatment, and the knockdown of Smad4 decreased MMP13 promoter activity in MDA-MB231 cells. Our findings indicate that Smad4 is a pre-requisite for providing stability to ATF3 via TGF-β1 in human breast cancer cells. The targeting of Smad4 may thus provide the sustainable loss of ATF3 expression that is needed to control breast cancer progression.
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Affiliation(s)
- M Rohini
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - B Arumugam
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - M Vairamani
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - N Selvamurugan
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India.
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9
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Rohini M, Haritha Menon A, Selvamurugan N. Role of activating transcription factor 3 and its interacting proteins under physiological and pathological conditions. Int J Biol Macromol 2018; 120:310-317. [PMID: 30144543 DOI: 10.1016/j.ijbiomac.2018.08.107] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/18/2018] [Accepted: 08/21/2018] [Indexed: 12/27/2022]
Abstract
Activating transcription factor 3 (ATF3) is a stress-responsive factor that belongs to the activator protein 1 (AP-1) family of transcription factors. ATF3 expression is stimulated by various factors such as hypoxia, cytokines, and chemotherapeutic and DNA damaging agents. Upon stimulation, ATF3 can form homodimers or heterodimers with other members of the AP-1 family to repress or activate transcription. Under physiological conditions, ATF3 expression is transient and plays a pivotal role in controlling the expression of cell-cycle regulators and tumor suppressor, DNA repair, and apoptosis genes. However, under pathological conditions such as those during breast cancer, a sustained and prolonged expression of ATF3 has been observed. In this review, the structure and function of ATF3, its posttranslational modifications (PTM), and its interacting proteins are discussed with a special emphasis on breast cancer metastasis.
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Affiliation(s)
- M Rohini
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - A Haritha Menon
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India
| | - N Selvamurugan
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603 203, Tamil Nadu, India.
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10
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La Fortezza M, Grigolon G, Cosolo A, Pindyurin A, Breimann L, Blum H, van Steensel B, Classen AK. DamID profiling of dynamic Polycomb-binding sites in Drosophila imaginal disc development and tumorigenesis. Epigenetics Chromatin 2018; 11:27. [PMID: 29871666 PMCID: PMC5987561 DOI: 10.1186/s13072-018-0196-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 05/21/2018] [Indexed: 02/06/2023] Open
Abstract
Background Tracking dynamic protein–chromatin interactions in vivo is key to unravel transcriptional and epigenetic transitions in development and disease. However, limited availability and heterogeneous tissue composition of in vivo source material impose challenges on many experimental approaches. Results Here we adapt cell-type-specific DamID-seq profiling for use in Drosophila imaginal discs and make FLP/FRT-based induction accessible to GAL driver-mediated targeting of specific cell lineages. In a proof-of-principle approach, we utilize ubiquitous DamID expression to describe dynamic transitions of Polycomb-binding sites during wing imaginal disc development and in a scrib tumorigenesis model. We identify Atf3 and Ets21C as novel Polycomb target genes involved in scrib tumorigenesis and suggest that target gene regulation by Atf3 and AP-1 transcription factors, as well as modulation of insulator function, plays crucial roles in dynamic Polycomb-binding at target sites. We establish these findings by DamID-seq analysis of wing imaginal disc samples derived from 10 larvae. Conclusions Our study opens avenues for robust profiling of small cell population in imaginal discs in vivo and provides insights into epigenetic changes underlying transcriptional responses to tumorigenic transformation. Electronic supplementary material The online version of this article (10.1186/s13072-018-0196-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marco La Fortezza
- Faculty of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Planegg, Martinsried, Germany.,Department of Environmental Systems Science, ETH Zurich, Universitätstrasse 16, 8092, Zurich, Switzerland
| | - Giovanna Grigolon
- Faculty of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Planegg, Martinsried, Germany.,Department of Health Sciences and Technology, ETH Zurich, Schorenstrasse 16, 8603, Schwerzenbach, Switzerland
| | - Andrea Cosolo
- Faculty of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Planegg, Martinsried, Germany.,Center for Biological Systems Analysis, Albert-Ludwigs-University Freiburg, Habsburgerstrasse 49, 79104, Freiburg, Germany
| | - Alexey Pindyurin
- Institute of Molecular and Cellular Biology, Siberian Branch of Russian Academy of Sciences, Acad. Lavrentiev Ave. 8/2, Novosibirsk, 630090, Russia
| | - Laura Breimann
- Faculty of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Planegg, Martinsried, Germany.,Max-Delbrück-Center for Molecular Medicine (MDC), Robert-Rössle-Str. 10, 13092, Berlin, Germany
| | - Helmut Blum
- Laboratory for Functional Genome Analysis, Gene Center Munich, Ludwig-Maximilians-University Munich, Feodor-Lynen-Str. 25, 81377, Munich, Germany
| | - Bas van Steensel
- Division Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Anne-Kathrin Classen
- Faculty of Biology, Ludwig-Maximilians-University Munich, Grosshaderner Strasse 2-4, 82152, Planegg, Martinsried, Germany. .,Center for Biological Systems Analysis, Albert-Ludwigs-University Freiburg, Habsburgerstrasse 49, 79104, Freiburg, Germany.
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11
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Donohoe CD, Csordás G, Correia A, Jindra M, Klein C, Habermann B, Uhlirova M. Atf3 links loss of epithelial polarity to defects in cell differentiation and cytoarchitecture. PLoS Genet 2018; 14:e1007241. [PMID: 29494583 PMCID: PMC5849342 DOI: 10.1371/journal.pgen.1007241] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 03/13/2018] [Accepted: 02/05/2018] [Indexed: 12/27/2022] Open
Abstract
Interplay between apicobasal cell polarity modules and the cytoskeleton is critical for differentiation and integrity of epithelia. However, this coordination is poorly understood at the level of gene regulation by transcription factors. Here, we establish the Drosophila activating transcription factor 3 (atf3) as a cell polarity response gene acting downstream of the membrane-associated Scribble polarity complex. Loss of the tumor suppressors Scribble or Dlg1 induces atf3 expression via aPKC but independent of Jun-N-terminal kinase (JNK) signaling. Strikingly, removal of Atf3 from Dlg1 deficient cells restores polarized cytoarchitecture, levels and distribution of endosomal trafficking machinery, and differentiation. Conversely, excess Atf3 alters microtubule network, vesicular trafficking and the partition of polarity proteins along the apicobasal axis. Genomic and genetic approaches implicate Atf3 as a regulator of cytoskeleton organization and function, and identify Lamin C as one of its bona fide target genes. By affecting structural features and cell morphology, Atf3 functions in a manner distinct from other transcription factors operating downstream of disrupted cell polarity. Epithelial cells form sheets and line both the outside and inside of our body. Their proper development and function require the asymmetric distribution of cellular components from the top to the bottom, known as apicobasal polarization. As loss of polarity hallmarks a majority of cancers in humans, understanding how epithelia respond to a collapse of the apicobasal axis is of great interest. Here, we show that in the fruit fly Drosophila melanogaster the breakdown of epithelial polarity engages Activating transcription factor 3 (Atf3), a protein that directly binds the DNA and regulates gene expression. We demonstrate that many of the pathological consequences of disturbed polarity require Atf3, as its loss in this context results in normalization of cellular architecture, vesicle trafficking and differentiation. Using unbiased genome-wide approaches we identify the genetic program controlled by Atf3 and experimentally verify select candidates. Given the evolutionary conservation of Atf3 between flies and man, we believe that our findings in the Drosophila model will contribute to a better understanding of diseases stemming from compromised epithelial polarity.
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Affiliation(s)
- Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Gábor Csordás
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Andreia Correia
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Marek Jindra
- Biology Center, Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Corinna Klein
- Max Planck Institute for Biology of Ageing, Cologne, Germany
| | | | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
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12
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Khan SJ, Abidi SNF, Skinner A, Tian Y, Smith-Bolton RK. The Drosophila Duox maturation factor is a key component of a positive feedback loop that sustains regeneration signaling. PLoS Genet 2017; 13:e1006937. [PMID: 28753614 PMCID: PMC5550008 DOI: 10.1371/journal.pgen.1006937] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/09/2017] [Accepted: 07/20/2017] [Indexed: 12/21/2022] Open
Abstract
Regenerating tissue must initiate the signaling that drives regenerative growth, and sustain that signaling long enough for regeneration to complete. How these key signals are sustained is unclear. To gain a comprehensive view of the changes in gene expression that occur during regeneration, we performed whole-genome mRNAseq of actively regenerating tissue from damaged Drosophila wing imaginal discs. We used genetic tools to ablate the wing primordium to induce regeneration, and carried out transcriptional profiling of the regeneration blastema by fluorescently labeling and sorting the blastema cells, thus identifying differentially expressed genes. Importantly, by using genetic mutants of several of these differentially expressed genes we have confirmed that they have roles in regeneration. Using this approach, we show that high expression of the gene moladietz (mol), which encodes the Duox-maturation factor NIP, is required during regeneration to produce reactive oxygen species (ROS), which in turn sustain JNK signaling during regeneration. We also show that JNK signaling upregulates mol expression, thereby activating a positive feedback signal that ensures the prolonged JNK activation required for regenerative growth. Thus, by whole-genome transcriptional profiling of regenerating tissue we have identified a positive feedback loop that regulates the extent of regenerative growth. Regenerating tissue must initiate the signaling that drives regenerative growth, and then sustain that signaling long enough for regeneration to complete. Drosophila imaginal discs, the epithelial structures in the larva that will form the adult animal during metamorphosis, have been an important model system for tissue repair and regeneration for over 60 years. Here we show that damage-induced JNK signaling leads to the upregulation of a gene called moladietz, which encodes a co-factor for an enzyme, NADPH dual oxidase (Duox), that generates reactive oxygen species (ROS), a key tissue-damage signal. High expression of moladietz induces continuous production of ROS in the regenerating tissue. The sustained production of ROS then continues to activate JNK signaling throughout the course of regeneration, ensuring maximal tissue regrowth.
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Affiliation(s)
- Sumbul Jawed Khan
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Syeda Nayab Fatima Abidi
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Andrea Skinner
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Yuan Tian
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
| | - Rachel K. Smith-Bolton
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
- * E-mail:
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An Ectopic Network of Transcription Factors Regulated by Hippo Signaling Drives Growth and Invasion of a Malignant Tumor Model. Curr Biol 2016; 26:2101-13. [DOI: 10.1016/j.cub.2016.06.035] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 05/21/2016] [Accepted: 06/16/2016] [Indexed: 12/19/2022]
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14
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An accelerated miRNA-based screen implicates Atf-3 in Drosophila odorant receptor expression. Sci Rep 2016; 6:20109. [PMID: 26848073 PMCID: PMC4742857 DOI: 10.1038/srep20109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 12/21/2015] [Indexed: 12/04/2022] Open
Abstract
The Drosophila olfactory system is highly stereotyped in form and function; olfactory sensory neurons (OSNs) expressing a specific odorant receptor (OR) always appear in the same antennal location and the axons of OSNs expressing the same OR converge on the same antennal lobe glomeruli. Although some transcription factors have been implicated in a combinatorial code specifying OR expression and OSN identity, it is clear other players remain unidentified. In hopes of mitigating the challenges of genome-wide screening, we examined the feasibility of a two-tiered approach comprising a primary “pooling” screen for miRNAs whose tissue-specific over-expression causes a phenotype of interest followed by a focused secondary screen using gene-specific RNAi. Since miRNAs down-regulate their targets, miRNA over-expression phenotypes should be attributable to target loss-of-function. It is the sequence-dependence of miRNA-target pairing that suggests candidates for the secondary screen. Since miRNAs are short, however, miRNA misexpression will likely uncover non-biological miRNA-target relationships. Rather than focusing on miRNA function itself where these non-biological relationships could be misleading, we propose using miRNAs as tools to focus a more traditional RNAi-based screen. Here we describe such a screen that uncovers a role for Atf3 in the expression of the odorant receptor Or47b.
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15
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Külshammer E, Mundorf J, Kilinc M, Frommolt P, Wagle P, Uhlirova M. Interplay among Drosophila transcription factors Ets21c, Fos and Ftz-F1 drives JNK-mediated tumor malignancy. Dis Model Mech 2015; 8:1279-93. [PMID: 26398940 PMCID: PMC4610234 DOI: 10.1242/dmm.020719] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 07/28/2015] [Indexed: 12/16/2022] Open
Abstract
Cancer initiation and maintenance of the transformed cell state depend on altered cellular signaling and aberrant activities of transcription factors (TFs) that drive pathological gene expression in response to cooperating genetic lesions. Deciphering the roles of interacting TFs is therefore central to understanding carcinogenesis and for designing cancer therapies. Here, we use an unbiased genomic approach to define a TF network that triggers an abnormal gene expression program promoting malignancy of clonal tumors, generated in Drosophila imaginal disc epithelium by gain of oncogenic Ras (RasV12) and loss of the tumor suppressor Scribble (scrib1). We show that malignant transformation of the rasV12scrib1 tumors requires TFs of distinct families, namely the bZIP protein Fos, the ETS-domain factor Ets21c and the nuclear receptor Ftz-F1, all acting downstream of Jun-N-terminal kinase (JNK). Depleting any of the three TFs improves viability of tumor-bearing larvae, and this positive effect can be enhanced further by their combined removal. Although both Fos and Ftz-F1 synergistically contribute to rasV12scrib1 tumor invasiveness, only Fos is required for JNK-induced differentiation defects and Matrix metalloprotease (MMP1) upregulation. In contrast, the Fos-dimerizing partner Jun is dispensable for JNK to exert its effects in rasV12scrib1 tumors. Interestingly, Ets21c and Ftz-F1 are transcriptionally induced in these tumors in a JNK- and Fos-dependent manner, thereby demonstrating a hierarchy within the tripartite TF network, with Fos acting as the most upstream JNK effector. Of the three TFs, only Ets21c can efficiently substitute for loss of polarity and cooperate with RasV12 in inducing malignant clones that, like rasV12scrib1 tumors, invade other tissues and overexpress MMP1 and the Drosophila insulin-like peptide 8 (Dilp8). While rasV12ets21c tumors require JNK for invasiveness, the JNK activity is dispensable for their growth. In conclusion, our study delineates both unique and overlapping functions of distinct TFs that cooperatively promote aberrant expression of target genes, leading to malignant tumor phenotypes. Summary: This study provides genetic evidence that malignancy driven by oncogenic Ras and loss of polarity requires transcription factors of three distinct protein families, acting in synergy downstream of JNK signaling.
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Affiliation(s)
- Eva Külshammer
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Juliane Mundorf
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Merve Kilinc
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Peter Frommolt
- Bioinformatics Facility, CECAD Research Center, University of Cologne, 50931 Cologne, Germany
| | - Prerana Wagle
- Bioinformatics Facility, CECAD Research Center, University of Cologne, 50931 Cologne, Germany
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
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16
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Chakrabarti S, Poidevin M, Lemaitre B. The Drosophila MAPK p38c regulates oxidative stress and lipid homeostasis in the intestine. PLoS Genet 2014; 10:e1004659. [PMID: 25254641 PMCID: PMC4177744 DOI: 10.1371/journal.pgen.1004659] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 08/11/2014] [Indexed: 01/09/2023] Open
Abstract
The p38 mitogen-activated protein (MAP) kinase signaling cassette has been implicated in stress and immunity in evolutionarily diverse species. In response to a wide variety of physical, chemical and biological stresses p38 kinases phosphorylate various substrates, transcription factors of the ATF family and other protein kinases, regulating cellular adaptation to stress. The Drosophila genome encodes three p38 kinases named p38a, p38b and p38c. In this study, we have analyzed the role of p38c in the Drosophila intestine. The p38c gene is expressed in the midgut and upregulated upon intestinal infection. We showed that p38c mutant flies are more resistant to infection with the lethal pathogen Pseudomonas entomophila but are more susceptible to the non-pathogenic bacterium Erwinia carotovora 15. This phenotype was linked to a lower production of Reactive Oxygen Species (ROS) in the gut of p38c mutants, whereby the transcription of the ROS-producing enzyme Duox is reduced in p38c mutant flies. Our genetic analysis shows that p38c functions in a pathway with Mekk1 and Mkk3 to induce the phosphorylation of Atf-2, a transcription factor that controls Duox expression. Interestingly, p38c deficient flies accumulate lipids in the intestine while expressing higher levels of antimicrobial peptide and metabolic genes. The role of p38c in lipid metabolism is mediated by the Atf3 transcription factor. This observation suggests that p38c and Atf3 function in a common pathway in the intestine to regulate lipid metabolism and immune homeostasis. Collectively, our study demonstrates that p38c plays a central role in the intestine of Drosophila. It also reveals that many roles initially attributed to p38a are in fact mediated by p38c. The p38 mitogen-activated protein (MAP) kinase is a signaling pathway that is involved in both stress and immunity in various species from yeast to human. p38 kinases regulate transcription factors of the ATF family and other protein kinases that then induce cellular adaptation to stress to a wide variety of physical, chemical and biological stresses. The Drosophila genome encodes three p38 kinases named p38a, p38b and p38c. In this study, we have analyzed the role of p38c in the Drosophila intestine. The p38c gene is expressed in the digestive tract and up-regulated upon intestinal infection. We observed a lower production of Reactive Oxygen Species (ROS) in the gut of p38c mutants upon bacterial infection. Consistent with this observation, the transcription of the Duox, a gene encoding an enzyme that produces ROS, is reduced in p38c mutant flies. Our analysis shows that p38c induces the phosphorylation of Atf-2, a transcription factor that controls Duox expression. Interestingly, our study also shows that p38c and Atf3 function in a common pathway in the intestine to regulate lipid metabolism and immune homeostasis. Collectively, our study demonstrates that p38c plays a central role in the intestine of Drosophila.
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Affiliation(s)
- Sveta Chakrabarti
- Global Health Institute, Station 19, EPFL, Lausanne, Switzerland
- * E-mail: (SC); (BL)
| | - Mickaël Poidevin
- Centre de Génétique Moléculaire (CGM), CNRS, Gif-sur-Yvette, France
| | - Bruno Lemaitre
- Global Health Institute, Station 19, EPFL, Lausanne, Switzerland
- * E-mail: (SC); (BL)
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Yamaguchi Y, Kuranaga E, Nakajima YI, Koto A, Takemoto K, Miura M. In Vivo Monitoring of Caspase Activation Using a Fluorescence Resonance Energy Transfer-Based Fluorescent Probe. Methods Enzymol 2014; 544:299-325. [DOI: 10.1016/b978-0-12-417158-9.00012-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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18
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Rynes J, Donohoe CD, Frommolt P, Brodesser S, Jindra M, Uhlirova M. Activating transcription factor 3 regulates immune and metabolic homeostasis. Mol Cell Biol 2012; 32:3949-62. [PMID: 22851689 PMCID: PMC3457521 DOI: 10.1128/mcb.00429-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 07/18/2012] [Indexed: 12/20/2022] Open
Abstract
Integration of metabolic and immune responses during animal development ensures energy balance, permitting both growth and defense. Disturbed homeostasis causes organ failure, growth retardation, and metabolic disorders. Here, we show that the Drosophila melanogaster activating transcription factor 3 (Atf3) safeguards metabolic and immune system homeostasis. Loss of Atf3 results in chronic inflammation and starvation responses mounted primarily by the larval gut epithelium, while the fat body suffers lipid overload, causing energy imbalance and death. Hyperactive proinflammatory and stress signaling through NF-κB/Relish, Jun N-terminal kinase, and FOXO in atf3 mutants deregulates genes important for immune defense, digestion, and lipid metabolism. Reducing the dose of either FOXO or Relish normalizes both lipid metabolism and gene expression in atf3 mutants. The function of Atf3 is conserved, as human ATF3 averts some of the Drosophila mutant phenotypes, improving their survival. The single Drosophila Atf3 may incorporate the diversified roles of two related mammalian proteins.
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Affiliation(s)
- Jan Rynes
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Department of Molecular Biology, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Colin D. Donohoe
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Peter Frommolt
- Bioinformatics Core Facility, CECAD, and Cologne Center for Genomics, Cologne, Germany
| | - Susanne Brodesser
- Lipidomics Core Facility, CECAD, and Institute for Medical Microbiology, Immunology and Hygiene, Cologne, Germany
| | - Marek Jindra
- Biology Center, Academy of Sciences of the Czech Republic, Ceske Budejovice, Czech Republic
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
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19
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Sztal T, Chung H, Berger S, Currie PD, Batterham P, Daborn PJ. A cytochrome p450 conserved in insects is involved in cuticle formation. PLoS One 2012; 7:e36544. [PMID: 22574182 PMCID: PMC3344891 DOI: 10.1371/journal.pone.0036544] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 04/09/2012] [Indexed: 01/20/2023] Open
Abstract
The sequencing of numerous insect genomes has revealed dynamic changes in the number and identity of cytochrome P450 genes in different insects. In the evolutionary sense, the rapid birth and death of many P450 genes is observed, with only a small number of P450 genes showing orthology between insects with sequenced genomes. It is likely that these conserved P450s function in conserved pathways. In this study, we demonstrate the P450 gene, Cyp301a1, present in all insect genomes sequenced to date, affects the formation of the adult cuticle in Drosophila melanogaster. A Cyp301a1 piggyBac insertion mutant and RNAi of Cyp301a1 both show a similar cuticle malformation phenotype, which can be reduced by 20-hydroxyecdysone, suggesting that Cyp301a1 is an important gene involved in the formation of the adult cuticle and may be involved in ecdysone regulation in this tissue.
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Affiliation(s)
- Tamar Sztal
- Department of Genetics, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia.
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20
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Bischoff M. Lamellipodia-based migrations of larval epithelial cells are required for normal closure of the adult epidermis of Drosophila. Dev Biol 2011; 363:179-90. [PMID: 22230614 PMCID: PMC3314956 DOI: 10.1016/j.ydbio.2011.12.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 11/29/2022]
Abstract
Cell migrations are an important feature of animal development. They are, furthermore, essential to wound healing and tumour progression. Despite recent progress, it is still mysterious how cell migration is spatially and temporally regulated during morphogenesis and how cell migration is coordinated with other cellular behaviours to shape tissues and organs. The formation of the abdominal epithelium of Drosophila during metamorphosis provides an attractive system to study morphogenesis. Here, the diploid adult histoblasts replace the polyploid larval epithelial cells (LECs). Using in vivo 4D microscopy, I show that, besides apical constriction and apoptosis, the LECs undergo extensive coordinated migrations. The migrations follow a transition from a stationary (epithelial) to a migratory mode. The migratory behaviour is stimulated by autocrine Dpp signalling. Directed apical lamellipodia-like protrusions propel the cells. Initially, planar cell polarity determines the orientation of LEC migration. While LECs are migrating they also constrict apically, and changes in activity of the small GTPase Rho1 can favour one behaviour over the other. This study shows that the LECs play a more active role in morphogenesis than previously thought, with their migrations contributing to abdominal closure. It furthermore provides insights into how the migratory behaviour of cells is regulated during morphogenesis.
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Affiliation(s)
- Marcus Bischoff
- University of Cambridge, Department of Zoology, Cambridge, UK.
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