1
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Prasad D, Illek K, Fischer F, Holstein K, Classen AK. Bilateral JNK activation is a hallmark of interface surveillance and promotes elimination of aberrant cells. eLife 2023; 12:e80809. [PMID: 36744859 PMCID: PMC9917460 DOI: 10.7554/elife.80809] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 02/03/2023] [Indexed: 02/07/2023] Open
Abstract
Tissue-intrinsic defense mechanisms eliminate aberrant cells from epithelia and thereby maintain the health of developing tissues or adult organisms. 'Interface surveillance' comprises one such distinct mechanism that specifically guards against aberrant cells which undergo inappropriate cell fate and differentiation programs. The cellular mechanisms which facilitate detection and elimination of these aberrant cells are currently unknown. We find that in Drosophila imaginal discs, clones of cells with inappropriate activation of cell fate programs induce bilateral JNK activation at clonal interfaces, where wild type and aberrant cells make contact. JNK activation is required to drive apoptotic elimination of interface cells. Importantly, JNK activity and apoptosis are highest in interface cells within small aberrant clones, which likely supports the successful elimination of aberrant cells when they arise. Our findings are consistent with a model where clone size affects the topology of interface contacts and thereby the strength of JNK activation in wild type and aberrant interface cells. Bilateral JNK activation is unique to 'interface surveillance' and is not observed in other tissue-intrinsic defense mechanisms, such as classical 'cell-cell competition'. Thus, bilateral JNK interface signaling provides an independent tissue-level mechanism to eliminate cells with inappropriate developmental fate but normal cellular fitness. Finally, oncogenic Ras-expressing clones activate 'interface surveillance' but evade elimination by bilateral JNK activation. Combined, our work establishes bilateral JNK interface signaling and interface apoptosis as a new hallmark of interface surveillance and highlights how oncogenic mutations evade tumor suppressor function encoded by this tissue-intrinsic surveillance system.
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Affiliation(s)
- Deepti Prasad
- Hilde-Mangold-Haus, University of FreiburgFreiburgGermany
- Spemann Graduate School of Biology and Medicine (SGBM), University of FreiburgFreiburgGermany
- Faculty of Biology, University of FreiburgFreiburgGermany
| | | | - Friedericke Fischer
- Hilde-Mangold-Haus, University of FreiburgFreiburgGermany
- Faculty of Biology, University of FreiburgFreiburgGermany
- International Max Planck Research School for Immunobiology, Epigenetics, and MetabolismFreiburgGermany
| | | | - Anne-Kathrin Classen
- Hilde-Mangold-Haus, University of FreiburgFreiburgGermany
- Faculty of Biology, University of FreiburgFreiburgGermany
- CIBSS Centre for Integrative Biological Signalling Studies, University of FreiburgFreiburgGermany
- BIOSS Centre for Biological Signalling Studies, University of FreiburgFreiburgGermany
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2
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Hung RJ, Li JSS, Liu Y, Perrimon N. Defining cell types and lineage in the Drosophila midgut using single cell transcriptomics. CURRENT OPINION IN INSECT SCIENCE 2021; 47:12-17. [PMID: 33609768 DOI: 10.1016/j.cois.2021.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
The Drosophila midgut has emerged in recent years as a model system to study stem cell renewal and differentiation and tissue homeostasis. Histological, genetic and gene expression studies have provided a wealth of information on gut cell types, regionalization, genes and pathways involved in cell proliferation and differentiation, stem cell renewal, and responses to changes in environmental factors such as the microbiota and nutrients. Here, we review the contribution of single cell transcriptomic methods to our understanding of gut cell type diversity, lineage and behavior.
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Affiliation(s)
- Ruei-Jiun Hung
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States
| | - Joshua Shing Shun Li
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States
| | - Yifang Liu
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, United States; Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, United States.
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3
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Iijima N, Sato K, Kuranaga E, Umetsu D. Differential cell adhesion implemented by Drosophila Toll corrects local distortions of the anterior-posterior compartment boundary. Nat Commun 2020; 11:6320. [PMID: 33303753 PMCID: PMC7729853 DOI: 10.1038/s41467-020-20118-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/16/2020] [Indexed: 11/25/2022] Open
Abstract
Maintaining lineage restriction boundaries in proliferating tissues is vital to animal development. A long-standing thermodynamics theory, the differential adhesion hypothesis, attributes cell sorting phenomena to differentially expressed adhesion molecules. However, the contribution of the differential adhesion system during tissue morphogenesis has been unsubstantiated despite substantial theoretical support. Here, we report that Toll-1, a transmembrane receptor protein, acts as a differentially expressed adhesion molecule that straightens the fluctuating anteroposterior compartment boundary in the abdominal epidermal epithelium of the Drosophila pupa. Toll-1 is expressed across the entire posterior compartment under the control of the selector gene engrailed and displays a sharp expression boundary that coincides with the compartment boundary. Toll-1 corrects local distortions of the boundary in the absence of cable-like Myosin II enrichment along the boundary. The reinforced adhesion of homotypic cell contacts, together with pulsed cell contraction, achieves a biased vertex sliding action by resisting the separation of homotypic cell contacts in boundary cells. This work reveals a self-organizing system that integrates a differential adhesion system with pulsed contraction of cells to maintain lineage restriction boundaries.
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Affiliation(s)
- Norihiro Iijima
- Laboratory for Histogenetic Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan
| | - Katsuhiko Sato
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020, Japan
- Global Station for Soft Matter, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, 001-0020, Japan
| | - Erina Kuranaga
- Laboratory for Histogenetic Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan.
| | - Daiki Umetsu
- Laboratory for Histogenetic Dynamics, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8578, Japan.
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4
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Wang J, Dahmann C. Establishing compartment boundaries in Drosophila wing imaginal discs: An interplay between selector genes, signaling pathways and cell mechanics. Semin Cell Dev Biol 2020; 107:161-169. [PMID: 32732129 DOI: 10.1016/j.semcdb.2020.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 07/13/2020] [Accepted: 07/14/2020] [Indexed: 01/02/2023]
Abstract
The partitioning of cells into groups or 'compartments' separated by straight and sharp boundaries is important for tissue formation in animal development. Cells from neighboring compartments are characterized by distinct fates and functions and their continuous separation at compartment boundaries maintains proper tissue organization. Signaling across compartment boundaries can induce the local expression of morphogens that in turn direct growth and patterning of the surrounding cells. Compartment boundaries play therefore an important role in tissue development. Compartment boundaries were first identified in the early 1970s in the Drosophila wing. Here, we review the role of compartment boundaries in growth and patterning of the developing wing and then discuss the genetic and physical mechanisms underlying cell separation at compartment boundaries in this tissue.
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Affiliation(s)
- Jing Wang
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany; Cluster of Excellence Physics of Life, Technische Universität Dresden, 01062 Dresden, Germany.
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5
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Chauhan N, Shrivastava NK, Agrawal N, Shakarad MN. Wing patterning in faster developing Drosophila is associated with high ecdysone titer and wingless expression. Mech Dev 2020; 163:103626. [PMID: 32526278 DOI: 10.1016/j.mod.2020.103626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 10/24/2022]
Abstract
'Developmental robustness' is the ability of biological systems to maintain a stable phenotype despite genetic, environmental or physiological perturbations. In holometabolous insects, accurate patterning and development is guaranteed by alignment of final gene expression patterns in tissues at specific developmental stage such as molting and pupariation, irrespective of individual rate of development. In the present study, we used faster developing Drosophila melanogaster populations that show reduction of ~22% in egg to adult development time. Flies from the faster developing population exhibit phenotype constancy, although significantly small in size. The reduction in development time in faster developing flies is possibly due to coordination between higher ecdysteroid release and higher expression of developmental genes. The two together might be ensuring appropriate pattern formation and early exit at each development stage in the populations selected for faster pre-adult development compared to their ancestral controls. We report that apart from plasticity in the rate of pattern progression, alteration in the level of gene expression may be responsible for pattern integrity even under reduced development time.
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Affiliation(s)
- Namita Chauhan
- Evolutionary Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India
| | | | - Namita Agrawal
- Fly Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India.
| | - Mallikarjun N Shakarad
- Evolutionary Biology Laboratory, Department of Zoology, University of Delhi, Delhi 110007, India.
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6
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Bajpai A, Sinha P. Hh signaling from de novo organizers drive lgl neoplasia in Drosophila epithelium. Dev Biol 2020; 457:1-8. [PMID: 31557471 PMCID: PMC7116463 DOI: 10.1016/j.ydbio.2019.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/22/2019] [Accepted: 09/20/2019] [Indexed: 01/20/2023]
Abstract
The Hedgehog (Hh) morphogen regulates growth and patterning. Since Hh signaling is also implicated in carcinogenesis, it is conceivable that de novo Hh-secreting organizers, if formed in association with oncogenic hit could be tumor-cooperative. Here we validate this hypothesis using the Drosophila model of cooperative epithelial carcinogenesis. We generate somatic clones with simultaneous loss of tumor suppressor, Lgl, and gain of the posterior compartment selector, Engrailed (En), known to induce synthesis of Hh. We show that lgl UAS-en clones in the anterior wing compartment trigger Hh signaling cascade via cross-talk with their Ci-expressing wild type cell neighbors. Hh-Dpp signaling from clone boundaries of such ectopically formed de novo organizers in turn drive lgl carcinogenesis. By contrast, Ci-expressing lgl clones transform by autocrine and/or juxtracine activation of Hh signaling in only the posterior compartment. We further show that sequestration of the Hh ligand or loss of Dpp receptor, Tkv, in these Hh-sending or -receiving lgl clones arrested their carcinogenesis. Our results therefore reveal a hitherto unrecognized mechanism of tumor cooperation by developmental organizers, which are induced fortuitously by oncogenic hits.
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Affiliation(s)
- Anjali Bajpai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208 016, India.
| | - Pradip Sinha
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208 016, India.
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7
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Kumar A, Rizvi MS, Athilingam T, Parihar SS, Sinha P. Heterophilic cell-cell adhesion of atypical cadherins Fat and Dachsous regulate epithelial cell size dynamics during Drosophila thorax morphogenesis. Mol Biol Cell 2019; 31:546-560. [PMID: 31877063 PMCID: PMC7202070 DOI: 10.1091/mbc.e19-08-0468] [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] [Indexed: 11/11/2022] Open
Abstract
Spatiotemporal changes in epithelial cell sizes-or epithelial cell size dynamics (ECD)-during morphogenesis entail interplay between two opposing forces: cell contraction via actomyosin cytoskeleton and cell expansion via cell-cell adhesion. Cell-cell adhesion-based ECD, however, has not yet been clearly demonstrated. For instance, changing levels of homophilic E-cadherin-based cell-cell adhesion induce cell sorting, but not ECD. Here we show that cell-expansive forces of heterophilic cell-cell adhesion regulate ECD: higher cell-cell adhesion results in cell size enlargement. Thus, ECD during morphogenesis in the heminotal epithelia of Drosophila pupae leading to thorax closure corresponds with spatiotemporal gradients of two heterophilic atypical cadherins-Fat (Ft) and Dachsous (Ds)-and the levels of Ft-Ds heterodimers formed concomitantly. Our mathematical modeling and genetic tests validate this mechanism of dynamic heterophilic cell-cell adhesion-based regulation of ECD. Conservation of these atypical cadherins suggests a wider prevalence of heterophilic cell-cell adhesion-based ECD regulation during animal morphogenesis.
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Affiliation(s)
- Amit Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
| | - Mohd Suhail Rizvi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
| | - Thamarailingam Athilingam
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
| | - Saurabh Singh Parihar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
| | - Pradip Sinha
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh 208016, India
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8
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Silva TP, Cotovio JP, Bekman E, Carmo-Fonseca M, Cabral JMS, Fernandes TG. Design Principles for Pluripotent Stem Cell-Derived Organoid Engineering. Stem Cells Int 2019; 2019:4508470. [PMID: 31149014 PMCID: PMC6501244 DOI: 10.1155/2019/4508470] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 02/12/2019] [Accepted: 02/24/2019] [Indexed: 12/17/2022] Open
Abstract
Human morphogenesis is a complex process involving distinct microenvironmental and physical signals that are manipulated in space and time to give rise to complex tissues and organs. Advances in pluripotent stem cell (PSC) technology have promoted the in vitro recreation of processes involved in human morphogenesis. The development of organoids from human PSCs represents one reliable source for modeling a large spectrum of human disorders, as well as a promising approach for drug screening and toxicological tests. Based on the "self-organization" capacity of stem cells, different PSC-derived organoids have been created; however, considerable differences between in vitro-generated PSC-derived organoids and their in vivo counterparts have been reported. Advances in the bioengineering field have allowed the manipulation of different components, including cellular and noncellular factors, to better mimic the in vivo microenvironment. In this review, we focus on different examples of bioengineering approaches used to promote the self-organization of stem cells, including assembly, patterning, and morphogenesis in vitro, contributing to tissue-like structure formation.
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Affiliation(s)
- Teresa P. Silva
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av Prof Egas Moniz, Edificio Egas Moniz, 1649-028 Lisboa, Portugal
| | - João P. Cotovio
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
| | - Evguenia Bekman
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av Prof Egas Moniz, Edificio Egas Moniz, 1649-028 Lisboa, Portugal
| | - Maria Carmo-Fonseca
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av Prof Egas Moniz, Edificio Egas Moniz, 1649-028 Lisboa, Portugal
| | - Joaquim M. S. Cabral
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
| | - Tiago G. Fernandes
- Department of Bioengineering and iBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Universidade de Lisboa, Lisboa, Portugal
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9
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Furman DP, Bukharina TV. The bristle pattern development in Drosophila melanogaster: the prepattern and achaete-scute genes. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj18.449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- D. P. Furman
- Institute of Cytology and Genetics, SB RAS; Novosibirsk State University
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10
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Kindberg AA, Bush JO. Cellular organization and boundary formation in craniofacial development. Genesis 2019; 57:e23271. [PMID: 30548771 PMCID: PMC6503678 DOI: 10.1002/dvg.23271] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 12/24/2022]
Abstract
Craniofacial morphogenesis is a highly dynamic process that requires changes in the behaviors and physical properties of cells in order to achieve the proper organization of different craniofacial structures. Boundary formation is a critical process in cellular organization, patterning, and ultimately tissue separation. There are several recurring cellular mechanisms through which boundary formation and cellular organization occur including, transcriptional patterning, cell segregation, cell adhesion and migratory guidance. Disruption of normal boundary formation has dramatic morphological consequences, and can result in human craniofacial congenital anomalies. In this review we discuss boundary formation during craniofacial development, specifically focusing on the cellular behaviors and mechanisms underlying the self-organizing properties that are critical for craniofacial morphogenesis.
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Affiliation(s)
- Abigail A. Kindberg
- Department of Cell and Tissue Biology, Program in Craniofacial Biology, and Institute of Human Genetics, University of California at San Francisco, San Francisco, CA 94143, USA
| | - Jeffrey O. Bush
- Department of Cell and Tissue Biology, Program in Craniofacial Biology, and Institute of Human Genetics, University of California at San Francisco, San Francisco, CA 94143, USA
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11
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Guo Z, Qin J, Zhou X, Zhang Y. Insect Transcription Factors: A Landscape of Their Structures and Biological Functions in Drosophila and beyond. Int J Mol Sci 2018; 19:ijms19113691. [PMID: 30469390 PMCID: PMC6274879 DOI: 10.3390/ijms19113691] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/16/2018] [Accepted: 11/16/2018] [Indexed: 12/17/2022] Open
Abstract
Transcription factors (TFs) play essential roles in the transcriptional regulation of functional genes, and are involved in diverse physiological processes in living organisms. The fruit fly Drosophila melanogaster, a simple and easily manipulated organismal model, has been extensively applied to study the biological functions of TFs and their related transcriptional regulation mechanisms. It is noteworthy that with the development of genetic tools such as CRISPR/Cas9 and the next-generation genome sequencing techniques in recent years, identification and dissection the complex genetic regulatory networks of TFs have also made great progress in other insects beyond Drosophila. However, unfortunately, there is no comprehensive review that systematically summarizes the structures and biological functions of TFs in both model and non-model insects. Here, we spend extensive effort in collecting vast related studies, and attempt to provide an impartial overview of the progress of the structure and biological functions of current documented TFs in insects, as well as the classical and emerging research methods for studying their regulatory functions. Consequently, considering the importance of versatile TFs in orchestrating diverse insect physiological processes, this review will assist a growing number of entomologists to interrogate this understudied field, and to propel the progress of their contributions to pest control and even human health.
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Affiliation(s)
- Zhaojiang Guo
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Jianying Qin
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
- Longping Branch, Graduate School of Hunan University, Changsha 410125, China.
| | - Xiaomao Zhou
- Longping Branch, Graduate School of Hunan University, Changsha 410125, China.
| | - Youjun Zhang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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12
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Kastl P, Manikowski D, Steffes G, Schürmann S, Bandari S, Klämbt C, Grobe K. Disrupting Hedgehog Cardin-Weintraub sequence and positioning changes cellular differentiation and compartmentalization in vivo. Development 2018; 145:145/18/dev167221. [PMID: 30242104 DOI: 10.1242/dev.167221] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/24/2018] [Indexed: 12/25/2022]
Abstract
Metazoan Hedgehog (Hh) morphogens are essential regulators of growth and patterning at significant distances from their source, despite being produced as N-terminally palmitoylated and C-terminally cholesteroylated proteins, which firmly tethers them to the outer plasma membrane leaflet of producing cells and limits their spread. One mechanism to overcome this limitation is proteolytic processing of both lipidated terminal peptides, called shedding, but molecular target site requirements for effective Hh shedding remained undefined. In this work, by using Drosophila melanogaster as a model, we show that mutagenesis of the N-terminal Cardin-Weintraub (CW) motif inactivates recombinant Hh proteins to variable degrees and, if overexpressed in the same compartment, converts them into suppressors of endogenous Hh function. In vivo, additional removal of N-palmitate membrane anchors largely restored endogenous Hh function, supporting the hypothesis that proteolytic CW processing controls Hh solubilization. Importantly, we also observed that CW repositioning impairs anterior/posterior compartmental boundary maintenance in the third instar wing disc. This demonstrates that Hh shedding not only controls the differentiation of anterior cells, but also maintains the sharp physical segregation between these receiving cells and posterior Hh-producing cells.
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Affiliation(s)
- Philipp Kastl
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Dominique Manikowski
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Georg Steffes
- Institute of Neurobiology and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Sabine Schürmann
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Shyam Bandari
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Christian Klämbt
- Institute of Neurobiology and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
| | - Kay Grobe
- Institute of Physiological Chemistry and Pathobiochemistry and Cells-in-Motion Cluster of Excellence (EXC1003-CiM), University of Münster, D-48149 Münster, Germany
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13
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Deshmukh R, Baral S, Gandhimathi A, Kuwalekar M, Kunte K. Mimicry in butterflies: co-option and a bag of magnificent developmental genetic tricks. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 7. [PMID: 28913870 DOI: 10.1002/wdev.291] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 07/04/2017] [Accepted: 07/20/2017] [Indexed: 01/05/2023]
Abstract
Butterfly wing patterns are key adaptations that are controlled by remarkable developmental and genetic mechanisms that facilitate rapid evolutionary change. With swift advancements in the fields of genomics and genetic manipulations, identifying the regulators of wing development and mimetic wing patterns has become feasible even in nonmodel organisms such as butterflies. Recent mapping and gene expression studies have identified single switch loci of major effects such as transcription factors and supergenes as the main drivers of adaptive evolution of mimetic and polymorphic butterfly wing patterns. We highlight several of these examples, with emphasis on doublesex, optix, WntA and other dynamic, yet essential, master regulators that control critical color variation and sex-specific traits. Co-option emerges as a predominant theme, where typically embryonic and other early-stage developmental genes and networks have been rewired to regulate polymorphic and sex-limited mimetic wing patterns in iconic butterfly adaptations. Drawing comparisons from our knowledge of wing development in Drosophila, we illustrate the functional space of genes that have been recruited to regulate butterfly wing patterns. We also propose a developmental pathway that potentially results in dorsoventral mismatch in butterfly wing patterns. Such dorsoventrally mismatched color patterns modulate signal components of butterfly wings that are used in intra- and inter-specific communication. Recent advances-fuelled by RNAi-mediated knockdowns and CRISPR/Cas9-based genomic edits-in the developmental genetics of butterfly wing patterns, and the underlying biological diversity and complexity of wing coloration, are pushing butterflies as an emerging model system in ecological genetics and evolutionary developmental biology. WIREs Dev Biol 2018, 7:e291. doi: 10.1002/wdev.291 This article is categorized under: Gene Expression and Transcriptional Hierarchies > Regulatory Mechanisms Comparative Development and Evolution > Regulation of Organ Diversity Comparative Development and Evolution > Evolutionary Novelties.
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Affiliation(s)
| | - Saurav Baral
- National Centre for Biological Sciences, Bengaluru, India
| | - A Gandhimathi
- National Centre for Biological Sciences, Bengaluru, India
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14
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Marty F, Rago G, Smith DF, Gao X, Eijkel GB, MacAleese L, Bonn M, Brunner E, Basler K, Heeren RMA. Combining Time-of-Flight Secondary Ion Mass Spectrometry Imaging Mass Spectrometry and CARS Microspectroscopy Reveals Lipid Patterns Reminiscent of Gene Expression Patterns in the Wing Imaginal Disc of Drosophila melanogaster. Anal Chem 2017; 89:9664-9670. [PMID: 28727418 PMCID: PMC5607455 DOI: 10.1021/acs.analchem.7b00125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
![]()
Using
label-free ToF-SIMS imaging mass spectrometry, we generated
a map of small molecules differentially expressed in the Drosophila wing imaginal disc. The distributions of these moieties were in
line with gene expression patterns observed during wing imaginal disc
development. Combining ToF-SIMS imaging and coherent anti-Stokes Raman
spectroscopy (CARS) microspectroscopy allowed us to locally identify
acylglycerols as the main constituents of the pattern differentiating
the future body wall tissue from the wing blade tissue. The findings
presented herein clearly demonstrate that lipid localization patterns
are strongly correlated with a developmental gene expression. From
this correlation, we hypothesize that lipids play a so far unrecognized
role in organ development.
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Affiliation(s)
- Florian Marty
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Gianluca Rago
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Donald F Smith
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Xiaoli Gao
- Institutional Mass Spectrometry Laboratory, The University of Texas Health Science Center at San Antonio , 8403 Floyd Curl Drive, MC-7760 San Antonio, Texas, United States
| | - Gert B Eijkel
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,The Maastricht Multimodal Molecular Imaging Institute, Maastricht University , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
| | - Luke MacAleese
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Mischa Bonn
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
| | - Erich Brunner
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zürich , Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
| | - Ron M A Heeren
- FOM-Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.,The Maastricht Multimodal Molecular Imaging Institute, Maastricht University , Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
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15
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Lu CP, Polak L, Keyes BE, Fuchs E. Spatiotemporal antagonism in mesenchymal-epithelial signaling in sweat versus hair fate decision. Science 2017; 354:354/6319/aah6102. [PMID: 28008008 DOI: 10.1126/science.aah6102] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/16/2016] [Accepted: 11/18/2016] [Indexed: 12/12/2022]
Abstract
The gain of eccrine sweat glands in hairy body skin has empowered humans to run marathons and tolerate temperature extremes. Epithelial-mesenchymal cross-talk is integral to the diverse patterning of skin appendages, but the molecular events underlying their specification remain largely unknown. Using genome-wide analyses and functional studies, we show that sweat glands are specified by mesenchymal-derived bone morphogenetic proteins (BMPs) and fibroblast growth factors that signal to epithelial buds and suppress epithelial-derived sonic hedgehog (SHH) production. Conversely, hair follicles are specified when mesenchymal BMP signaling is blocked, permitting SHH production. Fate determination is confined to a critical developmental window and is regionally specified in mice. In contrast, a shift from hair to gland fates is achieved in humans when a spike in BMP silences SHH during the final embryonic wave(s) of bud morphogenesis.
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Affiliation(s)
- Catherine P Lu
- Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Lisa Polak
- Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Brice E Keyes
- Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA
| | - Elaine Fuchs
- Laboratory of Mammalian Cell Biology and Development, The Rockefeller University, New York, NY 10065, USA. .,Howard Hughes Medical Institute, Chevy Chase, MD, 20815-6789, USA
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16
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17
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Pflugfelder G, Eichinger F, Shen J. T-Box Genes in Drosophila Limb Development. Curr Top Dev Biol 2017; 122:313-354. [DOI: 10.1016/bs.ctdb.2016.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Michel M, Aliee M, Rudolf K, Bialas L, Jülicher F, Dahmann C. The Selector Gene apterous and Notch Are Required to Locally Increase Mechanical Cell Bond Tension at the Drosophila Dorsoventral Compartment Boundary. PLoS One 2016; 11:e0161668. [PMID: 27552097 PMCID: PMC4995041 DOI: 10.1371/journal.pone.0161668] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/09/2016] [Indexed: 11/25/2022] Open
Abstract
The separation of cells with distinct fates and functions is important for tissue and organ formation during animal development. Regions of different fates within tissues are often separated from another along straight boundaries. These compartment boundaries play a crucial role in tissue patterning and growth by stably positioning organizers. In Drosophila, the wing imaginal disc is subdivided into a dorsal and a ventral compartment. Cells of the dorsal, but not ventral, compartment express the selector gene apterous. Apterous expression sets in motion a gene regulatory cascade that leads to the activation of Notch signaling in a few cell rows on either side of the dorsoventral compartment boundary. Both Notch and apterous mutant clones disturb the separation of dorsal and ventral cells. Maintenance of the straight shape of the dorsoventral boundary involves a local increase in mechanical tension at cell bonds along the boundary. The mechanisms by which cell bond tension is locally increased however remain unknown. Here we use a combination of laser ablation of cell bonds, quantitative image analysis, and genetic mutants to show that Notch and Apterous are required to increase cell bond tension along the dorsoventral compartment boundary. Moreover, clonal expression of the Apterous target gene capricious results in cell separation and increased cell bond tension at the clone borders. Finally, using a vertex model to simulate tissue growth, we find that an increase in cell bond tension at the borders of cell clones, but not throughout the cell clone, can lead to cell separation. We conclude that Apterous and Notch maintain the characteristic straight shape of the dorsoventral compartment boundary by locally increasing cell bond tension.
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Affiliation(s)
- Marcus Michel
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187, Dresden, Germany
| | - Katrin Rudolf
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Lisa Bialas
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187, Dresden, Germany
- * E-mail: (FJ); (CD)
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, 01062, Dresden, Germany
- * E-mail: (FJ); (CD)
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19
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Abstract
During animal development, cells with similar function and fate often stay together and sort out from cells with different fates. In Drosophila wing imaginal discs, cells of anterior and posterior fates are separated by a straight compartment boundary. Separation of anterior and posterior cells requires the homeodomain-containing protein Engrailed, which is expressed in posterior cells. Engrailed induces the expression of the short-range signaling molecule Hedgehog in posterior cells and confines Hedgehog signal transduction to anterior cells. Transduction of the Hedgehog signal in anterior cells is required for the separation of anterior and posterior cells. Previous work showed that this separation of cells involves a local increase in mechanical tension at cell junctions along the compartment boundary. However, how mechanical tension was locally increased along the compartment boundary remained unknown. A recent paper now shows that the difference in Hedgehog signal transduction between anterior and posterior cells is necessary and sufficient to increase mechanical tension. The local increase in mechanical tension biases junctional rearrangements during cell intercalations to maintain the straight shape of the compartment boundary. These data highlight how developmental signals can generate patterns of mechanical tension important for tissue organization.
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Affiliation(s)
- Marcus Michel
- a Institute of Genetics, Technische Universität Dresden , Dresden , Germany
| | - Christian Dahmann
- a Institute of Genetics, Technische Universität Dresden , Dresden , Germany
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20
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Abstract
Compaction is a critical first morphological event in the preimplantation development of the mammalian embryo. Characterized by the transformation of the embryo from a loose cluster of spherical cells into a tightly packed mass, compaction is a key step in the establishment of the first tissue-like structures of the embryo. Although early investigation of the mechanisms driving compaction implicated changes in cell-cell adhesion, recent work has identified essential roles for cortical tension and a compaction-specific class of filopodia. During the transition from 8 to 16 cells, as the embryo is compacting, it must also make fundamental decisions regarding cell position, polarity, and fate. Understanding how these and other processes are integrated with compaction requires further investigation. Emerging imaging-based techniques that enable quantitative analysis from the level of cell-cell interactions down to the level of individual regulatory molecules will provide a greater understanding of how compaction shapes the early mammalian embryo.
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Affiliation(s)
- M D White
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - S Bissiere
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - Y D Alvarez
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - N Plachta
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore.
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21
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Svendsen PC, Ryu JR, Brook WJ. The expression of the T-box selector gene midline in the leg imaginal disc is controlled by both transcriptional regulation and cell lineage. Biol Open 2015; 4:1707-14. [PMID: 26581591 PMCID: PMC4736030 DOI: 10.1242/bio.013565] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Drosophila Tbx20 homologs midline and H15 act as selector genes for ventral fate in Drosophila legs. midline and H15 expression defines the ventral domain of the leg and the two genes are necessary and sufficient for the development of ventral fate. Ventral-specific expression of midline and H15 is activated by Wingless (Wg) and repressed by Decapentaplegic (Dpp). Here we identify VLE, a 5 kb enhancer that drives ventral specific expression in the leg disc that is very similar to midline expression. Subdivision of VLE identifies two regions that mediate both activation and repression and third region that only mediates repression. Loss- and gain-of-function genetic mosaic analysis shows that the activating and repressing regions respond to Wg and Dpp signaling respectively. All three repression regions depend on the activity of Mothers-against-decapentaplegic, a Drosophila r-Smad that mediates Dpp signaling, and respond to ectopic expression of the Dpp target genes optomoter-blind and Dorsocross 3. However, only one repression region is responsive to loss of schnurri, a co-repressor required for direct repression by Dpp-signaling. Thus, Dpp signaling restricts midline expression through both direct repression and through the activation of downstream repressors. We also find that midline and H15 expression are both subject to cross-repression and feedback inhibition. Finally, a lineage analysis indicates that ventral midline-expressing cells and dorsal omb-expressing cells do not mix during development. Together this data indicates that the ventral-specific expression of midline results from both transcriptional regulation and from a lack of cell-mixing between dorsal and ventral cells.
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Affiliation(s)
- Pia C Svendsen
- Genes and Development Research Group, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary T2N4N1, Alberta, Canada
| | - Jae-Ryeon Ryu
- Genes and Development Research Group, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary T2N4N1, Alberta, Canada
| | - William J Brook
- Genes and Development Research Group, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary T2N4N1, Alberta, Canada
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22
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Rudolf K, Umetsu D, Aliee M, Sui L, Jülicher F, Dahmann C. A local difference in Hedgehog signal transduction increases mechanical cell bond tension and biases cell intercalations along the Drosophila anteroposterior compartment boundary. Development 2015; 142:3845-58. [DOI: 10.1242/dev.125542] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Tissue organization requires the interplay between biochemical signaling and cellular force generation. The formation of straight boundaries separating cells with different fates into compartments is important for growth and patterning during tissue development. In the developing Drosophila wing disc, maintenance of the straight anteroposterior (AP) compartment boundary involves a local increase in mechanical tension at cell bonds along the boundary. The biochemical signals that regulate mechanical tension along the AP boundary, however, remain unknown. Here, we show that a local difference in Hedgehog signal transduction activity between anterior and posterior cells is necessary and sufficient to increase mechanical tension along the AP boundary. This difference in Hedgehog signal transduction is also required to bias cell rearrangements during cell intercalations to keep the characteristic straight shape of the AP boundary. Moreover, severing cell bonds along the AP boundary does not reduce tension at neighboring bonds, implying that active mechanical tension is upregulated, cell bond by cell bond. Finally, differences in the expression of the homeodomain-containing protein Engrailed also contribute to the straight shape of the AP boundary, independently of Hedgehog signal transduction and without modulating cell bond tension. Our data reveal a novel link between local differences in Hedgehog signal transduction and a local increase in active mechanical tension of cell bonds that biases junctional rearrangements. The large-scale shape of the AP boundary thus emerges from biochemical signals inducing patterns of active tension on cell bonds.
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Affiliation(s)
- Katrin Rudolf
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
| | - Daiki Umetsu
- RIKEN Center for Developmental Biology, Kobe 650-0047, Japan
| | - Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, Dresden 01187, Germany
| | - Liyuan Sui
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, Dresden 01187, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, Dresden 01062, Germany
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23
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Rao PR, Lin L, Huang H, Guha A, Roy S, Kornberg TB. Developmental compartments in the larval trachea of Drosophila. eLife 2015; 4. [PMID: 26491942 PMCID: PMC4718809 DOI: 10.7554/elife.08666] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/21/2015] [Indexed: 12/14/2022] Open
Abstract
The Drosophila tracheal system is a branched tubular network that forms in the embryo by a post-mitotic program of morphogenesis. In third instar larvae (L3), cells constituting the second tracheal metamere (Tr2) reenter the cell cycle. Clonal analysis of L3 Tr2 revealed that dividing cells in the dorsal trunk, dorsal branch and transverse connective branches respect lineage restriction boundaries near branch junctions. These boundaries corresponded to domains of gene expression, for example where cells expressing Spalt, Delta and Serrate in the dorsal trunk meet vein–expressing cells in the dorsal branch or transverse connective. Notch signaling was activated to one side of these borders and was required for the identity, specializations and segregation of border cells. These findings suggest that Tr2 is comprised of developmental compartments and that developmental compartments are an organizational feature relevant to branched tubular networks. DOI:http://dx.doi.org/10.7554/eLife.08666.001 As a fruit fly develops, its cells may sort themselves into groups according to the type of cell that they will eventually become. Some groups form ‘developmental compartments’ that are separated by boundaries that cells cannot move across. All the descendants of a cell in a compartment will activate the same specific gene (called a ‘selector’ gene) that determines their identity and fate. Similar compartments also form in the developing hindbrains of mammals, but it is not clear how general this mechanism of tissue patterning is. Fruit fly larvae undergo a physical transformation called metamorphosis to become adult fruit flies. Here, Rao et al. discover that the cells in the developing airways (or trachea) of the larvae at the start of metamorphosis are organised into compartments. At this stage the cells in the trachea start to divide and grow to make the adult tracheal system. The experiments show that these cells do not spread from one main branch of the tracheal system into another. Instead, the cells cluster in locations where the different branches meet on either side of a straight boundary. The cells on each side of these boundaries activate different genes that regulate their identity and development. For example, cells in one branch of the system switch on a selector gene that makes a protein called Spalt. A pathway known as Notch signaling is activated by cells on the other side of a nearby boundary in a different branch of the tracheal system. This separation of Spalt production and Notch activation establishes a cell communication system that keeps the cells of the different compartments apart. Rao et al.’s findings reveal a role for the Notch protein in regulating the organization of cells into compartments to form branches in fruit fly airways. A future challenge is to find out if Notch plays a similar role in other branched tissues, such as blood vessels. DOI:http://dx.doi.org/10.7554/eLife.08666.002
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Affiliation(s)
- Prashanth R Rao
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Li Lin
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Hai Huang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Arjun Guha
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Sougata Roy
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
| | - Thomas B Kornberg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
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24
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Marada S, Truong A, Ogden SK. The small GTPase Rap1 is a modulator of Hedgehog signaling. Dev Biol 2015; 409:84-94. [PMID: 26481064 DOI: 10.1016/j.ydbio.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/31/2022]
Abstract
During development, the evolutionarily conserved Hedgehog (Hh) morphogen provides instructional cues that influence cell fate, cell affinity and tissue morphogenesis. To do so, the Hh signaling cascade must coordinate its activity with other morphogenetic signals. This can occur through engagement of or response to effectors that do not typically function as core Hh pathway components. Given the ability of small G proteins of the Ras family to impact cell survival, differentiation, growth and adhesion, we wanted to determine whether Hh and Ras signaling might intersect during development. We performed genetic modifier tests in Drosophila to examine the ability of select Ras family members to influence Hh signal output, and identified Rap1 as a positive modulator of Hh pathway activity. Our results suggest that Rap1 is activated to its GTP-bound form in response to Hh ligand, and that the GTPase exchange factor C3G likely contributes to this activation. The Rap1 effector Canoe (Cno) also impacts Hh signal output, suggesting that a C3G-Rap1-Cno axis intersects the Hh pathway during tissue morphogenesis.
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Affiliation(s)
- Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States; Rhodes College Summer Plus Program, Rhodes College, Memphis, TN 38112, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States.
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25
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Anais Tiberghien M, Lebreton G, Cribbs D, Benassayag C, Suzanne M. The Hox gene Dfd controls organogenesis by shaping territorial border through regulation of basal DE-Cadherin distribution. Dev Biol 2015. [PMID: 26206615 DOI: 10.1016/j.ydbio.2015.07.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Hox genes are highly conserved selector genes controlling tissue identity and organogenesis. Recent work indicates that Hox genes also controls cell segregation and segmental boundary in various species, however the underlying cellular mechanisms involved in this function are poorly understood. In Drosophila melanogaster, the Hox gene Deformed (Dfd) is required for specification and organogenesis of the adult Maxillary (Mx) palp. Here, we demonstrate that differential Dfd expression control Mx morphogenesis through the formation of a physical boundary separating the Mx field and the Peripodial Epithelium (PE). We show that this boundary relies on DE-cadherin (DE-cad) basal accumulation in Mx cells controlled by differential Dfd expression. Indeed, Dfd controls boundary formation through cell autonomous basal redistribution of DE-cad which leads to subsequent fold at the Dfd expression border. Finally, the loss of Mx DE-cad basal accumulation and hence of Mx-PE folding is sufficient to prevent Mx organogenesis thus revealing the crucial role of boundaries in organ differentiation. Altogether, these results reveal that Hox coordination of tissue morphogenesis relies on boundary fold formation through the modulation of DE-cad positioning.
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Affiliation(s)
- Marie Anais Tiberghien
- LBCMCP, Université Paul Sabatier, CNRS UMR 5088 Bâtiment 4R3-B1, 118 Route de Narbonne, 31062 Toulouse cedex, France
| | - Gaelle Lebreton
- IBV-Institut de Biologie Valrose, Bâtiment de biochimie, Université Nice Sophia Antipolis, Parc Valrose, 06108 Nice cedex, France
| | - David Cribbs
- CBD, Université Paul Sabatier, UMR5547 Batiment 4R3-B3, 118 Route de Narbonne, 31062 Toulouse cedex, France
| | - Corinne Benassayag
- LBCMCP, Université Paul Sabatier, CNRS UMR 5088 Bâtiment 4R3-B1, 118 Route de Narbonne, 31062 Toulouse cedex, France.
| | - Magali Suzanne
- LBCMCP, Université Paul Sabatier, CNRS UMR 5088 Bâtiment 4R3-B1, 118 Route de Narbonne, 31062 Toulouse cedex, France
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26
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Kashef J, Franz CM. Quantitative methods for analyzing cell–cell adhesion in development. Dev Biol 2015; 401:165-74. [DOI: 10.1016/j.ydbio.2014.11.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/07/2014] [Accepted: 11/08/2014] [Indexed: 11/26/2022]
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27
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Umetsu D, Dahmann C. Signals and mechanics shaping compartment boundaries in Drosophila. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:407-17. [PMID: 25755098 DOI: 10.1002/wdev.178] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/18/2014] [Accepted: 01/22/2015] [Indexed: 11/06/2022]
Abstract
During animal development groups of cells with similar fates and functions often stay together and separate from cells with different fates. An example for this cellular behavior is the formation of compartments, groups of cells with similar fates that are separated by sharp boundaries from neighboring groups of cells. Compartments play important roles during patterning by serving as units of growth and gene expression. Boundaries between compartments are associated with organizers that secrete signaling molecules instructing growth and differentiation throughout the tissue. The straight shape of the boundary between compartments is important for maintaining the position and shape of the organizer and thus for precise patterning. The straight shape of compartment boundaries, however, is challenged by cell divisions and cell intercalations that take place in many developing tissues. Early work established a role for selector genes and signaling pathways in setting up and keeping boundaries straight. Recent work in Drosophila has now begun to further unravel the physical and cellular mechanisms that maintain compartment boundaries. Key to the separation of compartments is a local increase of actomyosin-dependent mechanical tension at cell junctions along the boundary. Increased mechanical tension acts as a barrier to cell mixing during cell division and influences cell rearrangements during cell intercalations along the compartment boundary in a way that the straight shape of the boundary is maintained. An important question for the future is how the signaling pathways that maintain the straight shape of compartment boundaries control mechanical tension along these boundaries.
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Affiliation(s)
- Daiki Umetsu
- RIKEN Center for Developmental Biology, Kobe, Japan
| | - Christian Dahmann
- Technische Universität Dresden, Institute of Genetics, Dresden, Germany
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28
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Fagotto F. Regulation of Cell Adhesion and Cell Sorting at Embryonic Boundaries. Curr Top Dev Biol 2015; 112:19-64. [DOI: 10.1016/bs.ctdb.2014.11.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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29
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Umetsu D, Dunst S, Dahmann C. An RNA interference screen for genes required to shape the anteroposterior compartment boundary in Drosophila identifies the Eph receptor. PLoS One 2014; 9:e114340. [PMID: 25473846 PMCID: PMC4256218 DOI: 10.1371/journal.pone.0114340] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 11/07/2014] [Indexed: 12/01/2022] Open
Abstract
The formation of straight compartment boundaries separating groups of cells with distinct fates and functions is an evolutionarily conserved strategy during animal development. The physical mechanisms that shape compartment boundaries have recently been further elucidated, however, the molecular mechanisms that underlie compartment boundary formation and maintenance remain poorly understood. Here, we report on the outcome of an RNA interference screen aimed at identifying novel genes involved in maintaining the straight shape of the anteroposterior compartment boundary in Drosophila wing imaginal discs. Out of screening 3114 transgenic RNA interference lines targeting a total of 2863 genes, we identified a single novel candidate that interfered with the formation of a straight anteroposterior compartment boundary. Interestingly, the targeted gene encodes for the Eph receptor tyrosine kinase, an evolutionarily conserved family of signal transducers that has previously been shown to be important for maintaining straight compartment boundaries in vertebrate embryos. Our results identify a hitherto unknown role of the Eph receptor tyrosine kinase in Drosophila and suggest that Eph receptors have important functions in shaping compartment boundaries in both vertebrate and insect development.
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Affiliation(s)
- Daiki Umetsu
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
| | - Sebastian Dunst
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Christian Dahmann
- Institute of Genetics, Technische Universität Dresden, Dresden, Germany
- * E-mail:
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30
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Camp D, Haitian He B, Li S, Althaus IW, Holtz AM, Allen BL, Charron F, van Meyel DJ. Ihog and Boi elicit Hh signaling via Ptc but do not aid Ptc in sequestering the Hh ligand. Development 2014; 141:3879-88. [PMID: 25231763 DOI: 10.1242/dev.103564] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hedgehog (Hh) proteins are secreted molecules essential for tissue development in vertebrates and invertebrates. Hh reception via the 12-pass transmembrane protein Patched (Ptc) elicits intracellular signaling through Smoothened (Smo). Hh binding to Ptc is also proposed to sequester the ligand, limiting its spatial range of activity. In Drosophila, Interference hedgehog (Ihog) and Brother of ihog (Boi) are two conserved and redundant transmembrane proteins that are essential for Hh pathway activation. How Ihog and Boi activate signaling in response to Hh remains unknown; each can bind both Hh and Ptc and so it has been proposed that they are essential for both Hh reception and sequestration. Using genetic epistasis we established here that Ihog and Boi, and their orthologs in mice, act upstream or at the level of Ptc to allow Hh signal transduction. In the Drosophila developing wing model we found that it is through Hh pathway activation that Ihog and Boi maintain the boundary between the anterior and posterior compartments. We dissociated the contributions of Ptc from those of Ihog/Boi and, surprisingly, found that cells expressing Ptc can retain and sequester the Hh ligand without Ihog and Boi, but that Ihog and Boi cannot do so without Ptc. Together, these results reinforce the central role for Ptc in Hh binding in vivo and demonstrate that, although Ihog and Boi are dispensable for Hh sequestration, they are essential for pathway activation because they allow Hh to inhibit Ptc and thereby relieve its repression of Smo.
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Affiliation(s)
- Darius Camp
- McGill Centre for Research in Neuroscience and the McGill University Health Centre Research Institute, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4 Molecular Biology of Neural Development, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7 Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada H3A 1A3
| | - Billy Haitian He
- McGill Centre for Research in Neuroscience and the McGill University Health Centre Research Institute, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4
| | - Sally Li
- McGill Centre for Research in Neuroscience and the McGill University Health Centre Research Institute, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4
| | - Irene W Althaus
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alexander M Holtz
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Frédéric Charron
- Molecular Biology of Neural Development, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7 Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada H3A 1A3 Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4 Program in Neuroengineering, McGill University, Montreal, Quebec, Canada H3A 2K6 Department of Medicine, University of Montreal, Montreal, Quebec, Canada H3T 1J4 Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 0C7 Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1
| | - Donald J van Meyel
- McGill Centre for Research in Neuroscience and the McGill University Health Centre Research Institute, 1650 Cedar Avenue, Montreal, Quebec, Canada H3G 1A4 Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada H3A 1A3 Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4 Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1
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Mao F, Yang X, Fu L, Lv X, Zhang Z, Wu W, Yang S, Zhou Z, Zhang L, Zhao Y. The Kto-Skd complex can regulate ptc expression by interacting with Cubitus interruptus (Ci) in the Hedgehog signaling pathway. J Biol Chem 2014; 289:22333-41. [PMID: 24962581 DOI: 10.1074/jbc.m114.560995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The hedgehog (Hh) signaling pathway plays a very important role in metazoan development by controlling pattern formation. Drosophila imaginal discs are subdivided into anterior and posterior compartments that derive from adjacent cell populations. The anterior/posterior (A/P) boundaries, which are critical to maintaining the position of organizers, are established by a complex mechanism involving Hh signaling. Here, we uncover the regulation of ptc in the Hh signaling pathway by two subunits of mediator complex, Kto and Skd, which can also regulate boundary location. Collectively, we provide further evidence that Kto-Skd affects the A/P-axial development of the whole wing disc. Kto can interact with Cubitus interruptus (Ci), bind to the Ci-binding region on ptc promoter, which are both regulated by Hh signals to down-regulate ptc expression.
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Affiliation(s)
- Feifei Mao
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Xiaofeng Yang
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Lin Fu
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Xiangdong Lv
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Zhao Zhang
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Wenqing Wu
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Siqi Yang
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Zhaocai Zhou
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Lei Zhang
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Yun Zhao
- From the State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
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32
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Marianes A, Spradling AC. Physiological and stem cell compartmentalization within the Drosophila midgut. eLife 2013; 2:e00886. [PMID: 23991285 PMCID: PMC3755342 DOI: 10.7554/elife.00886] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
The Drosophila midgut is maintained throughout its length by superficially similar, multipotent intestinal stem cells that generate new enterocytes and enteroendocrine cells in response to tissue requirements. We found that the midgut shows striking regional differentiation along its anterior-posterior axis. At least ten distinct subregions differ in cell morphology, physiology and the expression of hundreds of genes with likely tissue functions. Stem cells also vary regionally in behavior and gene expression, suggesting that they contribute to midgut sub-specialization. Clonal analyses showed that stem cells generate progeny located outside their own subregion at only one of six borders tested, suggesting that midgut subregions resemble cellular compartments involved in tissue development. Tumors generated by disrupting Notch signaling arose preferentially in three subregions and tumor cells also appeared to respect regional borders. Thus, apparently similar intestinal stem cells differ regionally in cell production, gene expression and in the ability to spawn tumors. DOI:http://dx.doi.org/10.7554/eLife.00886.001.
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Affiliation(s)
- Alexis Marianes
- Department of Embryology , Howard Hughes Medical Institute, Carnegie Institution for Science , Baltimore , United States
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33
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Li Y, Jiang Y, Chen Y, Karandikar U, Hoffman K, Chattopadhyay A, Mardon G, Chen R. optix functions as a link between the retinal determination network and the dpp pathway to control morphogenetic furrow progression in Drosophila. Dev Biol 2013; 381:50-61. [PMID: 23792115 DOI: 10.1016/j.ydbio.2013.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 06/10/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
Abstract
optix, the Drosophila ortholog of the SIX3/6 gene family in vertebrate, encodes a homeodomain protein with a SIX protein-protein interaction domain. In vertebrates, Six3/6 genes are required for normal eye as well as brain development. However, the normal function of optix in Drosophila remains unknown due to lack of loss-of-function mutation. Previous studies suggest that optix is likely to play an important role as part of the retinal determination (RD) network. To elucidate normal optix function during retinal development, multiple null alleles for optix have been generated. Loss-of-function mutations in optix result in lethality at the pupae stage. Surprisingly, close examination of its function during eye development reveals that, unlike other members of the RD network, optix is required only for morphogenetic furrow (MF) progression, but not initiation. The mechanisms by which optix regulates MF progression is likely through regulation of signaling molecules in the furrow. Specifically, although unaffected during MF initiation, expression of dpp in the MF is dramatically reduced in optix mutant clones. In parallel, we find that optix is regulated by sine oculis and eyes absent, key members of the RD network. Furthermore, positive feedback between optix and sine oculis and eyes absent is observed, which is likely mediated through dpp signaling pathway. Together with the observation that optix expression does not depend on hh or dpp, we propose that optix functions together with hh to regulate dpp in the MF, serving as a link between the RD network and the patterning pathways controlling normal retinal development.
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Affiliation(s)
- Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77303, USA
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34
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Epithelial neoplasia in Drosophila entails switch to primitive cell states. Proc Natl Acad Sci U S A 2013; 110:E2163-72. [PMID: 23708122 DOI: 10.1073/pnas.1212513110] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Only select cell types in an organ display neoplasia when targeted oncogenically. How developmental lineage hierarchies of these cells prefigure their neoplastic propensities is not yet well-understood. Here we show that neoplastic Drosophila epithelial cells reverse their developmental commitments and switch to primitive cell states. In a context of alleviated tissue surveillance, for example, loss of Lethal giant larvae (Lgl) tumor suppressor in the wing primordium induced epithelial neoplasia in its Homothorax (Hth)-expressing proximal domain. Transcriptional profile of proximally transformed mosaic wing epithelium and functional tests revealed tumor cooperation by multiple signaling pathways. In contrast, lgl(-) clones in the Vestigial (Vg)-expressing distal wing epithelium were eliminated by cell death. Distal lgl(-) clones, however, could transform when both tissue surveillance and cell death were compromised genetically and, alternatively, when the transcription cofactor of Hippo signaling pathway, Yorkie (Yki), was activated, or when Ras/EGFR signaling was up-regulated. Furthermore, transforming distal lgl(-) clones displayed loss of Vg, suggesting reversal of their terminal cell fate commitment. In contrast, reinforcing a distal (wing) cell fate commitment in lgl(-) clones by gaining Vg arrested their neoplasia and induced cell death. We also show that neoplasia in both distal and proximal lgl(-) clones could progress in the absence of Hth, revealing Hth-independent wing epithelial neoplasia. Likewise, neoplasia in the eye primordium resulted in loss of Elav, a retinal cell marker; these, however, switched to an Hth-dependent primitive cell state. These results suggest a general characteristic of "cells-of-origin" in epithelial cancers, namely their propensity for switch to primitive cell states.
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35
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Curt JR, de Navas LF, Sánchez-Herrero E. Differential activity of Drosophila Hox genes induces myosin expression and can maintain compartment boundaries. PLoS One 2013; 8:e57159. [PMID: 23451173 PMCID: PMC3581558 DOI: 10.1371/journal.pone.0057159] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/17/2013] [Indexed: 01/20/2023] Open
Abstract
Compartments are units of cell lineage that subdivide territories with different developmental potential. In Drosophila, the wing and haltere discs are subdivided into anterior and posterior (A/P) compartments, which require the activity of Hedgehog, and into dorsal and ventral (D/V) compartments, needing Notch signaling. There is enrichment in actomyosin proteins at the compartment boundaries, suggesting a role for these proteins in their maintenance. Compartments also develop in the mouse hindbrain rhombomeres, which are characterized by the expression of different Hox genes, a group of genes specifying different structures along their main axis of bilaterians. We show here that the Drosophila Hox gene Ultrabithorax can maintain the A/P and D/V compartment boundaries when Hedgehog or Notch signaling is compromised, and that the interaction of cells with and without Ultrabithorax expression induces high levels of non-muscle myosin II. In the absence of Ultrabithorax there is occasional mixing of cells from different segments. We also show a similar role in cell segregation for the Abdominal-B Hox gene. Our results suggest that the juxtaposition of cells with different Hox gene expression leads to their sorting out, probably through the accumulation of non-muscle myosin II at the boundary of the different cell territories. The increase in myosin expression seems to be a general mechanism used by Hox genes or signaling pathways to maintain the segregation of different groups of cells.
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Affiliation(s)
- Jesús R Curt
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
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36
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Foty RA, Steinberg MS. Differential adhesion in model systems. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2013; 2:631-45. [DOI: 10.1002/wdev.104] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Seong KH, Ishii S. Su(fu) switches Rdx functions to fine-tune hedgehog signaling in the Drosophila wing disk. Genes Cells 2012; 18:66-78. [PMID: 23216924 DOI: 10.1111/gtc.12018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 10/16/2012] [Indexed: 11/30/2022]
Abstract
Hedgehog (Hh) signaling plays a central role in pattern formation by regulating transcription factor Cubitus interruptus (Ci). Previously, Roadkill (Rdx, also called HIB) was shown to inhibit Ci activity by two distinct mechanisms, depending on the Hh signal strength (Seong et al. 2010, PLoS One 5, e15365). In the anterior region abutting the anterior/posterior (A/P) boundary of the wing disk, where cells receive a strong Hh signal, Rdx blocks the nuclear entry of Ci-155. In contrast, in the region farther from the A/P boundary, where cells receive moderate levels of Hh, Rdx induces Ci-155 degradation in the nucleus. Here, we report that Suppressor of fused, Su(fu), causes the Rdx switch between mechanisms. A strong Hh signal induces rdx expression and suppresses su(fu) expression, whereas moderate levels of Hh induce moderate levels of rdx expression and high levels of su(fu) expression. Rdx blocks entry of Ci-155 into the nucleus in the absence of Su(fu) and Rdx induces the degradation of Ci-155 in the nucleus in the presence of a threshold level of Su(fu). Thus, the Su(fu)-induced switch between the dual actions of Rdx in response to the Hh signal strength plays a role in fine-tuning Hh signaling.
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Affiliation(s)
- Ki-Hyeon Seong
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074, Japan
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38
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Levayer R. [Regulation of intercellular adhesion during epithelial morphogenesis]. Biol Aujourdhui 2012; 206:219-36. [PMID: 23171844 DOI: 10.1051/jbio/2012021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Indexed: 11/14/2022]
Abstract
The epithelium is one of the most abundant tissues in metazoans. It is required to generate stable chemical and mechanical barriers between physiological compartments (fluid matrix/external environment). This function is based on multiple intercellular junctions, which insulate and stabilize cell-cell contacts in the tissue. Despite this apparent robustness, epithelia can be extensively remodeled during wound healing, embryogenesis and tumor progression. The capacity to be remodeled while keeping tissue cohesion requires a perfect balance between stability and plasticity of intercellular junctions. The balance is partially regulated by intercellular adhesion, which is mostly based on adherens junctions and the transmembrane protein E-cadherin. The aim of this review is to report the molecular basis of the balance between plasticity and robustness in the epithelium. We will first present the minimal physical framework used to describe epithelial cell shape. We will then describe the main processes involved in intercellular adhesion regulation and their functions during epithelial morphogenesis. Eventually, we will analyze the relationship and the coupling between adhesive forces and cortical tension.
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Affiliation(s)
- Romain Levayer
- Institut de Biologie du Developpement de Marseille Luminy, Marseille, France.
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Nienhaus U, Aegerter-Wilmsen T, Aegerter CM. In-vivo imaging of the Drosophila wing imaginal disc over time: novel insights on growth and boundary formation. PLoS One 2012; 7:e47594. [PMID: 23091633 PMCID: PMC3473014 DOI: 10.1371/journal.pone.0047594] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/12/2012] [Indexed: 01/12/2023] Open
Abstract
In developmental biology, the sequence of gene induction and pattern formation is best studied over time as an organism develops. However, in the model system of Drosophila larvae this oftentimes proves difficult due to limitations in imaging capabilities. Using the larval wing imaginal disc, we show that both overall growth, as well as the creation of patterns such as the distinction between the anterior(A) and posterior(P) compartments and the dorsal(D) and ventral(V) compartments can be studied directly by imaging the wing disc as it develops inside a larva. Imaged larvae develop normally, as can be seen by the overall growth curve of the wing disc. Yet, the fact that we can follow the development of individual discs through time provides the opportunity to simultaneously assess individual variability. We for instance find that growth rates can vary greatly over time. In addition, we observe that mechanical forces act on the wing disc within the larva at times when there is an increase in growth rates. Moreover, we observe that A/P boundary formation follows the established sequence and a smooth boundary is present from the first larval instar on. The division of the wing disc into a dorsal and a ventral compartment, on the other hand, develops quite differently. Contrary to expectation, the specification of the dorsal compartment starts with only one or two cells in the second larval instar and a smooth boundary is not formed until the third larval instar.
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40
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Deckelbaum RA, Holmes G, Zhao Z, Tong C, Basilico C, Loomis CA. Regulation of cranial morphogenesis and cell fate at the neural crest-mesoderm boundary by engrailed 1. Development 2012; 139:1346-58. [PMID: 22395741 DOI: 10.1242/dev.076729] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The characterization of mesenchymal progenitors is central to understanding development, postnatal pathology and evolutionary adaptability. The precise identity of the mesenchymal precursors that generate the coronal suture, an important structural boundary in mammalian skull development, remains unclear. We show in mouse that coronal suture progenitors originate from hedgehog-responsive cephalic paraxial mesoderm (Mes) cells, which migrate rapidly to a supraorbital domain and establish a unidirectional lineage boundary with neural crest (NeuC) mesenchyme. Lineage tracing reveals clonal and stereotypical expansion of supraorbital mesenchymal cells to form the coronal suture between E11.0 and E13.5. We identify engrailed 1 (En1) as a necessary regulator of cell movement and NeuC/Mes lineage boundary positioning during coronal suture formation. In addition, we provide genetic evidence that En1 functions upstream of fibroblast growth factor receptor 2 (Fgfr2) in regulating early calvarial osteogenic differentiation, and postulate that it plays an additional role in precluding premature osteogenic conversion of the sutural mesenchyme.
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Affiliation(s)
- Ron A Deckelbaum
- Department of Pathology, New York University School of Medicine, 550 1st Avenue, New York, NY 10016, USA.
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41
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Aliee M, Röper JC, Landsberg KP, Pentzold C, Widmann TJ, Jülicher F, Dahmann C. Physical mechanisms shaping the Drosophila dorsoventral compartment boundary. Curr Biol 2012; 22:967-76. [PMID: 22560616 DOI: 10.1016/j.cub.2012.03.070] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 02/28/2012] [Accepted: 03/27/2012] [Indexed: 11/27/2022]
Abstract
BACKGROUND Separating cells with distinct identities and fates by straight and sharp compartment boundaries is important for growth and pattern formation during animal development. The physical mechanisms shaping compartment boundaries, however, are not fully understood. RESULTS We combine theory and quantitative experiments to investigate the roles of different mechanisms to shape compartment boundaries. Our theoretical work shows that cell elongation created by anisotropic stress, cell proliferation rate, orientation of cell division, and cell bond tension all have distinct effects on the morphology of compartment boundaries during tissue growth. Our experiments using the developing Drosophila wing reveal that the roughness of the dorsoventral compartment boundary is dynamic and that it decreases during development. By measuring tissue relaxation in response to laser ablation of cell bonds at different developmental times, we demonstrate that decreased boundary roughness correlates with increased cell bond tension along the compartment boundary. Finally, by using experimentally determined values for cell bond tension, cell elongation and bias in orientation of cell division in simulations of tissue growth, we can reproduce the main features of the time evolution of the dorsoventral compartment boundary shape. CONCLUSIONS Local increase of cell bond tension along the boundary as well as global anisotropies in the tissue contribute to shaping boundaries in cell networks. We propose a simple scenario that combines time-dependent cell bond tension at the boundary, oriented cell division, and cell elongation in the tissue that can account for the main features of the dynamics of the shape of the dorsoventral compartment boundary.
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Affiliation(s)
- Maryam Aliee
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
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42
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Cytoneme-mediated delivery of hedgehog regulates the expression of bone morphogenetic proteins to maintain germline stem cells in Drosophila. PLoS Biol 2012; 10:e1001298. [PMID: 22509132 PMCID: PMC3317903 DOI: 10.1371/journal.pbio.1001298] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 02/17/2012] [Indexed: 11/19/2022] Open
Abstract
Stem cells reside in specialised microenvironments, or niches, which often contain support cells that control stem cell maintenance and proliferation. Hedgehog (Hh) proteins mediate homeostasis in several adult niches, but a detailed understanding of Hh signalling in stem cell regulation is lacking. Studying the Drosophila female germline stem cell (GSC) niche, we show that Hh acts as a critical juxtacrine signal to maintain the normal GSC population of the ovary. Hh production in cap cells, a type of niche support cells, is regulated by the Engrailed transcription factor. Hh is then secreted to a second, adjacent population of niche cells, the escort cells, where it activates transcription of the GSC essential factors Decapentaplegic (Dpp) and Glass bottom boat (Gbb). In wild-type niches, Hh protein decorates short filopodia that originate in the support cap cells and that are functionally relevant, as they are required to transduce the Hh pathway in the escort cells and to maintain a normal population of GSCs. These filopodia, reminiscent of wing disc cytonemes, grow several fold in length if Hh signalling is impaired within the niche. Because these long cytonemes project directionally towards the signalling-deficient region, cap cells sense and react to the strength of Hh pathway transduction in the niche. Thus, the GSC niche responds to insufficient Hh signalling by increasing the range of Hh spreading. Although the signal(s) perceived by the cap cells and the receptor(s) involved are still unknown, our results emphasise the integration of signals necessary to maintain a functional niche and the plasticity of cellular niches to respond to challenging physiological conditions.
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43
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Sarpal R, Pellikka M, Patel RR, Hui FYW, Godt D, Tepass U. Mutational analysis supports a core role for Drosophila α-catenin in adherens junction function. J Cell Sci 2012; 125:233-45. [PMID: 22266901 DOI: 10.1242/jcs.096644] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
α-catenin associates the cadherin-catenin complex with the actin cytoskeleton. α-catenin binds to β-catenin, which links it to the cadherin cytoplasmic tail, and F-actin, but also to a multitude of actin-associated proteins. These interactions suggest a highly complex cadherin-actin interface. Moreover, mammalian αE-catenin has been implicated in a cadherin-independent cytoplasmic function in Arp2/3-dependent actin regulation, and in cell signaling. The function and regulation of individual molecular interactions of α-catenin, in particular during development, are not well understood. We have generated mutations in Drosophila α-Catenin (α-Cat) to investigate α-Catenin function in this model, and to establish a setup for testing α-Catenin-related constructs in α-Cat-null mutant cells in vivo. Our analysis of α-Cat mutants in embryogenesis, imaginal discs and oogenesis reveals defects consistent with a loss of cadherin function. Compromising components of the Arp2/3 complex or its regulator SCAR ameliorate the α-Cat loss-of-function phenotype in embryos but not in ovaries, suggesting negative regulatory interactions between α-Catenin and the Arp2/3 complex in some tissues. We also show that the α-Cat mutant phenotype can be rescued by the expression of a DE-cadherin::α-Catenin fusion protein, which argues against an essential cytosolic, cadherin-independent role of Drosophila α-Catenin.
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Affiliation(s)
- Ritu Sarpal
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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44
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Bhaskar PK, Mukherjee A, Mutsuddi M. Dynamic pattern of expression of dlin52, a member of the Myb/MuvB complex, during Drosophila development. Gene Expr Patterns 2012; 12:77-84. [PMID: 22178095 DOI: 10.1016/j.gep.2011.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 11/21/2011] [Accepted: 11/26/2011] [Indexed: 01/24/2023]
Abstract
The DREAM (DP, RB, E2F and MuvB) complex is required in humans to arrest the expression of cell cycle genes during quiescence. One of its members LIN52 has been isolated from the repressor complex but little is known about its molecular function. It has been reported recently that the serine residue 28 of LIN52 is phosphorylated by DYRK1A, and point mutation of this residue or down regulation of DYRK1A (which phosphorylates LIN52) leads to disruption of DREAM complex assembly, which is needed for G(0) arrest. Function of all the members of the dMyb complex (homologue of DREAM complex) in Drosophila melanogaster is not well characterized. We have studied the Drosophila orthologue of LIN52, known as dlin52, which is strongly conserved across various taxa from worms to human. dlin52 is reported to be present in a large protein complex containing important transcriptional regulators of cell proliferation and cell death like dE2F1, dMyb and dRbf. We have examined the expression of dlin52 transcripts and protein during development. Strong nuclear expression of dlin52 is seen in larval eye-antennal discs, brain, fat body, wing discs and salivary glands. dlin52 is abundantly expressed in endoreplicated tissues like salivary glands, fat body, and certain regions of the gut, and the nurse cells from adult ovaries. dlin52 is also expressed in the larval optic lobe, as well as in the developing neurons of ventral ganglion, indicating that this gene has an important role to play in cell cycle regulation and neuronal development. Robust expression of dlin52 protein was observed in quiescent cells like that of the imaginal cells of larval salivary gland, while marginal expression was seen in the germarium of adult ovary. Study of the spatial and temporal pattern of expression of this gene will help in better understanding of the function of this protein during various developmental processes.
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Affiliation(s)
- Pradeep Kumar Bhaskar
- Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221005, India
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45
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Lecuit T, Lenne PF, Munro E. Force generation, transmission, and integration during cell and tissue morphogenesis. Annu Rev Cell Dev Biol 2011; 27:157-84. [PMID: 21740231 DOI: 10.1146/annurev-cellbio-100109-104027] [Citation(s) in RCA: 386] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cell shape changes underlie a large set of biological processes ranging from cell division to cell motility. Stereotyped patterns of cell shape changes also determine tissue remodeling events such as extension or invagination. In vitro and cell culture systems have been essential to understanding the fundamental physical principles of subcellular mechanics. These are now complemented by studies in developing organisms that emphasize how cell and tissue morphogenesis emerge from the interplay between force-generating machines, such as actomyosin networks, and adhesive clusters that transmit tensile forces at the cell cortex and stabilize cell-cell and cell-substrate interfaces. Both force production and transmission are self-organizing phenomena whose adaptive features are essential during tissue morphogenesis. A new era is opening that emphasizes the similarities of and allows comparisons between distant dynamic biological phenomena because they rely on core machineries that control universal features of cytomechanics.
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Affiliation(s)
- Thomas Lecuit
- Developmental Biology Institute of Marseilles-Luminy, Centre National de la Recherche Scientifique, Université de la Méditerranée, 13288 Marseille Cedex 9, France.
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Monier B, Pélissier-Monier A, Sanson B. Establishment and maintenance of compartmental boundaries: role of contractile actomyosin barriers. Cell Mol Life Sci 2011; 68:1897-910. [PMID: 21437644 PMCID: PMC11114499 DOI: 10.1007/s00018-011-0668-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 02/12/2011] [Accepted: 03/08/2011] [Indexed: 12/29/2022]
Abstract
During animal development, tissues and organs are partitioned into compartments that do not intermix. This organizing principle is essential for correct tissue morphogenesis. Given that cell sorting defects during compartmentalization in humans are thought to cause malignant invasion and congenital defects such as cranio-fronto-nasal syndrome, identifying the molecular and cellular mechanisms that keep cells apart at boundaries between compartments is important. In both vertebrates and invertebrates, transcription factors and short-range signalling pathways, such as EPH/Ephrin, Hedgehog, or Notch signalling, govern compartmental cell sorting. However, the mechanisms that mediate cell sorting downstream of these factors have remained elusive for decades. Here, we review recent data gathered in Drosophila that suggest that the generation of cortical tensile forces at compartmental boundaries by the actomyosin cytoskeleton could be a general mechanism that inhibits cell mixing between compartments.
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Affiliation(s)
- Bruno Monier
- Department of Physiology, Development and Neuroscience, Anatomy Building, Downing Street, Cambridge, CB2 3DY UK
- Present Address: Institut de Biologie du Développement de Marseille-Luminy, UMR6216, Campus de Luminy, Case 907, 13288 Marseille cedex 9, France
| | - Anne Pélissier-Monier
- Department of Physiology, Development and Neuroscience, Anatomy Building, Downing Street, Cambridge, CB2 3DY UK
- Wellcome Trust, Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Present Address: Institut de Biologie du Développement de Marseille-Luminy, UMR6216, Campus de Luminy, Case 907, 13288 Marseille cedex 9, France
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, Anatomy Building, Downing Street, Cambridge, CB2 3DY UK
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Schilling S, Willecke M, Aegerter-Wilmsen T, Cirpka OA, Basler K, von Mering C. Cell-sorting at the A/P boundary in the Drosophila wing primordium: a computational model to consolidate observed non-local effects of Hh signaling. PLoS Comput Biol 2011; 7:e1002025. [PMID: 21490725 PMCID: PMC3072364 DOI: 10.1371/journal.pcbi.1002025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 02/16/2011] [Indexed: 12/31/2022] Open
Abstract
Non-intermingling, adjacent populations of cells define compartment boundaries;
such boundaries are often essential for the positioning and the maintenance of
tissue-organizers during growth. In the developing wing primordium of
Drosophila melanogaster, signaling by the secreted protein
Hedgehog (Hh) is required for compartment boundary maintenance. However, the
precise mechanism of Hh input remains poorly understood. Here, we combine
experimental observations of perturbed Hh signaling with computer simulations of
cellular behavior, and connect physical properties of cells to their Hh
signaling status. We find that experimental disruption of Hh signaling has
observable effects on cell sorting surprisingly far from the compartment
boundary, which is in contrast to a previous model that confines Hh influence to
the compartment boundary itself. We have recapitulated our experimental
observations by simulations of Hh diffusion and transduction coupled to
mechanical tension along cell-to-cell contact surfaces. Intriguingly, the best
results were obtained under the assumption that Hh signaling cannot alter the
overall tension force of the cell, but will merely re-distribute it locally
inside the cell, relative to the signaling status of neighboring cells. Our
results suggest a scenario in which homotypic interactions of a putative Hh
target molecule at the cell surface are converted into a mechanical force. Such
a scenario could explain why the mechanical output of Hh signaling appears to be
confined to the compartment boundary, despite the longer range of the Hh
molecule itself. Our study is the first to couple a cellular vertex model
describing mechanical properties of cells in a growing tissue, to an explicit
model of an entire signaling pathway, including a freely diffusible component.
We discuss potential applications and challenges of such an approach. In developing animal tissues, cells can often re-arrange locally and mix
relatively freely. However, in some stereotypic and crucially important
instances during body development, cells will strictly not intermingle, and
instead form sharp boundaries along which they will sort out from each other.
This mechanism helps organisms to establish signaling centers and to maintain
distinct cellular identities. Often, cells at such boundaries will remain in
close physical contact and are morphologically alike. Thus, the boundary itself
can be difficult to observe unless the expression status of specific marker
genes is monitored experimentally. How are these ‘compartment
boundaries’ established? Here we devise a computational model that aims to
describe one such boundary in a well-studied animal tissue: the developing wing
primordium of Drosophila melanogaster. We model the production,
diffusion and local sensing of an essential signaling molecule, the
Hedgehog protein. We reveal one possible mechanism by which
Hedgehog sensing can influence the mechanical properties of cells, and compare
the simulated outcome to observations in experimentally perturbed, actual wing
discs. Our relatively simple model suffices to establish a straight and stable
compartment boundary.
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Affiliation(s)
- Sabine Schilling
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
- Swiss Institute of Bioinformatics, University of Zurich, Zurich,
Switzerland
| | - Maria Willecke
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
| | | | - Olaf A. Cirpka
- Center for Applied Geoscience, University of Tuebingen, Tuebingen,
Germany
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
| | - Christian von Mering
- Institute of Molecular Life Sciences, University of Zurich, Zurich,
Switzerland
- Swiss Institute of Bioinformatics, University of Zurich, Zurich,
Switzerland
- * E-mail:
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Abstract
During the development of multicellular organisms, cell fate specification is followed by the sorting of different cell types into distinct domains from where the different tissues and organs are formed. Cell sorting involves both the segregation of a mixed population of cells with different fates and properties into distinct domains, and the active maintenance of their segregated state. Because of its biological importance and apparent resemblance to fluid segregation in physics, cell sorting was extensively studied by both biologists and physicists over the last decades. Different theories were developed that try to explain cell sorting on the basis of the physical properties of the constituent cells. However, only recently the molecular and cellular mechanisms that control the physical properties driving cell sorting, have begun to be unraveled. In this review, we will provide an overview of different cell-sorting processes in development and discuss how these processes can be explained by the different sorting theories, and how these theories in turn can be connected to the molecular and cellular mechanisms driving these processes.
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Affiliation(s)
- S F Gabby Krens
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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Hartman TR, Zinshteyn D, Schofield HK, Nicolas E, Okada A, O'Reilly AM. Drosophila Boi limits Hedgehog levels to suppress follicle stem cell proliferation. ACTA ACUST UNITED AC 2010; 191:943-52. [PMID: 21098113 PMCID: PMC2995164 DOI: 10.1083/jcb.201007142] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Boi receptor regulates stem cell function by sequestering the diffusible hedgehog ligand. Stem cells depend on signals from cells within their microenvironment, or niche, as well as factors secreted by distant cells to regulate their maintenance and function. Here we show that Boi, a Hedgehog (Hh)-binding protein, is a novel suppressor of proliferation of follicle stem cells (FSCs) in the Drosophila ovary. Hh is expressed in apical cells, distant from the FSC niche, and diffuses to reach FSCs, where it promotes FSC proliferation. We show that Boi is expressed in apical cells and exerts its suppressive effect on FSC proliferation by binding to and sequestering Hh on the apical cell surface, thereby inhibiting Hh diffusion. Our studies demonstrate that cells distant from the local niche can regulate stem cell function through ligand sequestration, a mechanism that likely is conserved in other epithelial tissues.
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