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Matamoro-Vidal A, Cumming T, Davidović A, Levillayer F, Levayer R. Patterned apoptosis has an instructive role for local growth and tissue shape regulation in a fast-growing epithelium. Curr Biol 2024; 34:376-388.e7. [PMID: 38215743 PMCID: PMC10808510 DOI: 10.1016/j.cub.2023.12.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/13/2023] [Accepted: 12/11/2023] [Indexed: 01/14/2024]
Abstract
What regulates organ size and shape remains one fundamental mystery of modern biology. Research in this area has primarily focused on deciphering the regulation in time and space of growth and cell division, while the contribution of cell death has been overall neglected. This includes studies of the Drosophila wing, one of the best-characterized systems for the study of growth and patterning, undergoing massive growth during larval stage and important morphogenetic remodeling during pupal stage. So far, it has been assumed that cell death was relatively neglectable in this tissue both during larval stage and pupal stage, and as a result, the pattern of growth was usually attributed to the distribution of cell division. Here, using systematic mapping and registration combined with quantitative assessment of clone size and disappearance as well as live imaging, we outline a persistent pattern of cell death and clone elimination emerging in the larval wing disc and persisting during pupal wing morphogenesis. Local variation of cell death is associated with local variation of clone size, pointing to an impact of cell death on local growth that is not fully compensated by proliferation. Using morphometric analyses of adult wing shape and genetic perturbations, we provide evidence that patterned death locally and globally affects adult wing shape and size. This study describes a roadmap for precise assessment of the contribution of cell death to tissue shape and outlines an important instructive role of cell death in modulating quantitatively local growth and morphogenesis of a fast-growing tissue.
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Affiliation(s)
- Alexis Matamoro-Vidal
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France
| | - Tom Cumming
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France; PPU program Institut Pasteur, Sorbonne Université, Collège Doctoral, 75005 Paris, France
| | - Anđela Davidović
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, 75015 Paris, France
| | - Florence Levillayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France
| | - Romain Levayer
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Cell Death and Epithelial Homeostasis Unit, 75015 Paris, France.
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2
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Crucianelli C, Jaiswal J, Vijayakumar Maya A, Nogay L, Cosolo A, Grass I, Classen AK. Distinct signaling signatures drive compensatory proliferation via S-phase acceleration. PLoS Genet 2022; 18:e1010516. [PMID: 36520882 PMCID: PMC9799308 DOI: 10.1371/journal.pgen.1010516] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/29/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022] Open
Abstract
Regeneration relies on cell proliferation to restore damaged tissues. Multiple signaling pathways activated by local or paracrine cues have been identified to promote regenerative proliferation. How different types of tissue damage may activate distinct signaling pathways and how these differences converge on regenerative proliferation is less well defined. To better understand how tissue damage and proliferative signals are integrated during regeneration, we investigate models of compensatory proliferation in Drosophila imaginal discs. We find that compensatory proliferation is associated with a unique cell cycle profile, which is characterized by short G1 and G2 phases and, surprisingly, by acceleration of the S-phase. S-phase acceleration can be induced by two distinct signaling signatures, aligning with inflammatory and non-inflammatory tissue damage. Specifically, non-autonomous activation of JAK/STAT and Myc in response to inflammatory damage, or local activation of Ras/ERK and Hippo/Yki in response to elevated cell death, promote accelerated nucleotide incorporation during S-phase. This previously unappreciated convergence of different damaging insults on the same regenerative cell cycle program reconciles previous conflicting observations on proliferative signaling in different tissue regeneration and tumor models.
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Affiliation(s)
- Carlo Crucianelli
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Janhvi Jaiswal
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Ananthakrishnan Vijayakumar Maya
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- International Max Planck Research School for Immunobiology, Epigenetics, and Metabolism, Freiburg, Germany
| | - Liyne Nogay
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- International Max Planck Research School for Immunobiology, Epigenetics, and Metabolism, Freiburg, Germany
| | - Andrea Cosolo
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Isabelle Grass
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Anne-Kathrin Classen
- Hilde-Mangold-Haus, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- * E-mail:
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3
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Abstract
Drosophila melanogaster has historically been a workhorse model organism for studying developmental biology. In addition, Drosophila is an excellent model for studying how damaged tissues and organs can regenerate. Recently, new precision approaches that enable both highly targeted injury and genetic manipulation have accelerated progress in this field. Here, we highlight these techniques and review examples of recently discovered mechanisms that regulate regeneration in Drosophila larval and adult tissues. We also discuss how, by applying these powerful approaches, studies of Drosophila can continue to guide the future of regeneration research.
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Affiliation(s)
- Donald T Fox
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Regeneration Next, Duke University, Durham, NC 27710, USA
| | - Erez Cohen
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Regeneration Next, Duke University, Durham, NC 27710, USA
| | - Rachel Smith-Bolton
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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4
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Hariharan IK, Serras F. Imaginal disc regeneration takes flight. Curr Opin Cell Biol 2017; 48:10-16. [PMID: 28376317 PMCID: PMC5591769 DOI: 10.1016/j.ceb.2017.03.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 03/07/2017] [Accepted: 03/10/2017] [Indexed: 12/20/2022]
Abstract
Drosophila imaginal discs, the larval precursors of adult structures such as the wing and leg, are capable of regenerating after damage. During the course of regeneration, discs can sometimes generate structures that are appropriate for a different type of disc, a phenomenon termed transdetermination. Until recently, these phenomena were studied by physically fragmenting discs and then transplanting them into the abdomens of adult female flies. This field has experienced a renaissance following the development of genetic ablation systems that can damage precisely defined regions of the disc without the need for surgery. Together with more traditional approaches, these newer methods have generated many novel insights into wound healing, the mechanisms that drive regenerative growth, plasticity during regeneration and systemic effects of tissue damage and regeneration.
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Affiliation(s)
- Iswar K Hariharan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA.
| | - Florenci Serras
- Departament de Genètica, Facultat de Biologia and Institute de Biomedicina (IBUB), Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
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5
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Cap-n-Collar Promotes Tissue Regeneration by Regulating ROS and JNK Signaling in the Drosophila melanogaster Wing Imaginal Disc. Genetics 2017; 206:1505-1520. [PMID: 28512185 DOI: 10.1534/genetics.116.196832] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 05/10/2017] [Indexed: 01/03/2023] Open
Abstract
Regeneration is a complex process that requires an organism to recognize and repair tissue damage, as well as grow and pattern new tissue. Here, we describe a genetic screen to identify novel regulators of regeneration. We ablated the Drosophila melanogaster larval wing primordium by inducing apoptosis in a spatially and temporally controlled manner and allowed the tissue to regenerate and repattern. To identify genes that regulate regeneration, we carried out a dominant-modifier screen by assessing the amount and quality of regeneration in adult wings heterozygous for isogenic deficiencies. We have identified 31 regions on the right arm of the third chromosome that modify the regenerative response. Interestingly, we observed several distinct phenotypes: mutants that regenerated poorly, mutants that regenerated faster or better than wild-type, and mutants that regenerated imperfectly and had patterning defects. We mapped one deficiency region to cap-n-collar (cnc), the Drosophila Nrf2 ortholog, which is required for regeneration. Cnc regulates reactive oxygen species levels in the regenerating epithelium, and affects c-Jun N-terminal protein kinase (JNK) signaling, growth, debris localization, and pupariation timing. Here, we present the results of our screen and propose a model wherein Cnc regulates regeneration by maintaining an optimal level of reactive oxygen species to promote JNK signaling.
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Kasumovic MM, Chen Z, Wilkins MR. Australian black field crickets show changes in neural gene expression associated with socially-induced morphological, life-history, and behavioral plasticity. BMC Genomics 2016; 17:827. [PMID: 27776492 PMCID: PMC5078956 DOI: 10.1186/s12864-016-3119-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 09/23/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition. To do this, we use the Australian black field cricket (Teleogryllus commodus), a species with sex-specific developmental trajectories moderated by the density and quality of calls heard during immaturity. In this study, we manipulated the social information males and females could hear by rearing individuals in either calling or silent treatments. We next used RNA-Seq to develop a reference transcriptome to study changes in brain gene expression at two points prior to sexual maturation. RESULTS We show accelerated development in both sexes when exposed to calling; changes were also seen in growth, lifespan, and reproductive effort. Functional relationships between genes and phenotypes were apparent from ontological enrichment analysis. We demonstrate that increased investment towards traits such as growth and reproductive effort were often associated with the expression of a greater number of genes with similar effect, thus providing a suite of candidate genes for future research in this and other invertebrate organisms. CONCLUSIONS Our results provide interesting insight into the genomic underpinnings of developmental plasticity and highlight the potential of a genomic exploration of other evolutionary theories such as condition dependence and sex-specific developmental strategies.
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Affiliation(s)
- Michael M Kasumovic
- Ecology & Evolution Research Centre, School of Biological, Earth and Environmental Sciences, UNSW, Sydney, Australia.
| | - Zhiliang Chen
- Systems Biology Initiative, UNSW, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, Australia
| | - Marc R Wilkins
- Systems Biology Initiative, UNSW, Sydney, Australia
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, Australia
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7
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Lee CH, Rimesso G, Reynolds DM, Cai J, Baker NE. Whole-Genome Sequencing and iPLEX MassARRAY Genotyping Map an EMS-Induced Mutation Affecting Cell Competition in Drosophila melanogaster. G3 (BETHESDA, MD.) 2016; 6:3207-3217. [PMID: 27574103 PMCID: PMC5068942 DOI: 10.1534/g3.116.029421] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 08/04/2016] [Indexed: 01/09/2023]
Abstract
Cell competition, the conditional loss of viable genotypes only when surrounded by other cells, is a phenomenon observed in certain genetic mosaic conditions. We conducted a chemical mutagenesis and screen to recover new mutations that affect cell competition between wild-type and RpS3 heterozygous cells. Mutations were identified by whole-genome sequencing, making use of software tools that greatly facilitate the distinction between newly induced mutations and other sources of apparent sequence polymorphism, thereby reducing false-positive and false-negative identification rates. In addition, we utilized iPLEX MassARRAY for genotyping recombinant chromosomes. These approaches permitted the mapping of a new mutation affecting cell competition when only a single allele existed, with a phenotype assessed only in genetic mosaics, without the benefit of complementation with existing mutations, deletions, or duplications. These techniques expand the utility of chemical mutagenesis and whole-genome sequencing for mutant identification. We discuss mutations in the Atm and Xrp1 genes identified in this screen.
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Affiliation(s)
- Chang-Hyun Lee
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Gerard Rimesso
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - David M Reynolds
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Jinlu Cai
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461
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Smith-Bolton R. Drosophila Imaginal Discs as a Model of Epithelial Wound Repair and Regeneration. Adv Wound Care (New Rochelle) 2016; 5:251-261. [PMID: 27274435 DOI: 10.1089/wound.2014.0547] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Significance: The Drosophila larval imaginal discs, which form the adult fly during metamorphosis, are an established model system for the study of epithelial tissue damage. The disc proper is a simple columnar epithelium, but it contains complex patterning and cell-fate specification, and is genetically tractable. These features enable unbiased genetic screens to identify genes involved in all aspects of the wound response, from sensing damage to wound closure, initiation of regeneration, and re-establishment of proper cell fates. Identification of the genes that facilitate epithelial wound closure and regeneration will enable development of more sophisticated wound treatments for clinical use. Recent Advances: Imaginal disc epithelia can be damaged in many different ways, including fragmentation, induction of cell death, and irradiation. Recent work has demonstrated that the tissue's response to damage varies depending on how the wound was induced. Here, we summarize the different responses activated in these epithelial tissues after the different types of damage. Critical Issues: These studies highlight that not all wounds elicit the same response from the surrounding tissue. A complete understanding of the various wound-healing mechanisms in Drosophila will be a first step in understanding how to manage damaged human tissues and optimize healing in different clinical contexts. Future Directions: Further work is necessary to understand the similarities and differences among an epithelial tissue's responses to different insults. Ongoing studies will identify the genes and pathways employed by injured imaginal discs. Thus, work in this genetically tractable system complements work in more conventional wound-healing models.
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Affiliation(s)
- Rachel Smith-Bolton
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
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9
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Pérez-Garijo A, Steller H. Spreading the word: non-autonomous effects of apoptosis during development, regeneration and disease. Development 2016; 142:3253-62. [PMID: 26443630 DOI: 10.1242/dev.127878] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Apoptosis, in contrast to other forms of cell death such as necrosis, was originally regarded as a 'silent' mechanism of cell elimination designed to degrade the contents of doomed cells. However, during the past decade it has become clear that apoptotic cells can produce diverse signals that have a profound impact on neighboring cells and tissues. For example, apoptotic cells can release factors that influence the proliferation and survival of adjacent tissues. Apoptosis can also affect tissue movement and morphogenesis by modifying tissue tension in surrounding cells. As we review here, these findings reveal unexpected roles for apoptosis in tissue remodeling during development, as well as in regeneration and cancer.
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Affiliation(s)
- Ainhoa Pérez-Garijo
- Strang Laboratory of Apoptosis and Cancer Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Hermann Steller
- Strang Laboratory of Apoptosis and Cancer Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
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10
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Novel Genes Involved in Controlling Specification of Drosophila FMRFamide Neuropeptide Cells. Genetics 2015; 200:1229-44. [PMID: 26092715 DOI: 10.1534/genetics.115.178483] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/16/2015] [Indexed: 01/28/2023] Open
Abstract
The expression of neuropeptides is often extremely restricted in the nervous system, making them powerful markers for addressing cell specification . In the developing Drosophila ventral nerve cord, only six cells, the Ap4 neurons, of some 10,000 neurons, express the neuropeptide FMRFamide (FMRFa). Each Ap4/FMRFa neuron is the last-born cell generated by an identifiable and well-studied progenitor cell, neuroblast 5-6 (NB5-6T). The restricted expression of FMRFa and the wealth of information regarding its gene regulation and Ap4 neuron specification makes FMRFa a valuable readout for addressing many aspects of neural development, i.e., spatial and temporal patterning cues, cell cycle control, cell specification, axon transport, and retrograde signaling. To this end, we have conducted a forward genetic screen utilizing an Ap4-specific FMRFa-eGFP transgenic reporter as our readout. A total of 9781 EMS-mutated chromosomes were screened for perturbations in FMRFa-eGFP expression, and 611 mutants were identified. Seventy-nine of the strongest mutants were mapped down to the affected gene by deficiency mapping or whole-genome sequencing. We isolated novel alleles for previously known FMRFa regulators, confirming the validity of the screen. In addition, we identified novel essential genes, including several with previously undefined functions in neural development. Our identification of genes affecting most major steps required for successful terminal differentiation of Ap4 neurons provides a comprehensive view of the genetic flow controlling the generation of highly unique neuronal cell types in the developing nervous system.
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11
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Slade JD, Staveley BE. Compensatory growth in novel Drosophila Akt1 mutants. BMC Res Notes 2015; 8:77. [PMID: 25889856 PMCID: PMC4372305 DOI: 10.1186/s13104-015-1032-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/24/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Organisms, tissues and cells are genetically programmed to grow to a specific largely pre-set size and shape within the appropriate developmental timing. In the event of mutation, cell death, or tissue damage, the remaining cells may increase their rate of growth to compensate and generate an intact, potentially smaller, tissue or organism in order to achieve the desired size. A delay in the developmental timing could aid in this process. The insulin receptor signalling pathway with its central component, the Akt1 kinase, and endpoint regulator, the transcription factor foxo, plays a significant role in the control of growth. Drosophila melanogaster is an excellent model organism with a well-studied life cycle and a consistently developing compound eye that can undergo analysis to compare changes in the properties of adult ommatidia as an indicator of growth. FINDINGS Imprecise excision of a PZ P-element inserted in the upstream region of Akt1 generated several novel hypomorphic alleles with internally deleted regions of the Pelement. These mutations lead to small, viable Drosophila that present with delays in development. Suppression of this phenotype by the directed expression of Akt1 (+) indicates that the phenotypes observed are Akt1 dependent. Somatic clones of the eyes, consisting of homozygous tissue in otherwise heterozygous organisms that develop within a standard timeframe, signify that more severe phenotypes are masked by an extension in the time of development of homozygous mutants. Generation of Drosophila having the hypomorphic Akt1 alleles and a null allele of the downstream target foxo result in a phenotype very similar to that of the foxo mutant and do not resemble the Akt1 mutants. CONCLUSION The developmental delay of these novel Akt1 hypomorphs results in a latent phenotype uncovered by generation of somatic clones. The compensatory growth occurring during the extended time of development appears to be implemented through alteration of foxo activity. Production of clones is an effective and informative way to observe the effects of mutations that result in small, viable, developmentally delayed flies.
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Affiliation(s)
- Jennifer D Slade
- Department of Biology, Memorial University of Newfoundland, 232 Elizabeth Avenue, St. John's, Newfoundland and Labrador, A1B 3X9, Canada.
| | - Brian E Staveley
- Department of Biology, Memorial University of Newfoundland, 232 Elizabeth Avenue, St. John's, Newfoundland and Labrador, A1B 3X9, Canada.
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12
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Gurling M, Talavera K, Garriga G. The DEP domain-containing protein TOE-2 promotes apoptosis in the Q lineage of C. elegans through two distinct mechanisms. Development 2014; 141:2724-34. [PMID: 24961802 DOI: 10.1242/dev.110486] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroblast divisions in the nematode Caenorhabditis elegans often give rise to a larger neuron and a smaller cell that dies. We have previously identified genes that, when mutated, result in neuroblast divisions that generate daughter cells that are more equivalent in size. This effect correlates with the survival of daughter cells that would normally die. We now describe a role for the DEP domain-containing protein TOE-2 in promoting the apoptotic fate in the Q lineage. TOE-2 localized at the plasma membrane and accumulated in the cleavage furrow of the Q.a and Q.p neuroblasts, suggesting that TOE-2 might position the cleavage furrow asymmetrically to generate daughter cells of different sizes. This appears to be the case for Q.a divisions where loss of TOE-2 led to a more symmetric division and to survival of the smaller Q.a daughter. Localization of TOE-2 to the membrane is required for this asymmetry, but, surprisingly, the DEP domain is dispensable. By contrast, loss of TOE-2 led to loss of the apoptotic fate in the smaller Q.p daughter but did not affect the size asymmetry of the Q.p daughters. This function of TOE-2 required the DEP domain but not localization to the membrane. We propose that TOE-2 ensures an apoptotic fate for the small Q.a daughter by promoting asymmetry in the daughter cell sizes of the Q.a neuroblast division but by a mechanism that is independent of cell size in the Q.p division.
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Affiliation(s)
- Mark Gurling
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Karla Talavera
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Gian Garriga
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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13
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Schneeberger K. Using next-generation sequencing to isolate mutant genes from forward genetic screens. Nat Rev Genet 2014; 15:662-76. [PMID: 25139187 DOI: 10.1038/nrg3745] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The long-lasting success of forward genetic screens relies on the simple molecular basis of the characterized phenotypes, which are typically caused by mutations in single genes. Mapping the location of causal mutations using genetic crosses has traditionally been a complex, multistep procedure, but next-generation sequencing now allows the rapid identification of causal mutations at single-nucleotide resolution even in complex genetic backgrounds. Recent advances of this mapping-by-sequencing approach include methods that are independent of reference genome sequences, genetic crosses and any kind of linkage information, which make forward genetics amenable for species that have not been considered for forward genetic screens so far.
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Affiliation(s)
- Korbinian Schneeberger
- Genome Plasticity and Computational Genetics, Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany
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14
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Muñoz-Soriano V, López-Domenech S, Paricio N. Why mammalian wound-healing researchers may wish to turn toDrosophilaas a model. Exp Dermatol 2014; 23:538-42. [DOI: 10.1111/exd.12472] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2014] [Indexed: 01/10/2023]
Affiliation(s)
- Verónica Muñoz-Soriano
- Departamento de Genética; Facultad CC Biológicas; Universidad de Valencia; Burjasot Spain
| | - Sandra López-Domenech
- Departamento de Genética; Facultad CC Biológicas; Universidad de Valencia; Burjasot Spain
| | - Nuria Paricio
- Departamento de Genética; Facultad CC Biológicas; Universidad de Valencia; Burjasot Spain
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15
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Fan Y, Wang S, Hernandez J, Yenigun VB, Hertlein G, Fogarty CE, Lindblad JL, Bergmann A. Genetic models of apoptosis-induced proliferation decipher activation of JNK and identify a requirement of EGFR signaling for tissue regenerative responses in Drosophila. PLoS Genet 2014; 10:e1004131. [PMID: 24497843 PMCID: PMC3907308 DOI: 10.1371/journal.pgen.1004131] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 12/06/2013] [Indexed: 11/19/2022] Open
Abstract
Recent work in several model organisms has revealed that apoptotic cells are able to stimulate neighboring surviving cells to undergo additional proliferation, a phenomenon termed apoptosis-induced proliferation. This process depends critically on apoptotic caspases such as Dronc, the Caspase-9 ortholog in Drosophila, and may have important implications for tumorigenesis. While it is known that Dronc can induce the activity of Jun N-terminal kinase (JNK) for apoptosis-induced proliferation, the mechanistic details of this activation are largely unknown. It is also controversial if JNK activity occurs in dying or in surviving cells. Signaling molecules of the Wnt and BMP families have been implicated in apoptosis-induced proliferation, but it is unclear if they are the only ones. To address these questions, we have developed an efficient assay for screening and identification of genes that regulate or mediate apoptosis-induced proliferation. We have identified a subset of genes acting upstream of JNK activity including Rho1. We also demonstrate that JNK activation occurs both in apoptotic cells as well as in neighboring surviving cells. In a genetic screen, we identified signaling by the EGFR pathway as important for apoptosis-induced proliferation acting downstream of JNK signaling. These data underscore the importance of genetic screening and promise an improved understanding of the mechanisms of apoptosis-induced proliferation. Work in recent years has revealed that apoptotic caspases not only induce apoptosis, but also have non-apoptotic functions. One of these functions is apoptosis-induced proliferation, a relatively recently discovered phenomenon by which apoptotic cells induce proliferation of surviving neighboring cells. This phenomenon may have important implications for stem cell activity, tissue regeneration and tumorigenesis. Here, we describe the development of a genetic model of apoptosis-induced proliferation and the use of this model for convenient and unbiased genetic screening to identify genes involved in the process. We tested mutants of our RNAi transgenic lines targeting the core components of the apoptotic pathway and of JNK signaling, a known mediator of apoptosis-induced proliferation. These assays demonstrate the feasibility of the system for systematic genetic screening and identified several new genes upstream of JNK that are involved in apoptosis-induced proliferation. Finally, we tested the model in a pilot screen for chromosome arm 2L and identified spi, the EGF ligand in flies, as important for apoptosis-induced proliferation. We confirmed the involvement of EGF in a genuine apoptosis-induced regeneration system. These data underscore the importance of genetic screening and promise an improved understanding of the mechanisms of apoptosis-induced proliferation and regeneration.
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Affiliation(s)
- Yun Fan
- University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America
- * E-mail: (YF); (AB)
| | - Shiuan Wang
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Jacob Hernandez
- MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America
| | - Vildan Betul Yenigun
- MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America
| | - Gillian Hertlein
- Länderinstitut für Bienenkunde, Humboldt Universität zu Berlin, Hohen Neuendorf, Germany
| | - Caitlin E. Fogarty
- University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America
| | - Jillian L. Lindblad
- University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America
| | - Andreas Bergmann
- University of Massachusetts Medical School, Department of Cancer Biology, Worcester, Massachusetts, United States of America
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- MD Anderson Cancer Center, Department of Biochemistry & Molecular Biology, Houston, Texas, United States of America
- * E-mail: (YF); (AB)
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16
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Lin H, Miller ML, Granas DM, Dutcher SK. Whole genome sequencing identifies a deletion in protein phosphatase 2A that affects its stability and localization in Chlamydomonas reinhardtii. PLoS Genet 2013; 9:e1003841. [PMID: 24086163 PMCID: PMC3784568 DOI: 10.1371/journal.pgen.1003841] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/13/2013] [Indexed: 11/19/2022] Open
Abstract
Whole genome sequencing is a powerful tool in the discovery of single nucleotide polymorphisms (SNPs) and small insertions/deletions (indels) among mutant strains, which simplifies forward genetics approaches. However, identification of the causative mutation among a large number of non-causative SNPs in a mutant strain remains a big challenge. In the unicellular biflagellate green alga Chlamydomonas reinhardtii, we generated a SNP/indel library that contains over 2 million polymorphisms from four wild-type strains, one highly polymorphic strain that is frequently used in meiotic mapping, ten mutant strains that have flagellar assembly or motility defects, and one mutant strain, imp3, which has a mating defect. A comparison of polymorphisms in the imp3 strain and the other 15 strains allowed us to identify a deletion of the last three amino acids, Y313F314L315, in a protein phosphatase 2A catalytic subunit (PP2A3) in the imp3 strain. Introduction of a wild-type HA-tagged PP2A3 rescues the mutant phenotype, but mutant HA-PP2A3 at Y313 or L315 fail to rescue. Our immunoprecipitation results indicate that the Y313, L315, or YFLΔ mutations do not affect the binding of PP2A3 to the scaffold subunit, PP2A-2r. In contrast, the Y313, L315, or YFLΔ mutations affect both the stability and the localization of PP2A3. The PP2A3 protein is less abundant in these mutants and fails to accumulate in the basal body area as observed in transformants with either wild-type HA-PP2A3 or a HA-PP2A3 with a V310T change. The accumulation of HA-PP2A3 in the basal body region disappears in mated dikaryons, which suggests that the localization of PP2A3 may be essential to the mating process. Overall, our results demonstrate that the terminal YFL tail of PP2A3 is important in the regulation on Chlamydomonas mating.
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Affiliation(s)
- Huawen Lin
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michelle L. Miller
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - David M. Granas
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Center for Genomic Sciences and System Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Susan K. Dutcher
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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17
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Saastamoinen M, Ikonen S, Wong SC, Lehtonen R, Hanski I. Plastic larval development in a butterfly has complex environmental and genetic causes and consequences for population dynamics. J Anim Ecol 2013; 82:529-39. [PMID: 23347450 DOI: 10.1111/1365-2656.12034] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 11/10/2012] [Indexed: 11/29/2022]
Abstract
1. In insects, the length of larval development time typically influences adult body size and individual fitness, and hence development time can be expected to respond in an adaptive manner to variation in environmental conditions. In the wild, larval growth may be influenced by individual condition, which can be affected by population-level parameters such as population density and abundance and quality of resources. 2. We sampled larvae of the Glanville fritillary butterfly (Melitaea cinxia) from 514 local populations across a large metapopulation before the winter diapause and reared the larvae in common garden conditions after diapause. Here, we report that small post-diapause larvae prolonged their development via an extra larval instar, apparently to compensate for their 'bad start' after diapause. The number of instars was additionally a plastic response to environmental conditions, as the frequency of the extra instar increased under cooler thermal conditions. 3. The benefit of the extra instar is clear, as it allows individuals to develop into larger adults, but the cost is delayed adult eclosion, which is likely to select against the extra instar especially in males, in which early eclosion is critical for mating success. In support of this, the frequency of the extra instar was significantly lower in males (7%) than in females (42%). 4. Polymorphisms in three genes, serpin-1, vitellin-degrading protease precursor and phosphoglucose isomerase, which are known to influence development in insects, were associated with the occurrence of the extra instar. 5. At the level of local populations, the frequency of the extra instar was higher in newly established populations than that in old local ones, possibly reflecting maternal effects, as new populations are often established by females with heavy investment in dispersal. The frequency of the extra instar in turn correlated with the change in population size over 1 year and the risk of local extinction in the natural metapopulation of the Glanville fritillary. 6. Our results highlight the importance of the physiological condition of individuals in shaping subsequent life-history events and even population dynamics.
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Affiliation(s)
- Marjo Saastamoinen
- Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), Helsinki, FI-00014, Finland
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18
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St Johnston D. Using mutants, knockdowns, and transgenesis to investigate gene function in Drosophila. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2012; 2:587-613. [PMID: 24014449 DOI: 10.1002/wdev.101] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The sophisticated genetic techniques available in Drosophila are largely responsible for its success as a model organism. One of the most important of these is the ability to disrupt gene function in vivo and observe the resulting phenotypes. This review considers the ever-increasing repertoire of approaches for perturbing the functions of specific genes in flies, ranging from classical and transposon-mediated mutageneses to newer techniques, such as homologous recombination and RNA interference. Since most genes are used over and over again in different contexts during development, many important advances have depended on being able to interfere with gene function at specific times or places in the developing animal, and a variety of approaches are now available to do this. Most of these techniques rely on being able to create genetically modified strains of Drosophila and the different methods for generating lines carrying single copy transgenic constructs will be described, along with the advantages and disadvantages of each approach.
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Affiliation(s)
- Daniel St Johnston
- The Gurdon Institute and the Department of Genetics, University of Cambridge, Cambridge CB2 1QN, UK.
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19
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Worley MI, Setiawan L, Hariharan IK. Regeneration and transdetermination in Drosophila imaginal discs. Annu Rev Genet 2012; 46:289-310. [PMID: 22934642 DOI: 10.1146/annurev-genet-110711-155637] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The study of regeneration in Drosophila imaginal discs provides an opportunity to use powerful genetic tools to address fundamental problems pertaining to tissue regeneration and cell plasticity. We present a historical overview of the field and describe how the application of modern methods has made the study of disc regeneration amenable to genetic analysis. Discs respond to tissue damage in several ways: (a) Removal of part of the disc elicits localized cell proliferation and regeneration of the missing tissue. (b) Damage at specific locations in the disc can cause cells to generate disc-inappropriate structures (e.g., wing instead of leg), a phenomenon known as transdetermination. (c) Diffuse damage to imaginal discs, results in compensatory proliferation of surviving cells. Candidate-gene approaches have implicated the JNK, Wingless, and Hippo pathways in regeneration. Recently developed systems will enable extensive genetic screens that could provide new insights into tissue regeneration, transdetermination and compensatory proliferation.
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Affiliation(s)
- Melanie I Worley
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3200, USA.
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20
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Ryoo HD, Bergmann A. The role of apoptosis-induced proliferation for regeneration and cancer. Cold Spring Harb Perspect Biol 2012; 4:a008797. [PMID: 22855725 DOI: 10.1101/cshperspect.a008797] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Genes dedicated to killing cells must have evolved because of their positive effects on organismal survival. Positive functions of apoptotic genes have been well established in a large number of biological contexts, including their role in eliminating damaged and potentially cancerous cells. More recently, evidence has suggested that proapoptotic proteins-mostly caspases-can induce proliferation of neighboring surviving cells to replace dying cells. This process, that we will refer to as "apoptosis-induced proliferation," may be critical for stem cell activity and tissue regeneration. Depending on the caspases involved, at least two distinct types of apoptosis-induced proliferation can be distinguished. One of these types have been studied using a model in which cells have initiated cell death, but are prevented from executing it because of effector caspase inhibition, thereby generating "undead" cells that emit persistent mitogen signaling and overgrowth. Such conditions are likely to contribute to certain forms of cancer. In this review, we summarize the current knowledge of apoptosis-induced proliferation and discuss its relevance for tissue regeneration and cancer.
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Affiliation(s)
- Hyung Don Ryoo
- Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA
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