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Tajiri R, Hirano A, Kaibara YY, Tezuka D, Chen Z, Kojima T. Notch signaling generates the "cut here line" on the cuticle of the puparium in Drosophila melanogaster. iScience 2023; 26:107279. [PMID: 37529108 PMCID: PMC10387574 DOI: 10.1016/j.isci.2023.107279] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 05/25/2023] [Accepted: 06/30/2023] [Indexed: 08/03/2023] Open
Abstract
During a molt or eclosion, insects shed their cuticle, an extracellular matrix made by underlying epidermal cells, by cleavage along a defined line. This means that the "cut here line" is pre-formed on the cuticle, and its formation is indispensable for insect life. Here, we show that the proper formation of the operculum ridge (OR), which is the "cut here line" on the puparium (pupal case) of Drosophila melanogaster, involves Notch signaling activation in the epidermal cells just beneath the future OR region (OR-forming cells). The inhibition of Notch signaling causes defects in eclosion due to failure in OR cleavage, the chitin organization and several cuticular proteins localization, glucose dehydrogenase (Gld) activity, and OR-forming cell shape. Our findings provide the first insight into the molecular basis of the structure and formation of the "cut here line" on the cuticle.
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Affiliation(s)
- Reiko Tajiri
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Ayaka Hirano
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Yu-ya Kaibara
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Daiki Tezuka
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Zhengyang Chen
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
| | - Tetsuya Kojima
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, the University of Tokyo, Biosciences Building 501, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan
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Dong W, Flaven-Pouchon J, Gao YH, Song CY, El Wakil A, Zhang JZ, Moussian B. Chitinase 6 is required for procuticle thickening and organ shape in Drosophila wing. INSECT SCIENCE 2023; 30:268-278. [PMID: 36114809 DOI: 10.1111/1744-7917.13115] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 08/09/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
The polysaccharide chitin is a major scaffolding molecule in the insect cuticle. In order to be functional, both chitin amounts and chitin organization have been shown to be important parameters. Despite great advances in the past decade, the molecular mechanisms of chitin synthesis and organization are not fully understood. Here, we have characterized the function of the Chitinase 6 (Cht6) in the formation of the wing, which is a simple flat cuticle organ, in the fruit fly Drosophila melanogaster. Reduction of Cht6 function by RNA interference during wing development does not affect chitin organization, but entails a thinner cuticle suggesting reduced chitin amounts. This phenotype is opposed to the one reported recently to be caused by reduction of Cht10 expression. Probably as a consequence, cuticle permeability to xenobiotics is enhanced in Cht6-less wings. We also observed massive deformation of these wings. In addition, the shape of the abdomen is markedly changed upon abdominal suppression of Cht6. Finally, we found that suppression of Cht6 transcript levels influences the expression of genes coding for enzymes of the chitin biosynthesis pathway. This finding indicates that wing epidermal cells respond to activity changes of Cht6 probably trying to adjust chitin amounts. Together, in a working model, we propose that Cht6-introduced modifications of chitin are needed for chitin synthesis to proceed correctly. Cuticle thickness, according to our hypothesis, is in turn required for correct organ or body part shape. The molecular mechanisms of this processes shall be characterized in the future.
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Affiliation(s)
- Wei Dong
- Institute of Applied Biology, Shanxi University, Taiyuan, China
| | | | - Ying-Hao Gao
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- College of Life Science, Shanxi University, Taiyuan, China
| | - Chen-Yang Song
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- College of Life Science, Shanxi University, Taiyuan, China
| | - Abeer El Wakil
- Faculty of Education, Department of Biological and Geological Sciences, Alexandria University, Alexandria, Egypt
| | - Jian-Zhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan, China
| | - Bernard Moussian
- Institute of Applied Biology, Shanxi University, Taiyuan, China
- Interfaculty Institute of Cell Biology, University of Tübingen, Tübingen, Germany
- INRAE, CNRS, Université Côte d'Azur, Institut Sophia Agrobiotech, Sophia Antipolis, France
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3
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Eigenfeld M, Kerpes R, Becker T. Recombinant protein linker production as a basis for non-invasive determination of single-cell yeast age in heterogeneous yeast populations. RSC Adv 2021; 11:31923-31932. [PMID: 35495491 PMCID: PMC9041608 DOI: 10.1039/d1ra05276d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022] Open
Abstract
The physiological and metabolic diversity of a yeast culture is the sum of individual cell phenotypes. As well as environmental conditions, genetics, and numbers of cell divisions, a major factor influencing cell characteristics is cell age. A postcytokinesis bud scar on the mother cell, a benchmark in the replicative life span, is a quantifiable indicator of cell age, characterized by significant amounts of chitin. We developed a binding process for visualizing the bud scars of Saccharomyces pastorianus var. carlsbergensis using a protein linker containing a polyhistidine tag, a superfolder green fluorescent protein (sfGFP), and a chitin-binding domain (His6-SUMO-sfGFP-ChBD). The binding did not affect yeast viability; thus, our method provides the basis for non-invasive cell age determination using flow cytometry. The His6-SUMO-sfGFP-ChBD protein was synthesized in Escherichia coli, purified using two-stage chromatography, and checked for monodispersity and purity. Linker-cell binding and the characteristics of the bound complex were determined using flow cytometry and confocal laser scanning microscopy (CLSM). Flow cytometry showed that protein binding increased to 60 455 ± 2706 fluorescence units per cell. The specific coupling of the linker to yeast cells was additionally verified by CLSM and adsorption isotherms using yeast cells, E. coli cells, and chitin resin. We found a relationship between the median bud scar number, the median of the fluorescence units, and the chitin content of yeast cells. A fast measurement of yeast population dynamics by flow cytometry is possible, using this protein binding technique. Rapid qualitative determination of yeast cell age distribution can therefore be performed.
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Affiliation(s)
- Marco Eigenfeld
- Technical University of Munich, Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology Weihenstephaner Steig 20 85354 Freising Germany
| | - Roland Kerpes
- Technical University of Munich, Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology Weihenstephaner Steig 20 85354 Freising Germany
| | - Thomas Becker
- Technical University of Munich, Chair of Brewing and Beverage Technology, Research Group Beverage and Cereal Biotechnology Weihenstephaner Steig 20 85354 Freising Germany
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4
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Mechano-chemical enforcement of tendon apical ECM into nano-filaments during Drosophila flight muscle development. Curr Biol 2021; 31:1366-1378.e7. [PMID: 33545042 DOI: 10.1016/j.cub.2021.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 11/16/2020] [Accepted: 01/06/2021] [Indexed: 02/06/2023]
Abstract
Contractile tension is critical for musculoskeletal system development and maintenance. In insects, the muscular force is transmitted to the exoskeleton through the tendon cells and tendon apical extracellular matrix (ECM). In Drosophila, we found tendon cells secrete Dumpy (Dpy), a zona pellucida domain (ZPD) protein, to form the force-resistant filaments in the exuvial space, anchoring the tendon cells to the pupal cuticle. We showed that Dpy undergoes filamentous conversion in response to the tension increment during indirect flight muscle development. We also found another ZPD protein Quasimodo (Qsm) protects the notum epidermis from collapsing under the muscle tension by enhancing the tensile strength of Dpy filaments. Qsm is co-transported with Dpy in the intracellular vesicles and diffuses into the exuvial space after secretion. Tissue-specific qsm expression rescued the qsm mutant phenotypes in distant tissues, suggesting Qsm can function in a long-range, non-cell-autonomous manner. In the cell culture assay, Qsm interacts with Dpy-ZPD and promotes secretion and polymerization of Dpy-ZPD. The roles of Qsm underlies the positive feedback mechanism of force-dependent organization of Dpy filaments, providing new insights into apical ECM remodeling through the unconventional interaction of ZPD proteins.
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Tsurkan MV, Voronkina A, Khrunyk Y, Wysokowski M, Petrenko I, Ehrlich H. Progress in chitin analytics. Carbohydr Polym 2021; 252:117204. [DOI: 10.1016/j.carbpol.2020.117204] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/25/2022]
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Pan BY, Li GY, Wu Y, Zhou ZS, Zhou M, Li C. Glucose Utilization in the Regulation of Chitin Synthesis in Brown Planthopper. JOURNAL OF INSECT SCIENCE (ONLINE) 2019; 19:5574393. [PMID: 31557289 PMCID: PMC6761884 DOI: 10.1093/jisesa/iez081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Indexed: 06/10/2023]
Abstract
Glucose-6-phosphatase (G6Pase) and hexokinase (HK) are two key enzymes in the glycolysis and gluconeogenesis pathways, which catalyze the synthesis and degradation of glucose in insects, respectively. G6Pase and HK play an important role in insect growth by regulating the metabolism of glucose, leading to the efficient metabolism of other macromolecules. However, it is unclear whether these genes could be investigated for pest control through their actions on chitin metabolism. We studied the potential functions of G6Pase and HK genes in the regulation of chitin metabolism pathways by RNAi technology. Interference with G6Pase expression did not affect trehalose and chitin metabolism pathways in brown planthopper, Nilaparvata lugens (Stål). However, knockdown of the HK gene resulted in a significant decrease of expression of genes associated with the trehalose metabolic pathway but had no significant effect on trehalase activity, trehalose content, or glucogen content. Additionally, HK knockdown resulting in downregulation of the genes involved in chitin metabolism in the brown planthopper. These insects also showed wing deformities and difficulty in molting to varying degrees. We suggest that the silencing of HK expression directly inhibited the decomposition of glucose, leading to impaired chitin synthesis.
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Affiliation(s)
- Bi-Ying Pan
- Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, Department of Biology and Engineering of Environment, Guiyang University, Guiyang, P.R. China
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, P.R. China
| | - Guo-Yong Li
- Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, Department of Biology and Engineering of Environment, Guiyang University, Guiyang, P.R. China
| | - Yan Wu
- Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, Department of Biology and Engineering of Environment, Guiyang University, Guiyang, P.R. China
| | - Zhong-Shi Zhou
- Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, Department of Biology and Engineering of Environment, Guiyang University, Guiyang, P.R. China
| | - Min Zhou
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, P.R. China
| | - Can Li
- Guizhou Provincial Key Laboratory for Rare Animal and Economic Insect of the Mountainous Region, Department of Biology and Engineering of Environment, Guiyang University, Guiyang, P.R. China
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Hinaux H, Bachem K, Battistara M, Rossi M, Xin Y, Jaenichen R, Le Poul Y, Arnoult L, Kobler JM, Grunwald Kadow IC, Rodermund L, Prud'homme B, Gompel N. Revisiting the developmental and cellular role of the pigmentation gene yellow in Drosophila using a tagged allele. Dev Biol 2018; 438:111-123. [PMID: 29634916 DOI: 10.1016/j.ydbio.2018.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/28/2018] [Accepted: 04/06/2018] [Indexed: 10/17/2022]
Abstract
Pigmentation is a diverse and ecologically relevant trait in insects. Pigment formation has been studied extensively at the genetic and biochemical levels. The temporality of pigment formation during animal development, however, is more elusive. Here, we examine this temporality, focusing on yellow, a gene involved in the formation of black melanin. We generated a protein-tagged yellow allele in the fruit fly Drosophila melanogaster, which allowed us to precisely describe Yellow expression pattern at the tissue and cellular levels throughout development. We found Yellow expressed in the pupal epidermis in patterns prefiguring black pigmentation. We also found Yellow expressed in a few central neurons from the second larval instar to adult stages, including a subset of neurons adjacent to the clock neurons marked by the gene Pdf. We then specifically examined the dynamics of Yellow expression domain and subcellular localization in relationship to pigment formation. In particular, we showed how a late step of re-internalization is regulated by the large low-density lipoprotein receptor-related protein Megalin. Finally we suggest a new function for Yellow in the establishment of sharp pigmentation pattern boundaries, whereby this protein may assume a structural role, anchoring pigment deposits or pigmentation enzymes in the cuticle.
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Affiliation(s)
- Hélène Hinaux
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Katharina Bachem
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Margherita Battistara
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Matteo Rossi
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Yaqun Xin
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Rita Jaenichen
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Yann Le Poul
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Laurent Arnoult
- Aix-Marseille Université, CNRS, IBDM, Institut de Biologie du Développement de Marseille, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Johanna M Kobler
- Technical University of Munich, School of Life Sciences, ZIEL - Institute for Food And Health, Liesel-Beckmann-Str. 4, 85354 Freising, Germany; Chemosensory Coding, Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany
| | - Ilona C Grunwald Kadow
- Technical University of Munich, School of Life Sciences, ZIEL - Institute for Food And Health, Liesel-Beckmann-Str. 4, 85354 Freising, Germany
| | - Lisa Rodermund
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany
| | - Benjamin Prud'homme
- Aix-Marseille Université, CNRS, IBDM, Institut de Biologie du Développement de Marseille, Campus de Luminy Case 907, 13288 Marseille Cedex 9, France
| | - Nicolas Gompel
- Ludwig-Maximilians Universität München, Fakultät für Biologie, Biozentrum, Grosshaderner Strasse 2, 82152 Planegg-Martinsried, Germany.
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Rosa JB, Metzstein MM, Ghabrial AS. An Ichor-dependent apical extracellular matrix regulates seamless tube shape and integrity. PLoS Genet 2018; 14:e1007146. [PMID: 29309404 PMCID: PMC5774827 DOI: 10.1371/journal.pgen.1007146] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/19/2018] [Accepted: 12/09/2017] [Indexed: 01/25/2023] Open
Abstract
During sprouting angiogenesis in the vertebrate vascular system, and primary branching in the Drosophila tracheal system, specialized tip cells direct branch outgrowth and network formation. When tip cells lumenize, they form subcellular (seamless) tubes. How these seamless tubes are made, shaped and maintained remains poorly understood. Here we characterize a Drosophila mutant called ichor (ich), and show that ich is essential for the integrity and shape of seamless tubes in tracheal terminal cells. We find that Ich regulates seamless tubulogenesis via its role in promoting the formation of a mature apical extracellular matrix (aECM) lining the lumen of the seamless tubes. We determined that ich encodes a zinc finger protein (CG11966) that acts, as a transcriptional activator required for the expression of multiple aECM factors, including a novel membrane-anchored trypsin protease (CG8213). Thus, the integrity and shape of seamless tubes are regulated by the aECM that lines their lumens.
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Affiliation(s)
- Jeffrey B. Rosa
- Department of Cell & Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Mark M. Metzstein
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Amin S. Ghabrial
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States of America
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9
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Adler PN. Gene expression and morphogenesis during the deposition of Drosophila wing cuticle. Fly (Austin) 2017. [PMID: 28631994 DOI: 10.1080/19336934.2017.1295188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The exoskeleton of insects and other arthropods is a very versatile material that is characterized by a complex multilayer structure. In Sobala and Adler (2016) we analyzed the process of wing cuticle deposition by RNAseq and electron microscopy. In this extra view we discuss the unique aspects of the envelope the first and most outermost layer and the gene expression program seen at the end of cuticle deposition. We discussed the role of undulae in the deposition of cuticle and how the hydrophobicity of wing cuticle arises.
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Affiliation(s)
- Paul N Adler
- a Biology Department, Cell Biology Department , University of Virginia , Charlottesville , VA , USA
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Wiens MD, Shen Y, Li X, Salem MA, Smisdom N, Zhang W, Brown A, Campbell RE. A Tandem Green-Red Heterodimeric Fluorescent Protein with High FRET Efficiency. Chembiochem 2016; 17:2361-2367. [PMID: 27781394 DOI: 10.1002/cbic.201600492] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Indexed: 12/28/2022]
Abstract
The tetrameric red fluorescent protein from Discosoma sp. coral (DsRed) has previously been engineered to produce dimeric and monomeric fluorescent variants with excitation and emission profiles that span the visible spectrum. The brightest of the effectively monomeric DsRed variants is tdTomato-a tandem fusion of a dimeric DsRed variant. Here we describe the engineering of brighter red (RRvT), green (GGvT), and green-red heterodimeric (GRvT) tdTomato variants. GRvT exhibited 99 % intramolecular FRET efficiency, resulting in long Stokes shift red fluorescence. These new variants could prove useful for multicolor live-cell imaging applications.
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Affiliation(s)
- Matthew D Wiens
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Yi Shen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Xi Li
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - M Alaraby Salem
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Nick Smisdom
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
- Present address: Faculty of Medicine and Life Sciences, Universiteit Hasselt, Martelarenlaan 42, 3500, Hasselt, Belgium
| | - Wei Zhang
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Alex Brown
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
| | - Robert E Campbell
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta, T6G 2G2, Canada
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Sobala LF, Adler PN. The Gene Expression Program for the Formation of Wing Cuticle in Drosophila. PLoS Genet 2016; 12:e1006100. [PMID: 27232182 PMCID: PMC4883753 DOI: 10.1371/journal.pgen.1006100] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/11/2016] [Indexed: 11/19/2022] Open
Abstract
The cuticular exoskeleton of insects and other arthropods is a remarkably versatile material with a complex multilayer structure. We made use of the ability to isolate cuticle synthesizing cells in relatively pure form by dissecting pupal wings and we used RNAseq to identify genes expressed during the formation of the adult wing cuticle. We observed dramatic changes in gene expression during cuticle deposition, and combined with transmission electron microscopy, we were able to identify candidate genes for the deposition of the different cuticular layers. Among genes of interest that dramatically change their expression during the cuticle deposition program are ones that encode cuticle proteins, ZP domain proteins, cuticle modifying proteins and transcription factors, as well as genes of unknown function. A striking finding is that mutations in a number of genes that are expressed almost exclusively during the deposition of the envelope (the thin outermost layer that is deposited first) result in gross defects in the procuticle (the thick chitinous layer that is deposited last). An attractive hypothesis to explain this is that the deposition of the different cuticle layers is not independent with the envelope instructing the formation of later layers. Alternatively, some of the genes expressed during the deposition of the envelope could form a platform that is essential for the deposition of all cuticle layers. Insects and other arthropods are an extremely successful group of animals. A unique and key feature of their lifestyle is their chitin containing cuticular exoskeleton, a complex layered material, which remains rather poorly understood for so prominent of a biological material. We have characterized the gene expression pattern of wing epithelial cells over the period of cuticle formation and also carried out transmission electron microscopy, which allows us to identify genes that likely play a role in the formation of different cuticle layers. Functional studies suggest that the deposition of the earliest layer influences the deposition of the later ones.
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Affiliation(s)
- Lukasz F. Sobala
- Biology Department and Cell Biology Department, University of Virginia, Charlottesville, Virginia, United States of America
| | - Paul N. Adler
- Biology Department and Cell Biology Department, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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