1
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Kurio M, Tsukasa Y, Uemura T, Usui T. Refinement of a technique for collecting and evaluating the osmolality of haemolymph from Drosophila larvae. J Exp Biol 2024; 227:jeb247249. [PMID: 38634259 DOI: 10.1242/jeb.247249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Accepted: 04/11/2024] [Indexed: 04/19/2024]
Abstract
Ex vivo physiological experiments using small insect models such as Drosophila larvae have become increasingly useful to address fundamental biological questions. To perform such experiments, various artificial saline solutions have been developed, but their osmolality varies significantly from one to the next. Such a variation of osmolality stems, in part, from the difficulty of determining the true value of haemolymph osmolality in Drosophila larvae. Thus, there is a pressing need to refine protocols for collecting and measuring the osmolality of the larval haemolymph. Two major obstacles are thought to impede the accurate analysis of haemolymph collected from small insects: melanin formation and gut-derived contamination. Here, we greatly refined existing haemolymph collection methods, evaluated the purity of the collected haemolymph under melanin-free conditions, and concluded that the true value of haemolymph osmolality is close to 306.0 mOsm kg-1 in Drosophila larvae.
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Affiliation(s)
- Misato Kurio
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yuma Tsukasa
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
- Center for Living Systems Information Science (CeLiSIS), Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tadao Usui
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
- Center for Living Systems Information Science (CeLiSIS), Kyoto University, Yoshida-Konoecho, Sakyo-ku, Kyoto 606-8501, Japan
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2
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Li P, Messina G, Lehner CF. Nuclear elongation during spermiogenesis depends on physical linkage of nuclear pore complexes to bundled microtubules by Drosophila Mst27D. PLoS Genet 2023; 19:e1010837. [PMID: 37428798 PMCID: PMC10359004 DOI: 10.1371/journal.pgen.1010837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023] Open
Abstract
Spermatozoa in animal species are usually highly elongated cells with a long motile tail attached to a head that contains the haploid genome in a compact and often elongated nucleus. In Drosophila melanogaster, the nucleus is compacted two hundred-fold in volume during spermiogenesis and re-modeled into a needle that is thirty-fold longer than its diameter. Nuclear elongation is preceded by a striking relocalization of nuclear pore complexes (NPCs). While NPCs are initially located throughout the nuclear envelope (NE) around the spherical nucleus of early round spermatids, they are later confined to one hemisphere. In the cytoplasm adjacent to this NPC-containing NE, the so-called dense complex with a strong bundle of microtubules is assembled. While this conspicuous proximity argued for functional significance of NPC-NE and microtubule bundle, experimental confirmation of their contributions to nuclear elongation has not yet been reported. Our functional characterization of the spermatid specific Mst27D protein now resolves this deficit. We demonstrate that Mst27D establishes physical linkage between NPC-NE and dense complex. The C-terminal region of Mst27D binds to the nuclear pore protein Nup358. The N-terminal CH domain of Mst27D, which is similar to that of EB1 family proteins, binds to microtubules. At high expression levels, Mst27D promotes bundling of microtubules in cultured cells. Microscopic analyses indicated co-localization of Mst27D with Nup358 and with the microtubule bundles of the dense complex. Time-lapse imaging revealed that nuclear elongation is accompanied by a progressive bundling of microtubules into a single elongated bundle. In Mst27D null mutants, this bundling process does not occur and nuclear elongation is abnormal. Thus, we propose that Mst27D permits normal nuclear elongation by promoting the attachment of the NPC-NE to the microtubules of the dense complex, as well as the progressive bundling of these microtubules.
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Affiliation(s)
- Pengfei Li
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
| | - Giovanni Messina
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
| | - Christian F Lehner
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
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3
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Giri R, Brady S, Papadopoulos DK, Carthew RW. Single-cell Senseless protein analysis reveals metastable states during the transition to a sensory organ fate. iScience 2022; 25:105097. [PMID: 36157584 PMCID: PMC9494244 DOI: 10.1016/j.isci.2022.105097] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 08/02/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
Cell fate decisions can be envisioned as bifurcating dynamical systems, and the decision that Drosophila cells make during sensory organ differentiation has been described as such. We extended these studies by focusing on the Senseless protein which orchestrates sensory cell fate transitions. Wing cells contain intermediate Senseless numbers before their fate transition, after which they express much greater numbers of Senseless molecules as they differentiate. However, the dynamics are inconsistent with it being a simple bistable system. Cells with intermediate Senseless are best modeled as residing in four discrete states, each with a distinct protein number and occupying a specific region of the tissue. Although the states are stable over time, the number of molecules in each state vary with time. The fold change in molecule number between adjacent states is invariant and robust to absolute protein number variation. Thus, cells transitioning to sensory fates exhibit metastability with relativistic properties.
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Affiliation(s)
- Ritika Giri
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA,NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA
| | - Shannon Brady
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Dimitrios K. Papadopoulos
- Center for Molecular Medicine (CMM), Department of Clinical Neuroscience, Karolinska Institute, 17176 Stockholm, Sweden,Department of Biology, University of Crete, Voutes University Campus, Heraklion, Crete 70013, Greece
| | - Richard W. Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA,NSF-Simons Center for Quantitative Biology, Northwestern University, Evanston, IL 60208, USA,Corresponding author
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4
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Marchetti M, Zhang C, Edgar BA. An improved organ explant culture method reveals stem cell lineage dynamics in the adult Drosophila intestine. eLife 2022; 11:e76010. [PMID: 36005292 PMCID: PMC9578704 DOI: 10.7554/elife.76010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
In recent years, live-imaging techniques have been developed for the adult midgut of Drosophila melanogaster that allow temporal characterization of key processes involved in stem cell and tissue homeostasis. However, these organ culture techniques have been limited to imaging sessions of <16 hours, an interval too short to track dynamic processes such as damage responses and regeneration, which can unfold over several days. Therefore, we developed an organ explant culture protocol capable of sustaining midguts ex vivo for up to 3 days. This was made possible by the formulation of a culture medium specifically designed for adult Drosophila tissues with an increased Na+/K+ ratio and trehalose concentration, and by placing midguts at an air-liquid interface for enhanced oxygenation. We show that midgut progenitor cells can respond to gut epithelial damage ex vivo, proliferating and differentiating to replace lost cells, but are quiescent in healthy intestines. Using ex vivo gene induction to promote stem cell proliferation using RasG12V or string and Cyclin E overexpression, we demonstrate that progenitor cell lineages can be traced through multiple cell divisions using live imaging. We show that the same culture set-up is useful for imaging adult renal tubules and ovaries for up to 3 days and hearts for up to 10 days. By enabling both long-term imaging and real-time ex vivo gene manipulation, our simple culture protocol provides a powerful tool for studies of epithelial biology and cell lineage behavior.
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Affiliation(s)
- Marco Marchetti
- Department of Oncological Sciences, Huntsman Cancer Institute, University of UtahSalt Lake CityUnited States
| | - Chenge Zhang
- Department of Oncological Sciences, Huntsman Cancer Institute, University of UtahSalt Lake CityUnited States
| | - Bruce A Edgar
- Department of Oncological Sciences, Huntsman Cancer Institute, University of UtahSalt Lake CityUnited States
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5
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Gallagher KD, Mani M, Carthew RW. Emergence of a geometric pattern of cell fates from tissue-scale mechanics in the Drosophila eye. eLife 2022; 11:72806. [PMID: 35037852 PMCID: PMC8863370 DOI: 10.7554/elife.72806] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 01/15/2022] [Indexed: 12/02/2022] Open
Abstract
Pattern formation of biological structures involves the arrangement of different types of cells in an ordered spatial configuration. In this study, we investigate the mechanism of patterning the Drosophila eye epithelium into a precise triangular grid of photoreceptor clusters called ommatidia. Previous studies had led to a long-standing biochemical model whereby a reaction-diffusion process is templated by recently formed ommatidia to propagate a molecular prepattern across the eye. Here, we find that the templating mechanism is instead, mechanochemical in origin; newly born columns of differentiating ommatidia serve as a template to spatially pattern flows that move epithelial cells into position to form each new column of ommatidia. Cell flow is generated by a source and sink, corresponding to narrow zones of cell dilation and contraction respectively, that straddle the growing wavefront of ommatidia. The newly formed lattice grid of ommatidia cells are immobile, deflecting, and focusing the flow of other cells. Thus, the self-organization of a regular pattern of cell fates in an epithelium is mechanically driven.
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Affiliation(s)
- Kevin D Gallagher
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States
| | - Madhav Mani
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States,Department of Engineering Sciences and Applied Mathematics, Northwestern UniversityEvanstonUnited States
| | - Richard W Carthew
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States,NSF Simons Center for Quantitative Biology, Northwestern UniversityEvanstonUnited States
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6
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Dye NA. Cultivation and Live Imaging of Drosophila Imaginal Discs. Methods Mol Biol 2022; 2540:317-334. [PMID: 35980586 DOI: 10.1007/978-1-0716-2541-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In this chapter, I present a method for the ex vivo cultivation and live imaging of Drosophila imaginal disc explants using low concentrations of the steroid hormone 20-hydroxyecdysone (20E). This method has been optimized for analyzing cellular dynamics during wing disc growth and leverages recent insights from in vivo experiments demonstrating that 20E is required for growth and patterning of the imaginal tissues. Using this protocol, we directly observe wing disc proliferation at a rapid rate for at least 13 h during live imaging. The orientation of tissue growth is also consistent with that inferred from indirect in vivo techniques. Thus, this method provides an improved way of studying dynamic cellular processes and tissue movements during imaginal disc development. I first describe the preparation of the growth medium and the dissection, and then I include a protocol for mounting and live imaging of the explants.
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Affiliation(s)
- Natalie A Dye
- Mildred Scheel Nachwuchszentrum (MSNZ) P2 & Cluster of Excellence Physics of Life, Technische Universität Dresden, Dresden, Germany.
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7
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Das A, Gangarde YM, Tomar V, Shinde O, Upadhyay T, Alam S, Ghosh S, Chaudhary V, Saraogi I. Small-Molecule Inhibitor Prevents Insulin Fibrillogenesis and Preserves Activity. Mol Pharm 2020; 17:1827-1834. [PMID: 32347728 DOI: 10.1021/acs.molpharmaceut.9b01080] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Amyloidosis is a well-known but poorly understood phenomenon caused by the aggregation of proteins, often leading to pathological conditions. For example, the aggregation of insulin poses significant challenges during the preparation of pharmaceutical insulin formulations commonly used to treat diabetic patients. Therefore, it is essential to develop inhibitors of insulin aggregation for potential biomedical applications and for important mechanistic insights into amyloidogenic pathways. Here, we have identified a small molecule M1, which causes a dose-dependent reduction in insulin fibril formation. Biophysical analyses and docking results suggest that M1 likely binds to partially unfolded insulin intermediates. Further, M1-treated insulin had lower cytotoxicity and remained functionally active in regulating cell proliferation in cultured Drosophila wing epithelium. Thus, M1 is of great interest as a novel agent for inhibiting insulin aggregation during biopharmaceutical manufacturing.
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8
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tpHusion: An efficient tool for clonal pH determination in Drosophila. PLoS One 2020; 15:e0228995. [PMID: 32059043 PMCID: PMC7021318 DOI: 10.1371/journal.pone.0228995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 01/27/2020] [Indexed: 02/04/2023] Open
Abstract
Genetically encoded pH indicators (GEpHI) have emerged as important tools for investigating intracellular pH (pHi) dynamics in Drosophila. However, most of the indicators are based on the Gal4/UAS binary expression system. Here, we report the generation of a ubiquitously-expressed GEpHI. The fusion protein of super ecliptic pHluorin and FusionRed was cloned under the tubulin promoter (tpHusion) to drive it independently of the Gal4/UAS system. The function of tpHusion was validated in various tissues from different developmental stages of Drosophila. Differences in pHi were also indicated correctly in fixed tissues. Finally, we describe the use of tpHusion for comparative analysis of pHi in manipulated clones and the surrounding cells in epithelial tissues. Our findings establish tpHusion as a robust tool for studying pHi in Drosophila.
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9
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Luhur A, Klueg KM, Zelhof AC. Generating and working with Drosophila cell cultures: Current challenges and opportunities. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 8:e339. [PMID: 30561900 DOI: 10.1002/wdev.339] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/30/2018] [Accepted: 11/21/2018] [Indexed: 12/26/2022]
Abstract
The use of Drosophila cell cultures has positively impacted both fundamental and biomedical research. The most widely used cell lines: Schneider, Kc, the CNS and imaginal disc lines continue to be the choice for many applications. Drosophila cell lines provide a homogenous source of cells suitable for biochemical experimentations, transcriptomics, functional genomics, and biomedical applications. They are amenable to RNA interference and serve as a platform for high-throughput screens to identify relevant candidate genes or drugs for any biological process. Currently, CRISPR-based functional genomics are also being developed for Drosophila cell lines. Even though many uniquely derived cell lines exist, cell genetic techniques such the transgenic UAS-GAL4-based RasV12 oncogene expression, CRISPR-Cas9 editing and recombination mediated cassette exchange are likely to drive the establishment of many more lines from specific tissues, cells, or genotypes. However, the pace of creating new lines is hindered by several factors inherent to working with Drosophila cell cultures: single cell cloning, optimal media formulations and culture conditions capable of supporting lines from novel tissue sources or genotypes. Moreover, even though many Drosophila cell lines are morphologically and transcriptionally distinct it may be necessary to implement a standard for Drosophila cell line authentication, ensuring the identity and purity of each cell line. Altogether, recent advances and a standardized authentication effort should improve the utility of Drosophila cell cultures as a relevant model for fundamental and biomedical research. This article is categorized under: Technologies > Analysis of Cell, Tissue, and Animal Phenotypes.
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Affiliation(s)
- Arthur Luhur
- Department of Biology, Drosophila Genomics Resource Center, Indiana University Bloomington, Bloomington, Indiana
| | - Kristin M Klueg
- Department of Biology, Drosophila Genomics Resource Center, Indiana University Bloomington, Bloomington, Indiana
| | - Andrew C Zelhof
- Department of Biology, Drosophila Genomics Resource Center, Indiana University Bloomington, Bloomington, Indiana
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10
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Yanku Y, Bitman-Lotan E, Zohar Y, Kurant E, Zilke N, Eilers M, Orian A. Drosophila HUWE1 Ubiquitin Ligase Regulates Endoreplication and Antagonizes JNK Signaling During Salivary Gland Development. Cells 2018; 7:E151. [PMID: 30261639 PMCID: PMC6210797 DOI: 10.3390/cells7100151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 09/20/2018] [Accepted: 09/21/2018] [Indexed: 01/18/2023] Open
Abstract
The HECT-type ubiquitin ligase HECT, UBA and WWE Domain Containing 1, (HUWE1) regulates key cancer-related pathways, including the Myc oncogene. It affects cell proliferation, stress and immune signaling, mitochondria homeostasis, and cell death. HUWE1 is evolutionarily conserved from Caenorhabditis elegance to Drosophila melanogaster and Humans. Here, we report that the Drosophila ortholog, dHUWE1 (CG8184), is an essential gene whose loss results in embryonic lethality and whose tissue-specific disruption establishes its regulatory role in larval salivary gland development. dHUWE1 is essential for endoreplication of salivary gland cells and its knockdown results in the inability of these cells to replicate DNA. Remarkably, dHUWE1 is a survival factor that prevents premature activation of JNK signaling, thus preventing the disintegration of the salivary gland, which occurs physiologically during pupal stages. This function of dHUWE1 is general, as its inhibitory effect is observed also during eye development and at the organismal level. Epistatic studies revealed that the loss of dHUWE1 is compensated by dMyc proeitn expression or the loss of dmP53. dHUWE1 is therefore a conserved survival factor that regulates organ formation during Drosophila development.
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Affiliation(s)
- Yifat Yanku
- Rappaport Research Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
| | - Eliya Bitman-Lotan
- Rappaport Research Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
| | - Yaniv Zohar
- Rappaport Research Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
- Institute of Pathology, RAMBAM Medical Center, Haifa 30196, Israel.
| | - Estee Kurant
- Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel.
| | - Norman Zilke
- Genome-Scale Biology Research Program Institute of Biomedicine University of Helsinki, 00290 Helsinki, Finland.
| | - Martin Eilers
- Theodor Boveri Institute, Biocenter, University of Würzburg, D-97074 Würzburg, Germany.
| | - Amir Orian
- Rappaport Research Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
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11
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Comparing and Contrasting the Effects of Drosophila Condensin II Subunit dCAP-D3 Overexpression and Depletion in Vivo. Genetics 2018; 210:531-546. [PMID: 30068527 PMCID: PMC6216582 DOI: 10.1534/genetics.118.301344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 07/31/2018] [Indexed: 11/18/2022] Open
Abstract
The Condensin II complex plays important, conserved roles in genome organization throughout the cell cycle and in the regulation of gene expression. Previous studies have linked decreased Condensin II subunit expression with a variety of diseases. Here, we show that elevated levels of Condensin II subunits are detected in somatic cancers. To evaluate potential biological effects of elevated Condensin II levels, we overexpressed the Condensin II subunit, dCAP-D3 in Drosophila melanogaster larval tissues and examined the effects on the mitotic- and interphase-specific functions of Condensin II. Interestingly, while ubiquitous overexpression resulted in pupal lethality, tissue specific overexpression of dCAP-D3 caused formation of nucleoplasmic protein aggregates which slowed mitotic prophase progression, mimicking results observed when dCAP-D3 levels are depleted. Surprisingly, dCAP-D3 aggregate formation resulted in faster transitions from metaphase to anaphase. Overexpressed dCAP-D3 protein failed to precipitate other Condensin II subunits in nondividing tissues, but did cause changes to gene expression which occurred in a manner opposite of what was observed when dCAP-D3 levels were depleted in both dividing and nondividing tissues. Our findings show that altering dCAP-D3 levels in either direction has detrimental effects on mitotic timing, the regulation of gene expression, and organism development. Taken together, these data suggest that the different roles for Condensin II throughout the cell cycle may be independent of each other and/or that dCAP-D3 may possess functions that are separate from those involving its association with the Condensin II complex. If conserved, these findings could have implications for tumors harboring elevated CAP-D3 levels.
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12
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Dye NA, Popović M, Spannl S, Etournay R, Kainmüller D, Ghosh S, Myers EW, Jülicher F, Eaton S. Cell dynamics underlying oriented growth of the Drosophila wing imaginal disc. Development 2017; 144:4406-4421. [PMID: 29038308 DOI: 10.1242/dev.155069] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 10/05/2017] [Indexed: 12/30/2022]
Abstract
Quantitative analysis of the dynamic cellular mechanisms shaping the Drosophila wing during its larval growth phase has been limited, impeding our ability to understand how morphogen patterns regulate tissue shape. Such analysis requires explants to be imaged under conditions that maintain both growth and patterning, as well as methods to quantify how much cellular behaviors change tissue shape. Here, we demonstrate a key requirement for the steroid hormone 20-hydroxyecdysone (20E) in the maintenance of numerous patterning systems in vivo and in explant culture. We find that low concentrations of 20E support prolonged proliferation in explanted wing discs in the absence of insulin, incidentally providing novel insight into the hormonal regulation of imaginal growth. We use 20E-containing media to observe growth directly and to apply recently developed methods for quantitatively decomposing tissue shape changes into cellular contributions. We discover that whereas cell divisions drive tissue expansion along one axis, their contribution to expansion along the orthogonal axis is cancelled by cell rearrangements and cell shape changes. This finding raises the possibility that anisotropic mechanical constraints contribute to growth orientation in the wing disc.
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Affiliation(s)
- Natalie A Dye
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany
| | - Marko Popović
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
| | - Stephanie Spannl
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany
| | - Raphaël Etournay
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany.,Unité de Génétique et Physiologie de l'Audition UMRS 1120, Département de Neurosciences, Institut Pasteur, 75015 Paris, France
| | - Dagmar Kainmüller
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany.,Janelia Farm Research Campus, 19700 Helix Dr, Ashburn, VA 20147, USA
| | - Suhrid Ghosh
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany
| | - Eugene W Myers
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany.,Center for Systems Biology Dresden, Pfotenhauerstrasse 108, 01309 Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany .,Center for Systems Biology Dresden, Pfotenhauerstrasse 108, 01309 Dresden, Germany
| | - Suzanne Eaton
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01309 Dresden, Germany .,Biotechnologisches Zentrum, Technische Universität Dresden, Tatzberg 47/49, 01309 Dresden, Germany
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13
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Hussain R, Shaukat Z, Khan M, Saint R, Gregory SL. Phosphoenolpyruvate Carboxykinase Maintains Glycolysis-driven Growth in Drosophila Tumors. Sci Rep 2017; 7:11531. [PMID: 28912546 PMCID: PMC5599506 DOI: 10.1038/s41598-017-11613-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/25/2017] [Indexed: 12/27/2022] Open
Abstract
Tumors frequently fail to pass on all their chromosomes correctly during cell division, and this chromosomal instability (CIN) causes irregular aneuploidy and oxidative stress in cancer cells. Our objective was to test knockdowns of metabolic enzymes in Drosophila to find interventions that could exploit the differences between normal and CIN cells to block CIN tumor growth without harming the host animal. We found that depleting by RNAi or feeding the host inhibitors against phosphoenolpyruvate carboxykinase (PEPCK) was able to block the growth of CIN tissue in a brat tumor explant model. Increasing NAD+ or oxidising cytoplasmic NADH was able to rescue the growth of PEPCK depleted tumors, suggesting a problem in clearing cytoplasmic NADH. Consistent with this, blocking the glycerol-3-phosphate shuttle blocked tumor growth, as well as lowering ROS levels. This work suggests that proliferating CIN cells are particularly vulnerable to inhibition of PEPCK, or its metabolic network, because of their compromised redox status.
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Affiliation(s)
- Rashid Hussain
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | - Zeeshan Shaukat
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | - Mahwish Khan
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia
| | | | - Stephen L Gregory
- Department of Genetics and Evolution, University of Adelaide, Adelaide, 5006, Australia.
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14
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Narciso CE, Contento NM, Storey TJ, Hoelzle DJ, Zartman JJ. Release of Applied Mechanical Loading Stimulates Intercellular Calcium Waves in Drosophila Wing Discs. Biophys J 2017; 113:491-501. [PMID: 28746859 PMCID: PMC5529297 DOI: 10.1016/j.bpj.2017.05.051] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 01/14/2023] Open
Abstract
Mechanical forces are critical but poorly understood inputs for organogenesis and wound healing. Calcium ions (Ca2+) are critical second messengers in cells for integrating environmental and mechanical cues, but the regulation of Ca2+ signaling is poorly understood in developing epithelial tissues. Here we report a chip-based regulated environment for microorgans that enables systematic investigations of the crosstalk between an organ's mechanical stress environment and biochemical signaling under genetic and chemical perturbations. This method enabled us to define the essential conditions for generating organ-scale intercellular Ca2+ waves in Drosophila wing discs that are also observed in vivo during organ development. We discovered that mechanically induced intercellular Ca2+ waves require fly extract growth serum as a chemical stimulus. Using the chip-based regulated environment for microorgans, we demonstrate that not the initial application but instead the release of mechanical loading is sufficient, but not necessary, to initiate intercellular Ca2+ waves. The Ca2+ response depends on the prestress intercellular Ca2+ activity and not on the magnitude or duration of the mechanical stimulation applied. Mechanically induced intercellular Ca2+ waves rely on IP3R-mediated Ca2+-induced Ca2+ release and propagation through gap junctions. Thus, intercellular Ca2+ waves in developing epithelia may be a consequence of stress dissipation during organ growth.
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Affiliation(s)
- Cody E Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Nicholas M Contento
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Thomas J Storey
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana
| | - David J Hoelzle
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana.
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana.
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15
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Strassburger K, Lorbeer FK, Lutz M, Graf F, Boutros M, Teleman AA. Oxygenation and adenosine deaminase support growth and proliferation of ex vivo cultured Drosophila wing imaginal discs. Development 2017; 144:2529-2538. [PMID: 28526754 DOI: 10.1242/dev.147538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 05/11/2017] [Indexed: 01/22/2023]
Abstract
The Drosophila wing imaginal disc has been an important model system over past decades for discovering novel biology related to development, signaling and epithelial morphogenesis. Novel experimental approaches have been enabled using a culture setup that allows ex vivo cultures of wing discs. Current setups, however, are not able to sustain both growth and cell-cycle progression of wing discs ex vivo We discover here a setup that requires both oxygenation of the tissue and adenosine deaminase activity in the medium, and supports both growth and proliferation of wing discs for 9 h. Nonetheless, further work will be required to extend the duration of the culturing and to enable live imaging of the cultured discs in the future.
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Affiliation(s)
| | | | - Marilena Lutz
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Fabian Graf
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Michael Boutros
- German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
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16
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Zhang CU, Cadigan KM. The matrix protein Tiggrin regulates plasmatocyte maturation in Drosophila larva. Development 2017; 144:2415-2427. [PMID: 28526755 DOI: 10.1242/dev.149641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Accepted: 05/11/2017] [Indexed: 01/24/2023]
Abstract
The lymph gland (LG) is a major source of hematopoiesis during Drosophila development. In this tissue, prohemocytes differentiate into multiple lineages, including macrophage-like plasmatocytes, which comprise the vast majority of mature hemocytes. Previous studies have uncovered genetic pathways that regulate prohemocyte maintenance and some cell fate choices between hemocyte lineages. However, less is known about how the plasmatocyte pool of the LG is established and matures. Here, we report that Tiggrin, a matrix protein expressed in the LG, is a specific regulator of plasmatocyte maturation. Tiggrin mutants exhibit precocious maturation of plasmatocytes, whereas Tiggrin overexpression blocks this process, resulting in a buildup of intermediate progenitors (IPs) expressing prohemocyte and hemocyte markers. These IPs likely represent a transitory state in prohemocyte to plasmatocyte differentiation. We also found that overexpression of Wee1 kinase, which slows G2/M progression, results in a phenotype similar to Tiggrin overexpression, whereas String/Cdc25 expression phenocopies Tiggrin mutants. Further analysis revealed that Wee1 inhibits plasmatocyte maturation through upregulation of Tiggrin transcription. Our results elucidate connections between the extracellular matrix and cell cycle regulators in the regulation of hematopoiesis.
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Affiliation(s)
- Chen U Zhang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ken M Cadigan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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17
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Calcium spikes, waves and oscillations in a large, patterned epithelial tissue. Sci Rep 2017; 7:42786. [PMID: 28218282 PMCID: PMC5317010 DOI: 10.1038/srep42786] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 01/17/2017] [Indexed: 12/31/2022] Open
Abstract
While calcium signaling in excitable cells, such as muscle or neurons, is extensively characterized, calcium signaling in epithelial tissues is little understood. Specifically, the range of intercellular calcium signaling patterns elicited by tightly coupled epithelial cells and their function in the regulation of epithelial characteristics are little explored. We found that in Drosophila imaginal discs, a widely studied epithelial model organ, complex spatiotemporal calcium dynamics occur. We describe patterns that include intercellular waves traversing large tissue domains in striking oscillatory patterns as well as spikes confined to local domains of neighboring cells. The spatiotemporal characteristics of intercellular waves and oscillations arise as emergent properties of calcium mobilization within a sheet of gap-junction coupled cells and are influenced by cell size and environmental history. While the in vivo function of spikes, waves and oscillations requires further characterization, our genetic experiments suggest that core calcium signaling components guide actomyosin organization. Our study thus suggests a possible role for calcium signaling in epithelia but importantly, introduces a model epithelium enabling the dissection of cellular mechanisms supporting the initiation, transmission and regeneration of long-range intercellular calcium waves and the emergence of oscillations in a highly coupled multicellular sheet.
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18
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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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19
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Long Term Ex Vivo Culture and Live Imaging of Drosophila Larval Imaginal Discs. PLoS One 2016; 11:e0163744. [PMID: 27685172 PMCID: PMC5042436 DOI: 10.1371/journal.pone.0163744] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/13/2016] [Indexed: 12/27/2022] Open
Abstract
Continuous imaging of live tissues provides clear temporal sequence of biological events. The Drosophila imaginal discs have been popular experimental subjects for the study of a wide variety of biological phenomena, but long term culture that allows normal development has not been satisfactory. Here we report a culture method that can sustain normal development for 18 hours and allows live imaging. The method is validated in multiple discs and for cell proliferation, differentiation and migration. However, it does not support disc growth and cannot support cell proliferation for more than 7 to 12 hr. We monitored the cellular behavior of retinal basal glia in the developing eye disc and found that distinct glia type has distinct properties of proliferation and migration. The live imaging provided direct proof that wrapping glia differentiated from existing glia after migrating to the anterior front, and unexpectedly found that they undergo endoreplication before wrapping axons, and their nuclei migrate up and down along the axons. UV-induced specific labeling of a single carpet glia also showed that the two carpet glia membrane do not overlap and suggests a tiling or repulsion mechanism between the two cells. These findings demonstrated the usefulness of an ex vivo culture method and live imaging.
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20
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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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21
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Heller D, Hoppe A, Restrepo S, Gatti L, Tournier AL, Tapon N, Basler K, Mao Y. EpiTools: An Open-Source Image Analysis Toolkit for Quantifying Epithelial Growth Dynamics. Dev Cell 2016; 36:103-116. [PMID: 26766446 PMCID: PMC4712040 DOI: 10.1016/j.devcel.2015.12.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 11/10/2015] [Accepted: 12/09/2015] [Indexed: 11/30/2022]
Abstract
Epithelia grow and undergo extensive rearrangements to achieve their final size and shape. Imaging the dynamics of tissue growth and morphogenesis is now possible with advances in time-lapse microscopy, but a true understanding of their complexities is limited by automated image analysis tools to extract quantitative data. To overcome such limitations, we have designed a new open-source image analysis toolkit called EpiTools. It provides user-friendly graphical user interfaces for accurately segmenting and tracking the contours of cell membrane signals obtained from 4D confocal imaging. It is designed for a broad audience, especially biologists with no computer-science background. Quantitative data extraction is integrated into a larger bioimaging platform, Icy, to increase the visibility and usability of our tools. We demonstrate the usefulness of EpiTools by analyzing Drosophila wing imaginal disc growth, revealing previously overlooked properties of this dynamic tissue, such as the patterns of cellular rearrangements.
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Affiliation(s)
- Davide Heller
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland; SIB Swiss Institute of Bioinformatics, Quartier Sorge - Batiment Genopode, 1015 Lausanne, Switzerland
| | - Andreas Hoppe
- Digital Imaging Research Centre, Faculty of Science, Engineering and Computing, Kingston University, Kingston-upon-Thames KT1 2EE, UK
| | - Simon Restrepo
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Lorenzo Gatti
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland; Institute of Applied Simulations, Zürich University of Applied Sciences, Einsiedlerstrasse 31a, 8820 Wädenswil, Switzerland; SIB Swiss Institute of Bioinformatics, Quartier Sorge - Batiment Genopode, 1015 Lausanne, Switzerland
| | - Alexander L Tournier
- Apoptosis and Proliferation Control Laboratory, Lincoln's Inn Fields Laboratory, Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Nicolas Tapon
- Apoptosis and Proliferation Control Laboratory, Lincoln's Inn Fields Laboratory, Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Konrad Basler
- Institute of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Yanlan Mao
- MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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22
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Abstract
The ex vivo cultivation and live imaging of wing discs open exciting new research avenues by overcoming the limitations of end-point analysis of fixed tissues. Here we describe how to prepare an optimized wing disc culture medium (WM1) and how to dissect and arrange wing discs for cultivation and live imaging. This protocol enables the study of dynamic phenomena such as cell division and delamination as well as the use of pharmacological compounds and biosensors. Wing discs cultured and imaged as described here, maintain constant levels of proliferation during the first ten hours of culture.
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23
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Narciso C, Wu Q, Brodskiy P, Garston G, Baker R, Fletcher A, Zartman J. Patterning of wound-induced intercellular Ca(2+) flashes in a developing epithelium. Phys Biol 2015; 12:056005. [PMID: 26331891 DOI: 10.1088/1478-3975/12/5/056005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Differential mechanical force distributions are increasingly recognized to provide important feedback into the control of an organ's final size and shape. As a second messenger that integrates and relays mechanical information to the cell, calcium ions (Ca(2+)) are a prime candidate for providing important information on both the overall mechanical state of the tissue and resulting behavior at the individual-cell level during development. Still, how the spatiotemporal properties of Ca(2+) transients reflect the underlying mechanical characteristics of tissues is still poorly understood. Here we use an established model system of an epithelial tissue, the Drosophila wing imaginal disc, to investigate how tissue properties impact the propagation of Ca(2+) transients induced by laser ablation. The resulting intercellular Ca(2+) flash is found to be mediated by inositol 1,4,5-trisphosphate and depends on gap junction communication. Further, we find that intercellular Ca(2+) transients show spatially non-uniform characteristics across the proximal-distal axis of the larval wing imaginal disc, which exhibit a gradient in cell size and anisotropy. A computational model of Ca(2+) transients is employed to identify the principle factors explaining the spatiotemporal patterning dynamics of intercellular Ca(2+) flashes. The relative Ca(2+) flash anisotropy is principally explained by local cell shape anisotropy. Further, Ca(2+) velocities are relatively uniform throughout the wing disc, irrespective of cell size or anisotropy. This can be explained by the opposing effects of cell diameter and cell elongation on intercellular Ca(2+) propagation. Thus, intercellular Ca(2+) transients follow lines of mechanical tension at velocities that are largely independent of tissue heterogeneity and reflect the mechanical state of the underlying tissue.
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Affiliation(s)
- Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, IN 46556, USA
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