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Bosso G, Cipressa F, Tullo L, Cenci G. Co-amplification of CBX3 with EGFR or RAC1 in human cancers corroborated by a conserved genetic interaction among the genes. Cell Death Discov 2023; 9:317. [PMID: 37633946 PMCID: PMC10460438 DOI: 10.1038/s41420-023-01598-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/29/2023] [Accepted: 08/09/2023] [Indexed: 08/28/2023] Open
Abstract
Chromobox Protein 3 (CBX3) overexpression is a common event occurring in cancer, promotes cancer cell proliferation and represents a poor prognosis marker in a plethora of human cancers. Here we describe that a wide spectrum of human cancers harbors a co-amplification of CBX3 gene with either EGFR or RAC1, which yields a statistically significant increase of both mRNA and protein levels of CBX3, EGFR and RAC1. We also reveal that the simultaneous overexpression of CBX3, RAC1 and EGFR gene products correlates with a worse prognosis compared to the condition when CBX3, RAC1 and EGFR are singularly upregulated. Furthermore, we also show that a co-occurrence of low-grade amplification, in addition to high-grade amplification, between CBX3 and EGFR or RAC1 is associated with a reduced patient lifespan. Finally, we find that CBX3 and RAC1/EGFR genetically interact in the model organism Drosophila melanogaster, suggesting that the simultaneous overexpression as well as well the co-occurrence of high- or low-grade copy number alterations in these genes is not accidental and could reflect evolutionarily conserved functional relationships.
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Affiliation(s)
- Giuseppe Bosso
- Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy.
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, E-28029, Spain.
| | - Francesca Cipressa
- Department of Ecological and Biological Sciences, Università degli Studi della Tuscia, Viterbo, Italy
| | - Liliana Tullo
- Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy
| | - Giovanni Cenci
- Department of Biology and Biotechnology "C. Darwin", Sapienza Università di Roma, Rome, Italy.
- Fondazione Cenci Bolognetti, Istituto Pasteur Italia, Rome, Italy.
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2
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Guo H, Liu XZ, Long GJ, Gong LL, Zhang MQ, Ma YF, Hull JJ, Dewer Y, He M, He P. Functional characterization of developmentally critical genes in the white-backed planthopper: Efficacy of nanoparticle-based dsRNA sprays for pest control. PEST MANAGEMENT SCIENCE 2023; 79:1048-1061. [PMID: 36325939 DOI: 10.1002/ps.7271] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/30/2022] [Accepted: 11/03/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Epidermal growth factor receptor (EGFR), zinc finger homeodomain-2 (zfh-2), Abdominal-A (Abd-A), and Abdominal-B (Abd-B) regulate the growth and development of the insect abdomen. However, their potential roles in pest control have not been fully assessed. The development of insecticide resistance to multiple chemistries in the white-backed planthopper (WBPH), a major pest of rice, has prompted interest in novel pest control approaches that are ecologically friendly. Although pest management approaches based on double-stranded RNA (dsRNA)-mediated RNA interference (RNAi) have potential, their susceptibility to degradation limits large-scale field applications. These limitations, however, can be overcome with nanoparticle-dsRNA complexes that have greater environmental stability and improved cellular uptake. RESULTS In this study, at 5 days post-injection, transcripts for the four gene targets were reduced relative to controls and all of the experimental groups exhibited significant phenotypic defects and increased mortality. To evaluate the potential of these gene targets for field applications, a nanocarrier-dsRNA spray delivery system was assessed for RNAi efficacy. At 11 days post-spray, significant phenotypic defects and increased mortality were observed in all experimental groups. CONCLUSION Taken together, the results confirm the suitability of the target genes (SfEGFR, Sfzfh-2, SfAbd-A, and SfAbd-B) for pest management and demonstrate the efficacy of the nanocarrier spray system for inducing RNAi-mediated knockdown. As such, the study lays the foundation for the further development and optimization of this technology for large-scale field applications. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Huan Guo
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Xuan-Zheng Liu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Gui-Jun Long
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Lang-Lang Gong
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Meng-Qi Zhang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Yun-Feng Ma
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - J Joe Hull
- Pest Management and Biocontrol Research Unit, US Arid Land Agricultural Research Center, USDA Agricultural Research Services, Maricopa, AZ, USA
| | - Youssef Dewer
- Phytotoxicity Research Department, Central Agricultural Pesticide Laboratory, Agricultural Research Center, Giza, Egypt
| | - Ming He
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
| | - Peng He
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China
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3
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Lee SW, Morishita Y. Two types of critical cell density for mechanical elimination of abnormal cell clusters from epithelial tissue. PLoS Comput Biol 2022; 18:e1010178. [PMID: 35696420 PMCID: PMC9232172 DOI: 10.1371/journal.pcbi.1010178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 06/24/2022] [Accepted: 05/07/2022] [Indexed: 11/18/2022] Open
Abstract
Recent technological advances in high-resolution imaging and artificial modulation of genetic functions at different times and regions have enabled direct observations of the formation and elimination of abnormal cell populations. A recent trend in cell competition research is the incorporation of cell mechanics. In different tissues and species, abnormal cells developing in epithelial tissues are mechanically eliminated by cell contraction via actomyosin accumulation at the interface between normal and abnormal cells. This mechanical cell elimination process has attracted attention as a potential universal defense mechanism. Here, we theoretically examined the conditions for mechanical elimination of growing abnormal cell populations. Simulations and mathematical analyses using a vertex dynamics model revealed two types of critical cell density associated with mechanical elimination of abnormal cell clusters. One is a subtype of homeostatic density, in which the frequencies of spontaneous mechanical cell elimination and proliferation are balanced, even if no explicit dependence of proliferation or apoptosis on the cell density is assumed. This density is related to the mechanical stability of a single cell. The other is density related to mechanical stability as a cell population under external pressure. Both density types are determined by tissue mechanical properties. In solid tissues, the former type is reached first as the intensity of interfacial contraction increases, and it functions as a critical density. On the other hand, the latter type becomes critical when tissues are highly fluid. The derived analytical solution explicitly reveals the dependence of critical contractile force and density on different parameters. We also found a negative correlation between the proliferation rate of abnormal cells and the likelihood of the abnormal cell population expanding by escaping elimination. This is counterintuitive because in the context of cell competition, fast-growing cell populations generally win. These findings provide new insight into, and interpretation of, the results from experimental studies. High-resolution imaging techniques have revealed that abnormal cells developing in epithelial tissues are mechanically eliminated via contraction at the interface between the abnormal cells and normal surrounding cells. This phenomenon is seen in various species and tissues and thus is regarded as a primitive defense system against precancerous cells common to all animals. For comprehensive understanding of this potential defense system, we derived mathematical conditions to achieve mechanical elimination of growing abnormal cell populations. We identified two characteristic cell density types associated with successful mechanical elimination of abnormal cell clusters. Both are determined by tissue physical properties, and the smaller of the two functions as a critical density above which abnormal cell populations cannot exist. We also found a counterintuitive phenomenon in which slower proliferation of abnormal cells promotes their growth as a population. Our results will help elucidate the mechanisms of intrinsic tissue defenses against cancer from the perspective of cell mechanics.
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Affiliation(s)
- Sang-Woo Lee
- Laboratory for Developmental Morphogeometry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Yoshihiro Morishita
- Laboratory for Developmental Morphogeometry, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
- * E-mail:
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4
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Costa-Rodrigues C, Couceiro J, Moreno E. Cell competition from development to neurodegeneration. Dis Model Mech 2021; 14:269331. [PMID: 34190316 PMCID: PMC8277968 DOI: 10.1242/dmm.048926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell competition is a process by which suboptimal cells are eliminated to the benefit of cells with higher fitness. It is a surveillance mechanism that senses differences in the fitness status by several modes, such as expression of fitness fingerprints, survival factor uptake rate and resistance to mechanical stress. Fitness fingerprints-mediated cell competition recognizes isoforms of the transmembrane protein Flower, and translates the relative fitness of cells into distinct fates through the Flower code. Impairments in cell competition potentiate the development of diseases like cancer and ageing-related pathologies. In cancer, malignant cells acquire a supercompetitor behaviour, killing the neighbouring cells and overtaking the tissue, thus avoiding elimination. Neurodegenerative disorders affect millions of people and are characterized by cognitive decline and locomotor deficits. Alzheimer's disease is the most common form of dementia, and one of the largely studied diseases. However, the cellular processes taking place remain unclear. Drosophila melanogaster is an emerging neurodegeneration model due to its versatility as a tool for genetic studies. Research in a Drosophila Alzheimer's disease model detected fitness markers in the suboptimal and hyperactive neurons, thus establishing a link between cell competition and Alzheimer's disease. In this Review, we overview cell competition and the new insights related to neurodegenerative disorders, and discuss how research in the field might contribute to the development of new therapeutic targets for these diseases.
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Affiliation(s)
| | - Joana Couceiro
- Champalimaud Centre for the Unknown, 1400-038 Lisbon, Portugal
| | - Eduardo Moreno
- Champalimaud Centre for the Unknown, 1400-038 Lisbon, Portugal
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5
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Kishi Y, Parker J. Cell type innovation at the tips of the animal tree. Curr Opin Genet Dev 2021; 69:112-121. [PMID: 33784538 DOI: 10.1016/j.gde.2021.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 01/20/2021] [Accepted: 01/24/2021] [Indexed: 11/16/2022]
Abstract
Understanding how organs originate is challenging due to the twin problems of explaining how new cell types evolve and how collective interactions between cell types arise and become selectively advantageous. Animals are assemblages of organs and cell types of different antiquities, and among the most rapidly and convergently evolving are exocrine glands and their constituent secretory cell types. Such structures have arisen independently thousands of times across the Metazoa, impacting how animals chemically interact with their environments. The recurrent evolution of exocrine systems provides a paradigm for examining how qualitative phenotypic novelties arise from variation at the cellular level. Here, we take a hierarchical perspective, focusing on the evolutionary assembly of novel biosynthetic pathways and secretory cell types, and how both selection and non-adaptive molecular processes may combine to build the complex, modular architectures of many animal glands.
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Affiliation(s)
- Yuriko Kishi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, 91125, United States
| | - Joseph Parker
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, 91125, United States.
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6
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Saiz N, Hadjantonakis AK. Coordination between patterning and morphogenesis ensures robustness during mouse development. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190562. [PMID: 32829684 PMCID: PMC7482220 DOI: 10.1098/rstb.2019.0562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2020] [Indexed: 12/11/2022] Open
Abstract
The mammalian preimplantation embryo is a highly tractable, self-organizing developmental system in which three cell types are consistently specified without the need for maternal factors or external signals. Studies in the mouse over the past decades have greatly improved our understanding of the cues that trigger symmetry breaking in the embryo, the transcription factors that control lineage specification and commitment, and the mechanical forces that drive morphogenesis and inform cell fate decisions. These studies have also uncovered how these multiple inputs are integrated to allocate the right number of cells to each lineage despite inherent biological noise, and as a response to perturbations. In this review, we summarize our current understanding of how these processes are coordinated to ensure a robust and precise developmental outcome during early mouse development. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.
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Affiliation(s)
- Néstor Saiz
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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7
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Kuzmicz-Kowalska K, Kicheva A. Regulation of size and scale in vertebrate spinal cord development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e383. [PMID: 32391980 PMCID: PMC8244110 DOI: 10.1002/wdev.383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/25/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022]
Abstract
All vertebrates have a spinal cord with dimensions and shape specific to their species. Yet how species‐specific organ size and shape are achieved is a fundamental unresolved question in biology. The formation and sculpting of organs begins during embryonic development. As it develops, the spinal cord extends in anterior–posterior direction in synchrony with the overall growth of the body. The dorsoventral (DV) and apicobasal lengths of the spinal cord neuroepithelium also change, while at the same time a characteristic pattern of neural progenitor subtypes along the DV axis is established and elaborated. At the basis of these changes in tissue size and shape are biophysical determinants, such as the change in cell number, cell size and shape, and anisotropic tissue growth. These processes are controlled by global tissue‐scale regulators, such as morphogen signaling gradients as well as mechanical forces. Current challenges in the field are to uncover how these tissue‐scale regulatory mechanisms are translated to the cellular and molecular level, and how regulation of distinct cellular processes gives rise to an overall defined size. Addressing these questions will help not only to achieve a better understanding of how size is controlled, but also of how tissue size is coordinated with the specification of pattern. This article is categorized under:Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Signaling Pathways > Global Signaling Mechanisms Nervous System Development > Vertebrates: General Principles
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8
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Bowling S, Lawlor K, Rodríguez TA. Cell competition: the winners and losers of fitness selection. Development 2019; 146:146/13/dev167486. [PMID: 31278123 DOI: 10.1242/dev.167486] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The process of cell competition results in the 'elimination of cells that are viable but less fit than surrounding cells'. Given the highly heterogeneous nature of our tissues, it seems increasingly likely that cells are engaged in a 'survival of the fittest' battle throughout life. The process has a myriad of positive roles in the organism: it selects against mutant cells in developing tissues, prevents the propagation of oncogenic cells and eliminates damaged cells during ageing. However, 'super-fit' cancer cells can exploit cell competition mechanisms to expand and spread. Here, we review the regulation, roles and risks of cell competition in organism development, ageing and disease.
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Affiliation(s)
- Sarah Bowling
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Katerina Lawlor
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
| | - Tristan A Rodríguez
- National Heart and Lung Institute, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK
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9
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Valon L, Levayer R. Dying under pressure: cellular characterisation and in vivo functions of cell death induced by compaction. Biol Cell 2019; 111:51-66. [PMID: 30609052 DOI: 10.1111/boc.201800075] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/05/2018] [Indexed: 12/16/2022]
Abstract
Cells and tissues are exposed to multiple mechanical stresses during development, tissue homoeostasis and diseases. While we start to have an extensive understanding of the influence of mechanics on cell differentiation and proliferation, how excessive mechanical stresses can also lead to cell death and may be associated with pathologies has been much less explored so far. Recently, the development of new perturbative approaches allowing modulation of pressure and deformation of tissues has demonstrated that compaction (the reduction of tissue size or volume) can lead to cell elimination. Here, we discuss the relevant type of stress and the parameters that could be causal to cell death from single cell to multicellular systems. We then compare the pathways and mechanisms that have been proposed to influence cell survival upon compaction. We eventually describe the relevance of compaction-induced death in vivo, and its functions in morphogenesis, tissue size regulation, tissue homoeostasis and cancer progression.
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Affiliation(s)
- Léo Valon
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Paris, 75015, France
| | - Romain Levayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, Paris, 75015, France
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10
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Moreno E, Valon L, Levillayer F, Levayer R. Competition for Space Induces Cell Elimination through Compaction-Driven ERK Downregulation. Curr Biol 2018; 29:23-34.e8. [PMID: 30554899 PMCID: PMC6331351 DOI: 10.1016/j.cub.2018.11.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/01/2018] [Accepted: 11/01/2018] [Indexed: 12/18/2022]
Abstract
The plasticity of developing tissues relies on the adjustment of cell survival and growth rate to environmental cues. This includes the effect of mechanical cues on cell survival. Accordingly, compaction of an epithelium can lead to cell extrusion and cell death. This process was proposed to contribute to tissue homeostasis but also to facilitate the expansion of pretumoral cells through the compaction and elimination of the neighboring healthy cells. However, we know very little about the pathways that can trigger apoptosis upon tissue deformation, and the contribution of compaction-driven death to clone expansion has never been assessed in vivo. Using the Drosophila pupal notum and a new live sensor of ERK, we show first that tissue compaction induces cell elimination through the downregulation of epidermal growth factor receptor/extracellular signal regulated kinase (EGFR/ERK) pathway and the upregulation of the pro-apoptotic protein Hid. Those results suggest that the sensitivity of EGFR/ERK pathway to mechanics could play a more general role in the fine tuning of cell elimination during morphogenesis and tissue homeostasis. Second, we assessed in vivo the contribution of compaction-driven death to pretumoral cell expansion. We found that the activation of the oncogene Ras in clones can downregulate ERK and activate apoptosis in the neighboring cells through their compaction, which eventually contributes to Ras clone expansion. The mechanical modulation of EGFR/ERK during growth-mediated competition for space may contribute to tumor progression. Caspase activity in Drosophila pupal notum is regulated by EGFR/ERK and hid EGFR/ERK can be activated or downregulated by tissue stretching or compaction Cell compaction near fast-growing clones downregulates ERK and triggers cell death Compaction-driven ERK downregulation promotes fast-growing clone expansion
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Affiliation(s)
- Eduardo Moreno
- Champalimaud Centre for the Unknown, Av. Brasília, 1400-038 Lisbon, Portugal.
| | - Léo Valon
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 25 rue du Dr. Roux, 75015 Paris, France
| | - Florence Levillayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 25 rue du Dr. Roux, 75015 Paris, France
| | - Romain Levayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, 25 rue du Dr. Roux, 75015 Paris, France.
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11
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Crossman SH, Streichan SJ, Vincent JP. EGFR signaling coordinates patterning with cell survival during Drosophila epidermal development. PLoS Biol 2018; 16:e3000027. [PMID: 30379844 PMCID: PMC6231689 DOI: 10.1371/journal.pbio.3000027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/12/2018] [Accepted: 10/12/2018] [Indexed: 11/19/2022] Open
Abstract
Extensive apoptosis is often seen in patterning mutants, suggesting that tissues can detect and eliminate potentially harmful mis-specified cells. Here, we show that the pattern of apoptosis in the embryonic epidermis of Drosophila is not a response to fate mis-specification but can instead be explained by the limiting availability of prosurvival signaling molecules released from locations determined by patterning information. In wild-type embryos, the segmentation cascade elicits the segmental production of several epidermal growth factor receptor (EGFR) ligands, including the transforming growth factor Spitz (TGFα), and the neuregulin, Vein. This leads to an undulating pattern of signaling activity, which prevents expression of the proapoptotic gene head involution defective (hid) throughout the epidermis. In segmentation mutants, where specific peaks of EGFR ligands fail to form, gaps in signaling activity appear, leading to coincident hid up-regulation and subsequent cell death. These data provide a mechanistic understanding of how cell survival, and thus appropriate tissue size, is made contingent on correct patterning.
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Affiliation(s)
| | - Sebastian J. Streichan
- Department of Physics, University of California, Santa Barbara, California, United States of America
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12
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Sriskanthadevan-Pirahas S, Deshpande R, Lee B, Grewal SS. Ras/ERK-signalling promotes tRNA synthesis and growth via the RNA polymerase III repressor Maf1 in Drosophila. PLoS Genet 2018; 14:e1007202. [PMID: 29401457 PMCID: PMC5814106 DOI: 10.1371/journal.pgen.1007202] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 02/15/2018] [Accepted: 01/16/2018] [Indexed: 12/28/2022] Open
Abstract
The small G-protein Ras is a conserved regulator of cell and tissue growth. These effects of Ras are mediated largely through activation of a canonical RAF-MEK-ERK kinase cascade. An important challenge is to identify how this Ras/ERK pathway alters cellular metabolism to drive growth. Here we report on stimulation of RNA polymerase III (Pol III)-mediated tRNA synthesis as a growth effector of Ras/ERK signalling in Drosophila. We find that activation of Ras/ERK signalling promotes tRNA synthesis both in vivo and in cultured Drosophila S2 cells. We also show that Pol III function is required for Ras/ERK signalling to drive proliferation in both epithelial and stem cells in Drosophila tissues. We find that the transcription factor Myc is required but not sufficient for Ras-mediated stimulation of tRNA synthesis. Instead we show that Ras signalling promotes Pol III function and tRNA synthesis by phosphorylating, and inhibiting the nuclear localization and function of the Pol III repressor Maf1. We propose that inhibition of Maf1 and stimulation of tRNA synthesis is one way by which Ras signalling enhances protein synthesis to promote cell and tissue growth.
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Affiliation(s)
- Shrivani Sriskanthadevan-Pirahas
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, Alberta, Canada
| | - Rujuta Deshpande
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, Alberta, Canada
| | - Byoungchun Lee
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, Alberta, Canada
| | - Savraj S. Grewal
- Clark H Smith Brain Tumour Centre, Arnie Charbonneau Cancer Institute, Alberta Children’s Hospital Research Institute, and Department of Biochemistry and Molecular Biology Calgary, University of Calgary, Calgary, Alberta, Canada
- * E-mail:
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13
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Lee SW, Morishita Y. Possible roles of mechanical cell elimination intrinsic to growing tissues from the perspective of tissue growth efficiency and homeostasis. PLoS Comput Biol 2017; 13:e1005651. [PMID: 28704373 PMCID: PMC5547694 DOI: 10.1371/journal.pcbi.1005651] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 07/27/2017] [Accepted: 06/27/2017] [Indexed: 11/19/2022] Open
Abstract
Cell competition is a phenomenon originally described as the competition between cell populations with different genetic backgrounds; losing cells with lower fitness are eliminated. With the progress in identification of related molecules, some reports described the relevance of cell mechanics during elimination. Furthermore, recent live imaging studies have shown that even in tissues composed of genetically identical cells, a non-negligible number of cells are eliminated during growth. Thus, mechanical cell elimination (MCE) as a consequence of mechanical cellular interactions is an unavoidable event in growing tissues and a commonly observed phenomenon. Here, we studied MCE in a genetically-homogeneous tissue from the perspective of tissue growth efficiency and homeostasis. First, we propose two quantitative measures, cell and tissue fitness, to evaluate cellular competitiveness and tissue growth efficiency, respectively. By mechanical tissue simulation in a pure population where all cells have the same mechanical traits, we clarified the dependence of cell elimination rate or cell fitness on different mechanical/growth parameters. In particular, we found that geometrical (specifically, cell size) and mechanical (stress magnitude) heterogeneities are common determinants of the elimination rate. Based on these results, we propose possible mechanical feedback mechanisms that could improve tissue growth efficiency and density/stress homeostasis. Moreover, when cells with different mechanical traits are mixed (e.g., in the presence of phenotypic variation), we show that MCE could drive a drastic shift in cell trait distribution, thereby improving tissue growth efficiency through the selection of cellular traits, i.e. intra-tissue "evolution". Along with the improvement of growth efficiency, cell density, stress state, and phenotype (mechanical traits) were also shown to be homogenized through growth. More theoretically, we propose a mathematical model that approximates cell competition dynamics, by which the time evolution of tissue fitness and cellular trait distribution can be predicted without directly simulating a cell-based mechanical model.
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Affiliation(s)
- Sang-Woo Lee
- Laboratory for Developmental Morphogeometry, RIKEN Quantitative Biology Center, Kobe, Japan
| | - Yoshihiro Morishita
- Laboratory for Developmental Morphogeometry, RIKEN Quantitative Biology Center, Kobe, Japan
- * E-mail:
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14
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Spencer AK, Schaumberg AJ, Zallen JA. Scaling of cytoskeletal organization with cell size in Drosophila. Mol Biol Cell 2017; 28:1519-1529. [PMID: 28404752 PMCID: PMC5449150 DOI: 10.1091/mbc.e16-10-0691] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 03/31/2017] [Accepted: 04/05/2017] [Indexed: 11/11/2022] Open
Abstract
Actin-rich denticle precursors are regularly distributed in the Drosophila embryo. Cytoskeletal scaling occurs through changes in denticle number and spacing. Denticle spacing scales with cell length over a 10-fold range. Accurate denticle positioning requires the microtubule cytoskeleton. Spatially organized macromolecular complexes are essential for cell and tissue function, but the mechanisms that organize micron-scale structures within cells are not well understood. Microtubule-based structures such as mitotic spindles scale with cell size, but less is known about the scaling of actin structures within cells. Actin-rich denticle precursors cover the ventral surface of the Drosophila embryo and larva and provide templates for cuticular structures involved in larval locomotion. Using quantitative imaging and statistical modeling, we demonstrate that denticle number and spacing scale with cell length over a wide range of cell sizes in embryos and larvae. Denticle number and spacing are reduced under space-limited conditions, and both features robustly scale over a 10-fold increase in cell length during larval growth. We show that the relationship between cell length and denticle spacing can be recapitulated by specific mathematical equations in embryos and larvae and that accurate denticle spacing requires an intact microtubule network and the microtubule minus end–binding protein, Patronin. These results identify a novel mechanism of microtubule-dependent actin scaling that maintains precise patterns of actin organization during tissue growth.
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Affiliation(s)
- Alison K Spencer
- Gerstner Sloan Kettering Graduate School of Biomedical Sciences.,Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Andrew J Schaumberg
- Weill Cornell Graduate School of Medical Sciences and the Tri-Institutional PhD Program in Computational Biology and Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Jennifer A Zallen
- Howard Hughes Medical Institute and Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065
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15
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Kursawe J, Bardenet R, Zartman JJ, Baker RE, Fletcher AG. Robust cell tracking in epithelial tissues through identification of maximum common subgraphs. J R Soc Interface 2016; 13:20160725. [PMID: 28334699 PMCID: PMC5134023 DOI: 10.1098/rsif.2016.0725] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/17/2016] [Indexed: 11/30/2022] Open
Abstract
Tracking of cells in live-imaging microscopy videos of epithelial sheets is a powerful tool for investigating fundamental processes in embryonic development. Characterizing cell growth, proliferation, intercalation and apoptosis in epithelia helps us to understand how morphogenetic processes such as tissue invagination and extension are locally regulated and controlled. Accurate cell tracking requires correctly resolving cells entering or leaving the field of view between frames, cell neighbour exchanges, cell removals and cell divisions. However, current tracking methods for epithelial sheets are not robust to large morphogenetic deformations and require significant manual interventions. Here, we present a novel algorithm for epithelial cell tracking, exploiting the graph-theoretic concept of a 'maximum common subgraph' to track cells between frames of a video. Our algorithm does not require the adjustment of tissue-specific parameters, and scales in sub-quadratic time with tissue size. It does not rely on precise positional information, permitting large cell movements between frames and enabling tracking in datasets acquired at low temporal resolution due to experimental constraints such as phototoxicity. To demonstrate the method, we perform tracking on the Drosophila embryonic epidermis and compare cell-cell rearrangements to previous studies in other tissues. Our implementation is open source and generally applicable to epithelial tissues.
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Affiliation(s)
- Jochen Kursawe
- Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK
| | - Rémi Bardenet
- CNRS and CRIStAL, Université de Lille, 59651 Villeneuve d'Ascq, France
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 205D McCourtney Hall of Molecular Science and Engineering, Notre Dame, IN 46556, USA
| | - Ruth E Baker
- Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG, UK
| | - Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH, UK
- Bateson Centre, University of Sheffield, Sheffield S10 2TN, UK
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16
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Kursawe J, Brodskiy PA, Zartman JJ, Baker RE, Fletcher AG. Capabilities and Limitations of Tissue Size Control through Passive Mechanical Forces. PLoS Comput Biol 2015; 11:e1004679. [PMID: 26713738 PMCID: PMC4703071 DOI: 10.1371/journal.pcbi.1004679] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/24/2015] [Indexed: 12/29/2022] Open
Abstract
Embryogenesis is an extraordinarily robust process, exhibiting the ability to control tissue size and repair patterning defects in the face of environmental and genetic perturbations. The size and shape of a developing tissue is a function of the number and size of its constituent cells as well as their geometric packing. How these cellular properties are coordinated at the tissue level to ensure developmental robustness remains a mystery; understanding this process requires studying multiple concurrent processes that make up morphogenesis, including the spatial patterning of cell fates and apoptosis, as well as cell intercalations. In this work, we develop a computational model that aims to understand aspects of the robust pattern repair mechanisms of the Drosophila embryonic epidermal tissues. Size control in this system has previously been shown to rely on the regulation of apoptosis rather than proliferation; however, to date little work has been done to understand the role of cellular mechanics in this process. We employ a vertex model of an embryonic segment to test hypotheses about the emergence of this size control. Comparing the model to previously published data across wild type and genetic perturbations, we show that passive mechanical forces suffice to explain the observed size control in the posterior (P) compartment of a segment. However, observed asymmetries in cell death frequencies across the segment are demonstrated to require patterning of cellular properties in the model. Finally, we show that distinct forms of mechanical regulation in the model may be distinguished by differences in cell shapes in the P compartment, as quantified through experimentally accessible summary statistics, as well as by the tissue recoil after laser ablation experiments.
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Affiliation(s)
- Jochen Kursawe
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - Pavel A. Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
| | - Jeremiah J. Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana, United States of America
- * E-mail: (JJZ); (AGF)
| | - Ruth E. Baker
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - Alexander G. Fletcher
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
- * E-mail: (JJZ); (AGF)
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17
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Scaling the Drosophila Wing: TOR-Dependent Target Gene Access by the Hippo Pathway Transducer Yorkie. PLoS Biol 2015; 13:e1002274. [PMID: 26474042 PMCID: PMC4608745 DOI: 10.1371/journal.pbio.1002274] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/08/2015] [Indexed: 12/19/2022] Open
Abstract
Organ growth is controlled by patterning signals that operate locally (e.g., Wingless/Ints [Wnts], Bone Morphogenetic Proteins [BMPs], and Hedgehogs [Hhs]) and scaled by nutrient-dependent signals that act systemically (e.g., Insulin-like peptides [ILPs] transduced by the Target of Rapamycin [TOR] pathway). How cells integrate these distinct inputs to generate organs of the appropriate size and shape is largely unknown. The transcriptional coactivator Yorkie (Yki, a YES-Associated Protein, or YAP) acts downstream of patterning morphogens and other tissue-intrinsic signals to promote organ growth. Yki activity is regulated primarily by the Warts/Hippo (Wts/Hpo) tumour suppressor pathway, which impedes nuclear access of Yki by a cytoplasmic tethering mechanism. Here, we show that the TOR pathway regulates Yki by a separate and novel mechanism in the Drosophila wing. Instead of controlling Yki nuclear access, TOR signaling governs Yki action after it reaches the nucleus by allowing it to gain access to its target genes. When TOR activity is inhibited, Yki accumulates in the nucleus but is sequestered from its normal growth-promoting target genes—a phenomenon we term “nuclear seclusion.” Hence, we posit that in addition to its well-known role in stimulating cellular metabolism in response to nutrients, TOR also promotes wing growth by liberating Yki from nuclear seclusion, a parallel pathway that we propose contributes to the scaling of wing size with nutrient availability. From dwarves to giants, scaling is a universal property of animal organs, but its mechanistic basis is poorly understood. Here, the authors identify a molecular circuit underlying scaling of the Drosophila wing. What mechanisms control the sizes of animal organs? It is known that organ growth is the product of two systems: an intrinsic system that coordinates cell proliferation with the specification of cell fate (patterning), and an extrinsic system that synchronizes growth with nutrient levels. Developing organs integrate these two inputs to ensure that properly proportioned structures develop which are of the right scale to match overall body size. However, the mechanisms used to integrate these distinct growth control systems have remained largely mysterious. In this study, we have addressed how intrinsic and extrinsic systems combine to drive growth of the Drosophila wing. Focusing on the Target of Rapamycin (TOR) pathway—a major, nutrient-dependent regulator of organ growth—and Yorkie—the transcriptional activator downstream of the Hippo pathway and a key, organ-intrinsic growth regulator—we have identified a circuit in which TOR activity limits Yorkie’s capacity to promote wing growth, in part through a novel mode of transcription factor regulation that we term “nuclear seclusion.” We find that inhibiting TOR leads to the retention of Yorkie in the nucleus but diminishes its transcriptional activity by diverting it away from target genes. We posit that subjugating Yorkie in this way contributes to how fluctuations in TOR activity scale wing size according to nutrient levels.
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18
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Formesyn EM, Cardoen D, Ernst UR, Danneels EL, Van Vaerenbergh M, De Koker D, Verleyen P, Wenseleers T, Schoofs L, de Graaf DC. Reproduction of honeybee workers is regulated by epidermal growth factor receptor signaling. Gen Comp Endocrinol 2014; 197:1-4. [PMID: 24333651 DOI: 10.1016/j.ygcen.2013.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 11/28/2013] [Accepted: 12/03/2013] [Indexed: 11/19/2022]
Abstract
Eusocial insect societies display a remarkable reproductive division of labor between a single fertile queen and thousands of largely sterile workers. In most species, however, the workers retain the capacity to reproduce, particularly in queenless colonies where typically many workers lay eggs. As yet, the molecular determinants that initiate this shift in worker fertility are still poorly documented. By using RNA interference we here demonstrate that the knockdown of epidermal growth factor receptor, a gene which was previously shown to be involved in queen-worker caste differentiation, also induces reproduction in worker honeybees (Apis mellifera). These data show that worker fertility and queen-worker caste determination partly rely on the same gene regulatory networks, thereby providing a major breakthrough in our understanding of the molecular determinants of the social insects' spectacular reproductive division of labor.
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Affiliation(s)
- Ellen M Formesyn
- Laboratory of Zoophysiology, Ghent University, B-9000 Ghent, Belgium
| | - Dries Cardoen
- Laboratory of Socio-ecology and Social Evolution, KU Leuven, B-3000 Leuven, Belgium
| | - Ulrich R Ernst
- Research Group of Functional Genomics and Proteomics, KU Leuven, B-3000 Leuven, Belgium
| | - Ellen L Danneels
- Laboratory of Zoophysiology, Ghent University, B-9000 Ghent, Belgium
| | | | - Dieter De Koker
- Laboratory of Zoophysiology, Ghent University, B-9000 Ghent, Belgium
| | - Peter Verleyen
- Research Group of Functional Genomics and Proteomics, KU Leuven, B-3000 Leuven, Belgium
| | - Tom Wenseleers
- Laboratory of Socio-ecology and Social Evolution, KU Leuven, B-3000 Leuven, Belgium
| | - Liliane Schoofs
- Research Group of Functional Genomics and Proteomics, KU Leuven, B-3000 Leuven, Belgium
| | - Dirk C de Graaf
- Laboratory of Zoophysiology, Ghent University, B-9000 Ghent, Belgium.
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Simakov DSA, Cheung LS, Pismen LM, Shvartsman SY. EGFR-dependent network interactions that pattern Drosophila eggshell appendages. Development 2012; 139:2814-20. [PMID: 22782725 DOI: 10.1242/dev.077669] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Similar to other organisms, Drosophila uses its Epidermal Growth Factor Receptor (EGFR) multiple times throughout development. One crucial EGFR-dependent event is patterning of the follicular epithelium during oogenesis. In addition to providing inductive cues necessary for body axes specification, patterning of the follicle cells initiates the formation of two respiratory eggshell appendages. Each appendage is derived from a primordium comprising a patch of cells expressing broad (br) and an adjacent stripe of cells expressing rhomboid (rho). Several mechanisms of eggshell patterning have been proposed in the past, but none of them can explain the highly coordinated expression of br and rho. To address some of the outstanding issues in this system, we synthesized the existing information into a revised mathematical model of follicle cell patterning. Based on the computational model analysis, we propose that dorsal appendage primordia are established by sequential action of feed-forward loops and juxtacrine signals activated by the gradient of EGFR signaling. The model describes pattern formation in a large number of mutants and points to several unanswered questions related to the dynamic interaction of the EGFR and Notch pathways.
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Affiliation(s)
- David S A Simakov
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Israel
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20
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Dabour N, Bando T, Nakamura T, Miyawaki K, Mito T, Ohuchi H, Noji S. Cricket body size is altered by systemic RNAi against insulin signaling components and epidermal growth factor receptor. Dev Growth Differ 2011; 53:857-69. [PMID: 21777227 DOI: 10.1111/j.1440-169x.2011.01291.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A long-standing problem of developmental biology is how body size is determined. In Drosophila melanogaster, the insulin/insulin-like growth factor (I/IGF) and target of rapamycin (TOR) signaling pathways play important roles in this process. However, the detailed mechanisms by which insect body growth is regulated are not known. Therefore, we have attempted to utilize systemic nymphal RNA interference (nyRNAi) to knockdown expression of insulin signaling components including Insulin receptor (InR), Insulin receptor substrate (chico), Phosphatase and tensin homologue (Pten), Target of rapamycin (Tor), RPS6-p70-protein kinase (S6k), Forkhead box O (FoxO) and Epidermal growth factor receptor (Egfr) and observed the effects on body size in the Gryllus bimaculatus cricket. We found that crickets treated with double-stranded RNA (dsRNA) against Gryllus InR, chico, Tor, S6k and Egfr displayed smaller body sizes, while Gryllus FoxO nyRNAi-ed crickets exhibited larger than normal body sizes. Furthermore, RNAi against Gryllus chico and Tor displayed slow growth and RNAi against Gryllus chico displayed longer lifespan than control crickets. Since no significant difference in ability of food uptake was observed between the Gryllus chico(nyRNAi) nymphs and controls, we conclude that the adult cricket body size can be altered by knockdown of expressions of Gryllus InR, chico, Tor, S6k, FoxO and Egfr by systemic RNAi. Our results suggest that the cricket is a promising model to study mechanisms underlying controls of body size and life span with RNAi methods.
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Affiliation(s)
- Noha Dabour
- Department of Life Systems, Institute of Technology and Science, The University of Tokushima, Tokushima, Japan
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Abstract
Myc genes play a major role in human cancer, and they are important regulators of growth and proliferation during normal development. Despite intense study over the last three decades, many aspects of Myc function remain poorly understood. The identification of a single Myc homolog in the model organism Drosophila melanogaster more than 10 years ago has opened new possibilities for addressing these issues. This review summarizes what the last decade has taught us about Myc biology in the fruit fly.
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Affiliation(s)
- Peter Gallant
- Zoologisches Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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22
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Lin N, Zhang C, Pang J, Zhou L. By design or by chance: cell death during Drosophila embryogenesis. Apoptosis 2009; 14:935-42. [PMID: 19466551 DOI: 10.1007/s10495-009-0360-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cell death plays an essential role during Drosophila embryogenesis. However, it remains an enigma as to what mechanisms determine (or select) the specific cells to be eliminated at a particular developmental stage. Is it mostly dependent on the lineage of the cell, signifying genetic predetermination, or is it due to the failure of a cell to compete for growth factors, which is more or less by chance? Recent developments in studying the molecular mechanism of cell death during Drosophila embryogenesis has provided much insight into our understanding of the relative importance of, and the interaction between, these two mechanisms in shaping the embryo.
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Affiliation(s)
- Nianwei Lin
- Department of Molecular Genetics and Microbiology, UF Shands Cancer Center, University of Florida, Gainesville, FL 32610-0232, USA
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Aritakula A, Ramasamy A. Drosophila-based in vivo assay for the validation of inhibitors of the epidermal growth factor receptor/Ras pathway. J Biosci 2009; 33:731-42. [PMID: 19179761 DOI: 10.1007/s12038-008-0093-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Overexpression of epidermal growth factor receptor (EGFR) is a common phenomenon observed in most cancers. Clinical treatment of such cancer involves the use of chemotherapeutic agents such as ge ? tinib and erlotinib which are inhibitors of tyrosine kinase (TK). These small molecules bind to the ATP-binding sites of the TK domain of EGFR.Our in silico analysis suggests that the TK domains of Drosophila and human EGFR are highly conserved. We therefore employed the Drosophila system to validate the in silico observations made with two important anticancer drugs.Since a large number of mutant flies are available,it was possible to investigate the various components of the EGFR/Ras/Raf/MAPK pathways and the phosphorylation status of diphosphorylated extracellular signal-regulated kinase (dp-ERK1/2). These studies confirm the binding of the anilinoquinazolines to the Drosophila EGFR protein and modulation of its activity. Thus,Drosophila appears to be a robust and simple model system for screening newer anticancer drugs that act as TK inhibitors (TKIs).
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Affiliation(s)
- Anuradha Aritakula
- Division of Biological Sciences,Vittal Mallya Scientific Research Foundation, K R Road,P O Box 406, Bangalore 560 004, India.
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