1
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Nikonova E, DeCata J, Canela M, Barz C, Esser A, Bouterwek J, Roy A, Gensler H, Heß M, Straub T, Forne I, Spletter ML. Bruno 1/CELF regulates splicing and cytoskeleton dynamics to ensure correct sarcomere assembly in Drosophila flight muscles. PLoS Biol 2024; 22:e3002575. [PMID: 38683844 PMCID: PMC11081514 DOI: 10.1371/journal.pbio.3002575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 05/09/2024] [Accepted: 03/04/2024] [Indexed: 05/02/2024] Open
Abstract
Muscles undergo developmental transitions in gene expression and alternative splicing that are necessary to refine sarcomere structure and contractility. CUG-BP and ETR-3-like (CELF) family RNA-binding proteins are important regulators of RNA processing during myogenesis that are misregulated in diseases such as Myotonic Dystrophy Type I (DM1). Here, we report a conserved function for Bruno 1 (Bru1, Arrest), a CELF1/2 family homolog in Drosophila, during early muscle myogenesis. Loss of Bru1 in flight muscles results in disorganization of the actin cytoskeleton leading to aberrant myofiber compaction and defects in pre-myofibril formation. Temporally restricted rescue and RNAi knockdown demonstrate that early cytoskeletal defects interfere with subsequent steps in sarcomere growth and maturation. Early defects are distinct from a later requirement for bru1 to regulate sarcomere assembly dynamics during myofiber maturation. We identify an imbalance in growth in sarcomere length and width during later stages of development as the mechanism driving abnormal radial growth, myofibril fusion, and the formation of hollow myofibrils in bru1 mutant muscle. Molecularly, we characterize a genome-wide transition from immature to mature sarcomere gene isoform expression in flight muscle development that is blocked in bru1 mutants. We further demonstrate that temporally restricted Bru1 rescue can partially alleviate hypercontraction in late pupal and adult stages, but it cannot restore myofiber function or correct structural deficits. Our results reveal the conserved nature of CELF function in regulating cytoskeletal dynamics in muscle development and demonstrate that defective RNA processing due to misexpression of CELF proteins causes wide-reaching structural defects and progressive malfunction of affected muscles that cannot be rescued by late-stage gene replacement.
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Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jenna DeCata
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
| | - Marc Canela
- Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Christiane Barz
- Muscle Dynamics Group, Max Planck Institute of Biochemistry, München, Germany
| | - Alexandra Esser
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jessica Bouterwek
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Akanksha Roy
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Heidemarie Gensler
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Martin Heß
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Tobias Straub
- Biomedical Center, Bioinformatics Core Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Ignasi Forne
- Biomedical Center, Protein Analysis Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Maria L. Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
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2
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Lim-Kian-Siang G, Izawa-Ishiguro AR, Rao Y. Neurexin-1-dependent circuit activity is required for the maintenance of photoreceptor subtype identity in Drosophila. Mol Brain 2024; 17:2. [PMID: 38167109 PMCID: PMC10759516 DOI: 10.1186/s13041-023-01073-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024] Open
Abstract
In the human and Drosophila color vision system, each photoreceptor neuron (cone cell in humans and R7/R8 photoreceptor cell in Drosophila) makes a stochastic decision to express a single photopigment of the same family with the exclusion of the others. While recent studies have begun to reveal the mechanisms that specify the generation of cone subtypes during development in mammals, nothing is known about how the mosaic of mutually exclusive cone subtypes is maintained in the mammalian retina. In Drosophila, recent work has led to the identification of several intrinsic factors that maintain the identity of R8 photoreceptor subtypes in adults. Whether and how extrinsic mechanisms are involved, however, remain unknown. In this study, we present evidence that supports that the Drosophila transsynaptic adhesion molecule Neurexin 1 (Dnrx-1) is required non-cell autonomously in R8p subtypes for the maintenance of R8y subtype identity. Silencing the activity of R8p subtypes caused a phenotype identical to that in dnrx-1 mutants. These results support a novel role for Nrx-1-dependent circuit activity in mediating the communication between R8 photoreceptor subtypes for maintaining the subtype identity in the retina.
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Affiliation(s)
- Gabrielle Lim-Kian-Siang
- McGill Centre for Research in Neuroscience, Montreal, Canada
- Integrated Program in Neuroscience, McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada
| | - Arianna R Izawa-Ishiguro
- McGill Centre for Research in Neuroscience, Montreal, Canada
- Integrated Program in Neuroscience, McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada
| | - Yong Rao
- McGill Centre for Research in Neuroscience, Montreal, Canada.
- Department of Neurology and Neurosurgery, Montreal, Canada.
- Integrated Program in Neuroscience, McGill University Health Centre, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada.
- Centre for Research in Neuroscience, McGill University Health Centre, Room L7-136, 1650 Cedar Avenue, Montreal, QC, H3G 1A4, Canada.
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3
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Longden KD, Rogers EM, Nern A, Dionne H, Reiser MB. Different spectral sensitivities of ON- and OFF-motion pathways enhance the detection of approaching color objects in Drosophila. Nat Commun 2023; 14:7693. [PMID: 38001097 PMCID: PMC10673857 DOI: 10.1038/s41467-023-43566-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Color and motion are used by many species to identify salient objects. They are processed largely independently, but color contributes to motion processing in humans, for example, enabling moving colored objects to be detected when their luminance matches the background. Here, we demonstrate an unexpected, additional contribution of color to motion vision in Drosophila. We show that behavioral ON-motion responses are more sensitive to UV than for OFF-motion, and we identify cellular pathways connecting UV-sensitive R7 photoreceptors to ON and OFF-motion-sensitive T4 and T5 cells, using neurogenetics and calcium imaging. Remarkably, this contribution of color circuitry to motion vision enhances the detection of approaching UV discs, but not green discs with the same chromatic contrast, and we show how this could generalize for systems with ON- and OFF-motion pathways. Our results provide a computational and circuit basis for how color enhances motion vision to favor the detection of saliently colored objects.
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Affiliation(s)
- Kit D Longden
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA.
| | - Edward M Rogers
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA
| | - Aljoscha Nern
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA
| | - Heather Dionne
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA
| | - Michael B Reiser
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA.
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4
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Ralhan I, Chang J, Moulton MJ, Goodman LD, Lee NY, Plummer G, Pasolli HA, Matthies D, Bellen HJ, Ioannou MS. Autolysosomal exocytosis of lipids protect neurons from ferroptosis. J Cell Biol 2023; 222:e202207130. [PMID: 37036445 PMCID: PMC10098143 DOI: 10.1083/jcb.202207130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 11/25/2022] [Accepted: 03/20/2023] [Indexed: 04/11/2023] Open
Abstract
During oxidative stress neurons release lipids that are internalized by glia. Defects in this coordinated process play an important role in several neurodegenerative diseases. Yet, the mechanisms of lipid release and its consequences on neuronal health are unclear. Here, we demonstrate that lipid-protein particle release by autolysosome exocytosis protects neurons from ferroptosis, a form of cell death driven by lipid peroxidation. We show that during oxidative stress, peroxidated lipids and iron are released from neurons by autolysosomal exocytosis which requires the exocytic machinery VAMP7 and syntaxin 4. We observe membrane-bound lipid-protein particles by TEM and demonstrate that these particles are released from neurons using cryoEM. Failure to release these lipid-protein particles causes lipid hydroperoxide and iron accumulation and sensitizes neurons to ferroptosis. Our results reveal how neurons protect themselves from peroxidated lipids. Given the number of brain pathologies that involve ferroptosis, defects in this pathway likely play a key role in the pathophysiology of neurodegenerative disease.
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Affiliation(s)
- Isha Ralhan
- Department of Physiology, University of Alberta, Edmonton, Canada
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Canada
| | - Jinlan Chang
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - Matthew J. Moulton
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Lindsey D. Goodman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
| | - Nathanael Y.J. Lee
- Department of Physiology, University of Alberta, Edmonton, Canada
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Canada
| | - Greg Plummer
- Faculty of Medicine & Dentistry Cell Imaging Core, University of Alberta, Edmonton, Canada
| | - H. Amalia Pasolli
- Electron Microscopy Resource Center, The Rockefeller University, New York, NY, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Doreen Matthies
- Unit on Structural Biology, Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Maria S. Ioannou
- Department of Physiology, University of Alberta, Edmonton, Canada
- Group on Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Canada
- Department of Cell Biology, University of Alberta, Edmonton, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
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5
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Sakakibara Y, Yamashiro R, Chikamatsu S, Hirota Y, Tsubokawa Y, Nishijima R, Takei K, Sekiya M, Iijima KM. Drosophila Toll-9 is induced by aging and neurodegeneration to modulate stress signaling and its deficiency exacerbates tau-mediated neurodegeneration. iScience 2023; 26:105968. [PMID: 36718365 PMCID: PMC9883205 DOI: 10.1016/j.isci.2023.105968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/06/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Drosophila Toll-9 is most closely related to mammalian Toll-like receptors; however, physiological functions of Toll-9 remain elusive. We examined the roles of Toll-9 in fly brains in aging and neurodegeneration. Toll-9 mRNA levels were increased in aged fly heads accompanied by activation of nuclear factor-kappa B (NF-kB) and stress-activated protein kinase (SAPK) signaling, and many of these changes were modulated by Toll-9 in glial cells. The loss of Toll-9 did not affect lifespan or brain integrity, whereas it exacerbated hydrogen peroxide-induced lethality. Toll-9 expression was also induced by nerve injury but did not affect acute stress response or glial engulfment activity, suggesting Toll-9 may modulate subsequent neurodegeneration. In a fly tauopathy model, Toll-9 deficiency enhanced neurodegeneration and disease-related tau phosphorylation with reduced SAPK activity, and blocking SAPK enhanced tau phosphorylation and neurodegeneration. In sum, Toll-9 is induced upon aging and nerve injury and affects neurodegeneration by modulating stress kinase signaling.
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Affiliation(s)
- Yasufumi Sakakibara
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Risa Yamashiro
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Sachie Chikamatsu
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan
| | - Yu Hirota
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Reseach Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Yoko Tsubokawa
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Risa Nishijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Kimi Takei
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan
| | - Michiko Sekiya
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan,Corresponding author
| | - Koichi M. Iijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi 474-8511, Japan,Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya 467-8603, Japan,Corresponding author
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6
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Rylee J, Mahato S, Aldrich J, Bergh E, Sizemore B, Feder LE, Grega S, Helms K, Maar M, Britt SG, Zelhof AC. A TRiP RNAi screen to identify molecules necessary for Drosophila photoreceptor differentiation. G3 GENES|GENOMES|GENETICS 2022; 12:6758253. [DOI: 10.1093/g3journal/jkac257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/15/2022] [Indexed: 11/06/2022]
Abstract
Abstract
Drosophila rhabdomeric terminal photoreceptor differentiation is an extended process taking several days to complete. Following ommatidial patterning by the morphogenetic furrow, photoreceptors are sequentially recruited and specified, and terminal differentiation begins. Key events of terminal differentiation include the establishment of apical and basolateral domains, rhabdomere and stalk formation, inter-rhabdomeral space formation, and expression of phototransduction machinery. While many key regulators of these processes have been identified, the complete network of transcription factors to downstream effector molecules necessary for regulating each of these major events remains incomplete. Here, we report an RNAi screen to identify additional molecules and cellular pathways required for photoreceptor terminal differentiation. First, we tested several eye-specific GAL4 drivers for correct spatial and temporal specificity and identified Pph13-GAL4 as the most appropriate GAL4 line for our screen. We screened lines available through the Transgenic RNAi Project and isolated lines that when combined with Pph13-GAL4 resulted in the loss of the deep pseudopupil, as a readout for abnormal differentiation. In the end, we screened 6,189 lines, representing 3,971 genes, and have identified 64 genes, illuminating potential new regulatory molecules and cellular pathways for the differentiation and organization of Drosophila rhabdomeric photoreceptors.
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Affiliation(s)
- Johnathan Rylee
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Simpla Mahato
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - John Aldrich
- Department of Neurology and Ophthalmology, Dell Medical School, University of Texas , Austin, TX 78712, USA
| | - Emma Bergh
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Brandon Sizemore
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Lauren E Feder
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Shaun Grega
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Kennedy Helms
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Megan Maar
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
| | - Steven G Britt
- Department of Neurology and Ophthalmology, Dell Medical School, University of Texas , Austin, TX 78712, USA
| | - Andrew C Zelhof
- Department of Biology, Indiana University , Bloomington, IN 47405, USA
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7
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Jauregui-Lozano J, Hall H, Stanhope SC, Bakhle K, Marlin MM, Weake VM. The Clock:Cycle complex is a major transcriptional regulator of Drosophila photoreceptors that protects the eye from retinal degeneration and oxidative stress. PLoS Genet 2022; 18:e1010021. [PMID: 35100266 PMCID: PMC8830735 DOI: 10.1371/journal.pgen.1010021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/10/2022] [Accepted: 01/08/2022] [Indexed: 12/28/2022] Open
Abstract
The aging eye experiences physiological changes that include decreased visual function and increased risk of retinal degeneration. Although there are transcriptomic signatures in the aging retina that correlate with these physiological changes, the gene regulatory mechanisms that contribute to cellular homeostasis during aging remain to be determined. Here, we integrated ATAC-seq and RNA-seq data to identify 57 transcription factors that showed differential activity in aging Drosophila photoreceptors. These 57 age-regulated transcription factors include two circadian regulators, Clock and Cycle, that showed sustained increased activity during aging. When we disrupted the Clock:Cycle complex by expressing a dominant negative version of Clock (ClkDN) in adult photoreceptors, we observed changes in expression of 15-20% of genes including key components of the phototransduction machinery and many eye-specific transcription factors. Using ATAC-seq, we showed that expression of ClkDN in photoreceptors leads to changes in activity of 37 transcription factors and causes a progressive decrease in global levels of chromatin accessibility in photoreceptors. Supporting a key role for Clock-dependent transcription in the eye, expression of ClkDN in photoreceptors also induced light-dependent retinal degeneration and increased oxidative stress, independent of light exposure. Together, our data suggests that the circadian regulators Clock and Cycle act as neuroprotective factors in the aging eye by directing gene regulatory networks that maintain expression of the phototransduction machinery and counteract oxidative stress.
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Affiliation(s)
- Juan Jauregui-Lozano
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Hana Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, United States of America
| | - Sarah C. Stanhope
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Kimaya Bakhle
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Makayla M. Marlin
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana, United States of America
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8
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Kind E, Longden KD, Nern A, Zhao A, Sancer G, Flynn MA, Laughland CW, Gezahegn B, Ludwig HDF, Thomson AG, Obrusnik T, Alarcón PG, Dionne H, Bock DD, Rubin GM, Reiser MB, Wernet MF. Synaptic targets of photoreceptors specialized to detect color and skylight polarization in Drosophila. eLife 2021; 10:e71858. [PMID: 34913436 PMCID: PMC8789284 DOI: 10.7554/elife.71858] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 12/15/2021] [Indexed: 11/18/2022] Open
Abstract
Color and polarization provide complementary information about the world and are detected by specialized photoreceptors. However, the downstream neural circuits that process these distinct modalities are incompletely understood in any animal. Using electron microscopy, we have systematically reconstructed the synaptic targets of the photoreceptors specialized to detect color and skylight polarization in Drosophila, and we have used light microscopy to confirm many of our findings. We identified known and novel downstream targets that are selective for different wavelengths or polarized light, and followed their projections to other areas in the optic lobes and the central brain. Our results revealed many synapses along the photoreceptor axons between brain regions, new pathways in the optic lobes, and spatially segregated projections to central brain regions. Strikingly, photoreceptors in the polarization-sensitive dorsal rim area target fewer cell types, and lack strong connections to the lobula, a neuropil involved in color processing. Our reconstruction identifies shared wiring and modality-specific specializations for color and polarization vision, and provides a comprehensive view of the first steps of the pathways processing color and polarized light inputs.
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Affiliation(s)
- Emil Kind
- Instititut für Biologie – Abteilung Neurobiologie, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität BerlinBerlinGermany
| | - Kit D Longden
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Aljoscha Nern
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Arthur Zhao
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gizem Sancer
- Instititut für Biologie – Abteilung Neurobiologie, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität BerlinBerlinGermany
| | - Miriam A Flynn
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Connor W Laughland
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Bruck Gezahegn
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Henrique DF Ludwig
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Alex G Thomson
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Tessa Obrusnik
- Instititut für Biologie – Abteilung Neurobiologie, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität BerlinBerlinGermany
| | - Paula G Alarcón
- Instititut für Biologie – Abteilung Neurobiologie, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität BerlinBerlinGermany
| | - Heather Dionne
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Davi D Bock
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Michael B Reiser
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Mathias F Wernet
- Instititut für Biologie – Abteilung Neurobiologie, Fachbereich Biologie, Chemie & Pharmazie, Freie Universität BerlinBerlinGermany
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9
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Escobedo SE, Shah A, Easton AN, Hall H, Weake VM. Characterizing a gene expression toolkit for eye- and photoreceptor-specific expression in Drosophila. Fly (Austin) 2021; 15:73-88. [PMID: 33899690 PMCID: PMC8078738 DOI: 10.1080/19336934.2021.1915683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 03/16/2021] [Accepted: 04/08/2021] [Indexed: 10/21/2022] Open
Abstract
Binary expression systems are a powerful tool for tissue- and cell-specific research. Many of the currently available Drosophila eye-specific drivers have not been systematically characterized for their expression level and cell-type specificity in the adult eye or during development. Here, we used a luciferase reporter to measure expression levels of different drivers in the adult Drosophila eye, and characterized the cell type-specificity of each driver using a fluorescent reporter in live 10-day-old adult males. We also further characterized the expression pattern of these drivers in various developmental stages. We compared several Gal4 drivers from the Bloomington Drosophila Stock Center (BDSC) including GMR-Gal4, longGMR-Gal4 and Rh1-Gal4 with newly developed Gal4 and QF2 drivers that are specific to different cell types in the adult eye. In addition, we generated drug-inducible Rh1-GSGal4 lines and compared their induced expression with an available GMR-GSGal4 line. Although both lines had significant induction of gene expression measured by luciferase activity, Rh1-GSGal4 was expressed at levels below the detection of the fluorescent reporter by confocal microscopy, while GMR-GSGal4 showed substantial reporter expression in the absence of drug by microscopy. Overall, our study systematically characterizes and compares a large toolkit of eye- and photoreceptor-specific drivers, while also uncovering some of the limitations of currently available expression systems in the adult eye.
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Affiliation(s)
| | - Aashka Shah
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Alyssa N. Easton
- Department of Agriculture and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Hana Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Vikki M. Weake
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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10
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Girard V, Jollivet F, Knittelfelder O, Celle M, Arsac JN, Chatelain G, Van den Brink DM, Baron T, Shevchenko A, Kühnlein RP, Davoust N, Mollereau B. Abnormal accumulation of lipid droplets in neurons induces the conversion of alpha-Synuclein to proteolytic resistant forms in a Drosophila model of Parkinson's disease. PLoS Genet 2021; 17:e1009921. [PMID: 34788284 PMCID: PMC8635402 DOI: 10.1371/journal.pgen.1009921] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 12/01/2021] [Accepted: 11/02/2021] [Indexed: 11/18/2022] Open
Abstract
Parkinson’s disease (PD) is a neurodegenerative disorder characterized by alpha-synuclein (αSyn) aggregation and associated with abnormalities in lipid metabolism. The accumulation of lipids in cytoplasmic organelles called lipid droplets (LDs) was observed in cellular models of PD. To investigate the pathophysiological consequences of interactions between αSyn and proteins that regulate the homeostasis of LDs, we used a transgenic Drosophila model of PD, in which human αSyn is specifically expressed in photoreceptor neurons. We first found that overexpression of the LD-coating proteins Perilipin 1 or 2 (dPlin1/2), which limit the access of lipases to LDs, markedly increased triacylglyclerol (TG) loaded LDs in neurons. However, dPlin-induced-LDs in neurons are independent of lipid anabolic (diacylglycerol acyltransferase 1/midway, fatty acid transport protein/dFatp) and catabolic (brummer TG lipase) enzymes, indicating that alternative mechanisms regulate neuronal LD homeostasis. Interestingly, the accumulation of LDs induced by various LD proteins (dPlin1, dPlin2, CG7900 or KlarsichtLD-BD) was synergistically amplified by the co-expression of αSyn, which localized to LDs in both Drosophila photoreceptor neurons and in human neuroblastoma cells. Finally, the accumulation of LDs increased the resistance of αSyn to proteolytic digestion, a characteristic of αSyn aggregation in human neurons. We propose that αSyn cooperates with LD proteins to inhibit lipolysis and that binding of αSyn to LDs contributes to the pathogenic misfolding and aggregation of αSyn in neurons. Parkinson’s disease (PD) is a neurodegenerative disease characterized by the neurotoxic aggregation of the alpha-synuclein (αSyn) protein. Cellular models of the disease are also associated with an abnormal fat storage in the form of lipid droplets (LDs). However, in which cells, neuron or glial cells, LDs accumulate in the organism remains unknown. To understand the relationship between αSyn and the accumulation of LDs, we used a Drosophila (fruit fly) model of PD. We found that, in the presence of a protein that coats LDs, perilipin, LDs accumulate in photoreceptor neurons of the fly. Interestingly, the accumulation of LDs induced by perilipin or other LD-coating proteins was enhanced in the presence of αSyn. Using human neuronal cell lines and the fly, we could show that LD-coating and αSyn proteins localize at the surface of LDs. Finally, we observed that the process of αSyn aggregation was enhanced in the presence of LDs by using a biochemical approach. We thus propose that the association of αSyn with LDs could contribute to αSyn aggregation and progression of the pathology.
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Affiliation(s)
- Victor Girard
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Florence Jollivet
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Oskar Knittelfelder
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Marion Celle
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Jean-Noel Arsac
- Neurodegenerative Disease Unit; French Agency for Food, Environmental and Occupational Health & Safety Laboratory (Anses) of Lyon, University of Lyon, Lyon, France
| | - Gilles Chatelain
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
| | - Daan M. Van den Brink
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- Plant Systems Physiology, Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, The Netherlands
| | - Thierry Baron
- Neurodegenerative Disease Unit; French Agency for Food, Environmental and Occupational Health & Safety Laboratory (Anses) of Lyon, University of Lyon, Lyon, France
| | - Andrej Shevchenko
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ronald P. Kühnlein
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
- Field of Excellence BioHealth—University of Graz, Graz, Austria
| | - Nathalie Davoust
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- * E-mail: (ND); (BM)
| | - Bertrand Mollereau
- Laboratory of Biology and Modelling of the Cell, UMR5239 CNRS/ENS de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France
- * E-mail: (ND); (BM)
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11
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Huang HW, Ryoo HD. Drosophila fabp is required for light-dependent Rhodopsin-1 clearance and photoreceptor survival. PLoS Genet 2021; 17:e1009551. [PMID: 34714826 PMCID: PMC8580249 DOI: 10.1371/journal.pgen.1009551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 11/10/2021] [Accepted: 10/20/2021] [Indexed: 12/30/2022] Open
Abstract
Rhodopsins are light-detecting proteins coupled with retinal chromophores essential for visual function. Coincidentally, dysfunctional Rhodopsin homeostasis underlies retinal degeneration in humans and model organisms. Drosophila ninaEG69D mutant is one such example, where the encoded Rh1 protein imposes endoplasmic reticulum (ER) stress and causes light-dependent retinal degeneration. The underlying reason for such light-dependency remains unknown. Here, we report that Drosophila fatty acid binding protein (fabp) is a gene induced in ninaEG69D/+ photoreceptors, and regulates light-dependent Rhodopsin-1 (Rh1) protein clearance and photoreceptor survival. Specifically, our photoreceptor-specific gene expression profiling study in ninaEG69D/+ flies revealed increased expression of fabp together with other genes that control light-dependent Rh1 protein degradation. fabp induction in ninaEG69D photoreceptors required vitamin A and its transporter genes. In flies reared under light, loss of fabp caused an accumulation of Rh1 proteins in cytoplasmic vesicles. The increase in Rh1 levels under these conditions was dependent on Arrestin2 that mediates feedback inhibition of light-activated Rh1. fabp mutants exhibited light-dependent retinal degeneration, a phenotype also found in other mutants that block light-induced Rh1 degradation. These observations reveal a previously unrecognized link between light-dependent Rh1 proteostasis and the ER-stress imposing ninaEG69D mutant that cause retinal degeneration.
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Affiliation(s)
- Huai-Wei Huang
- Department of Cell Biology NYU Grossman School of Medicine New York, New York, United States of America
| | - Hyung Don Ryoo
- Department of Cell Biology NYU Grossman School of Medicine New York, New York, United States of America
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12
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Smylla TK, Wagner K, Huber A. Application of Fluorescent Proteins for Functional Dissection of the Drosophila Visual System. Int J Mol Sci 2021; 22:8930. [PMID: 34445636 PMCID: PMC8396179 DOI: 10.3390/ijms22168930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 11/22/2022] Open
Abstract
The Drosophila eye has been used extensively to study numerous aspects of biological systems, for example, spatio-temporal regulation of differentiation, visual signal transduction, protein trafficking and neurodegeneration. Right from the advent of fluorescent proteins (FPs) near the end of the millennium, heterologously expressed fusion proteins comprising FPs have been applied in Drosophila vision research not only for subcellular localization of proteins but also for genetic screens and analysis of photoreceptor function. Here, we summarize applications for FPs used in the Drosophila eye as part of genetic screens, to study rhodopsin expression patterns, subcellular protein localization, membrane protein transport or as genetically encoded biosensors for Ca2+ and phospholipids in vivo. We also discuss recently developed FPs that are suitable for super-resolution or correlative light and electron microscopy (CLEM) approaches. Illustrating the possibilities provided by using FPs in Drosophila photoreceptors may aid research in other sensory or neuronal systems that have not yet been studied as well as the Drosophila eye.
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Affiliation(s)
- Thomas K. Smylla
- Department of Biochemistry, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany; (K.W.); (A.H.)
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13
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Jauregui-Lozano J, Bakhle K, Weake VM. In vivo tissue-specific chromatin profiling in Drosophila melanogaster using GFP-tagged nuclei. Genetics 2021; 218:6281219. [PMID: 34022041 DOI: 10.1093/genetics/iyab079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/17/2021] [Indexed: 12/23/2022] Open
Abstract
The chromatin landscape defines cellular identity in multicellular organisms with unique patterns of DNA accessibility and histone marks decorating the genome of each cell type. Thus, profiling the chromatin state of different cell types in an intact organism under disease or physiological conditions can provide insight into how chromatin regulates cell homeostasis in vivo. To overcome the many challenges associated with characterizing chromatin state in specific cell types, we developed an improved approach to isolate Drosophila melanogaster nuclei tagged with a GFPKASH protein. The perinuclear space-localized KASH domain anchors GFP to the outer nuclear membrane, and expression of UAS-GFPKASH can be controlled by tissue-specific Gal4 drivers. Using this protocol, we profiled chromatin accessibility using an improved version of Assay for Transposable Accessible Chromatin followed by sequencing (ATAC-seq), called Omni-ATAC. In addition, we examined the distribution of histone marks using Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and Cleavage Under Targets and Tagmentation (CUT&Tag) in adult photoreceptor neurons. We show that the chromatin landscape of photoreceptors reflects the transcriptional state of these cells, demonstrating the quality and reproducibility of our approach for profiling the transcriptome and epigenome of specific cell types in Drosophila.
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Affiliation(s)
| | - Kimaya Bakhle
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA.,Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
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14
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Farnworth MS, Eckermann KN, Ahmed HMM, Mühlen DS, He B, Bucher G. The Red Flour Beetle as Model for Comparative Neural Development: Genome Editing to Mark Neural Cells in Tribolium Brain Development. Methods Mol Biol 2020; 2047:191-217. [PMID: 31552656 DOI: 10.1007/978-1-4939-9732-9_11] [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] [Indexed: 02/07/2023]
Abstract
With CRISPR/Cas (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated) scientists working with Tribolium castaneum can now generate transgenic lines with site-specific insertions at their region of interest. We present two methods to generate in vivo imaging lines suitable for marking subsets of neurons with fluorescent proteins. The first method relies on homologous recombination and uses a 2A peptide to create a bicistronic mRNA. In such lines, the target and the marker proteins are not fused but produced at equal amounts. This work-intensive method is compared with creating gene-specific enhancer traps that do not rely on homologous recombination. These are faster to generate but reflect the expression of the target gene less precisely. Which method to choose, strongly depends on the aims of each research project and in turn impacts of how neural cells and their development are marked. We describe the necessary steps from designing constructs and guide RNAs to embryonic injection and making homozygous stocks.
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Affiliation(s)
- Max S Farnworth
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany. .,Göttingen Graduate Center for Molecular Biosciences, Neurosciences and Biophysics, Göttingen, Germany.
| | - Kolja N Eckermann
- Göttingen Graduate Center for Molecular Biosciences, Neurosciences and Biophysics, Göttingen, Germany.,Department of Developmental Biology, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Hassan M M Ahmed
- Department of Developmental Biology, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany.,Department of Crop Protection, Faculty of Agriculture, University of Khartoum, Khartoum-North, Khartoum, Sudan
| | - Dominik S Mühlen
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany.,Göttingen Graduate Center for Molecular Biosciences, Neurosciences and Biophysics, Göttingen, Germany
| | - Bicheng He
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany
| | - Gregor Bucher
- Department of Evolutionary Developmental Genetics, Johann-Friedrich-Blumenbach Institute, GZMB, University of Göttingen, Göttingen, Germany.
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15
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Kraut RS, Knust E. Changes in endolysosomal organization define a pre-degenerative state in the crumbs mutant Drosophila retina. PLoS One 2019; 14:e0220220. [PMID: 31834921 PMCID: PMC6910688 DOI: 10.1371/journal.pone.0220220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/24/2019] [Indexed: 01/06/2023] Open
Abstract
Mutations in the epithelial polarity gene crumbs (crb) lead to retinal degeneration in Drosophila and in humans. The overall morphology of the retina and its deterioration in Drosophila crb mutants has been well-characterized, but the cell biological origin of the degeneration is not well understood. Degenerative conditions in the retina and elsewhere in the nervous system often involve defects in degradative intracellular trafficking pathways. So far, however, effects of crb on the endolysosomal system, or on the spatial organization of these compartments in photoreceptor cells have not been described. We therefore asked whether photoreceptors in crb mutants exhibit alterations in endolysosomal compartments under pre-degenerative conditions, where the retina is still morphologically intact. Data presented here show that, already well before the onset of degeneration, Arl8, Rab7, and Atg8-carrying endolysosomal and autophagosomal compartments undergo changes in morphology and positioning with respect to each other in crb mutant retinas. We propose that these changes may be early signs of the degeneration-prone condition in crb retinas.
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Affiliation(s)
- Rachel S. Kraut
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
- * E-mail:
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
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16
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Hartenstein V, Yuan M, Younossi-Hartenstein A, Karandikar A, Bernardo-Garcia FJ, Sprecher S, Knust E. Serial electron microscopic reconstruction of the drosophila larval eye: Photoreceptors with a rudimentary rhabdomere of microvillar-like processes. Dev Biol 2019; 453:56-67. [PMID: 31158364 DOI: 10.1016/j.ydbio.2019.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 11/26/2022]
Abstract
Photoreceptor cells (PRCs) across the animal kingdom are characterized by a stacking of apical membranes to accommodate the high abundance of photopigment. In arthropods and many other invertebrate phyla PRC membrane stacks adopt the shape of densely packed microvilli that form a structure called rhabdomere. PRCs and surrounding accessory cells, including pigment cells and lens-forming cells, are grouped in stereotyped units, the ommatidia. In larvae of holometabolan insects, eyes (called stemmata) are reduced in terms of number and composition of ommatidia. The stemma of Drosophila (Bolwig organ) is reduced to a bilateral cluster of subepidermal PRCs, lacking all other cell types. In the present paper we have analyzed the development and fine structure of the Drosophila larval PRCs. Shortly after their appearance in the embryonic head ectoderm, PRC precursors delaminate and lose expression of apical markers of epithelial cells, including Crumbs and several centrosome-associated proteins. In the early first instar larva, PRCs show an expanded, irregularly shaped apical surface that is folded into multiple horizontal microvillar-like processes (MLPs). Apical PRC membranes and MLPs are covered with a layer of extracellular matrix. MLPs are predominantly aligned along an axis that extends ventro-anteriorly to dorso-posteriorly, but vary in length, diameter, and spacing. Individual MLPs present a "beaded" shape, with thick segments (0.2-0.3 μm diameter) alternating with thin segments (>0.1 μm). We show that loss of the glycoprotein Chaoptin, which is absolutely essential for rhabdomere formation in the adult PRCs, does not lead to severe abnormalities in larval PRCs.
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Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA.
| | - Michaela Yuan
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
| | - Amelia Younossi-Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Aanavi Karandikar
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | | | - Simon Sprecher
- Department of Biology, University of Fribourg, 10, Ch. du Musée, 1700, Fribourg, Switzerland
| | - Elisabeth Knust
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
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17
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Huang HW, Brown B, Chung J, Domingos PM, Ryoo HD. highroad Is a Carboxypetidase Induced by Retinoids to Clear Mutant Rhodopsin-1 in Drosophila Retinitis Pigmentosa Models. Cell Rep 2019; 22:1384-1391. [PMID: 29425495 PMCID: PMC5832065 DOI: 10.1016/j.celrep.2018.01.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 12/15/2017] [Accepted: 01/10/2018] [Indexed: 11/02/2022] Open
Abstract
Rhodopsins require retinoid chromophores for their function. In vertebrates, retinoids also serve as signaling molecules, but whether these molecules similarly regulate gene expression in Drosophila remains unclear. Here, we report the identification of a retinoid-inducible gene in Drosophila, highroad, which is required for photoreceptors to clear folding-defective mutant Rhodopsin-1 proteins. Specifically, knockdown or genetic deletion of highroad blocks the degradation of folding-defective Rhodopsin-1 mutant, ninaEG69D. Moreover, loss of highroad accelerates the age-related retinal degeneration phenotype of ninaEG69D mutants. Elevated highroad transcript levels are detected in ninaEG69D flies, and interestingly, deprivation of retinoids in the fly diet blocks this effect. Consistently, mutations in the retinoid transporter, santa maria, impairs the induction of highroad in ninaEG69D flies. In cultured S2 cells, highroad expression is induced by retinoic acid treatment. These results indicate that cellular quality-control mechanisms against misfolded Rhodopsin-1 involve regulation of gene expression by retinoids.
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Affiliation(s)
- Huai-Wei Huang
- Department of Cell Biology, New York University School of Medicine 550 First Avenue, New York, NY 10016, USA
| | - Brian Brown
- Department of Cell Biology, New York University School of Medicine 550 First Avenue, New York, NY 10016, USA
| | - Jaehoon Chung
- Department of Cell Biology, New York University School of Medicine 550 First Avenue, New York, NY 10016, USA
| | - Pedro M Domingos
- Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Av. da República, Oeiras 2780-157, Portugal
| | - Hyung Don Ryoo
- Department of Cell Biology, New York University School of Medicine 550 First Avenue, New York, NY 10016, USA.
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18
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Imaging Flies by Fluorescence Microscopy: Principles, Technologies, and Applications. Genetics 2019; 211:15-34. [PMID: 30626639 PMCID: PMC6325693 DOI: 10.1534/genetics.118.300227] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/05/2018] [Indexed: 02/07/2023] Open
Abstract
The development of fluorescent labels and powerful imaging technologies in the last two decades has revolutionized the field of fluorescence microscopy, which is now widely used in diverse scientific fields from biology to biomedical and materials science. Fluorescence microscopy has also become a standard technique in research laboratories working on Drosophila melanogaster as a model organism. Here, we review the principles of fluorescence microscopy technologies from wide-field to Super-resolution microscopy and its application in the Drosophila research field.
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19
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Robin M, Issa AR, Santos CC, Napoletano F, Petitgas C, Chatelain G, Ruby M, Walter L, Birman S, Domingos PM, Calvi BR, Mollereau B. Drosophila p53 integrates the antagonism between autophagy and apoptosis in response to stress. Autophagy 2018; 15:771-784. [PMID: 30563404 DOI: 10.1080/15548627.2018.1558001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The tumor suppressor TP53/p53 is a known regulator of apoptosis and macroautophagy/autophagy. However, the molecular mechanism by which TP53 regulates 2 apparently incompatible processes remains unknown. We found that Drosophila lacking p53 displayed impaired autophagic flux, higher caspase activation and mortality in response to oxidative stress compared with wild-type flies. Moreover, autophagy and apoptosis were differentially regulated by the p53 (p53B) and ΔNp53 (p53A) isoforms: while the former induced autophagy in differentiated neurons, which protected against cell death, the latter inhibited autophagy by activating the caspases Dronc, Drice, and Dcp-1. Our results demonstrate that the differential use of p53 isoforms combined with the antagonism between apoptosis and autophagy ensures the generation of an appropriate p53 biological response to stress.
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Affiliation(s)
- Marion Robin
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Abdul Raouf Issa
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France.,e Department of Life Sciences , University of Trieste c/o CIB National Laboratory , Area Science Park , Trieste , Italy
| | - Cristiana C Santos
- c Instituto de Tecnologia Química e Biológica , Universidade Nova de Lisboa , Oeiras , Portugal
| | - Francesco Napoletano
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France.,e Department of Life Sciences , University of Trieste c/o CIB National Laboratory , Area Science Park , Trieste , Italy
| | - Céline Petitgas
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France
| | - Gilles Chatelain
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Mathilde Ruby
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Ludivine Walter
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
| | - Serge Birman
- b Genes Circuits Rhythms and Neuropathology , Brain Plasticity Unit, CNRS, ESPCI Paris, Labex Memolife, PSL Research University , Paris , France
| | - Pedro M Domingos
- c Instituto de Tecnologia Química e Biológica , Universidade Nova de Lisboa , Oeiras , Portugal
| | - Brian R Calvi
- d Department of Biology , Indiana University , Bloomington , IN , USA
| | - Bertrand Mollereau
- a Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland , Lyon , France
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20
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Van Den Brink DM, Cubizolle A, Chatelain G, Davoust N, Girard V, Johansen S, Napoletano F, Dourlen P, Guillou L, Angebault-Prouteau C, Bernoud-Hubac N, Guichardant M, Brabet P, Mollereau B. Physiological and pathological roles of FATP-mediated lipid droplets in Drosophila and mice retina. PLoS Genet 2018; 14:e1007627. [PMID: 30199545 PMCID: PMC6147681 DOI: 10.1371/journal.pgen.1007627] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 09/20/2018] [Accepted: 08/13/2018] [Indexed: 11/18/2022] Open
Abstract
Increasing evidence suggests that dysregulation of lipid metabolism is associated with neurodegeneration in retinal diseases such as age-related macular degeneration and in brain disorders such as Alzheimer’s and Parkinson’s diseases. Lipid storage organelles (lipid droplets, LDs), accumulate in many cell types in response to stress, and it is now clear that LDs function not only as lipid stores but also as dynamic regulators of the stress response. However, whether these LDs are always protective or can also be deleterious to the cell is unknown. Here, we investigated the consequences of LD accumulation on retinal cell homeostasis under physiological and stress conditions in Drosophila and in mice. In wild-type Drosophila, we show that dFatp is required and sufficient for expansion of LD size in retinal pigment cells (RPCs) and that LDs in RPCs are required for photoreceptor survival during aging. Similarly, in mice, LD accumulation induced by RPC-specific expression of human FATP1 was non-toxic and promoted mitochondrial energy metabolism in RPCs and non-autonomously in photoreceptor cells. In contrast, the inhibition of LD accumulation by dFatp knockdown suppressed neurodegeneration in Aats-metFBDrosophila mutants, which carry elevated levels of reactive oxygen species (ROS). This suggests that abnormal turnover of LD may be toxic for photoreceptors cells of the retina under oxidative stress. Collectively, these findings indicate that FATP-mediated LD formation in RPCs promotes RPC and neuronal homeostasis under physiological conditions but could be deleterious for the photoreceptors under pathological conditions. Lipids are major cell constituents and are present in the membranes, as free lipids in the cytoplasm, or stored in vesicles called lipid droplets (LDs). Under conditions of stress, lipids stored in LDs can be released to serve as substrates for energy metabolism by mitochondria. However, lipid storage is dysregulated in many degenerative disorders such as age-related macular degeneration, Parkinson’s and Alzheimer’s diseases. Thus, it is unclear whether accumulation of LDs is protective or toxic for neuronal cells. To address this question, we examined the consequences of removal or enforced LD accumulation on the health of retinal cells in flies and mice. Like humans, fly and mouse retinas contain retinal pigment cells (RPC) that support the functions of neighboring photoreceptor cells. We found that overexpression of the fatty acid transport protein (FATP) in RPCs induced accumulation of LDs in both transgenic flies and mice. Moreover, LD accumulation in RPCs was not harmful for juxtaposed photoreceptors during aging, but was toxic under stress conditions. We propose that lipid storage promotes cellular communication that affects photoreceptor health.
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Affiliation(s)
- Daan M. Van Den Brink
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
| | - Aurélie Cubizolle
- Institut des Neurosciences de Montpellier, INSERM U1051, CHU St Eloi, Montpellier, France
- Université de Montpellier, Montpellier, France
| | - Gilles Chatelain
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
| | - Nathalie Davoust
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
| | - Victor Girard
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
| | - Simone Johansen
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
| | - Francesco Napoletano
- Molecular Oncology Unit, Department of Life Sciences, University of Trieste c/o Laboratorio Nazionale CIB, Area Science Park, Trieste, Italy
| | - Pierre Dourlen
- Institut Pasteur de Lille; Inserm, U1167, RID-AGE-Risk Factors and Molecular Determinants of Aging-Related Diseases; University Lille, U1167-Excellence Laboratory LabEx DISTALZ, Lille, France
| | - Laurent Guillou
- Institut des Neurosciences de Montpellier, INSERM U1051, CHU St Eloi, Montpellier, France
- Université de Montpellier, Montpellier, France
| | - Claire Angebault-Prouteau
- Institut des Neurosciences de Montpellier, INSERM U1051, CHU St Eloi, Montpellier, France
- INSERM U1046, UMR CNRS 9214, Université de Montpellier, CHRU de Montpellier, Montpellier, France
| | - Nathalie Bernoud-Hubac
- Univ Lyon, CarMeN laboratory, INSA Lyon, INSERM U1060, INRA U1397, Université Claude Bernard Lyon 1, F-69621, Villeurbanne, France
| | - Michel Guichardant
- Univ Lyon, CarMeN laboratory, INSA Lyon, INSERM U1060, INRA U1397, Université Claude Bernard Lyon 1, F-69621, Villeurbanne, France
| | - Philippe Brabet
- Institut des Neurosciences de Montpellier, INSERM U1051, CHU St Eloi, Montpellier, France
- Université de Montpellier, Montpellier, France
| | - Bertrand Mollereau
- Université de Lyon, ENSL, UCBL, CNRS, LBMC, UMS 3444 Biosciences Lyon Gerland, Lyon, France
- * E-mail:
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Interactions Between the Circadian Clock and Heme Oxygenase in the Retina of Drosophila melanogaster. Mol Neurobiol 2016; 54:4953-4962. [PMID: 27520276 PMCID: PMC5533861 DOI: 10.1007/s12035-016-0026-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/01/2016] [Indexed: 01/14/2023]
Abstract
The Drosophila retina has an autonomous peripheral circadian clock in which the expression of the gene encoding heme oxygenase (HO) is under circadian control with the ho mRNA peaking at the beginning of the day and in the middle of the night. The function of HO in the retina is unknown, but we observed that it regulates the circadian clock and protects photoreceptors against DNA damage. The decline in HO level increases and decreases the expression of the canonical clock genes period (per) and Clock (Clk), respectively. The opposite result was observed after increasing HO expression. Among three products of HO activity—carbon monoxide (CO), ferrous ions, and biliverdin—the latter has no effect on per and Clk expressions, but CO exerts the same effect as the increase of ho expression. This suggests that HO action on the clock is mediated by CO, which may affect Clk expression during the day and the level of per expression. While ho expression is not stimulated by nitric oxide (NO), NO has the same effect on the clock as HO, increasing Clk expression and decreasing the expression of per.
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McClure CD, Southall TD. Getting Down to Specifics: Profiling Gene Expression and Protein-DNA Interactions in a Cell Type-Specific Manner. ADVANCES IN GENETICS 2015; 91:103-151. [PMID: 26410031 PMCID: PMC4604662 DOI: 10.1016/bs.adgen.2015.06.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The majority of multicellular organisms are comprised of an extraordinary range of cell types, with different properties and gene expression profiles. Understanding what makes each cell type unique and how their individual characteristics are attributed are key questions for both developmental and neurobiologists alike. The brain is an excellent example of the cellular diversity expressed in the majority of eukaryotes. The mouse brain comprises of approximately 75 million neurons varying in morphology, electrophysiology, and preferences for synaptic partners. A powerful process in beginning to pick apart the mechanisms that specify individual characteristics of the cell, as well as their fate, is to profile gene expression patterns, chromatin states, and transcriptional networks in a cell type-specific manner, i.e., only profiling the cells of interest in a particular tissue. Depending on the organism, the questions being investigated, and the material available, certain cell type-specific profiling methods are more suitable than others. This chapter reviews the approaches presently available for selecting and isolating specific cell types and evaluates their key features.
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Affiliation(s)
- Colin D. McClure
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Tony D. Southall
- Department of Life Sciences, Imperial College London, Sir Ernst Chain Building, South Kensington Campus, London SW7 2AZ, United Kingdom
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Abstract
Following neuronal cell death at the cellular level and over several time points is challenging in living animal because of the difficulty of accessing and identifying individual neurons. In the eye of a living Drosophila, it is possible to visualize neurons thanks to the cornea neutralization technique. This technique can be coupled to the generation of mosaic clones by the Tomato /GFP -FLP/FRT method to identify a group of photoreceptor neurons at a single-cell resolution. This method has proved to be efficient for the study of photoreceptor development and degeneration. In this chapter, I describe this method and focus on fatp mutant photoreceptor neuron degeneration.
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Affiliation(s)
- Pierre Dourlen
- Unité de Santé Publique et d'Epidémiologie moléculaire des maladies liées au vieillissement, Institut Pasteur de Lille, INSERM UMR744, 1 rue du Professeur Calmette, BP 245, 59019, Lille Cedex, France,
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24
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Transcriptional enhancers: from properties to genome-wide predictions. Nat Rev Genet 2014; 15:272-86. [PMID: 24614317 DOI: 10.1038/nrg3682] [Citation(s) in RCA: 912] [Impact Index Per Article: 91.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cellular development, morphology and function are governed by precise patterns of gene expression. These are established by the coordinated action of genomic regulatory elements known as enhancers or cis-regulatory modules. More than 30 years after the initial discovery of enhancers, many of their properties have been elucidated; however, despite major efforts, we only have an incomplete picture of enhancers in animal genomes. In this Review, we discuss how properties of enhancer sequences and chromatin are used to predict enhancers in genome-wide studies. We also cover recently developed high-throughput methods that allow the direct testing and identification of enhancers on the basis of their activity. Finally, we discuss recent technological advances and current challenges in the field of regulatory genomics.
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Schnaitmann C, Garbers C, Wachtler T, Tanimoto H. Color discrimination with broadband photoreceptors. Curr Biol 2013; 23:2375-82. [PMID: 24268411 DOI: 10.1016/j.cub.2013.10.037] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Color vision is commonly assumed to rely on photoreceptors tuned to narrow spectral ranges. In the ommatidium of Drosophila, the four types of so-called inner photoreceptors express different narrow-band opsins. In contrast, the outer photoreceptors have a broadband spectral sensitivity and were thought to exclusively mediate achromatic vision. RESULTS Using computational models and behavioral experiments, we demonstrate that the broadband outer photoreceptors contribute to color vision in Drosophila. The model of opponent processing that includes the opsin of the outer photoreceptors scored the best fit to wavelength discrimination data. To experimentally uncover the contribution of individual photoreceptor types, we restored phototransduction of targeted photoreceptor combinations in a blind mutant. Dichromatic flies with only broadband photoreceptors and one additional receptor type can discriminate different colors, indicating the existence of a specific output comparison of the outer and inner photoreceptors. Furthermore, blocking interneurons postsynaptic to the outer photoreceptors specifically impaired color but not intensity discrimination. CONCLUSIONS Our findings show that receptors with a complex and broad spectral sensitivity can contribute to color vision and reveal that chromatic and achromatic circuits in the fly share common photoreceptors.
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Dourlen P, Levet C, Mejat A, Gambis A, Mollereau B. The Tomato/GFP-FLP/FRT method for live imaging of mosaic adult Drosophila photoreceptor cells. J Vis Exp 2013:e50610. [PMID: 24084155 PMCID: PMC3923918 DOI: 10.3791/50610] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The Drosophila eye is widely used as a model for studies of development and neuronal degeneration. With the powerful mitotic recombination technique, elegant genetic screens based on clonal analysis have led to the identification of signaling pathways involved in eye development and photoreceptor (PR) differentiation at larval stages. We describe here the Tomato/GFP-FLP/FRT method, which can be used for rapid clonal analysis in the eye of living adult Drosophila. Fluorescent photoreceptor cells are imaged with the cornea neutralization technique, on retinas with mosaic clones generated by flipase-mediated recombination. This method has several major advantages over classical histological sectioning of the retina: it can be used for high-throughput screening and has proved an effective method for identifying the factors regulating PR survival and function. It can be used for kinetic analyses of PR degeneration in the same living animal over several weeks, to demonstrate the requirement for specific genes for PR survival or function in the adult fly. This method is also useful for addressing cell autonomy issues in developmental mutants, such as those in which the establishment of planar cell polarity is affected.
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Affiliation(s)
- Pierre Dourlen
- Laboratory of Molecular Biology of the Cell, Ecole Normale Supérieure de Lyon
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Chu WC, Lee YM, Henry Sun Y. FGF /FGFR signal induces trachea extension in the drosophila visual system. PLoS One 2013; 8:e73878. [PMID: 23991208 PMCID: PMC3753266 DOI: 10.1371/journal.pone.0073878] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 07/24/2013] [Indexed: 11/29/2022] Open
Abstract
The Drosophila compound eye is a large sensory organ that places a high demand on oxygen supplied by the tracheal system. Although the development and function of the Drosophila visual system has been extensively studied, the development and contribution of its tracheal system has not been systematically examined. To address this issue, we studied the tracheal patterns and developmental process in the Drosophila visual system. We found that the retinal tracheae are derived from air sacs in the head, and the ingrowth of retinal trachea begin at mid-pupal stage. The tracheal development has three stages. First, the air sacs form near the optic lobe in 42-47% of pupal development (pd). Second, in 47-52% pd, air sacs extend branches along the base of the retina following a posterior-to-anterior direction and further form the tracheal network under the fenestrated membrane (TNUFM). Third, the TNUFM extend fine branches into the retina following a proximal-to-distal direction after 60% pd. Furthermore, we found that the trachea extension in both retina and TNUFM are dependent on the FGF(Bnl)/FGFR(Btl) signaling. Our results also provided strong evidence that the photoreceptors are the source of the Bnl ligand to guide the trachea ingrowth. Our work is the first systematic study of the tracheal development in the visual system, and also the first study demonstrating the interactions of two well-studied systems: the eye and trachea.
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Affiliation(s)
- Wei-Chen Chu
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yuan-Ming Lee
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Yi Henry Sun
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
- * E-mail:
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Satoh T, Inagaki T, Liu Z, Watanabe R, Satoh AK. GPI biosynthesis is essential for rhodopsin sorting at the trans-Golgi network in Drosophila photoreceptors. Development 2013; 140:385-94. [PMID: 23250212 DOI: 10.1242/dev.083683] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Sorting of integral membrane proteins plays crucial roles in establishing and maintaining the polarized structures of epithelial cells and neurons. However, little is known about the sorting mechanisms of newly synthesized membrane proteins at the trans-Golgi network (TGN). To identify which genes are essential for these sorting mechanisms, we screened mutants in which the transport of Rhodopsin 1 (Rh1), an apical integral membrane protein in Drosophila photoreceptors, was affected. We found that deficiencies in glycosylphosphatidylinositol (GPI) synthesis and attachment processes cause loss of the apical transport of Rh1 from the TGN and mis-sorting to the endolysosomal system. Moreover, Na(+)K(+)-ATPase, a basolateral membrane protein, and Crumbs (Crb), a stalk membrane protein, were mistransported to the apical rhabdomeric microvilli in GPI-deficient photoreceptors. These results indicate that polarized sorting of integral membrane proteins at the TGN requires the synthesis and anchoring of GPI-anchored proteins. Little is known about the cellular biological consequences of GPI deficiency in animals in vivo. Our results provide new insights into the importance of GPI synthesis and aid the understanding of pathologies involving GPI deficiency.
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Affiliation(s)
- Takunori Satoh
- Division of Life Science, Graduate School of Integral Arts and Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-hiroshima 739-8521, Japan
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KAYAK-α modulates circadian transcriptional feedback loops in Drosophila pacemaker neurons. J Neurosci 2013; 32:16959-70. [PMID: 23175847 DOI: 10.1523/jneurosci.1888-12.2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Circadian rhythms are generated by well-conserved interlocked transcriptional feedback loops in animals. In Drosophila, the dimeric transcription factor CLOCK/CYCLE (CLK/CYC) promotes period (per), timeless (tim), vrille (vri), and PAR-domain protein 1 (Pdp1) transcription. PER and TIM negatively feed back on CLK/CYC transcriptional activity, whereas VRI and PDP1 negatively and positively regulate Clk transcription, respectively. Here, we show that the α isoform of the Drosophila FOS homolog KAYAK (KAY) is required for normal circadian behavior. KAY-α downregulation in circadian pacemaker neurons increases period length by 1.5 h. This behavioral phenotype is correlated with decreased expression of several circadian proteins. The strongest effects are on CLK and the neuropeptide PIGMENT DISPERSING FACTOR, which are both under VRI and PDP1 control. Consistently, KAY-α can bind to VRI and inhibit its interaction with the Clk promoter. Interestingly, KAY-α can also repress CLK activity. Hence, in flies with low KAY-α levels, CLK derepression would partially compensate for increased VRI repression, thus attenuating the consequences of KAY-α downregulation on CLK targets. We propose that the double role of KAY-α in the two transcriptional loops controlling Drosophila circadian behavior brings precision and stability to their oscillations.
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30
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Drosophila p53 isoforms differentially regulate apoptosis and apoptosis-induced proliferation. Cell Death Differ 2012; 20:108-16. [PMID: 22898807 DOI: 10.1038/cdd.2012.100] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Irradiated or injured cells enter apoptosis, and in turn, promote proliferation of surrounding unaffected cells. In Drosophila, apoptotic cells have an active role in proliferation, where the caspase Dronc and p53 induce mitogen expression and growth in the surrounding tissues. The Drosophila p53 gene structure is conserved and encodes at least two protein isoforms: a full-length isoform (Dp53) and an N-terminally truncated isoform (DΔNp53). Historically, DΔNp53 was the first p53 isoform identified and was thought to be responsible for all p53 biological activities. It was shown that DΔNp53 induces apoptosis by inducing the expression of IAP antagonists, such as Reaper. Here we investigated the roles of Dp53 and DΔNp53 in apoptosis and apoptosis-induced proliferation. We found that both isoforms were capable of activating apoptosis, but that they each induced distinct IAP antagonists. Expression of DΔNp53 induced Wingless (Wg) expression and enhanced proliferation in both 'undead cells' and in 'genuine' apoptotic cells. In contrast to DΔNp53, Dp53 did not induce Wg expression in the absence of the endogenous p53 gene. Thus, we propose that DΔNp53 is the main isoform that regulates apoptosis-induced proliferation. Understanding the roles of Drosophila p53 isoforms in apoptosis and in apoptosis-induced proliferation may shed new light on the roles of p53 isoforms in humans, with important implications in cancer biology.
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31
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Dourlen P, Bertin B, Chatelain G, Robin M, Napoletano F, Roux MJ, Mollereau B. Drosophila fatty acid transport protein regulates rhodopsin-1 metabolism and is required for photoreceptor neuron survival. PLoS Genet 2012; 8:e1002833. [PMID: 22844251 PMCID: PMC3405995 DOI: 10.1371/journal.pgen.1002833] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 06/05/2012] [Indexed: 01/16/2023] Open
Abstract
Tight regulation of the visual response is essential for photoreceptor function and survival. Visual response dysregulation often leads to photoreceptor cell degeneration, but the causes of such cell death are not well understood. In this study, we investigated a fatty acid transport protein (fatp) null mutation that caused adult-onset and progressive photoreceptor cell death. Consistent with fatp having a role in the retina, we showed that fatp is expressed in adult photoreceptors and accessory cells and that its re-expression in photoreceptors rescued photoreceptor viability in fatp mutants. The visual response in young fatp-mutant flies was abnormal with elevated electroretinogram amplitudes associated with high levels of Rhodopsin-1 (Rh1). Reducing Rh1 levels in rh1 mutants or depriving flies of vitamin A rescued photoreceptor cell death in fatp mutant flies. Our results indicate that fatp promotes photoreceptor survival by regulating Rh1 abundance.
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Affiliation(s)
- Pierre Dourlen
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
- * E-mail: (PD); (BM)
| | - Benjamin Bertin
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Gilles Chatelain
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Marion Robin
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Francesco Napoletano
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
| | - Michel J. Roux
- Translational Medicine and Neurogenetics, IGBMC, UMR7104 CNRS/Université de Strasbourg/Inserm U964, Strasbourg, France
| | - Bertrand Mollereau
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 344 Biosciences Lyon Gerland, Université de Lyon, Lyon, France
- * E-mail: (PD); (BM)
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32
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Fouillet A, Levet C, Virgone A, Robin M, Dourlen P, Rieusset J, Belaidi E, Ovize M, Touret M, Nataf S, Mollereau B. ER stress inhibits neuronal death by promoting autophagy. Autophagy 2012; 8:915-26. [PMID: 22660271 DOI: 10.4161/auto.19716] [Citation(s) in RCA: 179] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Endoplasmic reticulum (ER) stress has been implicated in neurodegenerative diseases but its relationship and role in disease progression remain unclear. Using genetic and pharmacological approaches, we showed that mild ER stress ("preconditioning") is neuroprotective in Drosophila and mouse models of Parkinson disease. In addition, we found that the combination of mild ER stress and apoptotic signals triggers an autophagic response both in vivo and in vitro. We showed that when autophagy is impaired, ER-mediated protection is lost. We further demonstrated that autophagy inhibits caspase activation and apoptosis. Based on our findings, we conclude that autophagy is required for the neuroprotection mediated by mild ER stress, and therefore ER preconditioning has potential therapeutic value for the treatment of neurodegenerative diseases.
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Affiliation(s)
- Antoine Fouillet
- Ecole Normale Supérieure de Lyon, Laboratoire de Biologie Moléculaire de la Cellule, Lyon, France
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Abstract
Since the discovery of a single white-eyed male in a population of red eyed flies over 100 years ago (Morgan, 1910), the compound eye of the fruit fly, Drosophila melanogaster, has been a favorite experimental system for identifying genes that regulate various aspects of development. For example, a fair amount of what we know today about enzymatic pathways and vesicular transport is due to the discovery and subsequent characterization of eye color mutants such as white. Likewise, our present day understanding of organogenesis has been aided considerably by studies of mutations, such as eyeless, that either reduce or eliminate the compound eyes. But by far the phenotype that has provided levers into the greatest number of experimental fields has been the humble "rough" eye. The fly eye is composed of several hundred unit-eyes that are also called ommatidia. These unit eyes are packed into a hexagonal array of remarkable precision. The structure of the eye is so precise that it has been compared with that of a crystal (Ready et al., 1976). Even the slightest perturbations to the structure of the ommatidium can be visually detected by light or electron microscopy. The cause for this is two-fold: (1) any defect that affects the hexagonal geometry of a single ommatidium can and will disrupt the positioning of surrounding unit eyes thereby propagating structural flaws and (2) disruptions in genes that govern the development of even a single cell within an ommatidium will affect all unit eyes. In both cases, the effect is the visual magnification of even the smallest imperfection. Studies of rough eye mutants have provided key insights into the areas of cell fate specification, lateral inhibition, signal transduction, transcription factor networks, planar cell polarity, cell proliferation, and programmed cell death just to name a few. This review will attempt to summarize the key steps that are required to assemble each ommatidium.
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Affiliation(s)
- Justin P Kumar
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
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34
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Gambis A, Dourlen P, Steller H, Mollereau B. Two-color in vivo imaging of photoreceptor apoptosis and development in Drosophila. Dev Biol 2011; 351:128-34. [PMID: 21215264 DOI: 10.1016/j.ydbio.2010.12.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 12/22/2010] [Accepted: 12/22/2010] [Indexed: 11/25/2022]
Abstract
We report a new two-color fluorescent imaging system to visualize the mosaic adult photoreceptor neurons (PRs) in real-time. Using this method, we examined a collection of 434 mutants and identified genes required for PR survival, planar cell polarity (PCP), patterning and differentiation. We could track the progression of PR degeneration in living flies. By introducing the expression of p35, a caspase inhibitor, we found mutations that specifically activate caspase-dependent death. Moreover, we showed that grh is required in R3 for correct PCP establishment. The "Tomato/GFP-FLP/FRT" method allows high-throughput, rapid and precise identification of survival and developmental pathways in living adult PRs at single-cell resolution.
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Affiliation(s)
- Alexis Gambis
- Howard Hughes Medical Institute, Laboratory of Apoptosis and Cancer, The Rockefeller University, New York, NY 10065, USA
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35
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Parton RM, Vallés AM, Dobbie IM, Davis I. Live cell imaging in Drosophila melanogaster. Cold Spring Harb Protoc 2010; 2010:pdb.top75. [PMID: 20360379 DOI: 10.1101/pdb.top75] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Although many of the techniques of live cell imaging in Drosophila melanogaster are also used by the greater community of cell biologists working on other model systems, studying living fly tissues presents unique difficulties with regard to keeping the cells alive, introducing fluorescent probes, and imaging through thick, hazy cytoplasm. This article outlines the major tissue types amenable to study by time-lapse cinematography and different methods for keeping the cells alive. It describes various imaging and associated techniques best suited to following changes in the distribution of fluorescently labeled molecules in real time in these tissues. Imaging, in general, is a rapidly developing discipline, and recent advances in imaging technology are able to greatly extend what can be achieved with live cell imaging of Drosophila tissues. As far as possible, this article includes the latest technical developments and discusses likely future developments in imaging methods that could have an impact on research using Drosophila.
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Charlton-Perkins M, Cook TA. Building a fly eye: terminal differentiation events of the retina, corneal lens, and pigmented epithelia. Curr Top Dev Biol 2010; 93:129-73. [PMID: 20959165 DOI: 10.1016/b978-0-12-385044-7.00005-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In the past, vast differences in ocular structure, development, and physiology throughout the animal kingdom led to the widely accepted notion that eyes are polyphyletic, that is, they have independently arisen multiple times during evolution. Despite the dissimilarity between vertebrate and invertebrate eyes, it is becoming increasingly evident that the development of the eye in both groups shares more similarity at the genetic level than was previously assumed, forcing a reexamination of eye evolution. Understanding the molecular underpinnings of cell type specification during Drosophila eye development has been a focus of research for many labs over the past 25 years, and many of these findings are nicely reviewed in Chapters 1 and 4. A somewhat less explored area of research, however, considers how these cells, once specified, develop into functional ocular structures. This review aims to summarize the current knowledge related to the terminal differentiation events of the retina, corneal lens, and pigmented epithelia in the fly eye. In addition, we discuss emerging evidence that the different functional components of the fly eye share developmental pathways and functions with the vertebrate eye.
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Affiliation(s)
- Mark Charlton-Perkins
- Department of Pediatric Ophthalmology, Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
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Seo J, Fortuno ES, Suh JM, Stenesen D, Tang W, Parks EJ, Adams CM, Townes T, Graff JM. Atf4 regulates obesity, glucose homeostasis, and energy expenditure. Diabetes 2009; 58:2565-73. [PMID: 19690063 PMCID: PMC2768187 DOI: 10.2337/db09-0335] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE We evaluate a potential role of activating transcription factor 4 (Atf4) in invertebrate and mammalian metabolism. RESEARCH DESIGN AND METHODS With two parallel approaches-a fat body-specific green fluorescent protein enhancer trap screen in D. melanogaster and expression profiling of developing murine fat tissues-we identified Atf4 as expressed in invertebrate and vertebrate metabolic tissues. We assessed the functional relevance of the evolutionarily conserved expression by analyzing Atf4 mutant flies and Atf4 mutant mice for possible metabolic phenotypes. RESULTS Flies with insertions at the Atf4 locus have reduced fat content, increased starvation sensitivity, and lower levels of circulating carbohydrate. Atf4 null mice are also lean, and they resist age-related and diet-induced obesity. Atf4 null mice have increased energy expenditure potentially accounting for the lean phenotype. Atf4 null mice are hypoglycemic, even before substantial changes in fat content, indicating that Atf4 regulates mammalian carbohydrate metabolism. In addition, the Atf4 mutation blunts diet-induced diabetes as well as hyperlipidemia and hepatosteatosis. Several aspects of the Atf4 mutant phenotype resemble mice with mutations in components of the target of rapamycin (TOR) pathway. Consistent with the phenotypic similarities, Atf4 null mice have reduced expression of genes that regulate intracellular amino acid concentrations and lower intracellular concentration of amino acids, a key TOR input. Further, Atf4 mutants have reduced S6K activity in liver and adipose tissues. CONCLUSIONS Atf4 regulates age-related and diet-induced obesity as well as glucose homeostasis in mammals and has conserved metabolic functions in flies.
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Affiliation(s)
- Jin Seo
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Edgardo S. Fortuno
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jae Myoung Suh
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Drew Stenesen
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Wei Tang
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Elizabeth J. Parks
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Christopher M. Adams
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, Iowa
| | - Tim Townes
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jonathan M. Graff
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas
- Corresponding author: Jonathan M. Graff,
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Mendes CS, Levet C, Chatelain G, Dourlen P, Fouillet A, Dichtel-Danjoy ML, Gambis A, Ryoo HD, Steller H, Mollereau B. ER stress protects from retinal degeneration. EMBO J 2009; 28:1296-307. [PMID: 19339992 DOI: 10.1038/emboj.2009.76] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Accepted: 03/04/2009] [Indexed: 11/09/2022] Open
Abstract
The unfolded protein response (UPR) is a specific cellular process that allows the cell to cope with the overload of unfolded/misfolded proteins in the endoplasmic reticulum (ER). ER stress is commonly associated with degenerative pathologies, but its role in disease progression is still a matter for debate. Here, we found that mutations in the ER-resident chaperone, neither inactivation nor afterpotential A (NinaA), lead to mild ER stress, protecting photoreceptor neurons from various death stimuli in adult Drosophila. In addition, Drosophila S2 cultured cells, when pre-exposed to mild ER stress, are protected from H(2)O(2), cycloheximide- or ultraviolet-induced cell death. We show that a specific ER-mediated signal promotes antioxidant defences and inhibits caspase-dependent cell death. We propose that an immediate consequence of the UPR not only limits the accumulation of misfolded proteins but also protects tissues from harmful exogenous stresses.
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Affiliation(s)
- César S Mendes
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
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39
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Watson MR, Lagow RD, Xu K, Zhang B, Bonini NM. A drosophila model for amyotrophic lateral sclerosis reveals motor neuron damage by human SOD1. J Biol Chem 2008; 283:24972-81. [PMID: 18596033 PMCID: PMC2529125 DOI: 10.1074/jbc.m804817200] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Indexed: 01/19/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a motor neuron disease that leads to loss of motor function and early death. About 5% of cases are inherited, with the majority of identified linkages in the gene encoding copper, zinc-superoxide dismutase (SOD1). Strong evidence indicates that the SOD1 mutations confer dominant toxicity on the protein. To provide new insight into mechanisms of ALS, we have generated and characterized a model for familial ALS in Drosophila with transgenic expression of human SOD1. Expression of wild type or disease-linked (A4V, G85R) mutants of human SOD1 selectively in motor neurons induced progressive climbing deficits. These effects were accompanied by defective neural circuit electrophysiology, focal accumulation of human SOD1 protein in motor neurons, and a stress response in surrounding glia. However, toxicity was not associated with oligomerization of SOD1 and did not lead to neuronal loss. These studies uncover cell-autonomous injury by SOD1 to motor neurons in vivo, as well as non-autonomous effects on glia, and provide the foundation for new insight into injury and protection of motor neurons in ALS.
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Affiliation(s)
- Melanie R. Watson
- Department of Biology,
University of Pennsylvania, the
Department of Neuroscience,
University of Pennsylvania School of Medicine, and the
Howard Hughes Medical Institute,
Philadelphia, Pennsylvania 19104 and the
Department of Zoology, University of
Oklahoma, Norman, Oklahoma 73019
| | - Robert D. Lagow
- Department of Biology,
University of Pennsylvania, the
Department of Neuroscience,
University of Pennsylvania School of Medicine, and the
Howard Hughes Medical Institute,
Philadelphia, Pennsylvania 19104 and the
Department of Zoology, University of
Oklahoma, Norman, Oklahoma 73019
| | - Kexiang Xu
- Department of Biology,
University of Pennsylvania, the
Department of Neuroscience,
University of Pennsylvania School of Medicine, and the
Howard Hughes Medical Institute,
Philadelphia, Pennsylvania 19104 and the
Department of Zoology, University of
Oklahoma, Norman, Oklahoma 73019
| | - Bing Zhang
- Department of Biology,
University of Pennsylvania, the
Department of Neuroscience,
University of Pennsylvania School of Medicine, and the
Howard Hughes Medical Institute,
Philadelphia, Pennsylvania 19104 and the
Department of Zoology, University of
Oklahoma, Norman, Oklahoma 73019
| | - Nancy M. Bonini
- Department of Biology,
University of Pennsylvania, the
Department of Neuroscience,
University of Pennsylvania School of Medicine, and the
Howard Hughes Medical Institute,
Philadelphia, Pennsylvania 19104 and the
Department of Zoology, University of
Oklahoma, Norman, Oklahoma 73019
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40
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Dai H, Ma L, Wang J, Jiang R, Wang Z, Fei J. Knockdown of ecdysis-triggering hormone gene with a binaryUAS/GAL4RNA interference system leads to lethal ecdysis deficiency in silkworm. Acta Biochim Biophys Sin (Shanghai) 2008. [DOI: 10.1111/j.1745-7270.2008.00460.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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41
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Katsov AY, Clandinin TR. Motion processing streams in Drosophila are behaviorally specialized. Neuron 2008; 59:322-35. [PMID: 18667159 PMCID: PMC3391501 DOI: 10.1016/j.neuron.2008.05.022] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2008] [Revised: 05/01/2008] [Accepted: 05/02/2008] [Indexed: 11/18/2022]
Abstract
Motion vision is an ancient faculty, critical to many animals in a range of ethological contexts, the underlying algorithms of which provide central insights into neural computation. However, how motion cues guide behavior is poorly understood, as the neural circuits that implement these computations are largely unknown in any organism. We develop a systematic, forward genetic approach using high-throughput, quantitative behavioral analyses to identify the neural substrates of motion vision in Drosophila in an unbiased fashion. We then delimit the behavioral contributions of both known and novel circuit elements. Contrary to expectation from previous studies, we find that orienting responses to motion are shaped by at least two neural pathways. These pathways are sensitive to different visual features, diverge immediately postsynaptic to photoreceptors, and are coupled to distinct behavioral outputs. Thus, behavioral responses to complex stimuli can rely on surprising neural specialization from even the earliest sensory processing stages.
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42
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Suh JM, Stenesen D, Peters JM, Inoue A, Cade A, Graff JM. An RGS-containing sorting nexin controls Drosophila lifespan. PLoS One 2008; 3:e2152. [PMID: 18478054 PMCID: PMC2359856 DOI: 10.1371/journal.pone.0002152] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 03/28/2008] [Indexed: 11/21/2022] Open
Abstract
The pursuit of eternal youth has existed for centuries and recent data indicate that fat-storing tissues control lifespan. In a D. melanogaster fat body insertional mutagenic enhancer trap screen designed to isolate genes that control longevity, we identified a regulator of G protein signaling (RGS) domain containing sorting nexin, termed snazarus (sorting nexin lazarus, snz). Flies with insertions into the 5′ UTR of snz live up to twice as long as controls. Transgenic expression of UAS-Snz from the snz Gal4 enhancer trap insertion, active in fat metabolic tissues, rescued lifespan extension. Further, the lifespan extension of snz mutants was independent of endosymbiont, e.g., Wolbachia, effects. Notably, old snz mutant flies remain active and fertile indicating that snz mutants have prolonged youthfulness, a goal of aging research. Since mammals have snz-related genes, it is possible that the functions of the snz family may be conserved to humans.
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Affiliation(s)
- Jae Myoung Suh
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Drew Stenesen
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - John M. Peters
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Akiko Inoue
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Angela Cade
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Jonathan M. Graff
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail:
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43
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Soustelle L, Aigouy B, Asensio ML, Giangrande A. UV laser mediated cell selective destruction by confocal microscopy. Neural Dev 2008; 3:11. [PMID: 18442390 PMCID: PMC2387153 DOI: 10.1186/1749-8104-3-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Accepted: 04/28/2008] [Indexed: 11/29/2022] Open
Abstract
Analysis of cell-cell interactions, cell function and cell lineages greatly benefits selective destruction techniques, which, at present, rely on dedicated, high energy, pulsed lasers and are limited to cells that are detectable by conventional microscopy. We present here a high resolution/sensitivity technique based on confocal microscopy and relying on commonly used UV lasers. Coupling this technique with time-lapse enables the destruction and following of any cell(s) in any pattern(s) in living animals as well as in cell culture systems.
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Affiliation(s)
- Laurent Soustelle
- Institut de Génétique et Biologie Moléculaire et Cellulaire, IGBMC/CNRS/ULP/INSERM - BP 10142 67404 ILLKIRCH, c.u. de Strasbourg, France.
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44
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Rister J, Pauls D, Schnell B, Ting CY, Lee CH, Sinakevitch I, Morante J, Strausfeld NJ, Ito K, Heisenberg M. Dissection of the Peripheral Motion Channel in the Visual System of Drosophila melanogaster. Neuron 2007; 56:155-70. [DOI: 10.1016/j.neuron.2007.09.014] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 08/14/2007] [Accepted: 09/06/2007] [Indexed: 11/29/2022]
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45
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Sprecher SG, Pichaud F, Desplan C. Adult and larval photoreceptors use different mechanisms to specify the same Rhodopsin fates. Genes Dev 2007; 21:2182-95. [PMID: 17785526 PMCID: PMC1950857 DOI: 10.1101/gad.1565407] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 07/16/2007] [Indexed: 11/25/2022]
Abstract
Although development of the adult Drosophila compound eye is very well understood, little is known about development of photoreceptors (PRs) in the simple larval eye. We show here that the larval eye is composed of 12 PRs, four of which express blue-sensitive rhodopsin5 (rh5) while the other eight contain green-sensitive rh6. This is similar to the 30:70 ratio of adult blue and green R8 cells. However, the stochastic choice of adult color PRs and the bistable loop of the warts and melted tumor suppressor genes that unambiguously specify rh5 and rh6 in R8 PRs are not involved in specification of larval PRs. Instead, primary PR precursors signal via EGFR to surrounding tissue to develop as secondary precursors, which will become Rh6-expressing PRs. EGFR signaling is required for the survival of the Rh6 subtype. Primary precursors give rise to the Rh5 subtype. Furthermore, the combinatorial action of the transcription factors Spalt, Seven-up, and Orthodenticle specifies the two PR subtypes. Therefore, even though the larval PRs and adult R8 PRs express the same rhodopsins (rh5 and rh6), they use very distinct mechanisms for their specification.
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Affiliation(s)
- Simon G. Sprecher
- Center for Developmental Genetics, Department of Biology, New York University, New York, New York 10003, USA
| | - Franck Pichaud
- Center for Developmental Genetics, Department of Biology, New York University, New York, New York 10003, USA
| | - Claude Desplan
- Center for Developmental Genetics, Department of Biology, New York University, New York, New York 10003, USA
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46
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Ash DM, Hackney JF, Jean-Francois M, Burton NC, Dobens LL. A dominant negative allele of the Drosophila leucine zipper protein Bunched blocks bunched function during tissue patterning. Mech Dev 2007; 124:559-69. [PMID: 17600691 DOI: 10.1016/j.mod.2007.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 05/08/2007] [Accepted: 05/11/2007] [Indexed: 02/01/2023]
Abstract
The bunched (bun) gene encodes the Drosophila member of the TSC-22/GILZ family of leucine zipper transcriptional regulators. The bun locus encodes multiple BUN protein isoforms and has diverse roles during patterning of the eye, wing margin, dorsal notum and eggshell. Here we report the construction and activity of a dominant negative allele (BunDN) of the BUN-B isoform. In the ovary, BunDN expression in the follicle cells (FC) resulted in epithelial defects including aberrant accumulation of DE-cadherin and failure to rearrange into columnar FC cell shapes. BunDN expression in the posterior FC led to loss of epithelial integrity associated with extensive apoptosis. BunDN FC phenotypes collectively resemble loss-of-function bun mutant phenotypes. BunDN expression using tissue-specific imaginal disk drivers resulted in characteristic cuticular patterning defects that were enhanced by bun mutations and suppressed by co-expression of the BUN-B protein isoform. These data indicate that BunDN has dominant negative activity useful to identify bun functions and genetic interactions that occur during tissue patterning.
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Affiliation(s)
- David M Ash
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, United States
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47
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Levine B, Jean-Francois M, Bernardi F, Gargiulo G, Dobens L. Notch signaling links interactions between the C/EBP homolog slow border cells and the GILZ homolog bunched during cell migration. Dev Biol 2007; 305:217-31. [PMID: 17383627 DOI: 10.1016/j.ydbio.2007.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 01/11/2007] [Accepted: 02/09/2007] [Indexed: 10/23/2022]
Abstract
In the follicle cell (FC) epithelium that surrounds the Drosophila egg, a complex set of cell signals specifies two cell fates that pattern the eggshell: the anterior centripetal FC that produce the operculum and the posterior columnar FC that produce the main body eggshell structure. We have previously shown that the long-range morphogen DPP represses the expression of the bunched (bun) gene in the anterior-most centripetal FC. bun, which encodes a homolog of vertebrate TSC-22/GILZ, in turn represses anterior gene expression and antagonizes Notch signaling to restrict centripetal FC fates in posterior cells. From a screen for novel targets of bun repression we have identified the C/EBP homolog slow border cells (slbo). At stage 10A, slbo expression overlaps bun in anterior FC; by stage 10B they repress each other's expression to establish a sharp slbo/bun expression boundary. The precise position of the slbo/bun expression boundary is sensitive to Notch signaling, which is required for both slbo activation and bun repression. As centripetal migration proceeds from stages 10B-14, slbo represses its own expression and both slbo loss-of-function mutations and overexpression approaches reveal that slbo is required to coordinate centripetal migration with nurse cell dumping. We propose that in anterior FC exposed to a Dpp morphogen gradient, high and low levels of slbo and bun, respectively, are established by modulation of Notch signaling to direct threshold cell fates. Interactions among Notch, slbo and bun resemble a conserved signaling cassette that regulates mammalian adipocyte differentiation.
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Affiliation(s)
- Benjamin Levine
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA
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48
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Rister J, Heisenberg M. Distinct functions of neuronal synaptobrevin in developing and mature fly photoreceptors. ACTA ACUST UNITED AC 2006; 66:1271-84. [PMID: 16967508 DOI: 10.1002/neu.20284] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Neuronal synaptobrevin (n-Syb, alias VAMP2), a synaptic vesicle membrane protein with a central role in neurotransmission, is specifically cleaved by the light chain of tetanus neurotoxin (TNT) that is known to reliably block neuroexocytosis. Here, we study fly photoreceptors transmitting continuous, graded signals to first order interneurons in the lamina, and report consequences of targeted expression of TNT in these cells using the UAS/GAL4 driver/effector system. Expressing the toxin throughout photoreceptor development causes developmental, electrophysiological, and behavioral defects. These can be differentiated by confining toxin expression to shorter developmental periods. Applying a method for controlled temporal and spatial TNT expression, we found that in the early pupa it impaired the development of the retina; in the midpupa, during synapse formation TNT caused a severe hypoplasia of the lamina that persisted into adulthood and left the photoreceptor-interneuron synapses of the lamina without function. Finally, during adulthood TNT neither blocks synaptic transmission in photoreceptors nor depletes the cells of n-Syb. Our study suggests a novel, cell type-specific function of n-Syb in synaptogenesis and it distinguishes between two synapse types: TNT resistant and TNT sensitive ones. These results need to be taken into account if TNT is used for neural circuit analysis.
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Affiliation(s)
- Jens Rister
- Lehrstuhl für Genetik und Neurobiologie der Universität Würzburg, Biozentrum Am Hubland, D-97074 Würzburg, Germany
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49
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Mollereau B, Domingos PM. Photoreceptor differentiation in Drosophila: from immature neurons to functional photoreceptors. Dev Dyn 2005; 232:585-92. [PMID: 15704118 DOI: 10.1002/dvdy.20271] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
How a pool of equipotent cells acquires a multitude of distinct fates is a major question in developmental biology. The study of photoreceptor (PR) cell differentiation in Drosophila has been used to address this question. PR differentiation is a process that extends over a period of 5 days: It begins in the larval eye imaginal disc when PRs are recruited and commit to particular PR fates, and it culminates in the pupal eye disc with the morphogenesis of the rhabdomeres and the initiation of rhodopsin expression. Several models for PR specification agree that the Ras and Notch signaling pathways are important for the specification of different PR subtypes (Freeman [1997] Development 124:261-270; Cooper and Bray [2000] Curr. Biol. 10:1507-1510; Tomlinson and Struhl [2001] Mol. Cell. 7:487-495). In the first part of this review, we briefly describe the different signaling pathways and transcription factors required for the specification and differentiation of the different PR subtypes in the larval eye disc. In the second part, we review the roles of several transcription factors, which are required for the terminal photoreceptor differentiation and rhodopsin expression.
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Affiliation(s)
- Bertrand Mollereau
- Strang Laboratory of Cancer Research, The Rockefeller University, New York, New York 10021, USA.
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50
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Tsuda H, Jafar-Nejad H, Patel AJ, Sun Y, Chen HK, Rose MF, Venken KJT, Botas J, Orr HT, Bellen HJ, Zoghbi HY. The AXH Domain of Ataxin-1 Mediates Neurodegeneration through Its Interaction with Gfi-1/Senseless Proteins. Cell 2005; 122:633-44. [PMID: 16122429 DOI: 10.1016/j.cell.2005.06.012] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Revised: 04/27/2005] [Accepted: 06/09/2005] [Indexed: 11/16/2022]
Abstract
Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease caused by an expanded glutamine tract in human Ataxin-1 (hAtx-1). The expansion stabilizes hAtx-1, leading to its accumulation. To understand how stabilized hAtx-1 induces selective neuronal degeneration, we studied Drosophila Atx-1 (dAtx-1), which has a conserved AXH domain but lacks a polyglutamine tract. Overexpression of hAtx-1 in fruit flies produces phenotypes similar to those of dAtx-1 but different from the polyglutamine peptide alone. We show that the Drosophila and mammalian transcription factors Senseless/Gfi-1 interact with Atx-1's AXH domain. In flies, overexpression of Atx-1 inhibits sensory-organ development by decreasing Senseless protein. Similarly, overexpression of wild-type and glutamine-expanded hAtx-1 reduces Gfi-1 levels in Purkinje cells. Deletion of the AXH domain abolishes the effects of glutamine-expanded hAtx-1 on Senseless/Gfi-1. Interestingly, loss of Gfi-1 mimics SCA1 phenotypes in Purkinje cells. These results indicate that the Atx-1/Gfi-1 interaction contributes to the selective Purkinje cell degeneration in SCA1.
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Affiliation(s)
- Hiroshi Tsuda
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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