1
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Zhang B, Duan H, Kavaler J, Wei L, Eberl DF, Lai EC. A nonneural miRNA cluster mediates hearing via repression of two neural targets. Genes Dev 2023; 37:1041-1051. [PMID: 38110249 PMCID: PMC10760640 DOI: 10.1101/gad.351052.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/29/2023] [Indexed: 12/20/2023]
Abstract
We show here that mir-279/996 are absolutely essential for development and function of Johnston's organ (JO), the primary proprioceptive and auditory organ in Drosophila Their deletion results in highly aberrant cell fate determination, including loss of scolopale cells and ectopic neurons, and mutants are electrophysiologically deaf. In vivo activity sensors and mosaic analyses indicate that these seed-related miRNAs function autonomously to suppress neural fate in nonneuronal cells. Finally, genetic interactions pinpoint two neural targets (elav and insensible) that underlie miRNA mutant JO phenotypes. This work uncovers how critical post-transcriptional regulation of specific miRNA targets governs cell specification and function of the auditory system.
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Affiliation(s)
- Binglong Zhang
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Hong Duan
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Joshua Kavaler
- Department of Biology, Colby College, Waterville, Maine 04901, USA
| | - Lu Wei
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Daniel F Eberl
- Department of Biology, University of Iowa, Iowa City, Iowa 52242, USA
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA;
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2
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Boyan G, Williams L, Ehrhardt E. Central projections from Johnston's organ in the locust: Axogenesis and brain neuroarchitecture. Dev Genes Evol 2023; 233:147-159. [PMID: 37695323 PMCID: PMC10746777 DOI: 10.1007/s00427-023-00710-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 08/25/2023] [Indexed: 09/12/2023]
Abstract
Johnston's organ (Jo) acts as an antennal wind-sensitive and/or auditory organ across a spectrum of insect species and its axons universally project to the brain. In the locust, this pathway is already present at mid-embryogenesis but the process of fasciculation involved in its construction has not been investigated. Terminal projections into the fine neuropilar organization of the brain also remain unresolved, information essential not only for understanding the neural circuitry mediating Jo-mediated behavior but also for providing comparative data offering insights into its evolution. In our study here, we employ neuron-specific, axon-specific, and epithelial domain labels to show that the pathway to the brain of the locust is built in a stepwise manner during early embryogenesis as processes from Jo cell clusters in the pedicel fasciculate first with one another, and then with the two tracts constituting the pioneer axon scaffold of the antenna. A comparison of fasciculation patterns confirms that projections from cell clusters of Jo stereotypically associate with only one axon tract according to their location in the pedicellar epithelium, consistent with a topographic plan. At the molecular level, all neuronal elements of the Jo pathway to the brain express the lipocalin Lazarillo, a cell surface epitope that regulates axogenesis in the primary axon scaffold itself, and putatively during fasciculation of the Jo projections to the brain. Central projections from Jo first contact the primary axon scaffold of the deutocerebral brain at mid-embryogenesis, and in the adult traverse mechanosensory/motor neuropils similar to those in Drosophila. These axons then terminate among protocerebral commissures containing premotor interneurons known to regulate flight behavior.
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Affiliation(s)
- George Boyan
- Graduate School of Systemic Neuroscience, Biocenter, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2, 82152, Munich, Planegg-Martinsried, Germany.
| | - Leslie Williams
- Graduate School of Systemic Neuroscience, Biocenter, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2, 82152, Munich, Planegg-Martinsried, Germany
| | - Erica Ehrhardt
- Graduate School of Systemic Neuroscience, Biocenter, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2, 82152, Munich, Planegg-Martinsried, Germany
- Institute of Zoology, AG Ito, Universität Zu Köln, Zülpicher Str. 47B, 50674, Cologne, Germany
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3
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Loh YM, Su MP, Ellis DA, Andrés M. The auditory efferent system in mosquitoes. Front Cell Dev Biol 2023; 11:1123738. [PMID: 36923250 PMCID: PMC10009176 DOI: 10.3389/fcell.2023.1123738] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/17/2023] [Indexed: 03/02/2023] Open
Abstract
Whilst acoustic communication forms an integral component of the mating behavior of many insect species, it is particularly crucial for disease-transmitting mosquitoes; swarming males rely on hearing the faint sounds of flying females for courtship initiation. That males can hear females within the din of a swarm is testament to their fabulous auditory systems. Mosquito hearing is highly frequency-selective, remarkably sensitive and, most strikingly, supported by an elaborate system of auditory efferent neurons that modulate the auditory function - the only documented example amongst insects. Peripheral release of octopamine, serotonin and GABA appears to differentially modulate hearing across major disease-carrying mosquito species, with receptors from other neurotransmitter families also identified in their ears. Because mosquito mating relies on hearing the flight tones of mating partners, the auditory efferent system offers new potential targets for mosquito control. It also represents a unique insect model for studying auditory efferent networks. Here we review current knowledge of the mosquito auditory efferent system, briefly compare it with its counterparts in other species and highlight future research directions to unravel its contribution to mosquito auditory perception.
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Affiliation(s)
- YuMin M. Loh
- Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Matthew P. Su
- Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
- Institute for Advanced Research, Nagoya University, Nagoya, Aichi, Japan
| | - David A. Ellis
- UCL Ear Institute, University College London, London, United Kingdom
- The Francis Crick Institute, London, United Kingdom
| | - Marta Andrés
- UCL Ear Institute, University College London, London, United Kingdom
- The Francis Crick Institute, London, United Kingdom
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4
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Boyan G, Ehrhardt E. Early embryonic development of Johnston's organ in the antenna of the desert locust Schistocerca gregaria. Dev Genes Evol 2022; 232:103-113. [PMID: 36138225 PMCID: PMC9691482 DOI: 10.1007/s00427-022-00695-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 09/13/2022] [Indexed: 01/30/2023]
Abstract
Johnston's organ has been shown to act as an antennal auditory organ across a spectrum of insect species. In the hemimetabolous desert locust Schistocerca gregaria, Johnston's organ must be functional on hatching and so develops in the pedicellar segment of the antenna during embryogenesis. Here, we employ the epithelial cell marker Lachesin to identify the pedicellar domain of the early embryonic antenna and then triple-label against Lachesin, the mitosis marker phosphohistone-3, and neuron-specific horseradish peroxidase to reveal the sense-organ precursors for Johnston's organ and their lineages. Beginning with a single progenitor at approximately a third of embryogenesis, additional precursors subsequently appear in both the ventral and dorsal pedicellar domains, each generating a lineage or clone. Lineage locations are remarkably conserved across preparations and ages, consistent with the epithelium possessing an underlying topographic coordinate system that determines the cellular organization of Johnston's organ. By mid-embryogenesis, twelve lineages are arranged circumferentially in the pedicel as in the adult structure. Each sense-organ precursor is associated with a smaller mitotically active cell from which the neuronal complement of each clone may derive. Neuron numbers within a clone increase in discrete steps with age and are invariant between clones and across preparations of a given age. At mid-embryogenesis, each clone comprises five cells consolidated into a tightly bound cartridge. A long scolopale extends apically from each cartridge to an insertion point in the epithelium, and bundled axons project basally toward the brain. Comparative data suggest mechanisms that might also regulate the developmental program of Johnston's organ in the locust.
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Affiliation(s)
- George Boyan
- Graduate School of Systemic Neuroscience, Biocenter, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2, 82152, Munich, Planegg-Martinsried, Germany.
| | - Erica Ehrhardt
- Graduate School of Systemic Neuroscience, Biocenter, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2, 82152, Munich, Planegg-Martinsried, Germany
- Institute of Zoology, Universität Zu Köln, Zülpicher Str. 47b, 50674, Cologne, Germany
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5
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Pinto J, Magni PA, O’Brien RC, Dadour IR. Chasing Flies: The Use of Wingbeat Frequency as a Communication Cue in Calyptrate Flies (Diptera: Calyptratae). INSECTS 2022; 13:822. [PMID: 36135523 PMCID: PMC9504876 DOI: 10.3390/insects13090822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/03/2022] [Accepted: 09/01/2022] [Indexed: 06/16/2023]
Abstract
The incidental sound produced by the oscillation of insect wings during flight provides an opportunity for species identification. Calyptrate flies include some of the fastest and most agile flying insects, capable of rapid changes in direction and the fast pursuit of conspecifics. This flight pattern makes the continuous and close recording of their wingbeat frequency difficult and limited to confined specimens. Advances in sound editor and analysis software, however, have made it possible to isolate low amplitude sounds using noise reduction and pitch detection algorithms. To explore differences in wingbeat frequency between genera and sex, 40 specimens of three-day old Sarcophaga crassipalpis, Lucilia sericata, Calliphora dubia, and Musca vetustissima were individually recorded in free flight in a temperature-controlled room. Results showed significant differences in wingbeat frequency between the four species and intersexual differences for each species. Discriminant analysis classifying the three carrion flies resulted in 77.5% classified correctly overall, with the correct classification of 82.5% of S. crassipalpis, 60% of C. dubia, and 90% of L. sericata, when both mean wingbeat frequency and sex were included. Intersexual differences were further demonstrated by male flies showing significantly higher variability than females in three of the species. These observed intergeneric and intersexual differences in wingbeat frequency start the discussion on the use of the metric as a communication signal by this taxon. The success of the methodology demonstrated differences at the genus level and encourages the recording of additional species and the use of wingbeat frequency as an identification tool for these flies.
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Affiliation(s)
- Julie Pinto
- Discipline of Medical, Molecular & Forensic Sciences, Murdoch University, Murdoch, WA 6150, Australia
| | - Paola A. Magni
- Discipline of Medical, Molecular & Forensic Sciences, Murdoch University, Murdoch, WA 6150, Australia
- King’s Centre, Murdoch University Singapore, Singapore 169662, Singapore
| | - R. Christopher O’Brien
- Forensic Sciences Department, Henry C. Lee College of Criminal Justice and Forensic Sciences, University of New Haven, West Haven, CT 06516, USA
| | - Ian R. Dadour
- Discipline of Medical, Molecular & Forensic Sciences, Murdoch University, Murdoch, WA 6150, Australia
- Source Certain, Wangara DC, WA 6947, Australia
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6
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Ray S, Singhvi A. Charging Up the Periphery: Glial Ionic Regulation in Sensory Perception. Front Cell Dev Biol 2021; 9:687732. [PMID: 34458255 PMCID: PMC8385785 DOI: 10.3389/fcell.2021.687732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/30/2021] [Indexed: 12/25/2022] Open
Abstract
The peripheral nervous system (PNS) receives diverse sensory stimuli from the environment and transmits this information to the central nervous system (CNS) for subsequent processing. Thus, proper functions of cells in peripheral sense organs are a critical gate-keeper to generating appropriate animal sensory behaviors, and indeed their dysfunction tracks sensory deficits, sensorineural disorders, and aging. Like the CNS, the PNS comprises two major cell types, neurons (or sensory cells) and glia (or glia-like supporting neuroepithelial cells). One classic function of PNS glia is to modulate the ionic concentration around associated sensory cells. Here, we review current knowledge of how non-myelinating support cell glia of the PNS regulate the ionic milieu around sensory cell endings across species and systems. Molecular studies reviewed here suggest that, rather than being a passive homeostatic response, glial ionic regulation may in fact actively modulate sensory perception, implying that PNS glia may be active contributors to sensorineural information processing. This is reminiscent of emerging studies suggesting analogous roles for CNS glia in modulating neural circuit processing. We therefore suggest that deeper molecular mechanistic investigations into critical PNS glial functions like ionic regulation are essential to comprehensively understand sensorineural health, disease, and aging.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States.,Department of Biological Structure, School of Medicine, University of Washington, Seattle, WA, United States
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7
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Fernández-Hernández I, Marsh EB, Bonaguidi MA. Mechanosensory neuron regeneration in adult Drosophila. Development 2021; 148:dev.187534. [PMID: 33597190 DOI: 10.1242/dev.187534] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/09/2021] [Indexed: 01/01/2023]
Abstract
Auditory and vestibular mechanosensory hair cells do not regenerate following injury or aging in the adult mammalian inner ear, inducing irreversible hearing loss and balance disorders for millions of people. Research on model systems showing replacement of mechanosensory cells can provide mechanistic insights into developing new regenerative therapies. Here, we developed lineage tracing systems to reveal the generation of mechanosensory neurons in the Johnston's organ (JO) of intact adult Drosophila, which are the functional counterparts to hair cells in vertebrates. New JO neurons develop cilia and target central brain circuitry. Unexpectedly, mitotic recombination clones point to JO neuron self-replication as a likely source of neuronal plasticity. This mechanism is further enhanced upon treatment with experimental and ototoxic compounds. Our findings introduce a new platform to expedite research on mechanisms and compounds mediating mechanosensory cell regeneration, with nascent implications for hearing and balance restoration.
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Affiliation(s)
- Ismael Fernández-Hernández
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Evan B Marsh
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Michael A Bonaguidi
- Department of Stem Cell Biology and Regenerative Medicine, Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA .,Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089, USA.,Department of Gerontology, Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.,Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 USA
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8
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Bravo González‐Blas C, Quan X, Duran‐Romaña R, Taskiran II, Koldere D, Davie K, Christiaens V, Makhzami S, Hulselmans G, de Waegeneer M, Mauduit D, Poovathingal S, Aibar S, Aerts S. Identification of genomic enhancers through spatial integration of single-cell transcriptomics and epigenomics. Mol Syst Biol 2020; 16:e9438. [PMID: 32431014 PMCID: PMC7237818 DOI: 10.15252/msb.20209438] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 01/02/2023] Open
Abstract
Single-cell technologies allow measuring chromatin accessibility and gene expression in each cell, but jointly utilizing both layers to map bona fide gene regulatory networks and enhancers remains challenging. Here, we generate independent single-cell RNA-seq and single-cell ATAC-seq atlases of the Drosophila eye-antennal disc and spatially integrate the data into a virtual latent space that mimics the organization of the 2D tissue using ScoMAP (Single-Cell Omics Mapping into spatial Axes using Pseudotime ordering). To validate spatially predicted enhancers, we use a large collection of enhancer-reporter lines and identify ~ 85% of enhancers in which chromatin accessibility and enhancer activity are coupled. Next, we infer enhancer-to-gene relationships in the virtual space, finding that genes are mostly regulated by multiple, often redundant, enhancers. Exploiting cell type-specific enhancers, we deconvolute cell type-specific effects of bulk-derived chromatin accessibility QTLs. Finally, we discover that Prospero drives neuronal differentiation through the binding of a GGG motif. In summary, we provide a comprehensive spatial characterization of gene regulation in a 2D tissue.
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Affiliation(s)
| | - Xiao‐Jiang Quan
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | | | - Ibrahim Ihsan Taskiran
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - Duygu Koldere
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | | | - Valerie Christiaens
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - Samira Makhzami
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - Gert Hulselmans
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - Maxime de Waegeneer
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - David Mauduit
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | | | - Sara Aibar
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
| | - Stein Aerts
- VIB Center for Brain & Disease ResearchLeuvenBelgium
- Department of Human GeneticsKU LeuvenLeuvenBelgium
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9
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Mamiya A, Gurung P, Tuthill JC. Neural Coding of Leg Proprioception in Drosophila. Neuron 2018; 100:636-650.e6. [PMID: 30293823 PMCID: PMC6481666 DOI: 10.1016/j.neuron.2018.09.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/01/2018] [Accepted: 09/05/2018] [Indexed: 01/12/2023]
Abstract
Animals rely on an internal sense of body position and movement to effectively control motor behavior. This sense of proprioception is mediated by diverse populations of mechanosensory neurons distributed throughout the body. Here, we investigate neural coding of leg proprioception in Drosophila, using in vivo two-photon calcium imaging of proprioceptive sensory neurons during controlled movements of the fly tibia. We found that the axons of leg proprioceptors are organized into distinct functional projections that contain topographic representations of specific kinematic features. Using subclass-specific genetic driver lines, we show that one group of axons encodes tibia position (flexion/extension), another encodes movement direction, and a third encodes bidirectional movement and vibration frequency. Overall, our findings reveal how proprioceptive stimuli from a single leg joint are encoded by a diverse population of sensory neurons, and provide a framework for understanding how proprioceptive feedback signals are used by motor circuits to coordinate the body.
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Affiliation(s)
- Akira Mamiya
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - Pralaksha Gurung
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
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10
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Li T, Bellen HJ, Groves AK. Using Drosophila to study mechanisms of hereditary hearing loss. Dis Model Mech 2018; 11:11/6/dmm031492. [PMID: 29853544 PMCID: PMC6031363 DOI: 10.1242/dmm.031492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Johnston's organ - the hearing organ of Drosophila - has a very different structure and morphology to that of the hearing organs of vertebrates. Nevertheless, it is becoming clear that vertebrate and invertebrate auditory organs share many physiological, molecular and genetic similarities. Here, we compare the molecular and cellular features of hearing organs in Drosophila with those of vertebrates, and discuss recent evidence concerning the functional conservation of Usher proteins between flies and mammals. Mutations in Usher genes cause Usher syndrome, the leading cause of human deafness and blindness. In Drosophila, some Usher syndrome proteins appear to physically interact in protein complexes that are similar to those described in mammals. This functional conservation highlights a rational role for Drosophila as a model for studying hearing, and for investigating the evolution of auditory organs, with the aim of advancing our understanding of the genes that regulate human hearing and the pathogenic mechanisms that lead to deafness.
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Affiliation(s)
- Tongchao Li
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Andrew K Groves
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
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11
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Pons M, Soulard C, Soustelle L, Parmentier ML, Grau Y, Layalle S. A New Behavioral Test and Associated Genetic Tools Highlight the Function of Ventral Abdominal Muscles in Adult Drosophila. Front Cell Neurosci 2017; 11:371. [PMID: 29209177 PMCID: PMC5702315 DOI: 10.3389/fncel.2017.00371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 11/08/2017] [Indexed: 11/23/2022] Open
Abstract
The function of the nervous system in complex animals is reflected by the achievement of specific behaviors. For years in Drosophila, both simple and complex behaviors have been studied and their genetic bases have emerged. The neuromuscular junction is maybe one of the prototypal simplest examples. A motor neuron establishes synaptic connections on its muscle cell target and elicits behavior: the muscle contraction. Different muscles in adult fly are related to specific behaviors. For example, the thoracic muscles are associated with flight and the leg muscles are associated with locomotion. However, specific tools are still lacking for the study of cellular physiology in distinct motor neuron subpopulations. Here we decided to use the abdominal muscles and in particular the ventral abdominal muscles (VAMs) in adult Drosophila as new model to link a precise behavior to specific motor neurons. Hence, we developed a new behavioral test based on the folding movement of the adult abdomen. Further, we performed a genetic screen and identify two specific Gal4 lines with restricted expression patterns to the adult motor neurons innervating the VAMs or their precursor cells. Using these genetic tools, we showed that the lack of the VAMs or the loss of the synaptic transmission in their innervating motor neurons lead to a significant impairment of the abdomen folding behavior. Altogether, our results allow establishing a direct link between specific motor neurons and muscles for the realization of particular behavior: the folding behavior of the abdomen in Drosophila.
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Affiliation(s)
- Marine Pons
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Claire Soulard
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Laurent Soustelle
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Marie-Laure Parmentier
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Yves Grau
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Sophie Layalle
- Institut de Génomique Fonctionnelle, CNRS, INSERM, Université de Montpellier, Montpellier, France
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12
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Vannini L, Willis JH. Immunolocalization of cuticular proteins in Johnston's organ and the corneal lens of Anopheles gambiae. ARTHROPOD STRUCTURE & DEVELOPMENT 2016; 45:519-535. [PMID: 27744002 PMCID: PMC5228451 DOI: 10.1016/j.asd.2016.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/03/2016] [Indexed: 05/03/2023]
Abstract
Previous work with EM immunolocalization examined the intracuticular placement of several antibodies directed against cuticular proteins (CPs) in various structures of Anopheles gambiae. Those structures had long stretches of fairly uniform cuticle. We have now used 19 antibodies directed against members of five CP families on two adult structures with considerable complexity, Johnston's organ and the corneal lens of the compound eye. We also localized chitin with colloidal-gold labeled wheat germ agglutinin. Twelve of these antibodies recognized structures in Johnston's organ. Only 6 were detected in the outer pedicel wall, but the internal structures were more complex with distinct distributions of members of the five CP families in six different structures. The corneal lens had four distinct regions of laminar cuticle. Thirteen of the 15 members of the CPR family were detected, none from the other CP families. Specific antibodies were localized to different regions and in different laminae within a region. The specificity of deployment of cuticular proteins revealed in this study is helping to explain why An. gambiae allocates about 2% of its protein coding genes to structural CPs.
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Affiliation(s)
- Laura Vannini
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Judith H Willis
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA.
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13
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Li T, Giagtzoglou N, Eberl DF, Jaiswal SN, Cai T, Godt D, Groves AK, Bellen HJ. The E3 ligase Ubr3 regulates Usher syndrome and MYH9 disorder proteins in the auditory organs of Drosophila and mammals. eLife 2016; 5. [PMID: 27331610 PMCID: PMC4978524 DOI: 10.7554/elife.15258] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/21/2016] [Indexed: 01/08/2023] Open
Abstract
Myosins play essential roles in the development and function of auditory organs and multiple myosin genes are associated with hereditary forms of deafness. Using a forward genetic screen in Drosophila, we identified an E3 ligase, Ubr3, as an essential gene for auditory organ development. Ubr3 negatively regulates the mono-ubiquitination of non-muscle Myosin II, a protein associated with hearing loss in humans. The mono-ubiquitination of Myosin II promotes its physical interaction with Myosin VIIa, a protein responsible for Usher syndrome type IB. We show that ubr3 mutants phenocopy pathogenic variants of Myosin II and that Ubr3 interacts genetically and physically with three Usher syndrome proteins. The interactions between Myosin VIIa and Myosin IIa are conserved in the mammalian cochlea and in human retinal pigment epithelium cells. Our work reveals a novel mechanism that regulates protein complexes affected in two forms of syndromic deafness and suggests a molecular function for Myosin IIa in auditory organs.
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Affiliation(s)
- Tongchao Li
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States
| | - Nikolaos Giagtzoglou
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Department of Neurology, Baylor College of Medicine, Houston, United States
| | - Daniel F Eberl
- Department of Biology, University of Iowa, Iowa City, United States
| | - Sonal Nagarkar Jaiswal
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States
| | - Tiantian Cai
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Dorothea Godt
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Andrew K Groves
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Hugo J Bellen
- Program in Developmental Biology, Baylor College of Medicine, Houston, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States
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14
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Chen JV, Kao LR, Jana SC, Sivan-Loukianova E, Mendonça S, Cabrera OA, Singh P, Cabernard C, Eberl DF, Bettencourt-Dias M, Megraw TL. Rootletin organizes the ciliary rootlet to achieve neuron sensory function in Drosophila. J Cell Biol 2015; 211:435-53. [PMID: 26483560 PMCID: PMC4621839 DOI: 10.1083/jcb.201502032] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 09/09/2015] [Indexed: 12/22/2022] Open
Abstract
Drosophila Rootletin organizes rootlets in sensory neurons, where it transmits multiple sensory inputs and maintains basal body cohesion, yet it is not required for cilium stability. Cilia are essential for cell signaling and sensory perception. In many cell types, a cytoskeletal structure called the ciliary rootlet links the cilium to the cell body. Previous studies indicated that rootlets support the long-term stability of some cilia. Here we report that Drosophila melanogaster Rootletin (Root), the sole orthologue of the mammalian paralogs Rootletin and C-Nap1, assembles into rootlets of diverse lengths among sensory neuron subtypes. Root mutant neurons lack rootlets and have dramatically impaired sensory function, resulting in behavior defects associated with mechanosensation and chemosensation. Root is required for cohesion of basal bodies, but the cilium structure appears normal in Root mutant neurons. We show, however, that normal rootlet assembly requires centrioles. The N terminus of Root contains a conserved domain and is essential for Root function in vivo. Ectopically expressed Root resides at the base of mother centrioles in spermatocytes and localizes asymmetrically to mother centrosomes in neuroblasts, both requiring Bld10, a basal body protein with varied functions.
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Affiliation(s)
- Jieyan V Chen
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306
| | - Ling-Rong Kao
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306
| | - Swadhin C Jana
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | | | | | - Oscar A Cabrera
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306
| | - Priyanka Singh
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Daniel F Eberl
- Biology Department, University of Iowa, Iowa City, IA 52242
| | | | - Timothy L Megraw
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL 32306
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15
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Schüler A, Schmitz G, Reft A, Özbek S, Thurm U, Bornberg-Bauer E. The Rise and Fall of TRP-N, an Ancient Family of Mechanogated Ion Channels, in Metazoa. Genome Biol Evol 2015; 7:1713-27. [PMID: 26100409 PMCID: PMC4494053 DOI: 10.1093/gbe/evv091] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mechanoreception, the sensing of mechanical forces, is an ancient means of orientation and communication and tightly linked to the evolution of motile animals. In flies, the transient-receptor-potential N protein (TRP-N) was found to be a cilia-associated mechanoreceptor. TRP-N belongs to a large and diverse family of ion channels. Its unusually long N-terminal repeat of 28 ankyrin domains presumably acts as the gating spring by which mechanical energy induces channel gating. We analyzed the evolutionary origins and possible diversification of TRP-N. Using a custom-made set of highly discriminative sequence profiles we scanned a representative set of metazoan genomes and subsequently corrected several gene models. We find that, contrary to other ion channel families, TRP-N is remarkably conserved in its domain arrangements and copy number (1) in all Bilateria except for amniotes, even in the wake of several whole-genome duplications. TRP-N is absent in Porifera but present in Ctenophora and Placozoa. Exceptional multiplications of TRP-N occurred in Cnidaria, independently along the Hydra and the Nematostella lineage. Molecular signals of subfunctionalization can be attributed to different mechanisms of activation of the gating spring. In Hydra this is further supported by in situ hybridization and immune staining, suggesting that at least three paralogs adapted to nematocyte discharge, which is key for predation and defense. We propose that these new candidate proteins help explain the sensory complexity of Cnidaria which has been previously observed but so far has lacked a molecular underpinning. Also, the ancient appearance of TRP-N supports a common origin of important components of the nervous systems in Ctenophores, Cnidaria, and Bilateria.
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Affiliation(s)
- Andreas Schüler
- Institute for Evolution and Biodiversity, University of Muenster, Germany
| | - Gregor Schmitz
- Institute for Evolution and Biodiversity, University of Muenster, Germany
| | - Abigail Reft
- Centre for Organismal Studies, University of Heidelberg, Germany
| | - Suat Özbek
- Centre for Organismal Studies, University of Heidelberg, Germany HEIKA-Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Heidelberg and Karlsruhe, Germany
| | - Ulrich Thurm
- Institute for Neurobiology and Behavioural Biology, University of Muenster, Germany
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16
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The Adhesion GPCR Latrophilin/CIRL Shapes Mechanosensation. Cell Rep 2015; 11:866-874. [DOI: 10.1016/j.celrep.2015.04.008] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 03/09/2015] [Accepted: 04/01/2015] [Indexed: 01/09/2023] Open
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17
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Abstract
Drosophila melanogaster is a powerful genetic model organism to understand the function of proteins in specific cellular processes. Cilia have been extensively studied in Drosophila playing various sensory functions that are essential for fly survival. Indeed, flies defective in cilia formation cannot walk, fly, or feed properly. Drosophila harbors different types of cilia that can be motile or immotile or that can show compartimentalized (intraflagellar transport (IFT)-dependent) or cytoplasmic (IFT-independent) mode of assembly. Therefore, Drosophila represents an advantageous model organism to study the function of novel ciliary candidates and to address specific questions such as their requirement for IFT-dependent processes versus other aspects of cilia-associated functions. This chapter describes protocols to visualize cilia by direct or indirect fluorescent labeling and protocols to analyze ciliary ultrastructure by electron microscopy.
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Raft S, Groves AK. Segregating neural and mechanosensory fates in the developing ear: patterning, signaling, and transcriptional control. Cell Tissue Res 2014; 359:315-32. [PMID: 24902666 DOI: 10.1007/s00441-014-1917-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 05/08/2014] [Indexed: 12/21/2022]
Abstract
The vertebrate inner ear is composed of multiple sensory receptor epithelia, each of which is specialized for detection of sound, gravity, or angular acceleration. Each receptor epithelium contains mechanosensitive hair cells, which are connected to the brainstem by bipolar sensory neurons. Hair cells and their associated neurons are derived from the embryonic rudiment of the inner ear epithelium, but the precise spatial and temporal patterns of their generation, as well as the signals that coordinate these events, have only recently begun to be understood. Gene expression, lineage tracing, and mutant analyses suggest that both neurons and hair cells are generated from a common domain of neural and sensory competence in the embryonic inner ear rudiment. Members of the Shh, Wnt, and FGF families, together with retinoic acid signals, regulate transcription factor genes within the inner ear rudiment to establish the axial identity of the ear and regionalize neurogenic activity. Close-range signaling, such as that of the Notch pathway, specifies the fate of sensory regions and individual cell types. We also describe positive and negative interactions between basic helix-loop-helix and SoxB family transcription factors that specify either neuronal or sensory fates in a context-dependent manner. Finally, we review recent work on inner ear development in zebrafish, which demonstrates that the relative timing of neurogenesis and sensory epithelial formation is not phylogenetically constrained.
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Affiliation(s)
- Steven Raft
- Section on Sensory Cell Regeneration and Development, National Institute on Deafness and Other Communication Disorders National Institutes of Health, 35 Convent Drive, Bethesda, MD, 20892, USA,
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19
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20
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Boekhoff-Falk G, Eberl DF. The Drosophila auditory system. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2013; 3:179-91. [PMID: 24719289 DOI: 10.1002/wdev.128] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/28/2013] [Accepted: 09/10/2013] [Indexed: 11/10/2022]
Abstract
Development of a functional auditory system in Drosophila requires specification and differentiation of the chordotonal sensilla of Johnston's organ (JO) in the antenna, correct axonal targeting to the antennal mechanosensory and motor center in the brain, and synaptic connections to neurons in the downstream circuit. Chordotonal development in JO is functionally complicated by structural, molecular, and functional diversity that is not yet fully understood, and construction of the auditory neural circuitry is only beginning to unfold. Here, we describe our current understanding of developmental and molecular mechanisms that generate the exquisite functions of the Drosophila auditory system, emphasizing recent progress and highlighting important new questions arising from research on this remarkable sensory system.
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Affiliation(s)
- Grace Boekhoff-Falk
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
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21
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Physiological, anatomical, and behavioral changes after acoustic trauma in Drosophila melanogaster. Proc Natl Acad Sci U S A 2013; 110:15449-54. [PMID: 24003166 DOI: 10.1073/pnas.1307294110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Noise-induced hearing loss (NIHL) is a growing health issue, with costly treatment and lost quality of life. Here we establish Drosophila melanogaster as an inexpensive, flexible, and powerful genetic model system for NIHL. We exposed flies to acoustic trauma and quantified physiological and anatomical effects. Trauma significantly reduced sound-evoked potential (SEP) amplitudes and increased SEP latencies in control genotypes. SEP amplitude but not latency effects recovered after 7 d. Although trauma produced no gross morphological changes in the auditory organ (Johnston's organ), mitochondrial cross-sectional area was reduced 7 d after exposure. In nervana 3 heterozygous flies, which slightly compromise ion homeostasis, trauma had exaggerated effects on SEP amplitude and mitochondrial morphology, suggesting a key role for ion homeostasis in resistance to acoustic trauma. Thus, Drosophila exhibit acoustic trauma effects resembling those found in vertebrates, including inducing metabolic stress in sensory cells. This report of noise trauma in Drosophila is a foundation for studying molecular and genetic sequelae of NIHL.
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22
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Pézier A, Blagburn JM. Auditory responses of engrailed and invected-expressing Johnston's Organ neurons in Drosophila melanogaster. PLoS One 2013; 8:e71419. [PMID: 23940751 PMCID: PMC3734059 DOI: 10.1371/journal.pone.0071419] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 07/03/2013] [Indexed: 11/23/2022] Open
Abstract
The roles of the transcription factor Engrailed (En), and its paralogue Invected (Inv), in adult Drosophila Johnston’s Organ sensory neurons are unknown. We used en-GAL4 driven CD8-GFP and antibody staining to characterize these neurons in the pedicel (second antennal segment). The majority of En and Inv-expressing Johnston’s Organ neurons (En-JONs) are located in the ventral part of the posterior group of JONs, with only a few in the medial group. Anatomical classification of En-JON axon projections shows they are mainly type A and E, with a few type B. Extracellular recording of sound-evoked potentials (SEPs) from the antennal nerve was used along with Kir2.1 silencing to assess the contribution that En-JONs make to the auditory response to pure-tone sound stimuli. Silencing En-JONs reduces the SEP amplitude at the onset of the stimulus by about half at 100, 200 and 400 Hz, and also reduces the steady-state response to 200 Hz. En-JONs respond to 82 dB and 92 dB sounds but not 98 dB. Despite their asymmetrical distribution in the Johnston’s Organ they respond equally strongly to both directions of movement of the arista. This implies that individual neurons are excited in both directions, a conclusion supported by reanalysis of the morphology of the pedicel-funicular joint. Other methods of silencing the JONs were also used: RNAi against the voltage-gated Na+ channel encoded by the para gene, expression of attenuated diphtheria toxin, and expression of a modified influenza toxin M2(H37A). Only the latter was found to be more effective than Kir2.1. Three additional JON subsets were characterized using Flylight GAL4 lines. inv-GAL4 88B12 and Gycβ100B-GAL4 12G03 express in different subsets of A group neurons and CG12484-GAL4 91G04 is expressed in B neurons. All three contribute to the auditory response to 200 Hz tones.
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Affiliation(s)
- Adeline Pézier
- Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico, United States of America
| | - Jonathan M. Blagburn
- Institute of Neurobiology, University of Puerto Rico, San Juan, Puerto Rico, United States of America
- * E-mail:
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23
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Heckman CA, Plummer HK. Filopodia as sensors. Cell Signal 2013; 25:2298-311. [PMID: 23876793 DOI: 10.1016/j.cellsig.2013.07.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 07/04/2013] [Accepted: 07/09/2013] [Indexed: 12/19/2022]
Abstract
Filopodia are sensors on both excitable and non-excitable cells. The sensing function is well documented in neurons and blood vessels of adult animals and is obvious during dorsal closure in embryonic development. Nerve cells extend neurites in a bidirectional fashion with growth cones at the tips where filopodia are concentrated. Their sensing of environmental cues underpins the axon's ability to "guide," bypassing non-target cells and moving toward the target to be innervated. This review focuses on the role of filopodia structure and dynamics in the detection of environmental cues, including both the extracellular matrix (ECM) and the surfaces of neighboring cells. Other protrusions including the stereocilia of the inner ear and epididymus, the invertebrate Type I mechanosensors, and the elongated processes connecting osteocytes, share certain principles of organization with the filopodia. Actin bundles, which may be inside or outside of the excitable cell, function to transduce stress from physical perturbations into ion signals. There are different ways of detecting such perturbations. Osteocyte processes contain an actin core and are physically anchored on an extracellular structure by integrins. Some Type I mechanosensors have bridge proteins that anchor microtubules to the membrane, but bundles of actin in accessory cells exert stress on this complex. Hair cells of the inner ear rely on attachments between the actin-based protrusions to activate ion channels, which then transduce signals to afferent neurons. In adherent filopodia, the focal contacts (FCs) integrated with ECM proteins through integrins may regulate integrin-coupled ion channels to achieve signal transduction. Issues that are not understood include the role of Ca(2+) influx in filopodia dynamics and how integrins coordinate or gate signals arising from perturbation of channels by environmental cues.
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Affiliation(s)
- C A Heckman
- Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0212, USA.
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24
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Kamikouchi A. Auditory neuroscience in fruit flies. Neurosci Res 2013; 76:113-8. [PMID: 23707240 DOI: 10.1016/j.neures.2013.04.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 04/09/2013] [Accepted: 04/16/2013] [Indexed: 10/26/2022]
Abstract
Since the first analysis of the Drosophila courtship song more than 50 years ago, the molecular and neural mechanisms underlying the acoustic communication between fruit flies has been studied extensively. The results of recent studies utilizing a wide array of genetic tools provide novel insights into the anatomic and functional characteristics of the auditory and other mechanosensory systems in the fruit fly. Johnston's hearing organ, the antennal ear of the fruit fly, serves as a complex sensor not only for near-field sound but also for gravity and wind. These auditory and non-auditory signals travel in parallel from the fly ear to the brain, feeding into neural pathways similar to the auditory and vestibular pathways of the human brain. This review discusses these recent findings and outlines auditory neuroscience in flies.
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Affiliation(s)
- Azusa Kamikouchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan.
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25
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Neuronal encoding of sound, gravity, and wind in the fruit fly. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:253-62. [PMID: 23494584 DOI: 10.1007/s00359-013-0806-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 01/01/2023]
Abstract
The fruit fly Drosophila melanogaster responds behaviorally to sound, gravity, and wind. Exposure to male courtship songs results in reduced locomotion in females, whereas males begin to chase each other. When agitated, fruit flies tend to move against gravity. When faced with air currents, they 'freeze' in place. Based on recent studies, Johnston's hearing organ, the antennal ear of the fruit fly, serves as a sensor for all of these mechanosensory stimuli. Compartmentalization of sense cells in Johnston's organ into vibration-sensitive and deflection-sensitive neural groups allows this single organ to mediate such varied functions. Sound and gravity/wind signals sensed by these two neuronal groups travel in parallel from the fly ear to the brain, feeding into neural pathways reminiscent of the auditory and vestibular pathways in the human brain. Studies of the similarities between mammals and flies will lead to a better understanding of the principles of how sound and gravity information is encoded in the brain. Here, we review recent advances in our understanding of these principles and discuss the advantages of the fruit fly as a model system to explore the fundamental principles of how neural circuits and their ensembles process and integrate sensory information in the brain.
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26
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Abstract
Necrotic cell death (necrosis) occurs in many acute-onset diseases. However, our poor understanding of its mechanism has greatly limited medical interventions. Here we describe two methods to establish necrosis models in Drosophila. Our strategy is to overload calcium by expression of leaky cation channels.
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Affiliation(s)
- Kai Liu
- State Key Lab of Biomembrane and Membrane Biotechnology, School of Life Sciences, Peking University, Beijing, China
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27
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Senthilan PR, Piepenbrock D, Ovezmyradov G, Nadrowski B, Bechstedt S, Pauls S, Winkler M, Möbius W, Howard J, Göpfert MC. Drosophila auditory organ genes and genetic hearing defects. Cell 2012; 150:1042-54. [PMID: 22939627 DOI: 10.1016/j.cell.2012.06.043] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 03/02/2012] [Accepted: 06/20/2012] [Indexed: 12/22/2022]
Abstract
The Drosophila auditory organ shares equivalent transduction mechanisms with vertebrate hair cells, and both are specified by atonal family genes. Using a whole-organ knockout strategy based on atonal, we have identified 274 Drosophila auditory organ genes. Only four of these genes had previously been associated with fly hearing, yet one in five of the genes that we identified has a human cognate that is implicated in hearing disorders. Mutant analysis of 42 genes shows that more than half of them contribute to auditory organ function, with phenotypes including hearing loss, auditory hypersusceptibility, and ringing ears. We not only discover ion channels and motors important for hearing, but also show that auditory stimulus processing involves chemoreceptor proteins as well as phototransducer components. Our findings demonstrate mechanosensory roles for ionotropic receptors and visual rhodopsins and indicate that different sensory modalities utilize common signaling cascades.
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Affiliation(s)
- Pingkalai R Senthilan
- Department of Cellular Neurobiology, University of Göttingen, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany
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28
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Duncan JS, Fritzsch B. Evolution of Sound and Balance Perception: Innovations that Aggregate Single Hair Cells into the Ear and Transform a Gravistatic Sensor into the Organ of Corti. Anat Rec (Hoboken) 2012; 295:1760-74. [DOI: 10.1002/ar.22573] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 07/24/2012] [Indexed: 01/20/2023]
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29
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Halachmi N, Nachman A, Salzberg A. Visualization of proprioceptors in Drosophila larvae and pupae. J Vis Exp 2012:e3846. [PMID: 22733157 PMCID: PMC3471288 DOI: 10.3791/3846] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Proprioception is the ability to sense the motion, or position, of body parts by responding to stimuli arising within the body. In fruitflies and other insects proprioception is provided by specialized sensory organs termed chordotonal organs (ChOs). Like many other organs in Drosophila, ChOs develop twice during the life cycle of the fly. First, the larval ChOs develop during embryogenesis. Then, the adult ChOs start to develop in the larval imaginal discs and continue to differentiate during metamorphosis. The development of larval ChOs during embryogenesis has been studied extensively. The centerpiece of each ChO is a sensory unit composed of a neuron and a scolopale cell. The sensory unit is stretched between two types of accessory cells that attach to the cuticle via specialized epidermal attachment cells. When a fly larva moves, the relative displacement of the epidermal attachment cells leads to stretching of the sensory unit and consequent opening of specific transient receptor potential vanilloid (TRPV) channels at the outer segment of the dendrite. The elicited signal is then transferred to the locomotor central pattern generator circuit in the central nervous system. Multiple ChOs have been described in the adult fly. These are located near the joints of the adult fly appendages (legs, wings and halters) and in the thorax and abdomen. In addition, several hundreds of ChOs collectively form the Johnston's organ in the adult antenna that transduce acoustic to mechanical energy. In contrast to the extensive knowledge about the development of ChOs in embryonic stages, very little is known about the morphology of these organs during larval stages. Moreover, with the exception of femoral ChOs and Johnston's organ, our knowledge about the development and structure of ChOs in the adult fly is very fragmentary. Here we describe a method for staining and visualizing ChOs in third instar larvae and pupae. This method can be applied together with genetic tools to better characterize the morphology and understand the development of the various ChOs in the fly.
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Affiliation(s)
- Naomi Halachmi
- Department of Genetics and Rappaport Institute for Research in Medical Sciences, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology
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30
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Enjolras C, Thomas J, Chhin B, Cortier E, Duteyrat JL, Soulavie F, Kernan MJ, Laurençon A, Durand B. Drosophila chibby is required for basal body formation and ciliogenesis but not for Wg signaling. ACTA ACUST UNITED AC 2012; 197:313-25. [PMID: 22508513 PMCID: PMC3328381 DOI: 10.1083/jcb.201109148] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In contrast to vertebrate CBY, which functions in WNT signaling, Drosophila CBY is essential for normal basal body structure and function but dispensable for Wg signaling. Centriole-to–basal body conversion, a complex process essential for ciliogenesis, involves the progressive addition of specific proteins to centrioles. CHIBBY (CBY) is a coiled-coil domain protein first described as interacting with β-catenin and involved in Wg-Int (WNT) signaling. We found that, in Drosophila melanogaster, CBY was exclusively expressed in cells that require functional basal bodies, i.e., sensory neurons and male germ cells. CBY was associated with the basal body transition zone (TZ) in these two cell types. Inactivation of cby led to defects in sensory transduction and in spermatogenesis. Loss of CBY resulted in altered ciliary trafficking into neuronal cilia, irregular deposition of proteins on spermatocyte basal bodies, and, consequently, distorted axonemal assembly. Importantly, cby1/1 flies did not show Wingless signaling defects. Hence, CBY is essential for normal basal body structure and function in Drosophila, potentially through effects on the TZ. The function of CBY in WNT signaling in vertebrates has either been acquired during vertebrate evolution or lost in Drosophila.
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Affiliation(s)
- Camille Enjolras
- Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 5534, Université Claude Bernard Lyon 1, Villeurbanne, Lyon F69622, France
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31
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Duncan JS, Fritzsch B. Transforming the vestibular system one molecule at a time: the molecular and developmental basis of vertebrate auditory evolution. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 739:173-86. [PMID: 22399402 DOI: 10.1007/978-1-4614-1704-0_11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
We review the molecular basis of auditory development and evolution. We propose that the auditory periphery (basilar papilla, organ of Corti) evolved by transforming a newly created and redundant vestibular (gravistatic) endorgan into a sensory epithelium that could respond to sound instead of gravity. Evolution altered this new epithelia's mechanoreceptive properties through changes of hair cells, positioned the epithelium in a unique position near perilymphatic space to extract sound moving between the round and the oval window, and transformed its otolith covering into a tympanic membrane. Another important step in the evolution of an auditory system was the evolution of a unique set of "auditory neurons" that apparently evolved from vestibular neurons. Evolution of mammalian auditory (spiral ganglion) neurons coincides with GATA3 being a transcription factor found selectively in the auditory afferents. For the auditory information to be processed, the CNS required a dedicated center for auditory processing, the auditory nuclei. It is not known whether the auditory nucleus is ontogenetically related to the vestibular or electroreceptive nuclei, two sensory systems found in aquatic but not in amniotic vertebrates, or a de-novo formation of the rhombic lip in line with other novel hindbrain structures such as pontine nuclei. Like other novel hindbrain structures, the auditory nuclei express exclusively the bHLH gene Atoh1, and loss of Atoh1 results in loss of most of this nucleus in mice. Only after the basilar papilla, organ of Corti evolved could efferent neurons begin to modulate their activity. These auditory efferents most likely evolved from vestibular efferent neurons already present. The most simplistic interpretation of available data suggest that the ear, sensory neurons, auditory nucleus, and efferent neurons have been transformed by altering the developmental genetic modules necessary for their development into a novel direction conducive for sound extraction, conduction, and processing.
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Affiliation(s)
- Jeremy S Duncan
- Department of Biology, University of Iowa, Iowa City, Iowa, USA.
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Jahan I, Pan N, Kersigo J, Calisto LE, Morris KA, Kopecky B, Duncan JS, Beisel KW, Fritzsch B. Expression of Neurog1 instead of Atoh1 can partially rescue organ of Corti cell survival. PLoS One 2012; 7:e30853. [PMID: 22292060 PMCID: PMC3265522 DOI: 10.1371/journal.pone.0030853] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/21/2011] [Indexed: 11/19/2022] Open
Abstract
In the mammalian inner ear neurosensory cell fate depends on three closely related transcription factors, Atoh1 for hair cells and Neurog1 and Neurod1 for neurons. We have previously shown that neuronal cell fate can be altered towards hair cell fate by eliminating Neurod1 mediated repression of Atoh1 expression in neurons. To test whether a similar plasticity is present in hair cell fate commitment, we have generated a knockin (KI) mouse line (Atoh1KINeurog1) in which Atoh1 is replaced by Neurog1. Expression of Neurog1 under Atoh1 promoter control alters the cellular gene expression pattern, differentiation and survival of hair cell precursors in both heterozygous (Atoh1+/KINeurog1) and homozygous (Atoh1KINeurog1/KINeurog1) KI mice. Homozygous KI mice develop patches of organ of Corti precursor cells that express Neurog1, Neurod1, several prosensory genes and neurotrophins. In addition, these patches of cells receive afferent and efferent processes. Some cells among these patches form multiple microvilli but no stereocilia. Importantly, Neurog1 expressing mutants differ from Atoh1 null mutants, as they have intermittent formation of organ of Corti-like patches, opposed to a complete ‘flat epithelium’ in the absence of Atoh1. In heterozygous KI mice co-expression of Atoh1 and Neurog1 results in change in fate and patterning of some hair cells and supporting cells in addition to the abnormal hair cell polarity in the later stages of development. This differs from haploinsufficiency of Atoh1 (Pax2cre; Atoh1f/+), indicating the effect of Neurog1 expression in developing hair cells. Our data suggest that Atoh1KINeurog1 can provide some degree of functional support for survival of organ of Corti cells. In contrast to the previously demonstrated fate plasticity of neurons to differentiate as hair cells, hair cell precursors can be maintained for a limited time by Neurog1 but do not transdifferentiate as neurons.
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Affiliation(s)
- Israt Jahan
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
| | - Ning Pan
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
| | - Jennifer Kersigo
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
| | - Lilian E. Calisto
- Creighton University, Department of Biomedical Sciences, Omaha, Nebraska, United States of America
| | - Ken A. Morris
- Creighton University, Department of Biomedical Sciences, Omaha, Nebraska, United States of America
| | - Benjamin Kopecky
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
| | - Jeremy S. Duncan
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
| | - Kirk W. Beisel
- Creighton University, Department of Biomedical Sciences, Omaha, Nebraska, United States of America
| | - Bernd Fritzsch
- University of Iowa, Department of Biology, Iowa City, Iowa, United States of America
- * E-mail:
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Duistermars BJ, Frye MA. Multisensory integration for odor tracking by flying Drosophila: Behavior, circuits and speculation. Commun Integr Biol 2011; 3:60-3. [PMID: 20539786 DOI: 10.4161/cib.3.1.10076] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 09/12/2009] [Indexed: 11/19/2022] Open
Abstract
Many see fruit flies as an annoyance, invading our homes with a nagging persistence and efficiency. Yet from a scientific perspective, these tiny animals are a wonder of multisensory integration, capable of tracking fragmented odor plumes amidst turbulent winds and constantly varying visual conditions. The peripheral olfactory, mechanosensory, and visual systems of the fruit fly, Drosophila melanogaster, have been studied in great detail;1-4 however, the mechanisms by which fly brains integrate information from multiple sensory modalities to facilitate robust odor tracking remain elusive. Our studies on olfactory orientation by flying flies reveal that these animals do not simply follow their "nose"; rather, fruit flies require mechanosensory and visual input to track odors in flight.5,6 Collectively, these results shed light on the neural circuits involved in odor localization by fruit flies in the wild and illuminate the elegant complexity underlying a behavior to which the annoyed and amazed are familiar.
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Eberl DF, Kernan MJ. Recording sound-evoked potentials from the Drosophila antennal nerve. Cold Spring Harb Protoc 2011; 2011:prot5576. [PMID: 21363940 DOI: 10.1101/pdb.prot5576] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Quantitative trait locus mapping of gravitaxis behaviour in Drosophila melanogaster. Genet Res (Camb) 2010; 92:167-74. [PMID: 20667161 DOI: 10.1017/s0016672310000194] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Drosophila melanogaster, like other organisms, move and orient themselves in response to the earth's gravitational force. The ability to sense and respond to gravity is essential for an organism to navigate and thrive in its environment. The genes underlying this behaviour in Drosophila remain elusive. Using 88 recombinant inbred lines, we have identified four quantitative trait loci (QTLs) that contribute to adult gravitaxis (geotaxis) behaviour in Drosophila. Candidate genes of interest were selected from the QTLs of highest significance based on their function in chordotonal organ formation. Quantitative complementation tests with these candidate genes revealed a role for skittles in adult gravitaxis behaviour in D. melanogaster.
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Increased activity of Diaphanous homolog 3 (DIAPH3)/diaphanous causes hearing defects in humans with auditory neuropathy and in Drosophila. Proc Natl Acad Sci U S A 2010; 107:13396-401. [PMID: 20624953 DOI: 10.1073/pnas.1003027107] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Auditory neuropathy is a rare form of deafness characterized by an absent or abnormal auditory brainstem response with preservation of outer hair cell function. We have identified Diaphanous homolog 3 (DIAPH3) as the gene responsible for autosomal dominant nonsyndromic auditory neuropathy (AUNA1), which we previously mapped to chromosome 13q21-q24. Genotyping of additional family members narrowed the interval to an 11-Mb, 3.28-cM gene-poor region containing only four genes, including DIAPH3. DNA sequencing of DIAPH3 revealed a c.-172G>A, g. 48G>A mutation in a highly conserved region of the 5' UTR. The c.-172G>A mutation occurs within a GC box sequence element and was not found in 379 controls. Using genome-wide expression arrays and quantitative RT-PCR, we demonstrate a 2- to 3-fold overexpression of DIAPH3 mRNA in lymphoblastoid cell lines from affected individuals. Likewise, a significant increase (approximately 1.5-fold) in DIAPH3 protein was found by quantitative immunoblotting of lysates from lymphoblastoid cell lines derived from affected individuals in comparison with controls. In addition, the c.-172G>A mutation is sufficient to drive overexpression of a luciferase reporter. Finally, the expression of a constitutively active form of diaphanous protein in the auditory organ of Drosophila melanogaster recapitulates the phenotype of impaired response to sound. To date, only two genes, the otoferlin gene OTOF and the pejvakin gene PJVK, are known to underlie nonsyndromic auditory neuropathy. Genetic testing for DIAPH3 may be useful for individuals with recessive as well as dominant inheritance of nonsyndromic auditory neuropathy.
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Nadrowski B, Effertz T, Senthilan PR, Göpfert MC. Antennal hearing in insects--new findings, new questions. Hear Res 2010; 273:7-13. [PMID: 20430076 DOI: 10.1016/j.heares.2010.03.092] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/18/2010] [Accepted: 03/02/2010] [Indexed: 12/13/2022]
Abstract
Mosquitoes, certain Drosophila species, and honey bees use Johnston's organ in their antennae to detect the wing-beat sounds of conspecifics. Recent studies on these insects have provided novel insights into the intricacies of insect hearing and sound communication, with main discoveries including transduction and amplification mechanisms as known from vertebrate hearing, functional and molecular diversifications of mechanosensory cells, and complex mating duets that challenge the frequency-limits of insect antennal ears. This review discusses these recent advances and outlines potential avenues for future research.
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Affiliation(s)
- Björn Nadrowski
- Department of Cellular Neurobiology, University of Göttingen, Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
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Unraveling the auditory system of Drosophila. Curr Opin Neurobiol 2010; 20:281-7. [PMID: 20362428 DOI: 10.1016/j.conb.2010.02.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 02/25/2010] [Accepted: 02/25/2010] [Indexed: 11/29/2022]
Abstract
Acoustic communication in flies is based on the production and perception of courtship song. Drosophila males sing to females during the courtship ritual, while females listen for the correct species-specific song parameters before deciding to mate. While we know that song is important for mating, the neural mechanisms involved in song recognition remain mysterious. However, the last few years have seen major advances in our understanding of the auditory system of Drosophila, including delineation of the neurons involved in song production, detailed characterization of the auditory receptor organ, and mapping of auditory projections into the brain. The stage is being set to tackle the auditory system of Drosophila in much the same way as has been done for its olfactory system. This review covers recent work and discusses prospects for future research on Drosophila audition.
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Multisensory systems integration for high-performance motor control in flies. Curr Opin Neurobiol 2010; 20:347-52. [PMID: 20202821 PMCID: PMC3635923 DOI: 10.1016/j.conb.2010.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
Abstract
Engineered tracking systems 'fuse' data from disparate sensor platforms, such as radar and video, to synthesize information that is more reliable than any single input. The mammalian brain registers visual and auditory inputs to directionally localize an interesting environmental feature. For a fly, sensory perception is challenged by the extreme performance demands of high speed flight. Yet even a fruit fly can robustly track a fragmented odor plume through varying visual environments, outperforming any human engineered robot. Flies integrate disparate modalities, such as vision and olfaction, which are neither related by spatiotemporal spectra nor processed by registered neural tissue maps. Thus, the fly is motivating new conceptual frameworks for how low-level multisensory circuits and functional algorithms produce high-performance motor control.
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Cosetti M, Culang D, Kotla S, O'Brien P, Eberl DF, Hannan F. Unique transgenic animal model for hereditary hearing loss. Ann Otol Rhinol Laryngol 2009; 117:827-33. [PMID: 19102128 DOI: 10.1177/000348940811701106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES This study capitalizes on the unique molecular and developmental similarities between the auditory organs of Drosophila and mammals, to investigate genes implicated in human syndromic and nonsyndromic hearing loss in a genetically tractable experimental animal model, the fruit fly Drosophila. METHODS The Drosophila counterparts of 3 human deafness genes (DIAPH1/DFNA1, ESPN/DFNB36, and TMHS/DF-NB67) were identified by sequence similarity. An electrophysiological assay was used to record sound-evoked potentials in response to an acoustic stimulus, the Drosophila courtship song. RESULTS Flies with mutations affecting the diaphanous,forked, and CG12026/TMHS genes displayed significant reductions in the amplitude of sound-evoked potentials compared to wild-type flies (p < 0.05 to p < 0.005). The mean responses were reduced from approximately 500 to 600 microV in wild-type flies to approximately 100 to 300 microV in most mutant flies. CONCLUSIONS The identification of significant auditory dysfunction in Drosophila orthologs of human deafness genes will facilitate exploration of the molecular biochemistry of auditory mechanosensation. This may eventually allow for novel diagnostic and therapeutic approaches to human hereditary hearing loss.
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Affiliation(s)
- Maura Cosetti
- Department of Otolaryngology, New York Eye and Ear Infirmary, New York, New York, USA
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Giraldez F, Fritzsch B. The molecular biology of ear development - "Twenty years are nothing". THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2008; 51:429-38. [PMID: 17891706 PMCID: PMC3901534 DOI: 10.1387/ijdb.072390fg] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Views of classical biological problems changed dramatically with the rise of molecular biology as a common framework. It was indeed the new language of life sciences. Molecular biology increasingly moved us towards a unified view of developmental genetics as ideas and techniques were imported to vertebrates from other biological systems where genetics was in a more advanced state. The ultimate advance has been the ability to actually perform genetic manipulations in vertebrate organisms that were almost unthinkable before. During the last two decades these technical advances entered into and affected the research on ear development. These events are still very recent and have been with us for no longer than two decades, which is the reason for the title of this article. This new scenario forms the basis of the current and productive work of many laboratories, and this is what this Special Issue of The International Journal of Developmental Biology wants to show, presenting a snapshot of insights at the beginning of the 21st Century. In this article, we give an overview of the topics that are addressed in this Ear Development Special Issue, and also we take the opportunity to informally dig into the genealogy of some of those topics, trying to link the current work with some classical work of the past.
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Affiliation(s)
- Fernando Giraldez
- Departament de Cincies Experimentals i de la Salut, Universitat Pompeu Fabra, Parc de Recerca Biomdica de Barcelona (PRBB), Barcelona, Spain.
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