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Dyson A, Gajjar G, Hoffman KC, Lewis D, Palega S, Rangel Silva E, Auwn J, Bellemer A. A nociceptor-specific RNAi screen in Drosophila larvae identifies RNA-binding proteins that regulate thermal nociception. PeerJ 2025; 13:e18857. [PMID: 39866556 PMCID: PMC11759608 DOI: 10.7717/peerj.18857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Accepted: 12/20/2024] [Indexed: 01/28/2025] Open
Abstract
Nociception is the process by which sensory neurons detect and encode potentially harmful environmental stimuli to generate behavioral responses. Nociceptor neurons exhibit plasticity in which their sensitivity to noxious stimuli and subsequent ability to drive behavior may be altered by environmental conditions, injury, infection, and inflammation. In some cases, nociceptor sensitization requires regulated changes in gene expression, and recent studies have indicated roles for post-transcriptional mechanisms in regulating these changes as an aspect of nociceptor plasticity. The larvae of Drosophila melanogaster have been developed as a powerful model for studying mechanisms of nociception, nociceptor plasticity, and nociceptor development. Diverse RNA-binding proteins regulate the development and morphology of larval nociceptors, implying important roles for post-transcriptional regulation of gene expression in these neurons, but the importance of these mechanisms for nociceptive behavior has not been investigated systematically. In this study, we conducted a nociceptor-specific RNAi screen of 112 candidate RNA-binding protein genes to identify those that are required for normal sensitivity to noxious thermal stimuli. The screen and subsequent validation experiments identified nine candidate genes (eIF2α, eIF4A, eIF4AIII, eIF4G2, mbl, SC35, snf, Larp4B and CG10445) that produce defects in nociceptive response latency when knocked down in larval nociceptors. Some of the genes identified have well-understood roles in the regulation of translation initiation and regulation of nociceptor sensitization in vertebrate and invertebrate animal models, suggesting an evolutionarily conserved role for these mechanisms in regulating nociceptor sensitivity. Other screen isolates have previously described roles in regulating nociceptor morphology and mRNA processing, but less clear roles in regulating nociceptor function. Further studies will be necessary to identify the mechanisms by which the identified RNA-binding proteins regulate sensory neuron function and the identities of the mRNAs that they target.
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Affiliation(s)
- Amber Dyson
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - Gita Gajjar
- Department of Biochemistry and Molecular Biology, East Carolina University, Greenville, North Carolina, United States
| | - Katherine C. Hoffman
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - Dakota Lewis
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - Sara Palega
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - Erik Rangel Silva
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - James Auwn
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
| | - Andrew Bellemer
- Department of Biology, Appalachian State University, Boone, North Carolina, United States
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2
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Bak NK, Mackay TFC, Morgante F, Nielsen KL, Nielsen JL, Kristensen TN, Rohde PD. The Role of Genetic Variation in Shaping Phenotypic Responses to Diet in Aging Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.09.632132. [PMID: 39868103 PMCID: PMC11761520 DOI: 10.1101/2025.01.09.632132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/28/2025]
Abstract
Nutrition plays a central role in healthy living, however, extensive variability in individual responses to dietary interventions complicates our understanding of its effects. Here we present a comprehensive study utilizing the Drosophila Genetic Reference Panel (DGRP), investigating how genetic variation influences responses to diet and aging. Quantitative genetic analyses of the impact of dietary restriction on lifespan, locomotor activity, dry weight, and heat knockdown time were performed. Locomotor activity, dry weight and heat knockdown time were measured on the same individual flies. We found significant genotype-by-diet interaction (GDI) and genotype-by-age interaction (GAI) for all traits. Therefore, environmental factors play a crucial role in shaping trait variation at different ages and diets, and/or distinct genetic variation influences these traits at different ages and diets. Our genome wide association study also identified a quantitative trait locus for age-dependent dietary response. The observed GDI and GAI indicates that susceptibility to environmental influences changes as organisms age, which could have significant implications for dietary recommendations and interventions aimed at promoting healthy aging in humans. The identification of associations between DNA sequence variation and age-dependent dietary responses opens new avenues for research into the genetic mechanisms underlying these interactions.
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Affiliation(s)
| | - Trudy F. C. Mackay
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, Greenwood, South Carolina, United States of America
| | - Fabio Morgante
- Center for Human Genetics and Department of Genetics and Biochemistry, Clemson University, Greenwood, South Carolina, United States of America
| | | | - Jeppe Lund Nielsen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | | | - Palle Duun Rohde
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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3
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Lee HMT, Lim HY, He H, Lau CY, Zheng C. MBL-1/Muscleblind regulates neuronal differentiation and controls the splicing of a terminal selector in Caenorhabditis elegans. PLoS Genet 2024; 20:e1011276. [PMID: 39423233 PMCID: PMC11524483 DOI: 10.1371/journal.pgen.1011276] [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: 04/26/2024] [Revised: 10/30/2024] [Accepted: 10/09/2024] [Indexed: 10/21/2024] Open
Abstract
The muscleblind family of mRNA splicing regulators is conserved across species and regulates the development of muscles and the nervous system. However, how Muscleblind proteins regulate neuronal fate specification and neurite morphogenesis at the single-neuron level is not well understood. In this study, we found that the C. elegans Muscleblind/MBL-1 promotes axonal growth in the touch receptor neurons (TRNs) by regulating microtubule stability and polarity. Transcriptomic analysis identified dozens of MBL-1-controlled splicing events in genes related to neuronal differentiation or microtubule functions. Among the MBL-1 targets, the LIM-domain transcription factor mec-3 is the terminal selector for the TRN fate and induces the expression of many TRN terminal differentiation genes. MBL-1 promotes the splicing of the mec-3 long isoform, which is essential for TRN fate specification, and inhibits the short isoforms that have much weaker activities in activating downstream genes. MBL-1 promotes mec-3 splicing through three "YGCU(U/G)Y" motifs located in or downstream of the included exon, which is similar to the mechanisms used by mammalian Muscleblind and suggests a deeply conserved context-dependency of the splicing regulation. Interestingly, the expression of mbl-1 in the TRNs is dependent on the mec-3 long isoform, indicating a positive feedback loop between the splicing regulator and the terminal selector. Finally, through a forward genetic screen, we found that MBL-1 promotes neurite growth partly by inhibiting the DLK-1/p38 MAPK pathway. In summary, our study provides mechanistic understanding of the role of Muscleblind in regulating cell fate specification and neuronal morphogenesis.
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Affiliation(s)
- Ho Ming Terence Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Hui Yuan Lim
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Haoming He
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Chun Yin Lau
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Chaogu Zheng
- School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
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4
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Odierna GL, Kerwin SK, Shin GJE, Millard SS. Drosophila larval motor patterning relies on regulated alternative splicing of Dscam2. Front Mol Neurosci 2024; 17:1415207. [PMID: 39092203 PMCID: PMC11292952 DOI: 10.3389/fnmol.2024.1415207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 05/31/2024] [Indexed: 08/04/2024] Open
Abstract
Recent studies capitalizing on the newly complete nanometer-resolution Drosophila larval connectome have made significant advances in identifying the structural basis of motor patterning. However, the molecular mechanisms utilized by neurons to wire these circuits remain poorly understood. In this study we explore how cell-specific expression of two Dscam2 isoforms, which mediate isoform-specific homophilic binding, contributes to motor patterning and output of Drosophila larvae. Ablating Dscam2 isoform diversity resulted in impaired locomotion. Electrophysiological assessment at the neuromuscular junction during fictive locomotion indicated that this behavioral defect was largely caused by weaker bouts of motor neuron activity. Morphological analyses of single motor neurons using MultiColour FlpOut revealed severe errors in dendrite arborization and assessment of cholinergic and GABAergic projections to the motor domain revealed altered morphology of interneuron processes. Loss of Dscam2 did not affect locomotor output, motor neuron activation or dendrite targeting. Our findings thus suggest that locomotor circuit phenotypes arise specifically from inappropriate Dscam2 interactions between premotor interneurons and motor neurons when they express the same isoform. Indeed, we report here that first-order premotor interneurons express Dscam2A. Since motor neurons express Dscam2B, our results provide evidence that Dscam2 isoform expression alternates between synaptic partners in the nerve cord. Our study demonstrates the importance of cell-specific alternative splicing in establishing the circuitry that underlies neuromotor patterning without inducing unwanted intercellular interactions.
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Affiliation(s)
- G. Lorenzo Odierna
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Sarah K. Kerwin
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Grace Ji-eun Shin
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, OH, United States
- The Neuroscience Research Institute, The Ohio State University, Columbus, OH, United States
- The Ohio State University Comprehensive Cancer Center, Columbus, OH, United States
| | - S. Sean Millard
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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5
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Xiao C, M’Angale PG, Wang S, Lemieux A, Thomson T. Identifying new players in structural synaptic plasticity through dArc1 interrogation. iScience 2023; 26:108048. [PMID: 37876812 PMCID: PMC10590816 DOI: 10.1016/j.isci.2023.108048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/28/2023] [Accepted: 09/22/2023] [Indexed: 10/26/2023] Open
Abstract
The formation, expansion, and pruning of synapses, known as structural synaptic plasticity, is needed for learning and memory, and perturbation of plasticity is associated with many neurological disorders and diseases. Previously, we observed that the Drosophila homolog of Activity-regulated cytoskeleton-associated protein (dArc1), forms a capsid-like structure, associates with its own mRNA, and is transported across synapses. We demonstrated that this transfer is needed for structural synaptic plasticity. To identify mRNAs that are modified by dArc1 in presynaptic neuron and postsynaptic muscle, we disrupted the expression of dArc1 and performed genomic analysis with deep sequencing. We found that dArc1 affects the expression of genes involved in metabolism, phagocytosis, and RNA-splicing. Through immunoprecipitation we also identified potential mRNA cargos of dArc1 capsids. This study suggests that dArc1 acts as a master regulator of plasticity by affecting several distinct and highly conserved cellular processes.
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Affiliation(s)
- Cong Xiao
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - P. Githure M’Angale
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Shuhao Wang
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Adrienne Lemieux
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Travis Thomson
- Department of Neurobiology, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
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6
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Puri D, Sharma S, Samaddar S, Ravivarma S, Banerjee S, Ghosh-Roy A. Muscleblind-1 interacts with tubulin mRNAs to regulate the microtubule cytoskeleton in C. elegans mechanosensory neurons. PLoS Genet 2023; 19:e1010885. [PMID: 37603562 PMCID: PMC10470942 DOI: 10.1371/journal.pgen.1010885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 08/31/2023] [Accepted: 07/26/2023] [Indexed: 08/23/2023] Open
Abstract
Regulation of the microtubule cytoskeleton is crucial for the development and maintenance of neuronal architecture, and recent studies have highlighted the significance of regulated RNA processing in the establishment and maintenance of neural circuits. In a genetic screen conducted using mechanosensory neurons of C. elegans, we identified a mutation in muscleblind-1/mbl-1 as a suppressor of loss of kinesin-13 family microtubule destabilizing factor klp-7. Muscleblind-1(MBL-1) is an RNA-binding protein that regulates the splicing, localization, and stability of RNA. Our findings demonstrate that mbl-1 is required cell-autonomously for axon growth and proper synapse positioning in the posterior lateral microtubule (PLM) neuron. Loss of mbl-1 leads to increased microtubule dynamics and mixed orientation of microtubules in the anterior neurite of PLM. These defects are also accompanied by abnormal axonal transport of the synaptic protein RAB-3 and reduction of gentle touch sensation in mbl-1 mutant. Our data also revealed that mbl-1 is genetically epistatic to mec-7 (β tubulin) and mec-12 (α tubulin) in regulating axon growth. Furthermore, mbl-1 is epistatic to sad-1, an ortholog of BRSK/Brain specific-serine/threonine kinase and a known regulator of synaptic machinery, for synapse formation at the correct location of the PLM neurite. Notably, the immunoprecipitation of MBL-1 resulted in the co-purification of mec-7, mec-12, and sad-1 mRNAs, suggesting a direct interaction between MBL-1 and these transcripts. Additionally, mbl-1 mutants exhibited reduced levels and stability of mec-7 and mec-12 transcripts. Our study establishes a previously unknown link between RNA-binding proteins and cytoskeletal machinery, highlighting their crucial roles in the development and maintenance of the nervous system.
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Affiliation(s)
- Dharmendra Puri
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sunanda Sharma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sarbani Samaddar
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sruthy Ravivarma
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
| | - Sourav Banerjee
- National Brain Research Centre, Manesar, Gurgaon, Haryana, India
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7
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Galindo SE, Shin GJE, Millard SS, Grueber WB. Regulated alternative splicing of Dscam2 is required for somatosensory circuit wiring. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.01.530539. [PMID: 36909552 PMCID: PMC10002739 DOI: 10.1101/2023.03.01.530539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Axon and dendrite placement and connectivity is guided by a wide range of secreted and surface molecules in the developing nervous system. Nevertheless, the extraordinary complexity of connections in the brain requires that this repertoire be further diversified to precisely and uniquely regulate cell-cell interactions. One important mechanism for molecular diversification is alternative splicing. Drosophila Down syndrome cell adhesion molecule (Dscam2) undergoes cell type-specific alternative splicing to produce two isoform-specific homophilic binding proteins. Regulated alternative splicing of Dscam2 is important for dendrite and axon patterning, but how this translates to circuit wiring and animal behavior is not well understood. Here, we examined the role of cell-type specific expression of Dscam2 isoforms in regulating synaptic partner selection in the larval somatosensory system. We found that synaptic partners in the nociceptive circuit express different Dscam2 isoforms. Forcing synaptic partners to express a common isoform resulted in nociceptive axon patterning defects and attenuated nocifensive behaviors, indicating that a role for Dscam2 alternative splicing is to ensure that synaptic partners do not express matching isoforms. These results point to a model in which regulated alternative splicing of Dscam2 across populations of neurons restricts connectivity to specific partners and prevents inappropriate synaptic connections.
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Affiliation(s)
- Samantha E. Galindo
- Department of Genetics and Development, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Grace Ji-eun Shin
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - S. Sean Millard
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Wesley B. Grueber
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
- Department of Neuroscience, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10027, USA
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8
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Pamudurti NR, Patop IL, Krishnamoorthy A, Bartok O, Maya R, Lerner N, Ashwall-Fluss R, Konakondla JVV, Beatus T, Kadener S. circMbl functions in cis and in trans to regulate gene expression and physiology in a tissue-specific fashion. Cell Rep 2022; 39:110740. [PMID: 35476987 PMCID: PMC9352392 DOI: 10.1016/j.celrep.2022.110740] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/11/2022] [Accepted: 04/05/2022] [Indexed: 11/03/2022] Open
Abstract
Muscleblind (mbl) is an essential muscle and neuronal splicing regulator. Mbl hosts multiple circular RNAs (circRNAs), including circMbl, which is conserved from flies to humans. Here, we show that mbl-derived circRNAs are key regulators of MBL by cis- and trans-acting mechanisms. By generating fly lines to specifically modulate the levels of all mbl RNA isoforms, including circMbl, we demonstrate that the two major mbl protein isoforms, MBL-O/P and MBL-C, buffer their own levels by producing different types of circRNA isoforms in the eye and fly brain, respectively. Moreover, we show that circMbl has unique functions in trans, as knockdown of circMbl results in specific morphological and physiological phenotypes. In addition, depletion of MBL-C or circMbl results in opposite behavioral phenotypes, showing that they also regulate each other in trans. Together, our results illuminate key aspects of mbl regulation and uncover cis and trans functions of circMbl in vivo.
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Affiliation(s)
| | | | | | - Osnat Bartok
- Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Roni Maya
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; Department of Neurobiology, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Noam Lerner
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; Department of Neurobiology, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Reut Ashwall-Fluss
- Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | | | - Tsevi Beatus
- The Rachel and Selim Benin School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel; Department of Neurobiology, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel
| | - Sebastian Kadener
- Biology Department, Brandeis University, Waltham, MA 02454, USA; Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
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9
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Kurmangaliyev YZ, Yoo J, Valdes-Aleman J, Sanfilippo P, Zipursky SL. Transcriptional Programs of Circuit Assembly in the Drosophila Visual System. Neuron 2020; 108:1045-1057.e6. [PMID: 33125872 DOI: 10.1016/j.neuron.2020.10.006] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/31/2020] [Accepted: 10/03/2020] [Indexed: 12/19/2022]
Abstract
Precise patterns of synaptic connections between neurons are encoded in their genetic programs. Here, we use single-cell RNA sequencing to profile neuronal transcriptomes at multiple stages in the developing Drosophila visual system. We devise an efficient strategy for profiling neurons at multiple time points in a single pool, thereby minimizing batch effects and maximizing the reliability of time-course data. A transcriptional atlas spanning multiple stages is generated, including more than 150 distinct neuronal populations; of these, 88 are followed through synaptogenesis. This analysis reveals a common (pan-neuronal) program unfolding in highly coordinated fashion in all neurons, including genes encoding proteins comprising the core synaptic machinery and membrane excitability. This program is overlaid by cell-type-specific programs with diverse cell recognition molecules expressed in different combinations and at different times. We propose that a pan-neuronal program endows neurons with the competence to form synapses and that cell-type-specific programs control synaptic specificity.
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Affiliation(s)
- Yerbol Z Kurmangaliyev
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Juyoun Yoo
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Javier Valdes-Aleman
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Piero Sanfilippo
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - S Lawrence Zipursky
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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10
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Kashkan I, Timofeyenko K, Kollárová E, Růžička K. In vivo Reporters for Visualizing Alternative Splicing of Hormonal Genes. PLANTS (BASEL, SWITZERLAND) 2020; 9:E868. [PMID: 32650629 PMCID: PMC7412054 DOI: 10.3390/plants9070868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 11/17/2022]
Abstract
Rapid progress in plant molecular biology in recent years has uncovered the main players in hormonal pathways and characterized transcriptomic networks associated with hormonal response. However, the role of RNA processing, in particular alternative splicing (AS), remains largely unexplored. Here, using example genes involved in cytokinin signaling, brassinosteroid synthesis and auxin transport, we present a set of reporters devised to visualize their AS events in vivo. These reporters show a differential tissue-specific expression of certain transcripts and reveal that expression of some of the them can be changed by the application of the exogenous hormone. Finally, based on the characterized AS event of the PIN7 auxin efflux carrier, we designed a system that allows a rapid genetic screening for the factors upstream of this AS event. Our innovative toolset can be therefore highly useful for exploring novel regulatory nodes of hormonal pathways and potentially helpful for plant researchers focusing on developmental aspects of AS.
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Affiliation(s)
- Ivan Kashkan
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, 165 02 Prague, Czech Republic; (I.K.); (K.T.)
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic;
| | - Ksenia Timofeyenko
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, 165 02 Prague, Czech Republic; (I.K.); (K.T.)
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic;
| | - Eva Kollárová
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic;
| | - Kamil Růžička
- Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany, Czech Academy of Sciences, 165 02 Prague, Czech Republic; (I.K.); (K.T.)
- Functional Genomics and Proteomics of Plants, Central European Institute of Technology and National Centre for Biomolecular Research, Masaryk University, 625 00 Brno, Czech Republic;
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11
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Odierna GL, Kerwin SK, Harris LE, Shin GJE, Lavidis NA, Noakes PG, Millard SS. Dscam2 suppresses synaptic strength through a PI3K-dependent endosomal pathway. J Cell Biol 2020; 219:151621. [PMID: 32259198 PMCID: PMC7265308 DOI: 10.1083/jcb.201909143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/19/2020] [Accepted: 03/05/2020] [Indexed: 11/22/2022] Open
Abstract
Dscam2 is a cell surface protein required for neuronal development in Drosophila; it can promote neural wiring through homophilic recognition that leads to either adhesion or repulsion between neurites. Here, we report that Dscam2 also plays a post-developmental role in suppressing synaptic strength. This function is dependent on one of two distinct extracellular isoforms of the protein and is autonomous to motor neurons. We link the PI3K enhancer, Centaurin gamma 1A, to the Dscam2-dependent regulation of synaptic strength and show that changes in phosphoinositide levels correlate with changes in endosomal compartments that have previously been associated with synaptic strength. Using transmission electron microscopy, we find an increase in synaptic vesicles at Dscam2 mutant active zones, providing a rationale for the increase in synaptic strength. Our study provides the first evidence that Dscam2 can regulate synaptic physiology and highlights how diverse roles of alternative protein isoforms can contribute to unique aspects of brain development and function.
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Affiliation(s)
- G Lorenzo Odierna
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Sarah K Kerwin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Lucy E Harris
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Grace Ji-Eun Shin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - S Sean Millard
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
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