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Gao H, Yuan X, Wang J, Yan Y, Zhang X, He T, Lin X, Zhang H, Liu Z. Knockdown of Fzr inhibited the growth of Nilaparvata lugens by blocking endocycle. PEST MANAGEMENT SCIENCE 2024. [PMID: 39229824 DOI: 10.1002/ps.8403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 07/29/2024] [Accepted: 08/23/2024] [Indexed: 09/05/2024]
Abstract
BACKGROUND The endocycle can generate cells referred to as 'polyploid'. Fizzy-related protein (Fzr) plays an important role in driving the mitosis-to-endocycle transition. The brown planthopper (BPH), Nilaparvata lugens (Stål), a serious insect pest, feeds exclusively on rice. However, polyploidy and its regulatory mechanisms are poorly understood in BPH. RESULTS Here, we found that the ploidy levels of follicles H (FH) and accessory gland (AG) significantly increased with BPH age when examining the polyploidy of FH and AG of salivary glands. Fzr was identified as an important regulator for polyploidy in BPH salivary gland. Knockdown of Fzr resulted in a decrease in cell size and DNA content in nymph salivary glands. Fzr knockdown transcriptionally upregulated cyclin-dependent kinase 1 (CDK1), CDK2, cyclin A (CycA) and CycB, and downregulated CycD, CycE, Myc and mini-chromosome maintenance protein 2-7 (MCM2-7). Phenotypically, Fzr knockdown significantly suppressed salivary protein production, feeding and survival in BPH nymphs. CONCLUSION Our results show that BPH salivary glands exhibit obvious polyploidy, and Fzr positively regulates the endocycle in nymph salivary gland. These findings provide clues for the study of the regulatory mechanisms of insect polyploidy. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Haoli Gao
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Xiaowei Yuan
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Jingting Wang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Yangyang Yan
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Xinyu Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Tianshun He
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
- The Sanya Institute of the Nanjing Agricultural University, Sanya, China
| | - Xumin Lin
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Huihui Zhang
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zewen Liu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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2
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Huang YT, Hesting LL, Calvi BR. An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc. PLoS Genet 2024; 20:e1011387. [PMID: 39226333 PMCID: PMC11398662 DOI: 10.1371/journal.pgen.1011387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 09/13/2024] [Accepted: 08/06/2024] [Indexed: 09/05/2024] Open
Abstract
A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.
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Affiliation(s)
- Yi-Ting Huang
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, Indiana, United States of America
| | - Lauren L Hesting
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, Indiana, United States of America
| | - Brian R Calvi
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, Indiana, United States of America
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3
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Ramkumar N, Richardson C, O'Brien M, Butt FA, Park J, Chao AT, Bagnat M, Poss K, Di Talia S. Phased ERK-responsiveness and developmental robustness regulate teleost skin morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.13.593750. [PMID: 38798380 PMCID: PMC11118522 DOI: 10.1101/2024.05.13.593750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Elongation of the vertebrate embryonic axis necessitates rapid expansion of the epidermis to accommodate the growth of underlying tissues. Here, we generated a toolkit to visualize and quantify signaling in entire cell populations of periderm, the outermost layer of the epidermis, in live developing zebrafish. We find that oriented cell divisions facilitate growth of the early periderm during axial elongation rather than cell addition from the basal layer. Activity levels of ERK, a downstream effector of MAPK pathway, gauged by a live biosensor, predicts cell cycle entry, and optogenetic ERK activation controls proliferation dynamics. As development proceeds, rates of peridermal cell proliferation decrease, ERK activity becomes more pulsatile and functionally transitions to promote hypertrophic cell growth. Targeted genetic blockade of cell division generates animals with oversized periderm cells, yet, unexpectedly, development to adulthood is not impaired. Our findings reveal stage-dependent differential responsiveness to ERK signaling and marked developmental robustness in growing teleost skin.
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4
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Herriage HC, Huang YT, Calvi BR. The antagonistic relationship between apoptosis and polyploidy in development and cancer. Semin Cell Dev Biol 2024; 156:35-43. [PMID: 37331841 PMCID: PMC10724375 DOI: 10.1016/j.semcdb.2023.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/23/2023] [Accepted: 05/30/2023] [Indexed: 06/20/2023]
Abstract
One of the important functions of regulated cell death is to prevent cells from inappropriately acquiring extra copies of their genome, a state known as polyploidy. Apoptosis is the primary cell death mechanism that prevents polyploidy, and defects in this apoptotic response can result in polyploid cells whose subsequent error-prone chromosome segregation are a major contributor to genome instability and cancer progression. Conversely, some cells actively repress apoptosis to become polyploid as part of normal development or regeneration. Thus, although apoptosis prevents polyploidy, the polyploid state can actively repress apoptosis. In this review, we discuss progress in understanding the antagonistic relationship between apoptosis and polyploidy in development and cancer. Despite recent advances, a key conclusion is that much remains unknown about the mechanisms that link apoptosis to polyploid cell cycles. We suggest that drawing parallels between the regulation of apoptosis in development and cancer could help to fill this knowledge gap and lead to more effective therapies.
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Affiliation(s)
- Hunter C Herriage
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Yi-Ting Huang
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Brian R Calvi
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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5
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Huang YT, Hesting LL, Calvi BR. An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.585098. [PMID: 38559130 PMCID: PMC10980049 DOI: 10.1101/2024.03.14.585098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogasterwing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer.
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Affiliation(s)
- Yi-Ting Huang
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, IN 47405
| | - Lauren L. Hesting
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, IN 47405
| | - Brian R. Calvi
- Department of Biology, Simon Cancer Center, Indiana University, Bloomington, IN 47405
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6
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Ptp61F integrates Hippo, TOR, and actomyosin pathways to control three-dimensional organ size. Cell Rep 2022; 41:111640. [DOI: 10.1016/j.celrep.2022.111640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 09/16/2022] [Accepted: 10/20/2022] [Indexed: 11/17/2022] Open
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7
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Abstract
The Drosophila wing imaginal disc is a tissue of undifferentiated cells that are precursors of the wing and most of the notum of the adult fly. The wing disc first forms during embryogenesis from a cluster of ∼30 cells located in the second thoracic segment, which invaginate to form a sac-like structure. They undergo extensive proliferation during larval stages to form a mature larval wing disc of ∼35,000 cells. During this time, distinct cell fates are assigned to different regions, and the wing disc develops a complex morphology. Finally, during pupal stages the wing disc undergoes morphogenetic processes and then differentiates to form the adult wing and notum. While the bulk of the wing disc comprises epithelial cells, it also includes neurons and glia, and is associated with tracheal cells and muscle precursor cells. The relative simplicity and accessibility of the wing disc, combined with the wealth of genetic tools available in Drosophila, have combined to make it a premier system for identifying genes and deciphering systems that play crucial roles in animal development. Studies in wing imaginal discs have made key contributions to many areas of biology, including tissue patterning, signal transduction, growth control, regeneration, planar cell polarity, morphogenesis, and tissue mechanics.
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Affiliation(s)
- Bipin Kumar Tripathi
- Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
| | - Kenneth D Irvine
- Department of Molecular Biology and Biochemistry, Waksman Institute, Rutgers University, Piscataway, NJ 08854, USA
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8
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Sablowski R, Gutierrez C. Cycling in a crowd: Coordination of plant cell division, growth, and cell fate. THE PLANT CELL 2022; 34:193-208. [PMID: 34498091 PMCID: PMC8774096 DOI: 10.1093/plcell/koab222] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/31/2021] [Indexed: 05/25/2023]
Abstract
The reiterative organogenesis that drives plant growth relies on the constant production of new cells, which remain encased by interconnected cell walls. For these reasons, plant morphogenesis strictly depends on the rate and orientation of both cell division and cell growth. Important progress has been made in recent years in understanding how cell cycle progression and the orientation of cell divisions are coordinated with cell and organ growth and with the acquisition of specialized cell fates. We review basic concepts and players in plant cell cycle and division, and then focus on their links to growth-related cues, such as metabolic state, cell size, cell geometry, and cell mechanics, and on how cell cycle progression and cell division are linked to specific cell fates. The retinoblastoma pathway has emerged as a major player in the coordination of the cell cycle with both growth and cell identity, while microtubule dynamics are central in the coordination of oriented cell divisions. Future challenges include clarifying feedbacks between growth and cell cycle progression, revealing the molecular basis of cell division orientation in response to mechanical and chemical signals, and probing the links between cell fate changes and chromatin dynamics during the cell cycle.
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Affiliation(s)
| | - Crisanto Gutierrez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Nicolas Cabrera 1, Cantoblanco, 28049 Madrid, Spain
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9
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Strassburger K, Lutz M, Müller S, Teleman AA. Ecdysone regulates Drosophila wing disc size via a TORC1 dependent mechanism. Nat Commun 2021; 12:6684. [PMID: 34795214 PMCID: PMC8602387 DOI: 10.1038/s41467-021-26780-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/15/2021] [Indexed: 11/09/2022] Open
Abstract
Most cells in a developing organ stop proliferating when the organ reaches a correct, final size. The underlying molecular mechanisms are not understood. We find that in Drosophila the hormone ecdysone controls wing disc size. To study how ecdysone affects wing size, we inhibit endogenous ecdysone synthesis and feed larvae exogenous ecdysone in a dose-controlled manner. For any given ecdysone dose, discs stop proliferating at a particular size, with higher doses enabling discs to reach larger sizes. Termination of proliferation coincides with a drop in TORC1, but not Dpp or Yki signaling. Reactivating TORC1 bypasses the termination of proliferation, indicating that TORC1 is a main downstream effector causing proliferation termination at the maximal ecdysone-dependent size. Experimental manipulation of Dpp or Yki signaling can bypass proliferation termination in hinge and notum regions, but not the pouch, suggesting that the mechanisms regulating proliferation termination may be distinct in different disc regions.
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Affiliation(s)
- Katrin Strassburger
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany ,grid.4488.00000 0001 2111 7257Present Address: Technische Universität Dresden, 01217 Dresden, Germany
| | - Marilena Lutz
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Sandra Müller
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
| | - Aurelio A. Teleman
- grid.7497.d0000 0004 0492 0584German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373Heidelberg University, 69120 Heidelberg, Germany ,grid.7700.00000 0001 2190 4373CellNetworks - Cluster of Excellence, Heidelberg University, Heidelberg, Germany
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10
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Cancer cells employ an evolutionarily conserved polyploidization program to resist therapy. Semin Cancer Biol 2020; 81:145-159. [PMID: 33276091 DOI: 10.1016/j.semcancer.2020.11.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 12/24/2022]
Abstract
Unusually large cancer cells with abnormal nuclei have been documented in the cancer literature since 1858. For more than 100 years, they have been generally disregarded as irreversibly senescent or dying cells, too morphologically misshapen and chromatin too disorganized to be functional. Cell enlargement, accompanied by whole genome doubling or more, is observed across organisms, often associated with mitigation strategies against environmental change, severe stress, or the lack of nutrients. Our comparison of the mechanisms for polyploidization in other organisms and non-transformed tissues suggest that cancer cells draw from a conserved program for their survival, utilizing whole genome doubling and pausing proliferation to survive stress. These polyaneuploid cancer cells (PACCs) are the source of therapeutic resistance, responsible for cancer recurrence and, ultimately, cancer lethality.
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11
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Gou J, Stotsky JA, Othmer HG. Growth control in the Drosophila wing disk. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2020; 12:e1478. [PMID: 31917525 DOI: 10.1002/wsbm.1478] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/02/2019] [Accepted: 12/17/2019] [Indexed: 12/16/2022]
Abstract
The regulation of size and shape is a fundamental requirement of biological development and has been a subject of scientific study for centuries, but we still lack an understanding of how organisms know when to stop growing. Imaginal wing disks of the fruit fly Drosophila melanogaster, which are precursors of the adult wings, are an archetypal tissue for studying growth control. The growth of the disks is dependent on many inter- and intra-organ factors such as morphogens, mechanical forces, nutrient levels, and hormones that influence gene expression and cell growth. Extracellular signals are transduced into gene-control signals via complex signal transduction networks, and since cells typically receive many different signals, a mechanism for integrating the signals is needed. Our understanding of the effect of morphogens on tissue-level growth regulation via individual pathways has increased significantly in the last half century, but our understanding of how multiple biochemical and mechanical signals are integrated to determine whether or not a cell decides to divide is still rudimentary. Numerous fundamental questions are involved in understanding the decision-making process, and here we review the major biochemical and mechanical pathways involved in disk development with a view toward providing a basis for beginning to understand how multiple signals can be integrated at the cell level, and how this translates into growth control at the level of the imaginal disk. This article is categorized under: Analytical and Computational Methods > Computational Methods Biological Mechanisms > Cell Signaling Models of Systems Properties and Processes > Cellular Models.
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Affiliation(s)
- Jia Gou
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
| | - Jay A Stotsky
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
| | - Hans G Othmer
- School of Mathematics, University of Minnesota, Minneapolis, Minnesota
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12
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Grendler J, Lowgren S, Mills M, Losick VP. Wound-induced polyploidization is driven by Myc and supports tissue repair in the presence of DNA damage. Development 2019; 146:dev173005. [PMID: 31315896 PMCID: PMC6703715 DOI: 10.1242/dev.173005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 07/05/2019] [Indexed: 12/19/2022]
Abstract
Tissue repair usually requires either polyploid cell growth or cell division, but the molecular mechanism promoting polyploidy and limiting cell division remains poorly understood. Here, we find that injury to the adult Drosophila epithelium causes cells to enter the endocycle through the activation of Yorkie-dependent genes (Myc and E2f1). Myc is even sufficient to induce the endocycle in the uninjured post-mitotic epithelium. As result, epithelial cells enter S phase but mitosis is blocked by inhibition of mitotic gene expression. The mitotic cell cycle program can be activated by simultaneously expressing the Cdc25-like phosphatase String (stg), while genetically depleting APC/C E3 ligase fizzy-related (fzr). However, forcing cells to undergo mitosis is detrimental to wound repair as the adult fly epithelium accumulates DNA damage, and mitotic errors ensue when cells are forced to proliferate. In conclusion, we find that wound-induced polyploidization enables tissue repair when cell division is not a viable option.
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Affiliation(s)
- Janelle Grendler
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Sara Lowgren
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Monique Mills
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
| | - Vicki P Losick
- Kathryn W. Davis Center for Regenerative Biology and Medicine, MDI Biological Laboratory, 159 Old Bar Harbor Rd, Bar Harbor, ME 04609, USA
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13
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Sun T, Song Y, Dai J, Mao D, Ma M, Ni JQ, Liang X, Pastor-Pareja JC. Spectraplakin Shot Maintains Perinuclear Microtubule Organization in Drosophila Polyploid Cells. Dev Cell 2019; 49:731-747.e7. [DOI: 10.1016/j.devcel.2019.03.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 02/05/2019] [Accepted: 03/26/2019] [Indexed: 02/06/2023]
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14
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Abstract
Polyploid cells, which contain multiple copies of the typically diploid genome, are widespread in plants and animals. Polyploidization can be developmentally programmed or stress induced, and arises from either cell-cell fusion or a process known as endoreplication, in which cells replicate their DNA but either fail to complete cytokinesis or to progress through M phase entirely. Polyploidization offers cells several potential fitness benefits, including the ability to increase cell size and biomass production without disrupting cell and tissue structure, and allowing improved cell longevity through higher tolerance to genomic stress and apoptotic signals. Accordingly, recent studies have uncovered crucial roles for polyploidization in compensatory cell growth during tissue regeneration in the heart, liver, epidermis and intestine. Here, we review current knowledge of the molecular pathways that generate polyploidy and discuss how polyploidization is used in tissue repair and regeneration.
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Affiliation(s)
| | - Bruce A Edgar
- Huntsman Cancer Institute, Salt Lake City, UT 84112, USA
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15
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Vollmer J, Casares F, Iber D. Growth and size control during development. Open Biol 2018; 7:rsob.170190. [PMID: 29142108 PMCID: PMC5717347 DOI: 10.1098/rsob.170190] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/17/2017] [Indexed: 11/30/2022] Open
Abstract
The size and shape of organs are characteristic for each species. Even when organisms develop to different sizes due to varying environmental conditions, such as nutrition, organ size follows species-specific rules of proportionality to the rest of the body, a phenomenon referred to as allometry. Therefore, for a given environment, organs stop growth at a predictable size set by the species's genotype. How do organs stop growth? How can related species give rise to organs of strikingly different size? No definitive answer has been given to date. One of the major models for the studies of growth termination is the vinegar fly Drosophila melanogaster. Therefore, this review will focus mostly on work carried out in Drosophila to try to tease apart potential mechanisms and identify routes for further investigation. One general rule, found across the animal kingdom, is that the rate of growth declines with developmental time. Therefore, answers to the problem of growth termination should explain this seemingly universal fact. In addition, growth termination is intimately related to the problems of robustness (i.e. precision) and plasticity in organ size, symmetric and asymmetric organ development, and of how the ‘target’ size depends on extrinsic, environmental factors.
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Affiliation(s)
- Jannik Vollmer
- D-BSSE, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland.,Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
| | - Fernando Casares
- CABD, CSIC-Universidad Pablo de Olavide-JA, 41013 Seville, Spain
| | - Dagmar Iber
- D-BSSE, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland .,Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058 Basel, Switzerland
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16
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Rink JC. Stem Cells, Patterning and Regeneration in Planarians: Self-Organization at the Organismal Scale. Methods Mol Biol 2018; 1774:57-172. [PMID: 29916155 DOI: 10.1007/978-1-4939-7802-1_2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The establishment of size and shape remains a fundamental challenge in biological research that planarian flatworms uniquely epitomize. Planarians can regenerate complete and perfectly proportioned animals from tiny and arbitrarily shaped tissue pieces; they continuously renew all organismal cell types from abundant pluripotent stem cells, yet maintain shape and anatomy in the face of constant turnover; they grow when feeding and literally degrow when starving, while scaling form and function over as much as a 40-fold range in body length or an 800-fold change in total cell numbers. This review provides a broad overview of the current understanding of the planarian stem cell system, the mechanisms that pattern the planarian body plan and how the interplay between patterning signals and cell fate choices orchestrates regeneration. What emerges is a conceptual framework for the maintenance and regeneration of the planarian body plan on basis of the interplay between pluripotent stem cells and self-organizing patterns and further, the general utility of planarians as model system for the mechanistic basis of size and shape.
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Affiliation(s)
- Jochen C Rink
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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17
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Miko M, Kyselovic J, Danisovic L, Barczi T, Polak S, Varga I. Two nuclei inside a single cardiac muscle cell. More questions than answers about the binucleation of cardiomyocytes. Biologia (Bratisl) 2017. [DOI: 10.1515/biolog-2017-0107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Kumar JP. The fly eye: Through the looking glass. Dev Dyn 2017; 247:111-123. [PMID: 28856763 DOI: 10.1002/dvdy.24585] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/14/2017] [Accepted: 08/14/2017] [Indexed: 12/20/2022] Open
Abstract
The developing eye-antennal disc of Drosophila melanogaster has been studied for more than a century, and it has been used as a model system to study diverse processes, such as tissue specification, organ growth, programmed cell death, compartment boundaries, pattern formation, cell fate specification, and planar cell polarity. The findings that have come out of these studies have informed our understanding of basic developmental processes as well as human disease. For example, the isolation of a white-eyed fly ultimately led to a greater appreciation of the role that sex chromosomes play in development, sex determination, and sex linked genetic disorders. Similarly, the discovery of the Sevenless receptor tyrosine kinase pathway not only revealed how the fate of the R7 photoreceptor is selected but it also helped our understanding of how disruptions in similar biochemical pathways result in tumorigenesis and cancer onset. In this article, I will discuss some underappreciated areas of fly eye development that are fertile for investigation and are ripe for producing exciting new breakthroughs. The topics covered here include organ shape, growth control, inductive signaling, and right-left symmetry. Developmental Dynamics 247:111-123, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Justin P Kumar
- Department of Biology, Indiana University, Bloomington, Indiana
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19
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Ma M, Cao X, Dai J, Pastor-Pareja JC. Basement Membrane Manipulation in Drosophila Wing Discs Affects Dpp Retention but Not Growth Mechanoregulation. Dev Cell 2017; 42:97-106.e4. [PMID: 28697337 DOI: 10.1016/j.devcel.2017.06.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 05/04/2017] [Accepted: 06/02/2017] [Indexed: 01/19/2023]
Abstract
Basement membranes (BMs) are extracellular matrix polymers basally underlying epithelia, where they regulate cell signaling and tissue mechanics. Constriction by the BM shapes Drosophila wing discs, a well-characterized model of tissue growth. Recently, the hypothesis that mechanical factors govern wing growth has received much attention, but it has not been definitively tested. In this study, we manipulated BM composition to cause dramatic changes in tissue tension. We found that increased tissue compression when perlecan was knocked down did not affect adult wing size. BM elimination, decreasing compression, reduced wing size but did not visibly affect Hippo signaling, widely postulated to mediate growth mechanoregulation. BM elimination, in contrast, attenuated signaling by bone morphogenetic protein/transforming growth factor β ligand Dpp, which was not efficiently retained within the tissue and escaped to the body cavity. Our results challenge mechanoregulation of wing growth, while uncovering a function of BMs in preserving a growth-promoting tissue environment.
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Affiliation(s)
- Mengqi Ma
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - Xueya Cao
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - Jianli Dai
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China
| | - José C Pastor-Pareja
- School of Life Sciences, Tsinghua University, Medical Science Building, D224, Beijing 100084, China.
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20
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Variable Cell Growth Yields Reproducible OrganDevelopment through Spatiotemporal Averaging. Dev Cell 2017; 38:15-32. [PMID: 27404356 DOI: 10.1016/j.devcel.2016.06.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 05/04/2016] [Accepted: 06/09/2016] [Indexed: 11/22/2022]
Abstract
Organ sizes and shapes are strikingly reproducible, despite the variable growth and division of individual cells within them. To reveal which mechanisms enable this precision, we designed a screen for disrupted sepal size and shape uniformity in Arabidopsis and identified mutations in the mitochondrial i-AAA protease FtsH4. Counterintuitively, through live imaging we observed that variability of neighboring cell growth was reduced in ftsh4 sepals. We found that regular organ shape results from spatiotemporal averaging of the cellular variability in wild-type sepals, which is disrupted in the less-variable cells of ftsh4 mutants. We also found that abnormal, increased accumulation of reactive oxygen species (ROS) in ftsh4 mutants disrupts organ size consistency. In wild-type sepals, ROS accumulate in maturing cells and limit organ growth, suggesting that ROS are endogenous signals promoting termination of growth. Our results demonstrate that spatiotemporal averaging of cellular variability is required for precision in organ size.
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21
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Ibar C, Glavic Á. Drosophila p115 is required for Cdk1 activation and G2/M cell cycle transition. Mech Dev 2017; 144:191-200. [PMID: 28396045 DOI: 10.1016/j.mod.2017.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 03/28/2017] [Accepted: 04/07/2017] [Indexed: 11/25/2022]
Abstract
Golgi complex inheritance and its relationship with the cell cycle are central in cell biology. Golgi matrix proteins, known as golgins, are one of the components that underlie the shape and functionality of this organelle. In mammalian cells, golgins are phosphorylated during mitosis to allow fragmentation of the Golgi ribbon and they also participate in spindle dynamics; both processes are required for cell cycle progression. Little is known about the function of golgins during mitosis in metazoans in vivo. This is particularly significant in Drosophila, in which the Golgi architecture is distributed in numerous units scattered throughout the cytoplasm, in contrast with mammalian cells. We examined the function of the ER/cis-Golgi golgin p115 during the proliferative phase of the Drosophila wing imaginal disc. Knockdown of p115 decreased tissue size. This phenotype was not caused by programmed cell death or cell size reductions, but by a reduction in the final cell number due to an accumulation of cells at the G2/M transition. This phenomenon frequently allows mitotic bypass and re-replication of DNA. These outcomes are similar to those observed following the partial loss of function of positive regulators of Cdk1 in Drosophila. In agreement with this, Cdk1 activation was reduced upon p115 knockdown. Interestingly, these phenotypes were fully rescued by Cdk1 overexpression and partially rescued by Myt1 depletion, but not by String (also known as Cdc25) overexpression. Additionally, we confirmed the physical interaction between p115 and Cdk1, suggesting that the formation of a complex where both proteins are present is essential for the full activation of Cdk1 and thus the correct progression of mitosis in proliferating tissues.
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Affiliation(s)
- Consuelo Ibar
- FONDAP Center for Genome Regulation, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile.
| | - Álvaro Glavic
- FONDAP Center for Genome Regulation, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile.
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22
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Montes AJ, Morata G. Homeostatic response to blocking cell division in Drosophila imaginal discs: Role of the Fat/Dachsous (Ft/Ds) pathway. Dev Biol 2017; 424:113-123. [PMID: 28300568 DOI: 10.1016/j.ydbio.2017.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/08/2017] [Accepted: 03/10/2017] [Indexed: 12/28/2022]
Abstract
One major problem in developmental biology is the identification of the mechanisms that control the final size of tissues and organs. We are addressing this issue in the imaginal discs of Drosophila by analysing the response to blocking cell division in large domains in the wing and leg discs. The affected domains may be zones of restricted lineage like compartments, or zones of open lineage that may integrate cells from the surrounding territory. Our results reveal the existence of a powerful homeostatic mechanism that can compensate for gross differences in growth rates and builds structures of normal size. This mechanism functions at the level of whole discs, inducing additional cell proliferation to generate the cells that populate the cell division-arrested territory and generating an active recruitment process to integrate those cells. The activation of this response mechanism is mediated by alterations in the normal activity of PCP genes of the Fat/Ds system: in discs mutant for dachs, ds or four jointed the response mechanism is not activated.
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Affiliation(s)
| | - Ginés Morata
- Centro de Biología Molecular CSIC-UAM, Madrid, Spain.
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23
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Vollmer J, Iber D. An Unbiased Analysis of Candidate Mechanisms for the Regulation of Drosophila Wing Disc Growth. Sci Rep 2016; 6:39228. [PMID: 27995964 PMCID: PMC5172366 DOI: 10.1038/srep39228] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/16/2016] [Indexed: 11/25/2022] Open
Abstract
The control of organ size presents a fundamental open problem in biology. A declining growth rate is observed in all studied higher animals, and the growth limiting mechanism may therefore be evolutionary conserved. Most studies of organ growth control have been carried out in Drosophila imaginal discs. We have previously shown that the area growth rate in the Drosophila eye primordium declines inversely proportional to the increase in its area, which is consistent with a dilution mechanism for growth control. Here, we show that a dilution mechanism cannot explain growth control in the Drosophila wing disc. We computationally evaluate a range of alternative candidate mechanisms and show that the experimental data can be best explained by a biphasic growth law. However, also logistic growth and an exponentially declining growth rate fit the data very well. The three growth laws correspond to fundamentally different growth mechanisms that we discuss. Since, as we show, a fit to the available experimental growth kinetics is insufficient to define the underlying mechanism of growth control, future experimental studies must focus on the molecular mechanisms to define the mechanism of growth control.
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Affiliation(s)
- Jannik Vollmer
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland.,Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058, Basel, Switzerland
| | - Dagmar Iber
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland.,Swiss Institute of Bioinformatics (SIB), Mattenstrasse 26, 4058, Basel, Switzerland
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24
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Eder D, Aegerter C, Basler K. Forces controlling organ growth and size. Mech Dev 2016; 144:53-61. [PMID: 27913118 DOI: 10.1016/j.mod.2016.11.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/02/2016] [Accepted: 11/24/2016] [Indexed: 12/25/2022]
Abstract
One of the fundamental questions in developmental biology is what determines the final size and shape of an organ. Recent research strongly emphasizes that besides cell-cell communication, biophysical principals govern organ development. The architecture and mechanics of a tissue guide cellular processes such as movement, growth or differentiation. Furthermore, mechanical cues do not only regulate processes at a cellular level but also provide constant feedback about size and shape on a tissue scale. Here we review several models and experimental systems which are contributing to our understanding of the roles mechanical forces play during organ development. One of the best understood processes is how the remodeling of bones is driven by mechanical load. Culture systems of single cells and of cellular monolayers provide further insights into the growth promoting capacity of mechanical cues. We focus on the Drosophila wing imaginal disc, a well-established model system for growth regulation. We discuss theoretical models that invoke mechanical feedback loops for growth regulation and experimental studies providing empirical support. Future progress in this exciting field will require the development of new tools to precisely measure and modify forces in living tissue systems.
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Affiliation(s)
- Dominik Eder
- Institute of Molecular Life Sciences, University of Zurich, CH-8057, Switzerland; Institute of Physics, University of Zurich, CH-8057, Switzerland
| | | | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zurich, CH-8057, Switzerland.
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25
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Losick VP. Wound-Induced Polyploidy Is Required for Tissue Repair. Adv Wound Care (New Rochelle) 2016; 5:271-278. [PMID: 27274437 DOI: 10.1089/wound.2014.0545] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Significance: All organs suffer wounds to some extent during an animal's lifetime and to compensate for cell loss, tissues often rely on cell division. However, many organs are made up of differentiated cells with only a limited capacity to divide. It is not well understood how cells are replaced in the absence of cell division. Recent Advances: Recent studies in the model organism Drosophila melanogaster have proven that wound-induced polyploidy (WIP) is an essential mechanism to replace tissue mass and restore tissue integrity in the absence of cell division. In this repair mechanism, preexisting differentiated cells increase their DNA content and cell size by becoming polyploid. Critical Issues: Cells within mammalian organs such as the liver, heart, and cornea have also been observed to increase their DNA ploidy in response to injury, suggesting that WIP may be an evolutionarily conserved mechanism to compensate for cell loss. Future Directions: The Hippo signal transduction pathway is required for differentiated cells to initiate WIP in Drosophila. Continued studies in Drosophila will help to identify other signaling pathways required for WIP as well as the conserved mechanisms that polyploid cells may play during wound repair in all organisms.
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Affiliation(s)
- Vicki P. Losick
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland
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26
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Trost M, Blattner AC, Lehner CF. Regulated protein depletion by the auxin-inducible degradation system in Drosophila melanogaster. Fly (Austin) 2016; 10:35-46. [PMID: 27010248 DOI: 10.1080/19336934.2016.1168552] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The analysis of consequences resulting after experimental elimination of gene function has been and will continue to be an extremely successful strategy in biological research. Mutational elimination of gene function has been widely used in the fly Drosophila melanogaster. RNA interference is used extensively as well. In the fly, exceptionally precise temporal and spatial control over elimination of gene function can be achieved in combination with sophisticated transgenic approaches and clonal analyses. However, the methods that act at the gene and transcript level cannot eliminate protein products which are already present at the time when mutant cells are generated or RNA interference is started. Targeted inducible protein degradation is therefore of considerable interest for controlled rapid elimination of gene function. To this end, a degradation system was developed in yeast exploiting TIR1, a plant F box protein, which can recruit proteins with an auxin-inducible degron to an E3 ubiquitin ligase complex, but only in the presence of the phytohormone auxin. Here we demonstrate that the auxin-inducible degradation system functions efficiently also in Drosophila melanogaster. Neither auxin nor TIR1 expression have obvious toxic effects in this organism, and in combination they result in rapid degradation of a target protein fused to the auxin-inducible degron.
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Affiliation(s)
- Martina Trost
- a Institute of Molecular Life Sciences (IMLS), University of Zurich , Zurich , Switzerland
| | - Ariane C Blattner
- a Institute of Molecular Life Sciences (IMLS), University of Zurich , Zurich , Switzerland
| | - Christian F Lehner
- a Institute of Molecular Life Sciences (IMLS), University of Zurich , Zurich , Switzerland
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27
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Vollmer J, Fried P, Sánchez-Aragón M, Lopes CS, Casares F, Iber D. A quantitative analysis of growth control in the Drosophila eye disc. Development 2016; 143:1482-90. [PMID: 26965369 DOI: 10.1242/dev.129775] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 02/29/2016] [Indexed: 01/03/2023]
Abstract
The size and shape of organs is species specific, and even in species in which organ size is strongly influenced by environmental cues, such as nutrition or temperature, it follows defined rules. Therefore, mechanisms must exist to ensure a tight control of organ size within a given species, while being flexible enough to allow for the evolution of different organ sizes in different species. We combined computational modeling and quantitative measurements to analyze growth control in the Drosophila eye disc. We find that the area growth rate declines inversely proportional to the increasing total eye disc area. We identify two growth laws that are consistent with the growth data and that would explain the extraordinary robustness and evolutionary plasticity of the growth process and thus of the final adult eye size. These two growth laws correspond to very different control mechanisms and we discuss how each of these laws constrains the set of candidate biological mechanisms for growth control in the Drosophila eye disc.
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Affiliation(s)
- Jannik Vollmer
- Department of Biosystems, Science and Engineering (D-BSSE), ETH Zurich, Mattenstraße 26, Basel 4058, Switzerland Swiss Institute of Bioinformatics (SIB), Mattenstraße 26, Basel 4058, Switzerland
| | - Patrick Fried
- Department of Biosystems, Science and Engineering (D-BSSE), ETH Zurich, Mattenstraße 26, Basel 4058, Switzerland Swiss Institute of Bioinformatics (SIB), Mattenstraße 26, Basel 4058, Switzerland
| | - Max Sánchez-Aragón
- Department of Gene Regulation and Morphogenesis, CABD, CSIC and Universidad Pablo de Olavide, Campus UPO, Seville 41013, Spain
| | - Carla S Lopes
- Department of Gene Regulation and Morphogenesis, CABD, CSIC and Universidad Pablo de Olavide, Campus UPO, Seville 41013, Spain
| | - Fernando Casares
- Department of Gene Regulation and Morphogenesis, CABD, CSIC and Universidad Pablo de Olavide, Campus UPO, Seville 41013, Spain
| | - Dagmar Iber
- Department of Biosystems, Science and Engineering (D-BSSE), ETH Zurich, Mattenstraße 26, Basel 4058, Switzerland Swiss Institute of Bioinformatics (SIB), Mattenstraße 26, Basel 4058, Switzerland
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28
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Losick VP, Jun AS, Spradling AC. Wound-Induced Polyploidization: Regulation by Hippo and JNK Signaling and Conservation in Mammals. PLoS One 2016; 11:e0151251. [PMID: 26958853 PMCID: PMC4784922 DOI: 10.1371/journal.pone.0151251] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 02/25/2016] [Indexed: 12/13/2022] Open
Abstract
Tissue integrity and homeostasis often rely on the proliferation of stem cells or differentiated cells to replace lost, aged, or damaged cells. Recently, we described an alternative source of cell replacement- the expansion of resident, non-dividing diploid cells by wound-induced polyploidization (WIP). Here we show that the magnitude of WIP is proportional to the extent of cell loss using a new semi-automated assay with single cell resolution. Hippo and JNK signaling regulate WIP; unexpectedly however, JNK signaling through AP-1 limits rather than stimulates the level of Yki activation and polyploidization in the Drosophila epidermis. We found that polyploidization also quantitatively compensates for cell loss in a mammalian tissue, mouse corneal endothelium, where increased cell death occurs with age in a mouse model of Fuchs Endothelial Corneal Dystrophy (FECD). Our results suggest that WIP is an evolutionarily conserved homeostatic mechanism that maintains the size and synthetic capacity of adult tissues.
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Affiliation(s)
- Vicki P. Losick
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute, 3250 San Martin Dr., Baltimore, MD 21218, United States of America
| | - Albert S. Jun
- Wilmer Eye Institute, Johns Hopkins School of Medicine, 400 N. Broadway, Baltimore, MD 21231, United States of America
| | - Allan C. Spradling
- Department of Embryology, Carnegie Institution for Science, Howard Hughes Medical Institute, 3250 San Martin Dr., Baltimore, MD 21218, United States of America
- * E-mail:
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29
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Hariharan IK. Organ Size Control: Lessons from Drosophila. Dev Cell 2015; 34:255-65. [PMID: 26267393 DOI: 10.1016/j.devcel.2015.07.012] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 07/13/2015] [Accepted: 07/22/2015] [Indexed: 12/23/2022]
Abstract
Of fundamental interest to biologists is how organs achieve a reproducible size during development. Studies of the developing Drosophila wing have provided many key insights that will help give a conceptual understanding of the process beyond the fly. In the wing, there is evidence for both "top-down" mechanisms, in which signals emanating from small subsets of cells direct global proliferation, and "bottom-up" mechanisms, in which the final size is an emergent property of local cell-cell interactions. Mechanical forces also appear to have an important role along with the Hippo pathway, which may integrate multiple types of inputs to regulate the extent of growth.
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Affiliation(s)
- Iswar K Hariharan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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30
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Etournay R, Popović M, Merkel M, Nandi A, Blasse C, Aigouy B, Brandl H, Myers G, Salbreux G, Jülicher F, Eaton S. Interplay of cell dynamics and epithelial tension during morphogenesis of the Drosophila pupal wing. eLife 2015; 4:e07090. [PMID: 26102528 PMCID: PMC4574473 DOI: 10.7554/elife.07090] [Citation(s) in RCA: 208] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 06/18/2015] [Indexed: 11/21/2022] Open
Abstract
How tissue shape emerges from the collective mechanical properties and behavior of individual cells is not understood. We combine experiment and theory to study this problem in the developing wing epithelium of Drosophila. At pupal stages, the wing-hinge contraction contributes to anisotropic tissue flows that reshape the wing blade. Here, we quantitatively account for this wing-blade shape change on the basis of cell divisions, cell rearrangements and cell shape changes. We show that cells both generate and respond to epithelial stresses during this process, and that the nature of this interplay specifies the pattern of junctional network remodeling that changes wing shape. We show that patterned constraints exerted on the tissue by the extracellular matrix are key to force the tissue into the right shape. We present a continuum mechanical model that quantitatively describes the relationship between epithelial stresses and cell dynamics, and how their interplay reshapes the wing.
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Affiliation(s)
- Raphaël Etournay
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Marko Popović
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Matthias Merkel
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Amitabha Nandi
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Corinna Blasse
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Benoît Aigouy
- Institut de Biologie du Développement de Marseille, Marseille, France
| | - Holger Brandl
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Gene Myers
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Guillaume Salbreux
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
- Lincoln's Inn Fields Laboratories, The Francis Crick Institute, London, United Kingdom
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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31
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Cho B, Pierre-Louis G, Sagner A, Eaton S, Axelrod JD. Clustering and negative feedback by endocytosis in planar cell polarity signaling is modulated by ubiquitinylation of prickle. PLoS Genet 2015; 11:e1005259. [PMID: 25996914 PMCID: PMC4440771 DOI: 10.1371/journal.pgen.1005259] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 05/01/2015] [Indexed: 11/18/2022] Open
Abstract
The core components of the planar cell polarity (PCP) signaling system, including both transmembrane and peripheral membrane associated proteins, form asymmetric complexes that bridge apical intercellular junctions. While these can assemble in either orientation, coordinated cell polarization requires the enrichment of complexes of a given orientation at specific junctions. This might occur by both positive and negative feedback between oppositely oriented complexes, and requires the peripheral membrane associated PCP components. However, the molecular mechanisms underlying feedback are not understood. We find that the E3 ubiquitin ligase complex Cullin1(Cul1)/SkpA/Supernumerary limbs(Slimb) regulates the stability of one of the peripheral membrane components, Prickle (Pk). Excess Pk disrupts PCP feedback and prevents asymmetry. We show that Pk participates in negative feedback by mediating internalization of PCP complexes containing the transmembrane components Van Gogh (Vang) and Flamingo (Fmi), and that internalization is activated by oppositely oriented complexes within clusters. Pk also participates in positive feedback through an unknown mechanism promoting clustering. Our results therefore identify a molecular mechanism underlying generation of asymmetry in PCP signaling. Many epithelial cells display a level of organization in which cellular structures or appendages are positioned asymmetrically within the cell along an axis perpendicular to the apical-basal axis of the cell. When the direction of this polarization is coordinated within the plane of the epithelium, this phenomenon is referred to as planar cell polarity (PCP). PCP is organized, at least in part, by a group of molecules that interact across cell-cell junctions and segregate into two groups that localize on opposite sides of each cell. Their asymmetric localization is thought to both produce molecular asymmetry, and to mark polarized domains within the cell for subsequent morphological polarization. In segregating to produce molecular asymmetry, these proteins participate in both positive and negative feedback, much like ferromagnets, to align their localization within and between neighboring cells. In this work, we identify a mechanism for negative feedback that utilizes the protein Prickle, one of the PCP signaling components. Levels of Prickle are precisely regulated, in part by a ubiquitinylation mechanism that targets excess protein for degradation. Prickle mediates internalization and removal of one class of PCP proteins, thereby causing repulsion of opposite ‘poles.’ Excess Prickle disrupts this mechanism and interferes with establishing polarity.
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Affiliation(s)
- Bomsoo Cho
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Gandhy Pierre-Louis
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Andreas Sagner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Jeffrey D. Axelrod
- Department of Pathology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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32
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Schoenfelder KP, Montague RA, Paramore SV, Lennox AL, Mahowald AP, Fox DT. Indispensable pre-mitotic endocycles promote aneuploidy in the Drosophila rectum. Development 2014; 141:3551-60. [PMID: 25142462 DOI: 10.1242/dev.109850] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The endocycle is a modified cell cycle that lacks M phase. Endocycles are well known for enabling continued growth of post-mitotic tissues. By contrast, we discovered pre-mitotic endocycles in precursors of Drosophila rectal papillae (papillar cells). Unlike all known proliferative Drosophila adult precursors, papillar cells endocycle before dividing. Furthermore, unlike diploid mitotic divisions, these polyploid papillar divisions are frequently error prone, suggesting papillar structures may accumulate long-term aneuploidy. Here, we demonstrate an indispensable requirement for pre-mitotic endocycles during papillar development and also demonstrate that such cycles seed papillar aneuploidy. We find blocking pre-mitotic endocycles disrupts papillar morphogenesis and causes organismal lethality under high-salt dietary stress. We further show that pre-mitotic endocycles differ from post-mitotic endocycles, as we find only the M-phase-capable polyploid cells of the papillae and female germline can retain centrioles. In papillae, this centriole retention contributes to aneuploidy, as centrioles amplify during papillar endocycles, causing multipolar anaphase. Such aneuploidy is well tolerated in papillae, as it does not significantly impair cell viability, organ formation or organ function. Together, our results demonstrate that pre-mitotic endocycles can enable specific organ construction and are a mechanism that promotes highly tolerated aneuploidy.
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Affiliation(s)
- Kevin P Schoenfelder
- Department of Pharmacology and Cancer Biology, Box 3813, Duke University Medical Center, Durham, NC 27710, USA
| | - Ruth A Montague
- Department of Pharmacology and Cancer Biology, Box 3813, Duke University Medical Center, Durham, NC 27710, USA
| | - Sarah V Paramore
- Department of Pharmacology and Cancer Biology, Box 3813, Duke University Medical Center, Durham, NC 27710, USA
| | - Ashley L Lennox
- Department of Pharmacology and Cancer Biology, Box 3813, Duke University Medical Center, Durham, NC 27710, USA
| | - Anthony P Mahowald
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Donald T Fox
- Department of Pharmacology and Cancer Biology, Box 3813, Duke University Medical Center, Durham, NC 27710, USA
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33
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Endocycles: a recurrent evolutionary innovation for post-mitotic cell growth. Nat Rev Mol Cell Biol 2014; 15:197-210. [PMID: 24556841 DOI: 10.1038/nrm3756] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In endoreplication cell cycles, known as endocycles, cells successively replicate their genomes without segregating chromosomes during mitosis and thereby become polyploid. Such cycles, for which there are many variants, are widespread in protozoa, plants and animals. Endocycling cells can achieve ploidies of >200,000 C (chromatin-value); this increase in genomic DNA content allows a higher genomic output, which can facilitate the construction of very large cells or enhance macromolecular secretion. These cells execute normal S phases, using a G1-S regulatory apparatus similar to the one used by mitotic cells, but their capability to segregate chromosomes has been suppressed, typically by downregulation of mitotic cyclin-dependent kinase activity. Endocycles probably evolved many times, and the various endocycle mechanisms found in nature highlight the versatility of the cell cycle control machinery.
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Tamori Y, Deng WM. Compensatory cellular hypertrophy: the other strategy for tissue homeostasis. Trends Cell Biol 2013; 24:230-7. [PMID: 24239163 DOI: 10.1016/j.tcb.2013.10.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/16/2013] [Accepted: 10/18/2013] [Indexed: 12/16/2022]
Abstract
Metazoan tissues have the ability to maintain tissue size and morphology while eliminating aberrant or damaged cells. In the tissue homeostasis system, cell division is the primary strategy cells use not only to increase tissue size during development but also to compensate for cell loss in tissue repair. Recent studies in Drosophila, however, have shown that cells in postmitotic tissues undergo hypertrophic growth without division, contributing to tissue repair as well as organ development. Indeed, similar compensatory cellular hypertrophy (CCH) can be observed in different contexts such as mammalian hepatocytes or corneal endothelial cells. Here we highlight these findings and discuss the underlying mechanisms of CCH, which is likely an evolutionarily conserved strategy for homeostatic tissue growth in metazoans.
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Affiliation(s)
- Yoichiro Tamori
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4295, USA.
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35
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Zoranovic T, Grmai L, Bach EA. Regulation of proliferation, cell competition, and cellular growth by the Drosophila JAK-STAT pathway. JAKSTAT 2013; 2:e25408. [PMID: 24069565 PMCID: PMC3772117 DOI: 10.4161/jkst.25408] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 06/06/2013] [Accepted: 06/14/2013] [Indexed: 01/08/2023] Open
Abstract
The JAK-STAT pathway is a key regulator of tissue size in Drosophila melanogaster. Here we provide an overview of its roles in processes that regulate the size of Drosophila imaginal discs, epithelia of diploid cells that proliferate and acquire specific fates in the larvae and that become functional in the adult. Drosophila has a single JAK and a single STAT gene, which has facilitated genetic dissection of this pathway. Moreover, the sophisticated genetic tools available in flies for clonal growth assays have made Drosophila an ideal organism in which to dissect the multiple roles of the JAK-STAT pathway in growth control. Studies in flies have revealed JAK-STAT pathway activity as a central node for diverse signals that control proliferation and mass accumulation. In addition, recent work has establish a new role for the pathway in cell competition, a process thought to be akin to the early stages of transformation in which more robust cells kill and take the place of less robust ones.
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Affiliation(s)
- Tamara Zoranovic
- Department of Biochemistry and Molecular Pharmacology; New York University School of Medicine; New York, NY USA
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36
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Ron M, Dorrity MW, de Lucas M, Toal T, Hernandez RI, Little SA, Maloof JN, Kliebenstein DJ, Brady SM. Identification of novel loci regulating interspecific variation in root morphology and cellular development in tomato. PLANT PHYSIOLOGY 2013; 162:755-68. [PMID: 23575417 PMCID: PMC3668068 DOI: 10.1104/pp.113.217802] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 04/09/2013] [Indexed: 05/20/2023]
Abstract
While the Arabidopsis (Arabidopsis thaliana) root has been elegantly characterized with respect to specification of cell identity, its development is missing a number of cellular features present in other species. We have characterized the root development of a wild and a domesticated tomato species, Solanum pennellii and Solanum lycopersicum 'M82.' We found extensive differences between these species for root morphology and cellular development including root length, a novel gravity set point angle, differences in cortical cell layer patterning, stem cell niche structure, and radial cell division. Using an introgression line population between these two species, we identified numerous loci that regulate these distinct aspects of development. Specifically we comprehensively identified loci that regulate (1) root length by distinct mechanisms including regulation of cell production within the meristem and the balance between cell division and expansion, (2) the gravity set point angle, and (3) radial cell division or expansion either in specific cell types or generally across multiple cell types. Our findings provide a novel perspective on the regulation of root growth and development between species. These loci have exciting implications with respect to regulation of drought resistance or salinity tolerance and regulation of root development in a family that has undergone domestication.
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Dui W, Wei B, He F, Lu W, Li C, Liang X, Ma J, Jiao R. The Drosophila F-box protein dSkp2 regulates cell proliferation by targeting Dacapo for degradation. Mol Biol Cell 2013; 24:1676-87, S1-7. [PMID: 23552694 PMCID: PMC3667721 DOI: 10.1091/mbc.e12-10-0772] [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] [Indexed: 01/08/2023] Open
Abstract
dSkp2 regulates cell cycle progression by antagonizing Dap in Drosophila, which resolves the question of whether dSkp2 has a role in regulating Dap stability and suggests the possibility of using Drosophila as a model system in which to study Skp2-mediated tumorigenesis. Cell cycle progression is controlled by a complex regulatory network consisting of interacting positive and negative factors. In humans, the positive regulator Skp2, an F-box protein, has been a subject of intense investigation in part because of its oncogenic activity. By contrast, the molecular and developmental functions of its Drosophila homologue, dSkp2, are poorly understood. Here we investigate the role of dSkp2 by focusing on its functional relationship with Dacapo (Dap), the Drosophila homologue of the cyclin-dependent kinase inhibitors p21cip1/p27kip1/p57kip2. We show that dSkp2 interacts physically with Dap and has a role in targeting Dap for ubiquitination and proteasome-mediated degradation. We present evidence that dSkp2 regulates cell cycle progression by antagonizing Dap in vivo. dSkp2 knockdown reduces cell density in the wing by prolonging the cell doubling time. In addition, the wing phenotype caused by dSkp2 knockdown resembles that caused by dap overexpression and can be partially suppressed by reducing the gene dose of dap. Our study thus documents a conserved functional relationship between dSkp2 and Dap in their control of cell cycle progression, suggesting the possibility of using Drosophila as a model system to study Skp2-mediated tumorigenesis.
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Affiliation(s)
- Wen Dui
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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38
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Transcriptional networks controlling the cell cycle. G3-GENES GENOMES GENETICS 2013; 3:75-90. [PMID: 23316440 PMCID: PMC3538345 DOI: 10.1534/g3.112.004283] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 11/07/2012] [Indexed: 01/09/2023]
Abstract
In this work, we map the transcriptional targets of 107 previously identified Drosophila genes whose loss caused the strongest cell-cycle phenotypes in a genome-wide RNA interference screen and mine the resulting data computationally. Besides confirming existing knowledge, the analysis revealed several regulatory systems, among which were two highly-specific and interconnected feedback circuits, one between the ribosome and the proteasome that controls overall protein homeostasis, and the other between the ribosome and Myc/Max that regulates the protein synthesis capacity of cells. We also identified a set of genes that alter the timing of mitosis without affecting gene expression, indicating that the cyclic transcriptional program that produces the components required for cell division can be partially uncoupled from the cell division process itself. These genes all have a function in a pathway that regulates the phosphorylation state of Cdk1. We provide evidence showing that this pathway is involved in regulation of cell size, indicating that a Cdk1-regulated cell size checkpoint exists in metazoans.
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Pandit SK, Westendorp B, Nantasanti S, van Liere E, Tooten PCJ, Cornelissen PWA, Toussaint MJM, Lamers WH, de Bruin A. E2F8 is essential for polyploidization in mammalian cells. Nat Cell Biol 2012; 14:1181-91. [DOI: 10.1038/ncb2585] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 08/16/2012] [Indexed: 12/14/2022]
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40
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O'Farrell PH. Quiescence: early evolutionary origins and universality do not imply uniformity. Philos Trans R Soc Lond B Biol Sci 2012; 366:3498-507. [PMID: 22084377 PMCID: PMC3203459 DOI: 10.1098/rstb.2011.0079] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cell cycle investigations have focused on relentless exponential proliferation of cells, an unsustainable situation in nature. Proliferation of cells, whether microbial or metazoan, is interrupted by periods of quiescence. The vast majority of cells in an adult metazoan lie quiescent. As disruptions in this quiescence are at the foundation of cancer, it will be important for the field to turn its attention to the mechanisms regulating quiescence. While often presented as a single topic, there are multiple forms of quiescence each with complex inputs, some of which are tied to conceptually challenging aspects of metazoan regulation such as size control. In an effort to expose the enormity of the challenge, I describe the differing biological purposes of quiescence, and the coupling of quiescence in metazoans to growth and to the structuring of tissues during development. I emphasize studies in the organism rather than in tissue culture, because these expose the diversity of regulation. While quiescence is likely to be a primitive biological process, it appears that in adapting quiescence to its many distinct biological settings, evolution has diversified it. Consideration of quiescence in different models gives us an overview of this diversity.
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Affiliation(s)
- Patrick H O'Farrell
- Department of Biochemistry, University of California, San Francisco, CA 94158-2200, USA.
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41
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Debat V, Bloyer S, Faradji F, Gidaszewski N, Navarro N, Orozco-terWengel P, Ribeiro V, Schlötterer C, Deutsch JS, Peronnet F. Developmental stability: a major role for cyclin G in drosophila melanogaster. PLoS Genet 2011; 7:e1002314. [PMID: 21998598 PMCID: PMC3188557 DOI: 10.1371/journal.pgen.1002314] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 08/01/2011] [Indexed: 01/22/2023] Open
Abstract
Morphological consistency in metazoans is remarkable given the pervasive occurrence of genetic variation, environmental effects, and developmental noise. Developmental stability, the ability to reduce developmental noise, is a fundamental property of multicellular organisms, yet its genetic bases remains elusive. Imperfect bilateral symmetry, or fluctuating asymmetry, is commonly used to estimate developmental stability. We observed that Drosophila melanogaster overexpressing Cyclin G (CycG) exhibit wing asymmetry clearly detectable by sight. Quantification of wing size and shape using geometric morphometrics reveals that this asymmetry is a genuine-but extreme-fluctuating asymmetry. Overexpression of CycG indeed leads to a 40-fold increase of wing fluctuating asymmetry, which is an unprecedented effect, for any organ and in any animal model, either in wild populations or mutants. This asymmetry effect is not restricted to wings, since femur length is affected as well. Inactivating CycG by RNAi also induces fluctuating asymmetry but to a lesser extent. Investigating the cellular bases of the phenotypic effects of CycG deregulation, we found that misregulation of cell size is predominant in asymmetric flies. In particular, the tight negative correlation between cell size and cell number observed in wild-type flies is impaired when CycG is upregulated. Our results highlight the role of CycG in the control of developmental stability in D. melanogaster. Furthermore, they show that wing developmental stability is normally ensured via compensatory processes between cell growth and cell proliferation. We discuss the possible role of CycG as a hub in a genetic network that controls developmental stability.
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Affiliation(s)
- Vincent Debat
- Muséum National d'Histoire Naturelle Département Systématique et Evolution UMR 7205, Centre National de la Recherche Scientifique, Paris, France
| | - Sébastien Bloyer
- Laboratoire de Biologie du Développement UMR 7622, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique, Paris, France
| | - Floria Faradji
- Laboratoire de Biologie du Développement UMR 7622, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique, Paris, France
| | - Nelly Gidaszewski
- Muséum National d'Histoire Naturelle Département Systématique et Evolution UMR 7205, Centre National de la Recherche Scientifique, Paris, France
| | - Nicolas Navarro
- Laboratory of Artificial and Natural Evolution Department of Zoology and Animal Biology, University of Geneva Sciences III, Geneva, Switzerland
| | - Pablo Orozco-terWengel
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Vienna, Austria
| | - Valérie Ribeiro
- Laboratoire de Biologie du Développement UMR 7622, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique, Paris, France
| | - Christian Schlötterer
- Institut für Populationsgenetik, Veterinärmedizinische Universität Wien, Vienna, Austria
| | - Jean S. Deutsch
- Laboratoire de Biologie du Développement UMR 7622, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique, Paris, France
| | - Frédérique Peronnet
- Laboratoire de Biologie du Développement UMR 7622, Université Pierre et Marie Curie-Paris 6, Centre National de la Recherche Scientifique, Paris, France
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Ghorbani M, Vasavan B, Kraja E, Swan A. Cks85A and Skp2 interact to maintain diploidy and promote growth in Drosophila. Dev Biol 2011; 358:213-23. [PMID: 21827746 DOI: 10.1016/j.ydbio.2011.07.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 07/23/2011] [Accepted: 07/24/2011] [Indexed: 10/17/2022]
Abstract
The Cks or Suc1 proteins are highly conserved small proteins that play remarkably diverse roles in the cell cycle. All Cks homologues have the ability to associate with Cyclin dependent kinases (Cdks) and in many cases this interaction has been shown to be important for function. Here we characterize the null and RNAi knockdown phenotype of the Drosophila Cks1 (Cks85A) gene. Cks85A is essential for viability in Drosophila. Cks85A null animals have reduced overall growth and this correlates with reduced ploidy and impaired DNA replication in endoreplicating cells. Interestingly, Cks85A is also required for the maintenance of diploidy in mitotically cycling cells. The requirement for Cks85A in growth is similar to that of the mammalian Cks1, which was found to interact with the SCF(Skp2) ubiquitin ligase. We identified the Drosophila Skp2 gene and generated null alleles. Comparison of these mutants to null mutants for Cks85A reveals a remarkably similar dual requirement in growth and in maintenance of diploidy. We find that Cks85A interacts directly with the SCF(Skp2) ubiquitin ligase and genetic evidence indicates that this is its major molecular function. The closely related Cks30A cannot interact with the SCF(Skp2) and cannot functionally compensate for loss of Cks85A. We also find that the critical growth promoting and diploidy maintaining functions of Cks85A and Skp2 are independent of known SCF(Skp2) substrates, p27 and Cdt1, indicating that other critical substrates remain to be identified.
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Affiliation(s)
- Mohammad Ghorbani
- Department of Biological Sciences, University of Windsor, Windsor, Ontario, Canada
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43
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Molecular mechanism of size control in development and human diseases. Cell Res 2011; 21:715-29. [PMID: 21483452 DOI: 10.1038/cr.2011.63] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
How multicellular organisms control their size is a fundamental question that fascinated generations of biologists. In the past 10 years, tremendous progress has been made toward our understanding of the molecular mechanism underlying size control. Original studies from Drosophila showed that in addition to extrinsic nutritional and hormonal cues, intrinsic mechanisms also play important roles in the control of organ size during development. Several novel signaling pathways such as insulin and Hippo-LATS signaling pathways have been identified that control organ size by regulating cell size and/or cell number through modulation of cell growth, cell division, and cell death. Later studies using mammalian cell and mouse models also demonstrated that the signaling pathways identified in flies are also conserved in mammals. Significantly, recent studies showed that dysregulation of size control plays important roles in the development of many human diseases such as cancer, diabetes, and hypertrophy.
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44
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Horiguchi G, Mollá-Morales A, Pérez-Pérez JM, Kojima K, Robles P, Ponce MR, Micol JL, Tsukaya H. Differential contributions of ribosomal protein genes to Arabidopsis thaliana leaf development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 65:724-36. [PMID: 21251100 DOI: 10.1111/j.1365-313x.2010.04457.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In Arabidopsis thaliana, mutations in genes encoding ribosomal proteins (r-proteins) perturb various developmental processes. Whether these perturbations are caused by overall ribosome insufficiency or partial dysfunction of the ribosome caused by deficiency of a particular ribosomal protein is not known. To distinguish these possibilities, a comparative study using several r-protein mutants was required. Here, we identified mutations in 11 r-protein genes from previously isolated denticulata and pointed-leaves mutants. Most of these mutations were associated with pointed leaves, with reduced growth due to a decrease in the number or size of palisade mesophyll and pavement cells. In addition, leaf abaxialization was usually observed when these r-protein mutations were combined with asymmetric leaves1 (as1) and as2 mutations. These results suggest that the establishment of leaf polarity is highly sensitive to ribosome functionality in general. However, several r-protein mutants showed a preference towards a specific developmental defect. For example, rpl4d mutations did not affect cell proliferation but caused strong abaxialization of leaves in the as1 and as2 backgrounds. On the other hand, rps28b enhanced leaf abaxialization of as2 to a weaker extent than expected on the basis of its negative effect on cell proliferation. In addition, hypomorphic rps6a alleles had the strongest effects on most of the phenotypes examined. These findings suggest that deficiencies in these three r-protein genes lead to production of dysfunctional ribosomes. Depending on their structural abnormalities, dysfunctional ribosomes may affect translation of specific transcripts involved in the regulation of some leaf developmental processes.
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Affiliation(s)
- Gorou Horiguchi
- Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
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45
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Abstract
Somatic tetraploid neurons are present in different structures of the vertebrate nervous system, including cortex and retina. In this chapter, we provide evidence that these neurons can be widely detected in the chick nervous system. We also discuss mechanisms creating neuronal tetraploidy in vertebrates, concluding that the neurotrophin receptor p75 could be responsible for the generation of these neurons in most neural tissues, as previously observed in the retina. Somatic tetraploidy in the chick retina correlates with increased neurons' soma size and dendritic arborization, giving rise to neurons known to innervate a specific layer of the optic tectum. Tetraploidy could therefore account for neuronal diversity in the normal nervous system. De novo generation of tetraploid neurons has been shown to occur in Alzheimer's disease. This suggests that the morphological changes expected to occur in the affected neurons could lead to altered neuronal function, thus providing a basis for neurodegeneration.
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46
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Thompson BJ. Developmental control of cell growth and division in Drosophila. Curr Opin Cell Biol 2010; 22:788-94. [DOI: 10.1016/j.ceb.2010.08.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/10/2010] [Accepted: 08/15/2010] [Indexed: 01/21/2023]
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47
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Sozzani R, Cui H, Moreno-Risueno MA, Busch W, Van Norman JM, Vernoux T, Brady SM, Dewitte W, Murray JAH, Benfey PN. Spatiotemporal regulation of cell-cycle genes by SHORTROOT links patterning and growth. Nature 2010; 466:128-32. [PMID: 20596025 DOI: 10.1038/nature09143] [Citation(s) in RCA: 296] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 04/28/2010] [Indexed: 12/18/2022]
Abstract
The development of multicellular organisms relies on the coordinated control of cell divisions leading to proper patterning and growth. The molecular mechanisms underlying pattern formation, particularly the regulation of formative cell divisions, remain poorly understood. In Arabidopsis, formative divisions generating the root ground tissue are controlled by SHORTROOT (SHR) and SCARECROW (SCR). Here we show, using cell-type-specific transcriptional effects of SHR and SCR combined with data from chromatin immunoprecipitation-based microarray experiments, that SHR regulates the spatiotemporal activation of specific genes involved in cell division. Coincident with the onset of a specific formative division, SHR and SCR directly activate a D-type cyclin; furthermore, altering the expression of this cyclin resulted in formative division defects. Our results indicate that proper pattern formation is achieved through transcriptional regulation of specific cell-cycle genes in a cell-type- and developmental-stage-specific context. Taken together, we provide evidence for a direct link between developmental regulators, specific components of the cell-cycle machinery and organ patterning.
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Affiliation(s)
- R Sozzani
- Department of Biology and IGSP Center for Systems Biology, Duke University, Durham, North Carolina 27708, USA
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48
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Neto-Silva RM, Wells BS, Johnston LA. Mechanisms of growth and homeostasis in the Drosophila wing. Annu Rev Cell Dev Biol 2010; 25:197-220. [PMID: 19575645 DOI: 10.1146/annurev.cellbio.24.110707.175242] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Animal shape and size is controlled with amazing precision during development. External factors such as nutrient availability and crowding can alter overall animal size, but individual body parts scale reproducibly to match the body even with challenges from a changing environment. How is such precision achieved? Here, we review selected research from the last few years in Drosophila--arguably the premier genetic model for the study of animal growth--that sheds light on how body and tissue size are regulated by forces intrinsic to individual organs. We focus on two topics currently under intense study: the influence of pattern regulators on organ and tissue growth and the role of local competitive interactions between cells in tissue homeostasis and final size.
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Affiliation(s)
- Ricardo M Neto-Silva
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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49
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Abstract
A great many cell types are necessary for the myriad capabilities of complex, multicellular organisms. One interesting aspect of this diversity of cell type is that many cells in diploid organisms are polyploid. This is called endopolyploidy and arises from cell cycles that are often characterized as "variant," but in fact are widespread throughout nature. Endopolyploidy is essential for normal development and physiology in many different organisms. Here we review how both plants and animals use variations of the cell cycle, termed collectively as endoreplication, resulting in polyploid cells that support specific aspects of development. In addition, we discuss briefly how endoreplication occurs in response to certain physiological stresses, and how it may contribute to the development of cancer. Finally, we describe the molecular mechanisms that support the onset and progression of endoreplication.
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50
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Segalen M, Bellaïche Y. Cell division orientation and planar cell polarity pathways. Semin Cell Dev Biol 2009; 20:972-7. [DOI: 10.1016/j.semcdb.2009.03.018] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/19/2009] [Accepted: 03/30/2009] [Indexed: 12/30/2022]
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