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Doe CQ, Thor S. 40 years of homeodomain transcription factors in the Drosophila nervous system. Development 2024; 151:dev202910. [PMID: 38819456 DOI: 10.1242/dev.202910] [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] [Indexed: 06/01/2024]
Abstract
Drosophila nervous system development progresses through a series of well-characterized steps in which homeodomain transcription factors (HDTFs) play key roles during most, if not all, phases. Strikingly, although some HDTFs have only one role, many others are involved in multiple steps of the developmental process. Most Drosophila HDTFs engaged in nervous system development are conserved in vertebrates and often play similar roles during vertebrate development. In this Spotlight, we focus on the role of HDTFs during embryogenesis, where they were first characterized.
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Affiliation(s)
- Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| | - Stefan Thor
- School of Biomedical Sciences, The University of Queensland, St Lucia, QLD 4072, Australia
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2
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Ramirez MD, Bui TN, Katz PS. Cellular-resolution gene expression mapping reveals organization in the head ganglia of the gastropod, Berghia stephanieae. J Comp Neurol 2024; 532:e25628. [PMID: 38852042 DOI: 10.1002/cne.25628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 04/25/2024] [Accepted: 05/09/2024] [Indexed: 06/10/2024]
Abstract
Gastropod molluscs such as Aplysia, Lymnaea, and Tritonia have been important for determining fundamental rules of motor control, learning, and memory because of their large, individually identifiable neurons. Yet only a small number of gastropod neurons have known molecular markers, limiting the ability to establish brain-wide structure-function relations. Here we combine high-throughput, single-cell RNA sequencing with in situ hybridization chain reaction in the nudibranch Berghia stephanieae to identify and visualize the expression of markers for cell types. Broad neuronal classes were characterized by genes associated with neurotransmitters, like acetylcholine, glutamate, serotonin, and GABA, as well as neuropeptides. These classes were subdivided by other genes including transcriptional regulators and unannotated genes. Marker genes expressed by neurons and glia formed discrete, previously unrecognized regions within and between ganglia. This study provides the foundation for understanding the fundamental cellular organization of gastropod nervous systems.
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Affiliation(s)
- M Desmond Ramirez
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Thi N Bui
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
| | - Paul S Katz
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, USA
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3
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Leung HH, Mansour C, Rousseau M, Nakhla A, Kiselyov K, Venkatachalam K, Wong CO. Drosophila tweety facilitates autophagy to regulate mitochondrial homeostasis and bioenergetics in Glia. Glia 2024; 72:433-451. [PMID: 37870193 PMCID: PMC10842981 DOI: 10.1002/glia.24484] [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: 06/02/2023] [Revised: 09/12/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023]
Abstract
Mitochondria support the energetic demands of the cells. Autophagic turnover of mitochondria serves as a critical pathway for mitochondrial homeostasis. It is unclear how bioenergetics and autophagy are functionally connected. Here, we identify an endolysosomal membrane protein that facilitates autophagy to regulate ATP production in glia. We determined that Drosophila tweety (tty) is highly expressed in glia and localized to endolysosomes. Diminished fusion between autophagosomes and endolysosomes in tty-deficient glia was rescued by expressing the human Tweety Homolog 1 (TTYH1). Loss of tty in glia attenuated mitochondrial turnover, elevated mitochondrial oxidative stress, and impaired locomotor functions. The cellular and organismal defects were partially reversed by antioxidant treatment. We performed live-cell imaging of genetically encoded metabolite sensors to determine the impact of tty and autophagy deficiencies on glial bioenergetics. We found that tty-deficient glia exhibited reduced mitochondrial pyruvate consumption accompanied by a shift toward glycolysis for ATP production. Likewise, genetic inhibition of autophagy in glia resulted in a similar glycolytic shift in bioenergetics. Furthermore, the survival of mutant flies became more sensitive to starvation, underlining the significance of tty in the crosstalk between autophagy and bioenergetics. Together, our findings uncover the role for tty in mitochondrial homeostasis via facilitating autophagy, which determines bioenergetic balance in glia.
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Affiliation(s)
- Ho Hang Leung
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
- Present address: South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA 5000, Australia
| | - Christina Mansour
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Morgan Rousseau
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center (UTHealth), Houston, TX 77030, USA
| | - Anwar Nakhla
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
| | - Kirill Kiselyov
- Department of Biological Sciences, University of Pittsburgh, PA 15260, USA
| | - Kartik Venkatachalam
- Department of Integrative Biology and Pharmacology, McGovern Medical School at the University of Texas Health Sciences Center (UTHealth), Houston, TX 77030, USA
| | - Ching-On Wong
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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4
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Brooks EC, Zeidler MP, Ong ACM, Evans IR. Macrophage subpopulation identity in Drosophila is modulated by apoptotic cell clearance and related signalling pathways. Front Immunol 2024; 14:1310117. [PMID: 38283366 PMCID: PMC10811221 DOI: 10.3389/fimmu.2023.1310117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024] Open
Abstract
In Drosophila blood, plasmatocytes of the haemocyte lineage represent the functional equivalent of vertebrate macrophages and have become an established in vivo model with which to study macrophage function and behaviour. However, the use of plasmatocytes as a macrophage model has been limited by a historical perspective that plasmatocytes represent a homogenous population of cells, in contrast to the high levels of heterogeneity of vertebrate macrophages. Recently, a number of groups have reported transcriptomic approaches which suggest the existence of plasmatocyte heterogeneity, while we identified enhancer elements that identify subpopulations of plasmatocytes which exhibit potentially pro-inflammatory behaviours, suggesting conservation of plasmatocyte heterogeneity in Drosophila. These plasmatocyte subpopulations exhibit enhanced responses to wounds and decreased rates of efferocytosis when compared to the overall plasmatocyte population. Interestingly, increasing the phagocytic requirement placed upon plasmatocytes is sufficient to decrease the size of these plasmatocyte subpopulations in the embryo. However, the mechanistic basis for this response was unclear. Here, we examine how plasmatocyte subpopulations are modulated by apoptotic cell clearance (efferocytosis) demands and associated signalling pathways. We show that loss of the phosphatidylserine receptor Simu prevents an increased phagocytic burden from modulating specific subpopulation cells, while blocking other apoptotic cell receptors revealed no such rescue. This suggests that Simu-dependent efferocytosis is specifically involved in determining fate of particular subpopulations. Supportive of our original finding, mutations in amo (the Drosophila homolog of PKD2), a calcium-permeable channel which operates downstream of Simu, phenocopy simu mutants. Furthermore, we show that Amo is involved in the acidification of the apoptotic cell-containing phagosomes, suggesting that this reduction in pH may be associated with macrophage reprogramming. Additionally, our results also identify Ecdysone receptor signalling, a pathway related to control of cell death during developmental transitions, as a controller of plasmatocyte subpopulation identity. Overall, these results identify fundamental pathways involved in the specification of plasmatocyte subpopulations and so further validate Drosophila plasmatocytes as a heterogeneous population of macrophage-like cells within this important developmental and immune model.
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Affiliation(s)
- Elliot C. Brooks
- School of Medicine and Population Health and the Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Martin P. Zeidler
- School of Biosciences and the Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Albert C. M. Ong
- School of Medicine and Population Health and the Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Iwan R. Evans
- School of Medicine and Population Health and the Bateson Centre, University of Sheffield, Sheffield, United Kingdom
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5
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Bollepogu Raja KK, Yeung K, Shim YK, Li Y, Chen R, Mardon G. A single cell genomics atlas of the Drosophila larval eye reveals distinct photoreceptor developmental timelines. Nat Commun 2023; 14:7205. [PMID: 37938573 PMCID: PMC10632452 DOI: 10.1038/s41467-023-43037-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 10/30/2023] [Indexed: 11/09/2023] Open
Abstract
The Drosophila eye is a powerful model system to study the dynamics of cell differentiation, cell state transitions, cell maturation, and pattern formation. However, a high-resolution single cell genomics resource that accurately profiles all major cell types of the larval eye disc and their spatiotemporal relationships is lacking. Here, we report transcriptomic and chromatin accessibility data for all known cell types in the developing eye. Photoreceptors appear as strands of cells that represent their dynamic developmental timelines. As photoreceptor subtypes mature, they appear to assume a common transcriptomic profile that is dominated by genes involved in axon function. We identify cell type maturation genes, enhancers, and potential regulators, as well as genes with distinct R3 or R4 photoreceptor specific expression. Finally, we observe that the chromatin accessibility between cones and photoreceptors is distinct. These single cell genomics atlases will greatly enhance the power of the Drosophila eye as a model system.
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Affiliation(s)
- Komal Kumar Bollepogu Raja
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Kelvin Yeung
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yoon-Kyung Shim
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Graeme Mardon
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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6
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Nil Z, Deshwar AR, Huang Y, Barish S, Zhang X, Choufani S, Le Quesne Stabej P, Hayes I, Yap P, Haldeman-Englert C, Wilson C, Prescott T, Tveten K, Vøllo A, Haynes D, Wheeler PG, Zon J, Cytrynbaum C, Jobling R, Blyth M, Banka S, Afenjar A, Mignot C, Robin-Renaldo F, Keren B, Kanca O, Mao X, Wegner DJ, Sisco K, Shinawi M, Wangler MF, Weksberg R, Yamamoto S, Costain G, Bellen HJ. Rare de novo gain-of-function missense variants in DOT1L are associated with developmental delay and congenital anomalies. Am J Hum Genet 2023; 110:1919-1937. [PMID: 37827158 PMCID: PMC10645550 DOI: 10.1016/j.ajhg.2023.09.009] [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: 05/25/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 10/14/2023] Open
Abstract
Misregulation of histone lysine methylation is associated with several human cancers and with human developmental disorders. DOT1L is an evolutionarily conserved gene encoding a lysine methyltransferase (KMT) that methylates histone 3 lysine-79 (H3K79) and was not previously associated with a Mendelian disease in OMIM. We have identified nine unrelated individuals with seven different de novo heterozygous missense variants in DOT1L through the Undiagnosed Disease Network (UDN), the SickKids Complex Care genomics project, and GeneMatcher. All probands had some degree of global developmental delay/intellectual disability, and most had one or more major congenital anomalies. To assess the pathogenicity of the DOT1L variants, functional studies were performed in Drosophila and human cells. The fruit fly DOT1L ortholog, grappa, is expressed in most cells including neurons in the central nervous system. The identified DOT1L variants behave as gain-of-function alleles in flies and lead to increased H3K79 methylation levels in flies and human cells. Our results show that human DOT1L and fly grappa are required for proper development and that de novo heterozygous variants in DOT1L are associated with a Mendelian disease.
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Affiliation(s)
- Zelha Nil
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Ashish R Deshwar
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Yan Huang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Scott Barish
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Xi Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China; National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410005, China
| | - Sanaa Choufani
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Polona Le Quesne Stabej
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, the University of Auckland, Auckland, New Zealand
| | - Ian Hayes
- Genetic Health Service New Zealand- Northern Hub, Auckland District Health Board, Auckland, New Zealand
| | - Patrick Yap
- Genetic Health Service New Zealand- Northern Hub, Auckland District Health Board, Auckland, New Zealand
| | | | - Carolyn Wilson
- Mission Fullerton Genetics Center, Asheville, NC 28803, USA
| | - Trine Prescott
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, 3710 Skien, Norway
| | - Arve Vøllo
- Department of Pediatrics, Hospital of Østfold, 1714 Grålum, Norway
| | - Devon Haynes
- Division of Genetics, Arnold Palmer Hospital for Children - Orlando Health, Orlando, FL, USA; Clinical Genetics Service, Guy's Hospital, Guy's and St Thomas' NHS Trust, London, England, UK
| | - Patricia G Wheeler
- Division of Genetics, Arnold Palmer Hospital for Children - Orlando Health, Orlando, FL, USA
| | - Jessica Zon
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Cheryl Cytrynbaum
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Rebekah Jobling
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada
| | - Moira Blyth
- North of Scotland Regional Genetics Service, Clinical Genetics Centre, Ashgrove House, Foresterhill, Aberdeen, UK
| | - Siddharth Banka
- Division of Evolution, Infection and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, M13 9WL Manchester, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, M13 9WL Manchester, UK
| | - Alexandra Afenjar
- Service de génétique, CRMR des malformations et maladies congénitales du cervelet et CRMR déficience intellectuelle, hôpital Trousseau, AP-HP, Paris, France
| | - Cyril Mignot
- Sorbonne Université, Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière and Hôpital Trousseau, Paris, France; Centre de Référence Déficiences Intellectuelles de Causes Rares, Paris, France
| | | | - Boris Keren
- AP-HP, Hôpital de la Pitié-Salpêtrière, Département de Génétique, 75013 Paris, France
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Xiao Mao
- National Health Commission Key Laboratory for Birth Defect Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410005, China; Clinical Research Center for Placental Medicine in Hunan Province, Hunan Provincial Maternal and Child Health Care Hospital, Changsha 410005, China
| | - Daniel J Wegner
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kathleen Sisco
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marwan Shinawi
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Rosanna Weksberg
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada; Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, 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 Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gregory Costain
- Division of Clinical and Metabolic Genetics, The Hospital for Sick Children, Toronto, ON, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, 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 Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
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González YR, Kamkar F, Jafar-Nejad P, Wang S, Qu D, Alvarez LS, Hawari D, Sonnenfeld M, Slack RS, Albert PR, Park DS, Joselin A. PFTK1 kinase regulates axogenesis during development via RhoA activation. BMC Biol 2023; 21:240. [PMID: 37907898 PMCID: PMC10617079 DOI: 10.1186/s12915-023-01732-w] [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: 09/26/2022] [Accepted: 10/11/2023] [Indexed: 11/02/2023] Open
Abstract
BACKGROUND PFTK1/Eip63E is a member of the cyclin-dependent kinases (CDKs) family and plays an important role in normal cell cycle progression. Eip63E expresses primarily in postnatal and adult nervous system in Drosophila melanogaster but its role in CNS development remains unknown. We sought to understand the function of Eip63E in the CNS by studying the fly ventral nerve cord during development. RESULTS Our results demonstrate that Eip63E regulates axogenesis in neurons and its deficiency leads to neuronal defects. Functional interaction studies performed using the same system identify an interaction between Eip63E and the small GTPase Rho1. Furthermore, deficiency of Eip63E homolog in mice, PFTK1, in a newly generated PFTK1 knockout mice results in increased axonal outgrowth confirming that the developmental defects observed in the fly model are due to defects in axogenesis. Importantly, RhoA phosphorylation and activity are affected by PFTK1 in primary neuronal cultures. We report that GDP-bound inactive RhoA is a substrate of PFTK1 and PFTK1 phosphorylation is required for RhoA activity. CONCLUSIONS In conclusion, our work establishes an unreported neuronal role of PFTK1 in axon development mediated by phosphorylation and activation of GDP-bound RhoA. The results presented add to our understanding of the role of Cdks in the maintenance of RhoA-mediated axon growth and its impact on CNS development and axonal regeneration.
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Affiliation(s)
| | - Fatemeh Kamkar
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Paymaan Jafar-Nejad
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
- Present Address: Ionis Pharmaceuticals Inc., Carlsbad, CA, 92010, USA
| | - Suzi Wang
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Dianbo Qu
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Leticia Sanchez Alvarez
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Dina Hawari
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Margaret Sonnenfeld
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Ruth S Slack
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - Paul R Albert
- Ottawa Hospital Research Institute and Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, K1H 8M5, Canada
| | - David S Park
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
| | - Alvin Joselin
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
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8
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Ju L, Glastad KM, Sheng L, Gospocic J, Kingwell CJ, Davidson SM, Kocher SD, Bonasio R, Berger SL. Hormonal gatekeeping via the blood-brain barrier governs caste-specific behavior in ants. Cell 2023; 186:4289-4309.e23. [PMID: 37683635 PMCID: PMC10807403 DOI: 10.1016/j.cell.2023.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/10/2023] [Accepted: 08/01/2023] [Indexed: 09/10/2023]
Abstract
Here, we reveal an unanticipated role of the blood-brain barrier (BBB) in regulating complex social behavior in ants. Using scRNA-seq, we find localization in the BBB of a key hormone-degrading enzyme called juvenile hormone esterase (Jhe), and we show that this localization governs the level of juvenile hormone (JH3) entering the brain. Manipulation of the Jhe level reprograms the brain transcriptome between ant castes. Although ant Jhe is retained and functions intracellularly within the BBB, we show that Drosophila Jhe is naturally extracellular. Heterologous expression of ant Jhe into the Drosophila BBB alters behavior in fly to mimic what is seen in ants. Most strikingly, manipulation of Jhe levels in ants reprograms complex behavior between worker castes. Our study thus uncovers a remarkable, potentially conserved role of the BBB serving as a molecular gatekeeper for a neurohormonal pathway that regulates social behavior.
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Affiliation(s)
- Linyang Ju
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Karl M Glastad
- Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| | - Lihong Sheng
- Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Janko Gospocic
- Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Urology and Institute of Neuropathology, Medical Center-University of Freiburg, Freiburg, Germany
| | - Callum J Kingwell
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA
| | - Shawn M Davidson
- Lewis-Sigler Institute for Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Sarah D Kocher
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Roberto Bonasio
- Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Shelley L Berger
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA; Epigenetics Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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9
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Hopkins BR, Barmina O, Kopp A. A single-cell atlas of the sexually dimorphic Drosophila foreleg and its sensory organs during development. PLoS Biol 2023; 21:e3002148. [PMID: 37379332 DOI: 10.1371/journal.pbio.3002148] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 05/03/2023] [Indexed: 06/30/2023] Open
Abstract
To respond to the world around them, animals rely on the input of a network of sensory organs distributed throughout the body. Distinct classes of sensory organs are specialized for the detection of specific stimuli such as strain, pressure, or taste. The features that underlie this specialization relate both to the neurons that innervate sensory organs and the accessory cells they comprise. To understand the genetic basis of this diversity of cell types, both within and between sensory organs, we performed single-cell RNA sequencing on the first tarsal segment of the male Drosophila melanogaster foreleg during pupal development. This tissue displays a wide variety of functionally and structurally distinct sensory organs, including campaniform sensilla, mechanosensory bristles, and chemosensory taste bristles, as well as the sex comb, a recently evolved male-specific structure. In this study, we characterize the cellular landscape in which the sensory organs reside, identify a novel cell type that contributes to the construction of the neural lamella, and resolve the transcriptomic differences among support cells within and between sensory organs. We identify the genes that distinguish between mechanosensory and chemosensory neurons, resolve a combinatorial transcription factor code that defines 4 distinct classes of gustatory neurons and several types of mechanosensory neurons, and match the expression of sensory receptor genes to specific neuron classes. Collectively, our work identifies core genetic features of a variety of sensory organs and provides a rich, annotated resource for studying their development and function.
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Affiliation(s)
- Ben R Hopkins
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Olga Barmina
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
| | - Artyom Kopp
- Department of Evolution and Ecology, University of California, Davis, California, United States of America
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10
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Titus MB, Chang AW, Popitsch N, Ebmeier CC, Bono JM, Olesnicky EC. The identification of protein and RNA interactors of the splicing factor Caper in the adult Drosophila nervous system. Front Mol Neurosci 2023; 16:1114857. [PMID: 37435576 PMCID: PMC10332324 DOI: 10.3389/fnmol.2023.1114857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 05/19/2023] [Indexed: 07/13/2023] Open
Abstract
Post-transcriptional gene regulation is a fundamental mechanism that helps regulate the development and healthy aging of the nervous system. Mutations that disrupt the function of RNA-binding proteins (RBPs), which regulate post-transcriptional gene regulation, have increasingly been implicated in neurological disorders including amyotrophic lateral sclerosis, Fragile X Syndrome, and spinal muscular atrophy. Interestingly, although the majority of RBPs are expressed widely within diverse tissue types, the nervous system is often particularly sensitive to their dysfunction. It is therefore critical to elucidate how aberrant RNA regulation that results from the dysfunction of ubiquitously expressed RBPs leads to tissue specific pathologies that underlie neurological diseases. The highly conserved RBP and alternative splicing factor Caper is widely expressed throughout development and is required for the development of Drosophila sensory and motor neurons. Furthermore, caper dysfunction results in larval and adult locomotor deficits. Nonetheless, little is known about which proteins interact with Caper, and which RNAs are regulated by Caper. Here we identify proteins that interact with Caper in both neural and muscle tissue, along with neural specific Caper target RNAs. Furthermore, we show that a subset of these Caper-interacting proteins and RNAs genetically interact with caper to regulate Drosophila gravitaxis behavior.
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Affiliation(s)
- M. Brandon Titus
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Adeline W. Chang
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Niko Popitsch
- Department of Biochemistry and Cell Biology, Max Perutz Labs, University of Vienna, Vienna, Austria
| | | | - Jeremy M. Bono
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Eugenia C. Olesnicky
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, CO, United States
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11
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Marques GS, Teles-Reis J, Konstantinides N, Brito PH, Homem CCF. Asynchronous transcription and translation of neurotransmitter-related genes characterize the initial stages of neuronal maturation in Drosophila. PLoS Biol 2023; 21:e3002115. [PMID: 37205703 DOI: 10.1371/journal.pbio.3002115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 04/06/2023] [Indexed: 05/21/2023] Open
Abstract
Neuron specification and maturation are essential for proper central nervous system development. However, the precise mechanisms that govern neuronal maturation, essential to shape and maintain neuronal circuitry, remain poorly understood. Here, we analyse early-born secondary neurons in the Drosophila larval brain, revealing that the early maturation of secondary neurons goes through 3 consecutive phases: (1) Immediately after birth, neurons express pan-neuronal markers but do not transcribe terminal differentiation genes; (2) Transcription of terminal differentiation genes, such as neurotransmitter-related genes VGlut, ChAT, or Gad1, starts shortly after neuron birth, but these transcripts are, however, not translated; (3) Translation of neurotransmitter-related genes only begins several hours later in mid-pupa stages in a coordinated manner with animal developmental stage, albeit in an ecdysone-independent manner. These results support a model where temporal regulation of transcription and translation of neurotransmitter-related genes is an important mechanism to coordinate neuron maturation with brain development.
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Affiliation(s)
- Graça S Marques
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa; Lisboa, Portugal
| | - José Teles-Reis
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa; Lisboa, Portugal
| | | | - Patrícia H Brito
- Applied Molecular Biosciences Unit-UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Catarina C F Homem
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NMS, FCM, Universidade NOVA de Lisboa; Lisboa, Portugal
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12
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Rathore S, Meece M, Charlton-Perkins M, Cook TA, Buschbeck EK. Probing the conserved roles of cut in the development and function of optically different insect compound eyes. Front Cell Dev Biol 2023; 11:1104620. [PMID: 37065850 PMCID: PMC10102356 DOI: 10.3389/fcell.2023.1104620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/13/2023] [Indexed: 04/03/2023] Open
Abstract
Astonishing functional diversity exists among arthropod eyes, yet eye development relies on deeply conserved genes. This phenomenon is best understood for early events, whereas fewer investigations have focused on the influence of later transcriptional regulators on diverse eye organizations and the contribution of critical support cells, such as Semper cells (SCs). As SCs in Drosophila melanogaster secrete the lens and function as glia, they are critical components of ommatidia. Here, we perform RNAi-based knockdowns of the transcription factor cut (CUX in vertebrates), a marker of SCs, the function of which has remained untested in these cell types. To probe for the conserved roles of cut, we investigate two optically different compound eyes: the apposition optics of D. melanogaster and the superposition optics of the diving beetle Thermonectus marmoratus. In both cases, we find that multiple aspects of ocular formation are disrupted, including lens facet organization and optics as well as photoreceptor morphogenesis. Together, our findings support the possibility of a generalized role for SCs in arthropod ommatidial form and function and introduces Cut as a central player in mediating this role.
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Affiliation(s)
- Shubham Rathore
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Michael Meece
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Mark Charlton-Perkins
- Division of Developmental Biology and Department of Pediatric Ophthalmology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genetics, Department of Ophthalmological, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
| | - Elke K. Buschbeck
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
- *Correspondence: Tiffany A. Cook, ; Elke K. Buschbeck,
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13
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Ayoub M, David LM, Shklyar B, Hakim-Mishnaevski K, Kurant E. Drosophila FGFR/Htl signaling shapes embryonic glia to phagocytose apoptotic neurons. Cell Death Discov 2023; 9:90. [PMID: 36898998 PMCID: PMC10006210 DOI: 10.1038/s41420-023-01382-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/19/2023] [Accepted: 02/24/2023] [Indexed: 03/12/2023] Open
Abstract
Glial phagocytosis of apoptotic neurons is crucial for development and proper function of the central nervous system. Relying on transmembrane receptors located on their protrusions, phagocytic glia recognize and engulf apoptotic debris. Like vertebrate microglia, Drosophila phagocytic glial cells form an elaborate network in the developing brain to reach and remove apoptotic neurons. However, the mechanisms controlling creation of the branched morphology of these glial cells critical for their phagocytic ability remain unknown. Here, we demonstrate that during early embryogenesis, the Drosophila fibroblast growth factor receptor (FGFR) Heartless (Htl) and its ligand Pyramus are essential in glial cells for the formation of glial extensions, the presence of which strongly affects glial phagocytosis of apoptotic neurons during later stages of embryonic development. Reduction in Htl pathway activity results in shorter lengths and lower complexity of glial branches, thereby disrupting the glial network. Our work thus illuminates the important role Htl signaling plays in glial subcellular morphogenesis and in establishing glial phagocytic ability.
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Affiliation(s)
- Malak Ayoub
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 3498838, Haifa, Israel
| | - Li-Mor David
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 3498838, Haifa, Israel
| | - Boris Shklyar
- Bioimaging Unit, Faculty of Natural Sciences, University of Haifa, 3498838, Haifa, Israel
| | - Ketty Hakim-Mishnaevski
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 3498838, Haifa, Israel
| | - Estee Kurant
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, 3498838, Haifa, Israel.
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14
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Yeung K, Bollepogu Raja KK, Shim YK, Li Y, Chen R, Mardon G. Single cell RNA sequencing of the adult Drosophila eye reveals distinct clusters and novel marker genes for all major cell types. Commun Biol 2022; 5:1370. [PMID: 36517671 PMCID: PMC9751288 DOI: 10.1038/s42003-022-04337-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/02/2022] [Indexed: 12/16/2022] Open
Abstract
The adult Drosophila eye is a powerful model system for phototransduction and neurodegeneration research. However, single cell resolution transcriptomic data are lacking for this tissue. We present single cell RNA-seq data on 1-day male and female, 3-day and 7-day old male adult eyes, covering early to mature adult eyes. All major cell types, including photoreceptors, cone and pigment cells in the adult eye were captured and identified. Our data sets identified novel cell type specific marker genes, some of which were validated in vivo. R7 and R8 photoreceptors form clusters that reflect their specific Rhodopsin expression and the specific Rhodopsin expression by each R7 and R8 cluster is the major determinant to their clustering. The transcriptomic data presented in this report will facilitate a deeper mechanistic understanding of the adult fly eye as a model system.
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Affiliation(s)
- Kelvin Yeung
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Komal Kumar Bollepogu Raja
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yoon-Kyung Shim
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Structural and Computation Biology and Molecular Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Structural and Computation Biology and Molecular Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Graeme Mardon
- Department of Pathology and Immunology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Program in Developmental Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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15
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Transcriptional profiling from whole embryos to single neuroblast lineages in Drosophila. Dev Biol 2022; 489:21-33. [PMID: 35660371 PMCID: PMC9805786 DOI: 10.1016/j.ydbio.2022.05.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/06/2022] [Accepted: 05/25/2022] [Indexed: 01/03/2023]
Abstract
Embryonic development results in the production of distinct tissue types, and different cell types within each tissue. A major goal of developmental biology is to uncover the "parts list" of cell types that comprise each organ. Here we perform single cell RNA sequencing (scRNA-seq) of the Drosophila embryo to identify the genes that characterize different cell and tissue types during development. We assay three different timepoints, revealing a coordinated change in gene expression within each tissue. Interestingly, we find that the elav and Mhc genes, whose protein products are widely used as markers for neurons and muscles, respectively, show broad pan-embryonic expression, indicating the importance of post-transcriptional regulation. We next focus on the central nervous system (CNS), where we identify genes whose expression is enriched at each stage of neuronal differentiation: from neural progenitors, called neuroblasts, to their immediate progeny ganglion mother cells (GMCs), followed by new-born neurons, young neurons, and the most mature neurons. Finally, we ask whether the clonal progeny of a single neuroblast (NB7-1) share a similar transcriptional identity. Surprisingly, we find that clonal identity does not lead to transcriptional clustering, showing that neurons within a lineage are diverse, and that neurons with a similar transcriptional profile (e.g. motor neurons, glia) are distributed among multiple neuroblast lineages. Although each lineage consists of diverse progeny, we were able to identify a previously uncharacterized gene, Fer3, as an excellent marker for the NB7-1 lineage. Within the NB7-1 lineage, neurons which share a temporal identity (e.g. Hunchback, Kruppel, Pdm, and Castor temporal transcription factors in the NB7-1 lineage) have shared transcriptional features, allowing for the identification of candidate novel temporal factors or targets of the temporal transcription factors. In conclusion, we have characterized the embryonic transcriptome for all major tissue types and for three stages of development, as well as the first transcriptomic analysis of a single, identified neuroblast lineage, finding a lineage-enriched transcription factor.
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16
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Almazán A, Çevrim Ç, Musser JM, Averof M, Paris M. Crustacean leg regeneration restores complex microanatomy and cell diversity. SCIENCE ADVANCES 2022; 8:eabn9823. [PMID: 36001670 PMCID: PMC9401613 DOI: 10.1126/sciadv.abn9823] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Animals can regenerate complex organs, yet this process frequently results in imprecise replicas of the original structure. In the crustacean Parhyale, embryonic and regenerating legs differ in gene expression dynamics but produce apparently similar mature structures. We examine the fidelity of Parhyale leg regeneration using complementary approaches to investigate microanatomy, sensory function, cellular composition, and cell molecular profiles. We find that regeneration precisely replicates the complex microanatomy and spatial distribution of external sensory organs and restores their sensory function. Single-nuclei sequencing shows that regenerated and uninjured legs are indistinguishable in terms of cell-type composition and transcriptional profiles. This remarkable fidelity highlights the ability of organisms to achieve identical outcomes via distinct processes.
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Affiliation(s)
- Alba Almazán
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Çağrı Çevrim
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Jacob M. Musser
- European Molecular Biology Laboratory, Developmental Biology Unit, Meyerhofstrasse 1, Heidelberg 69117, Germany
| | - Michalis Averof
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
| | - Mathilde Paris
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Centre National de la Recherche Scientifique (CNRS), École Normale Supérieure de Lyon and Université Claude Bernard Lyon 1, 69007 Lyon, France
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17
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Dillon N, Cocanougher B, Sood C, Yuan X, Kohn AB, Moroz LL, Siegrist SE, Zlatic M, Doe CQ. Single cell RNA-seq analysis reveals temporally-regulated and quiescence-regulated gene expression in Drosophila larval neuroblasts. Neural Dev 2022; 17:7. [PMID: 36002894 PMCID: PMC9404614 DOI: 10.1186/s13064-022-00163-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/19/2022] [Indexed: 12/12/2022] Open
Abstract
The mechanisms that generate neural diversity during development remains largely unknown. Here, we use scRNA-seq methodology to discover new features of the Drosophila larval CNS across several key developmental timepoints. We identify multiple progenitor subtypes - both stem cell-like neuroblasts and intermediate progenitors - that change gene expression across larval development, and report on new candidate markers for each class of progenitors. We identify a pool of quiescent neuroblasts in newly hatched larvae and show that they are transcriptionally primed to respond to the insulin signaling pathway to exit from quiescence, including relevant pathway components in the adjacent glial signaling cell type. We identify candidate "temporal transcription factors" (TTFs) that are expressed at different times in progenitor lineages. Our work identifies many cell type specific genes that are candidates for functional roles, and generates new insight into the differentiation trajectory of larval neurons.
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Affiliation(s)
- Noah Dillon
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, OR, 97403, Eugene, USA
| | - Ben Cocanougher
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Chhavi Sood
- Department of Biology, University of Virginia, VA, 22904, Charlottesville, USA
| | - Xin Yuan
- Department of Biology, University of Virginia, VA, 22904, Charlottesville, USA
| | - Andrea B Kohn
- Whitney Laboratory for Marine Biosciences, University of Florida, FL, 32080, St. Augustine, USA
| | - Leonid L Moroz
- Whitney Laboratory for Marine Biosciences, University of Florida, FL, 32080, St. Augustine, USA
| | - Sarah E Siegrist
- Department of Biology, University of Virginia, VA, 22904, Charlottesville, USA
| | - Marta Zlatic
- MRC Laboratory of Molecular Biology, Dept of Zoology, University of Cambridge, Cambridge, UK.,Janelia Research Campus, VA, Ashburn, USA
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, OR, 97403, Eugene, USA.
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18
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Jiao W, Spreemann G, Ruchti E, Banerjee S, Vernon S, Shi Y, Stowers RS, Hess K, McCabe BD. Intact Drosophila central nervous system cellular quantitation reveals sexual dimorphism. eLife 2022; 11:74968. [PMID: 35801638 PMCID: PMC9270032 DOI: 10.7554/elife.74968] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 06/09/2022] [Indexed: 12/15/2022] Open
Abstract
Establishing with precision the quantity and identity of the cell types of the brain is a prerequisite for a detailed compendium of gene and protein expression in the central nervous system (CNS). Currently, however, strict quantitation of cell numbers has been achieved only for the nervous system of Caenorhabditis elegans. Here, we describe the development of a synergistic pipeline of molecular genetic, imaging, and computational technologies designed to allow high-throughput, precise quantitation with cellular resolution of reporters of gene expression in intact whole tissues with complex cellular constitutions such as the brain. We have deployed the approach to determine with exactitude the number of functional neurons and glia in the entire intact larval Drosophila CNS, revealing fewer neurons and more glial cells than previously predicted. We also discover an unexpected divergence between the sexes at this juvenile developmental stage, with the female CNS having significantly more neurons than that of males. Topological analysis of our data establishes that this sexual dimorphism extends to deeper features of CNS organisation. We additionally extended our analysis to quantitate the expression of voltage-gated potassium channel family genes throughout the CNS and uncover substantial differences in abundance. Our methodology enables robust and accurate quantification of the number and positioning of cells within intact organs, facilitating sophisticated analysis of cellular identity, diversity, and gene expression characteristics.
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Affiliation(s)
- Wei Jiao
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Gard Spreemann
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Evelyne Ruchti
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Soumya Banerjee
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Samuel Vernon
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Ying Shi
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - R Steven Stowers
- Department of Microbiology and Cell Biology, Montana State University
| | - Kathryn Hess
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
| | - Brian D McCabe
- Brain Mind Institute, EPFL - Swiss Federal Institute of Technology
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19
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Raymond MH, Davidson AJ, Shen Y, Tudor DR, Lucas CD, Morioka S, Perry JSA, Krapivkina J, Perrais D, Schumacher LJ, Campbell RE, Wood W, Ravichandran KS. Live cell tracking of macrophage efferocytosis during Drosophila embryo development in vivo. Science 2022; 375:1182-1187. [PMID: 35271315 PMCID: PMC7612538 DOI: 10.1126/science.abl4430] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Apoptosis of cells and their subsequent removal via efferocytosis occurs in nearly all tissues during development, homeostasis, and disease. However, it has been difficult to track cell death and subsequent corpse removal in vivo. Here, we developed a genetically encoded fluorescent reporter, CharON, that could track emerging apoptotic cells and their efferocytic clearance by phagocytes. Using Drosophila expressing CharON, we uncovered multiple qualitative and quantitative features of coordinated clearance of apoptotic corpses during embryonic development. To confront high rate of emerging apoptotic corpses, the macrophages displayed heterogeneity in engulfment, with some efferocytic macrophages carrying high corpse burden. However, overburdened macrophages were compromised in clearing wound debris, revealing an inherent vulnerability. These findings reveal known and unexpected features of apoptosis and macrophage efferocytosis in vivo.
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Affiliation(s)
- Michael H Raymond
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.,Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
| | - Andrew J Davidson
- Centre for Inflammation Research, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Yi Shen
- Department of Chemistry, University of Alberta, Edmonton, Canada
| | - Daniel R Tudor
- Centre for Regenerative Medicine, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Christopher D Lucas
- Centre for Inflammation Research, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Sho Morioka
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.,Department of Medicine, Division of Nephrology and CIIR, University of Virginia, Charlottesville, VA, USA
| | - Justin S A Perry
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Julia Krapivkina
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience (IINS), UMR 5297, Bordeaux, France
| | - David Perrais
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience (IINS), UMR 5297, Bordeaux, France
| | - Linus J Schumacher
- Centre for Regenerative Medicine, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Robert E Campbell
- Department of Chemistry, University of Alberta, Edmonton, Canada.,Department of Chemistry, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Will Wood
- Centre for Inflammation Research, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Kodi S Ravichandran
- Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.,VIB/UGent Inflammation Research Centre, and Biomedical Molecular Biology, Ghent University, Belgium.,Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
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20
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Cellular diversity and gene expression profiles in the male and female brain of Aedes aegypti. BMC Genomics 2022; 23:119. [PMID: 35144549 PMCID: PMC8832747 DOI: 10.1186/s12864-022-08327-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/18/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Aedes aegypti is a medically-important mosquito vector that transmits arboviruses including yellow fever, dengue, chikungunya, and Zika viruses to humans. The mosquito exhibits typical sexually dimorphic behaviors such as courtship, mating, host seeking, bloodfeeding, and oviposition. All these behaviors are mainly regulated by the brain; however, little is known about the function and neuron composition of the mosquito brain. In this study, we generated an initial atlas of the adult male and female brain of Ae. aegypti using 10xGenomics based single-nucleus RNA sequencing. RESULTS We identified 35 brain cell clusters in male and female brains, and 15 of those clusters were assigned to known cell types. Identified cell types include glia (astrocytes), Kenyon cells, (ventral) projection neurons, monoaminergic neurons, medulla neurons, and proximal medulla neurons. In addition, the cell type compositions of male and female brains were compared to each other showing that they were quantitatively distinct, as 17 out of 35 cell clusters varied significantly in their cell type proportions. Overall, the transcriptomes from each cell cluster looked very similar between the male and female brain as only up to 25 genes were differentially expressed in these clusters. The sex determination factor Nix was highly expressed in neurons and glia of the male brain, whereas doublesex (dsx) was expressed in all neuron and glia cell clusters of the male and female brain. CONCLUSIONS An initial cell atlas of the brain of the mosquito Ae. aegypti has been generated showing that the cellular compositions of the male and female brains of this hematophagous insect differ significantly from each other. Although some of the rare brain cell types have not been detected in our single biological replicate, this study provides an important basis for the further development of a complete brain cell atlas as well as a better understanding of the neurobiology of the brains of male and female mosquitoes and their sexually dimorphic behaviors.
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21
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van Alphen B, Stewart S, Iwanaszko M, Xu F, Li K, Rozenfeld S, Ramakrishnan A, Itoh TQ, Sisobhan S, Qin Z, Lear BC, Allada R. Glial immune-related pathways mediate effects of closed head traumatic brain injury on behavior and lethality in Drosophila. PLoS Biol 2022; 20:e3001456. [PMID: 35081110 PMCID: PMC8791498 DOI: 10.1371/journal.pbio.3001456] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 10/22/2021] [Indexed: 02/07/2023] Open
Abstract
In traumatic brain injury (TBI), the initial injury phase is followed by a secondary phase that contributes to neurodegeneration, yet the mechanisms leading to neuropathology in vivo remain to be elucidated. To address this question, we developed a Drosophila head-specific model for TBI termed Drosophila Closed Head Injury (dCHI), where well-controlled, nonpenetrating strikes are delivered to the head of unanesthetized flies. This assay recapitulates many TBI phenotypes, including increased mortality, impaired motor control, fragmented sleep, and increased neuronal cell death. TBI results in significant changes in the transcriptome, including up-regulation of genes encoding antimicrobial peptides (AMPs). To test the in vivo functional role of these changes, we examined TBI-dependent behavior and lethality in mutants of the master immune regulator NF-κB, important for AMP induction, and found that while sleep and motor function effects were reduced, lethality effects were enhanced. Similarly, loss of most AMP classes also renders flies susceptible to lethal TBI effects. These studies validate a new Drosophila TBI model and identify immune pathways as in vivo mediators of TBI effects. Traumatic brain injury in Drosophila causes sleep and motor impairments, as well as a strong activation of the innate immune response that is crucial for survival. This study leverages Drosophila as a model organism to reveal neuroprotective and neurotoxic injury mechanisms more quickly using high throughout approaches.
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Affiliation(s)
- Bart van Alphen
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Samuel Stewart
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Marta Iwanaszko
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
- Department of Preventive Medicine—Biostatistics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Fangke Xu
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Keyin Li
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Sydney Rozenfeld
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Anujaianthi Ramakrishnan
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Taichi Q. Itoh
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Shiju Sisobhan
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Zuoheng Qin
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Bridget C. Lear
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
| | - Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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22
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Gregor KM, Becker SC, Hellhammer F, Baumgärtner W, Puff C. Immunohistochemical Characterization of the Nervous System of Culex pipiens (Diptera, Culicidae). BIOLOGY 2022; 11:57. [PMID: 35053056 PMCID: PMC8772823 DOI: 10.3390/biology11010057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 11/24/2022]
Abstract
Arthropod-borne diseases represent one of the greatest infection-related threats as a result of climate change and globalization. Repeatedly, arbovirus-infected mosquitoes show behavioral changes whose underlying mechanisms are still largely unknown, but might help to develop control strategies. However, in contrast to well-characterized insects such as fruit flies, little is known about neuroanatomy and neurotransmission in mosquitoes. To overcome this limitation, the study focuses on the immunohistochemical characterization of the nervous system of Culex pipiens biotype molestus in comparison to Drosophila melanogaster using 13 antibodies labeling nervous tissue, neurotransmitters or neurotransmitter-related enzymes. Antibodies directed against γ-aminobutyric acid, serotonin, tyrosine-hydroxylase and glutamine synthetase were suitable for investigations in Culex pipiens and Drosophila melanogaster, albeit species-specific spatial differences were observed. Likewise, similar staining results were achieved for neuronal glycoproteins, axons, dendrites and synaptic zones in both species. Interestingly, anti-phosphosynapsin and anti-gephyrin appear to represent novel markers for synapses and glial cells, respectively. In contrast, antibodies directed against acetylcholine, choline acetyltransferase, elav and repo failed to produce a signal in Culex pipiens comparable to that in Drosophila melanogaster. In summary, present results enable a detailed investigation of the nervous system of mosquitoes, facilitating further studies of behavioral mechanisms associated with arboviruses in the course of vector research.
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Affiliation(s)
- Katharina M. Gregor
- Department of Pathology, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany; (K.M.G.); (C.P.)
| | - Stefanie C. Becker
- Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany; (S.C.B.); (F.H.)
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany
| | - Fanny Hellhammer
- Institute for Parasitology, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany; (S.C.B.); (F.H.)
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany; (K.M.G.); (C.P.)
| | - Christina Puff
- Department of Pathology, University of Veterinary Medicine Hannover, Bünteweg 17, Lower Saxony, 30559 Hannover, Germany; (K.M.G.); (C.P.)
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23
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Klann M, Issa AR, Pinho S, Alonso CR. MicroRNA-Dependent Control of Sensory Neuron Function Regulates Posture Behavior in Drosophila. J Neurosci 2021; 41:8297-8308. [PMID: 34417328 PMCID: PMC8496190 DOI: 10.1523/jneurosci.0081-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/04/2021] [Accepted: 08/07/2021] [Indexed: 11/21/2022] Open
Abstract
All what we see, touch, hear, taste, or smell must first be detected by the sensory elements of our nervous system. Sensory neurons, therefore, represent a critical component in all neural circuits and their correct function is essential for the generation of behavior and adaptation to the environment. Here, we report that the evolutionarily-conserved microRNA (miRNA) miR-263b plays a key behavioral role in Drosophila melanogaster through effects on the function of larval sensory neurons. Several independent experiments (in 50:50 male:female populations) support this finding: first, miRNA expression analysis, via reporter expression and fluorescent-activated cell sorting (FACS)-quantitative PCR (qPCR) analysis, demonstrate miR-263b expression in larval sensory neurons. Second, behavioral tests in miR-263b null mutants show defects in self-righting, an innate and evolutionarily conserved posture-control behavior that allows larvae to rectify their position if turned upside-down. Third, competitive inhibition of miR-263b in sensory neurons using a miR-263b "sponge" leads to self-righting defects. Fourth, systematic analysis of sensory neurons in miR-263b mutants shows no detectable morphologic defects in their stereotypic pattern, while genetically-encoded calcium sensors expressed in the sensory domain reveal a reduction in neural activity in miR-263b mutants. Fifth, miR-263b null mutants show reduced "touch-response" behavior and a compromised response to sound, both characteristic of larval sensory deficits. Furthermore, bioinformatic miRNA target analysis, gene expression assays, and behavioral phenocopy experiments suggest that miR-263b might exert its effects, at least in part, through repression of the basic helix-loop-helix (bHLH) transcription factor Atonal Altogether, our study suggests a model in which miRNA-dependent control of transcription factor expression affects sensory function and behavior.SIGNIFICANCE STATEMENT Sensory neurons are key to neural circuit function, but how these neurons acquire their specific properties is not well understood. Here, we examine this problem, focusing on the roles played by microRNAs (miRNAs). Using Drosophila, we demonstrate that the evolutionarily-conserved miRNA miR-263b controls sensory neuron function allowing the animal to perform an adaptive, elaborate three-dimensional movement. Our work thus shows that microRNAs can control complex motor behaviors by modulating sensory neuron physiology, and suggests that similar miRNA-dependent mechanisms may operate in other species. The work contributes to advance the understanding of the molecular basis of behavior and the biological roles of microRNAs within the nervous system.
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Affiliation(s)
- Marleen Klann
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - A Raouf Issa
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Sofia Pinho
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Claudio R Alonso
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
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24
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Coates JA, Brooks E, Brittle AL, Armitage EL, Zeidler MP, Evans IR. Identification of functionally distinct macrophage subpopulations in Drosophila. eLife 2021; 10:e58686. [PMID: 33885361 PMCID: PMC8062135 DOI: 10.7554/elife.58686] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 03/30/2021] [Indexed: 12/24/2022] Open
Abstract
Vertebrate macrophages are a highly heterogeneous cell population, but while Drosophila blood is dominated by a macrophage-like lineage (plasmatocytes), until very recently these cells were considered to represent a homogeneous population. Here, we present our identification of enhancer elements labelling plasmatocyte subpopulations, which vary in abundance across development. These subpopulations exhibit functional differences compared to the overall population, including more potent injury responses and differential localisation and dynamics in pupae and adults. Our enhancer analysis identified candidate genes regulating plasmatocyte behaviour: pan-plasmatocyte expression of one such gene (Calnexin14D) improves wound responses, causing the overall population to resemble more closely the subpopulation marked by the Calnexin14D-associated enhancer. Finally, we show that exposure to increased levels of apoptotic cell death modulates subpopulation cell numbers. Taken together this demonstrates macrophage heterogeneity in Drosophila, identifies mechanisms involved in subpopulation specification and function and facilitates the use of Drosophila to study macrophage heterogeneity in vivo.
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Affiliation(s)
- Jonathon Alexis Coates
- Department of Biomedical Science and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
| | - Elliot Brooks
- Department of Infection, Immunity and Cardiovascular Disease and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
| | - Amy Louise Brittle
- Department of Infection, Immunity and Cardiovascular Disease and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
| | - Emma Louise Armitage
- Department of Infection, Immunity and Cardiovascular Disease and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
| | - Martin Peter Zeidler
- Department of Biomedical Science and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
| | - Iwan Robert Evans
- Department of Infection, Immunity and Cardiovascular Disease and the Bateson Centre, University of SheffieldSheffieldUnited Kingdom
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25
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Smolič T, Tavčar P, Horvat A, Černe U, Halužan Vasle A, Tratnjek L, Kreft ME, Scholz N, Matis M, Petan T, Zorec R, Vardjan N. Astrocytes in stress accumulate lipid droplets. Glia 2021; 69:1540-1562. [PMID: 33609060 PMCID: PMC8248329 DOI: 10.1002/glia.23978] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 01/14/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023]
Abstract
When the brain is in a pathological state, the content of lipid droplets (LDs), the lipid storage organelles, is increased, particularly in glial cells, but rarely in neurons. The biology and mechanisms leading to LD accumulation in astrocytes, glial cells with key homeostatic functions, are poorly understood. We imaged fluorescently labeled LDs by microscopy in isolated and brain tissue rat astrocytes and in glia-like cells in Drosophila brain to determine the (sub)cellular localization, mobility, and content of LDs under various stress conditions characteristic for brain pathologies. LDs exhibited confined mobility proximal to mitochondria and endoplasmic reticulum that was attenuated by metabolic stress and by increased intracellular Ca2+ , likely to enhance the LD-organelle interaction imaged by electron microscopy. When de novo biogenesis of LDs was attenuated by inhibition of DGAT1 and DGAT2 enzymes, the astrocyte cell number was reduced by ~40%, suggesting that in astrocytes LD turnover is important for cell survival and/or proliferative cycle. Exposure to noradrenaline, a brain stress response system neuromodulator, and metabolic and hypoxic stress strongly facilitated LD accumulation in astrocytes. The observed response of stressed astrocytes may be viewed as a support for energy provision, but also to be neuroprotective against the stress-induced lipotoxicity.
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Affiliation(s)
- Tina Smolič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Petra Tavčar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Anemari Horvat
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Urška Černe
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Ana Halužan Vasle
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Larisa Tratnjek
- Faculty of Medicine, Institute of Cell Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Mateja Erdani Kreft
- Faculty of Medicine, Institute of Cell Biology, University of Ljubljana, Ljubljana, Slovenia
| | - Nicole Scholz
- Division of General Biochemistry, Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, Leipzig, Germany
| | - Maja Matis
- Medical Faculty, Institute of Cell Biology, University of Münster, Münster, Germany.,Cells in Motion Interfaculty Centre, University of Münster, Münster, Germany
| | - Toni Petan
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
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26
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Gross-Thebing S, Truszkowski L, Tenbrinck D, Sánchez-Iranzo H, Camelo C, Westerich KJ, Singh A, Maier P, Prengel J, Lange P, Hüwel J, Gaede F, Sasse R, Vos BE, Betz T, Matis M, Prevedel R, Luschnig S, Diz-Muñoz A, Burger M, Raz E. Using migrating cells as probes to illuminate features in live embryonic tissues. SCIENCE ADVANCES 2020; 6:eabc5546. [PMID: 33277250 PMCID: PMC7821905 DOI: 10.1126/sciadv.abc5546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 10/21/2020] [Indexed: 05/03/2023]
Abstract
The biophysical and biochemical properties of live tissues are important in the context of development and disease. Methods for evaluating these properties typically involve destroying the tissue or require specialized technology and complicated analyses. Here, we present a novel, noninvasive methodology for determining the spatial distribution of tissue features within embryos, making use of nondirectionally migrating cells and software we termed "Landscape," which performs automatized high-throughput three-dimensional image registration. Using the live migrating cells as bioprobes, we identified structures within the zebrafish embryo that affect the distribution of the cells and studied one such structure constituting a physical barrier, which, in turn, influences amoeboid cell polarity. Overall, this work provides a unique approach for detecting tissue properties without interfering with animal's development. In addition, Landscape allows for integrating data from multiple samples, providing detailed and reliable quantitative evaluation of variable biological phenotypes in different organisms.
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Affiliation(s)
- Sargon Gross-Thebing
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Lukasz Truszkowski
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Daniel Tenbrinck
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany.
| | - Héctor Sánchez-Iranzo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Carolina Camelo
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Institute of Animal Physiology, University of Muenster, Schlossplatz 8, 48143 Muenster, Germany
| | - Kim J Westerich
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Amrita Singh
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Paul Maier
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Jonas Prengel
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Pia Lange
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Jan Hüwel
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Fjedor Gaede
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Ramona Sasse
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
- Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Bart E Vos
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Mechanics of Cellular Systems Group, Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Timo Betz
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Mechanics of Cellular Systems Group, Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
| | - Maja Matis
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
| | - Robert Prevedel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Stefan Luschnig
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
- Institute of Animal Physiology, University of Muenster, Schlossplatz 8, 48143 Muenster, Germany
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Martin Burger
- Applied Mathematics Muenster, University of Muenster, Einsteinstr. 62, 48149 Muenster, Germany
| | - Erez Raz
- Institute of Cell Biology, ZMBE, Von-Esmarch-Str. 56, 48149 Muenster, Germany.
- Cells in Motion (CiM) Interfaculty Center, 48149 Muenster, Germany
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27
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Tsao CK, Huang YF, Sun YH. Early lineage segregation of the retinal basal glia in the Drosophila eye disc. Sci Rep 2020; 10:18522. [PMID: 33116242 PMCID: PMC7595039 DOI: 10.1038/s41598-020-75581-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/16/2020] [Indexed: 11/09/2022] Open
Abstract
The retinal basal glia (RBG) is a group of glia that migrates from the optic stalk into the third instar larval eye disc while the photoreceptor cells (PR) are differentiating. The RBGs are grouped into three major classes based on molecular and morphological characteristics: surface glia (SG), wrapping glia (WG) and carpet glia (CG). The SGs migrate and divide. The WGs are postmitotic and wraps PR axons. The CGs have giant nucleus and extensive membrane extension that each covers half of the eye disc. In this study, we used lineage tracing methods to determine the lineage relationships among these glia subtypes and the temporal profile of the lineage decisions for RBG development. We found that the CG lineage segregated from the other RBG very early in the embryonic stage. It has been proposed that the SGs migrate under the CG membrane, which prevented SGs from contacting with the PR axons lying above the CG membrane. Upon passing the front of the CG membrane, which is slightly behind the morphogenetic furrow that marks the front of PR differentiation, the migrating SG contact the nascent PR axon, which in turn release FGF to induce SGs' differentiation into WG. Interestingly, we found that SGs are equally distributed apical and basal to the CG membrane, so that the apical SGs are not prevented from contacting PR axons by CG membrane. Clonal analysis reveals that the apical and basal RBG are derived from distinct lineages determined before they enter the eye disc. Moreover, the basal SG lack the competence to respond to FGFR signaling, preventing its differentiation into WG. Our findings suggest that this novel glia-to-glia differentiation is both dependent on early lineage decision and on a yet unidentified regulatory mechanism, which can provide spatiotemporal coordination of WG differentiation with the progressive differentiation of photoreceptor neurons.
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Affiliation(s)
- Chia-Kang Tsao
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Yu Fen Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,, 64 Marvin Lane, Piscataway, NJ, 08854, USA
| | - Y Henry Sun
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC. .,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.
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28
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Ogienko AA, Andreyeva EN, Omelina ES, Oshchepkova AL, Pindyurin AV. Molecular and cytological analysis of widely-used Gal4 driver lines for Drosophila neurobiology. BMC Genet 2020; 21:96. [PMID: 33092520 PMCID: PMC7583314 DOI: 10.1186/s12863-020-00895-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 07/28/2020] [Indexed: 11/13/2022] Open
Abstract
Background The Drosophila central nervous system (CNS) is a convenient model system for the study of the molecular mechanisms of conserved neurobiological processes. The manipulation of gene activity in specific cell types and subtypes of the Drosophila CNS is frequently achieved by employing the binary Gal4/UAS system. However, many Gal4 driver lines available from the Bloomington Drosophila Stock Center (BDSC) and commonly used in Drosophila neurobiology are still not well characterized. Among these are three lines with Gal4 driven by the elav promoter (BDSC #8760, #8765, and #458), one line with Gal4 driven by the repo promoter (BDSC #7415), and the 69B-Gal4 line (BDSC #1774). For most of these lines, the exact insertion sites of the transgenes and the detailed expression patterns of Gal4 are not known. This study is aimed at filling these gaps. Results We have mapped the genomic location of the Gal4-bearing P-elements carried by the BDSC lines #8760, #8765, #458, #7415, and #1774. In addition, for each of these lines, we have analyzed the Gal4-driven GFP expression pattern in the third instar larval CNS and eye-antennal imaginal discs. Localizations of the endogenous Elav and Repo proteins were used as markers of neuronal and glial cells, respectively. Conclusions We provide a mini-atlas of the spatial activity of Gal4 drivers that are widely used for the expression of UAS–target genes in the Drosophila CNS. The data will be helpful for planning experiments with these drivers and for the correct interpretation of the results.
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Affiliation(s)
- Anna A Ogienko
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, 630090, Russia
| | - Evgeniya N Andreyeva
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, 630090, Russia
| | - Evgeniya S Omelina
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, 630090, Russia
| | - Anastasiya L Oshchepkova
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, 630090, Russia.,Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of RAS, Novosibirsk, 630090, Russia
| | - Alexey V Pindyurin
- Institute of Molecular and Cellular Biology, Siberian Branch of RAS, Novosibirsk, 630090, Russia. .,Novosibirsk State University, Novosibirsk, 630090, Russia.
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29
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Das P, Bhadra MP. Histone deacetylase (Rpd3) regulates Drosophila early brain development via regulation of Tailless. Open Biol 2020; 10:200029. [PMID: 32873153 PMCID: PMC7536075 DOI: 10.1098/rsob.200029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/29/2020] [Indexed: 11/29/2022] Open
Abstract
Tailless is a committed transcriptional repressor and principal regulator of the brain and eye development in Drosophila. Rpd3, the histone deacetylase, is an established repressor that interacts with co-repressors like Sin3a, Prospero, Brakeless and Atrophin. This study aims at deciphering the role of Rpd3 in embryonic segmentation and larval brain development in Drosophila. It delineates the mechanism of Tailless regulation by Rpd3, along with its interacting partners. There was a significant reduction in Tailless in Rpd3 heteroallelic mutant embryos, substantiating that Rpd3 is indispensable for the normal Tailless expression. The expression of the primary readout, Tailless was correlative to the expression of the neural cell adhesion molecule homologue, Fascilin2 (Fas2). Rpd3 also aids in the proper development of the mushroom body. Both Tailless and Fas2 expression are reported to be antagonistic to the epidermal growth factor receptor (EGFR) expression. The decrease in Tailless and Fas2 expression highlights that EGFR is upregulated in the larval mutants, hindering brain development. This study outlines the axis comprising Rpd3, dEGFR, Tailless and Fas2, which interact to fine-tune the early segmentation and larval brain development. Therefore, Rpd3 along with Tailless has immense significance in early embryogenesis and development of the larval brain.
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Affiliation(s)
- Paromita Das
- Applied Biology Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR) Training and Development Complex, CSIR Campus, CSIR Road, Taramani, Chennai 600 113, India
| | - Manika Pal Bhadra
- Applied Biology Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR) Training and Development Complex, CSIR Campus, CSIR Road, Taramani, Chennai 600 113, India
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30
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Armitage EL, Roddie HG, Evans IR. Overexposure to apoptosis via disrupted glial specification perturbs Drosophila macrophage function and reveals roles of the CNS during injury. Cell Death Dis 2020; 11:627. [PMID: 32796812 PMCID: PMC7428013 DOI: 10.1038/s41419-020-02875-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 12/15/2022]
Abstract
Apoptotic cell clearance by phagocytes is a fundamental process during development, homeostasis and the resolution of inflammation. However, the demands placed on phagocytic cells such as macrophages by this process, and the limitations these interactions impose on subsequent cellular behaviours are not yet clear. Here, we seek to understand how apoptotic cells affect macrophage function in the context of a genetically tractable Drosophila model in which macrophages encounter excessive amounts of apoptotic cells. Loss of the glial-specific transcription factor Repo prevents glia from contributing to apoptotic cell clearance in the developing embryo. We show that this leads to the challenge of macrophages with large numbers of apoptotic cells in vivo. As a consequence, macrophages become highly vacuolated with cleared apoptotic cells, and their developmental dispersal and migration is perturbed. We also show that the requirement to deal with excess apoptosis caused by a loss of repo function leads to impaired inflammatory responses to injury. However, in contrast to migratory phenotypes, defects in wound responses cannot be rescued by preventing apoptosis from occurring within a repo mutant background. In investigating the underlying cause of these impaired inflammatory responses, we demonstrate that wound-induced calcium waves propagate into surrounding tissues, including neurons and glia of the ventral nerve cord, which exhibit striking calcium waves on wounding, revealing a previously unanticipated contribution of these cells during responses to injury. Taken together, these results demonstrate important insights into macrophage biology and how repo mutants can be used to study macrophage-apoptotic cell interactions in the fly embryo. Furthermore, this work shows how these multipurpose cells can be 'overtasked' to the detriment of their other functions, alongside providing new insights into which cells govern macrophage responses to injury in vivo.
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Affiliation(s)
- Emma Louise Armitage
- Department of Infection, Immunity and Cardiovascular Disease and The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Hannah Grace Roddie
- Department of Infection, Immunity and Cardiovascular Disease and The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Iwan Robert Evans
- Department of Infection, Immunity and Cardiovascular Disease and The Bateson Centre, University of Sheffield, Sheffield, UK.
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31
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Kim T, Song B, Lee IS. Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:E4859. [PMID: 32660023 PMCID: PMC7402321 DOI: 10.3390/ijms21144859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.
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Affiliation(s)
| | | | - Im-Soon Lee
- Department of Biological Sciences, Center for CHANS, Konkuk University, Seoul 05029, Korea; (T.K.); (B.S.)
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32
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Allen AM, Neville MC, Birtles S, Croset V, Treiber CD, Waddell S, Goodwin SF. A single-cell transcriptomic atlas of the adult Drosophila ventral nerve cord. eLife 2020; 9:e54074. [PMID: 32314735 PMCID: PMC7173974 DOI: 10.7554/elife.54074] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 04/03/2020] [Indexed: 02/07/2023] Open
Abstract
The Drosophila ventral nerve cord (VNC) receives and processes descending signals from the brain to produce a variety of coordinated locomotor outputs. It also integrates sensory information from the periphery and sends ascending signals to the brain. We used single-cell transcriptomics to generate an unbiased classification of cellular diversity in the VNC of five-day old adult flies. We produced an atlas of 26,000 high-quality cells, representing more than 100 transcriptionally distinct cell types. The predominant gene signatures defining neuronal cell types reflect shared developmental histories based on the neuroblast from which cells were derived, as well as their birth order. The relative position of cells along the anterior-posterior axis could also be assigned using adult Hox gene expression. This single-cell transcriptional atlas of the adult fly VNC will be a valuable resource for future studies of neurodevelopment and behavior.
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Affiliation(s)
- Aaron M Allen
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Megan C Neville
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Sebastian Birtles
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Vincent Croset
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | | | - Scott Waddell
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
| | - Stephen F Goodwin
- Centre for Neural Circuits and Behaviour, University of OxfordOxfordUnited Kingdom
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33
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Bittern J, Pogodalla N, Ohm H, Brüser L, Kottmeier R, Schirmeier S, Klämbt C. Neuron-glia interaction in the Drosophila nervous system. Dev Neurobiol 2020; 81:438-452. [PMID: 32096904 DOI: 10.1002/dneu.22737] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/11/2020] [Accepted: 02/24/2020] [Indexed: 12/14/2022]
Abstract
Animals are able to move and react in manifold ways to external stimuli. Thus, environmental stimuli need to be detected, information must be processed, and, finally, an output decision must be transmitted to the musculature to get the animal moving. All these processes depend on the nervous system which comprises an intricate neuronal network and many glial cells. Glial cells have an equally important contribution in nervous system function as their neuronal counterpart. Manifold roles are attributed to glia ranging from controlling neuronal cell number and axonal pathfinding to regulation of synapse formation, function, and plasticity. Glial cells metabolically support neurons and contribute to the blood-brain barrier. All of the aforementioned aspects require extensive cell-cell interactions between neurons and glial cells. Not surprisingly, many of these processes are found in all phyla executed by evolutionarily conserved molecules. Here, we review the recent advance in understanding neuron-glia interaction in Drosophila melanogaster to suggest that work in simple model organisms will shed light on the function of mammalian glial cells, too.
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Affiliation(s)
- Jonas Bittern
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Nicole Pogodalla
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Henrike Ohm
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Lena Brüser
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Rita Kottmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
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34
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Traniello IM, Bukhari SA, Kevill J, Ahmed AC, Hamilton AR, Naeger NL, Schroeder DC, Robinson GE. Meta-analysis of honey bee neurogenomic response links Deformed wing virus type A to precocious behavioral maturation. Sci Rep 2020; 10:3101. [PMID: 32080242 PMCID: PMC7033282 DOI: 10.1038/s41598-020-59808-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 02/04/2020] [Indexed: 02/06/2023] Open
Abstract
Crop pollination by the western honey bee Apis mellifera is vital to agriculture but threatened by alarmingly high levels of colony mortality, especially in Europe and North America. Colony loss is due, in part, to the high viral loads of Deformed wing virus (DWV), transmitted by the ectoparasitic mite Varroa destructor, especially throughout the overwintering period of a honey bee colony. Covert DWV infection is commonplace and has been causally linked to precocious foraging, which itself has been linked to colony loss. Taking advantage of four brain transcriptome studies that unexpectedly revealed evidence of covert DWV-A infection, we set out to explore whether this effect is due to DWV-A mimicking naturally occurring changes in brain gene expression that are associated with behavioral maturation. Consistent with this hypothesis, we found that brain gene expression profiles of DWV-A infected bees resembled those of foragers, even in individuals that were much younger than typical foragers. In addition, brain transcriptional regulatory network analysis revealed a positive association between DWV-A infection and transcription factors previously associated with honey bee foraging behavior. Surprisingly, single-cell RNA-Sequencing implicated glia, not neurons, in this effect; there are relatively few glial cells in the insect brain and they are rarely associated with behavioral plasticity. Covert DWV-A infection also has been linked to impaired learning, which together with precocious foraging can lead to increased occurrence of infected bees from one colony mistakenly entering another colony, especially under crowded modern apiary conditions. These findings provide new insights into the mechanisms by which DWV-A affects honey bee health and colony survival.
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Affiliation(s)
- Ian M Traniello
- Neuroscience Program, University of Illinois at Urbana-Champaign, (UIUC), Urbana, IL, USA.
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA.
| | - Syed Abbas Bukhari
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
- Department of Animal Biology, UIUC, Urbana, USA
| | - Jessica Kevill
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
| | - Amy Cash Ahmed
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
| | - Adam R Hamilton
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
| | - Nicholas L Naeger
- Department of Entomology, Washington State University, Pullman, WA, USA
| | - Declan C Schroeder
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
- School of Biological Sciences, University of Reading, Reading, UK
| | - Gene E Robinson
- Neuroscience Program, University of Illinois at Urbana-Champaign, (UIUC), Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
- Department of Entomology, UIUC, Urbana, USA
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35
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Delventhal R, O'Connor RM, Pantalia MM, Ulgherait M, Kim HX, Basturk MK, Canman JC, Shirasu-Hiza M. Dissection of central clock function in Drosophila through cell-specific CRISPR-mediated clock gene disruption. eLife 2019; 8:48308. [PMID: 31613218 PMCID: PMC6794090 DOI: 10.7554/elife.48308] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 09/24/2019] [Indexed: 12/22/2022] Open
Abstract
In Drosophila, ~150 neurons expressing molecular clock proteins regulate circadian behavior. Sixteen of these neurons secrete the neuropeptide Pdf and have been called ‘master pacemakers’ because they are essential for circadian rhythms. A subset of Pdf+ neurons (the morning oscillator) regulates morning activity and communicates with other non-Pdf+ neurons, including a subset called the evening oscillator. It has been assumed that the molecular clock in Pdf+ neurons is required for these functions. To test this, we developed and validated Gal4-UAS based CRISPR tools for cell-specific disruption of key molecular clock components, period and timeless. While loss of the molecular clock in both the morning and evening oscillators eliminates circadian locomotor activity, the molecular clock in either oscillator alone is sufficient to rescue circadian locomotor activity in the absence of the other. This suggests that clock neurons do not act in a hierarchy but as a distributed network to regulate circadian activity.
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Affiliation(s)
- Rebecca Delventhal
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Reed M O'Connor
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Meghan M Pantalia
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Matthew Ulgherait
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Han X Kim
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Maylis K Basturk
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
| | - Julie C Canman
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, United States
| | - Mimi Shirasu-Hiza
- Department of Genetics and Development, Columbia University Medical Center, New York, United States
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36
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Transcriptional Regulation of the Glutamate/GABA/Glutamine Cycle in Adult Glia Controls Motor Activity and Seizures in Drosophila. J Neurosci 2019; 39:5269-5283. [PMID: 31064860 PMCID: PMC6607755 DOI: 10.1523/jneurosci.1833-18.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 01/23/2023] Open
Abstract
The fruitfly Drosophila melanogaster has been extensively used as a genetic model for the maintenance of nervous system's functions. Glial cells are of utmost importance in regulating the neuronal functions in the adult organism and in the progression of neurological pathologies. Through a microRNA-based screen in adult Drosophila glia, we uncovered the essential role of a major glia developmental determinant, repo, in the adult fly. Here, we report that Repo expression is continuously required in adult glia to transcriptionally regulate the highly conserved function of neurotransmitter recycling in both males and females. Transient loss of Repo dramatically shortens fly lifespan, triggers motor deficits, and increases the sensibility to seizures, partly due to the impairment of the glutamate/GABA/glutamine cycle. Our findings highlight the pivotal role of transcriptional regulation of genes involved in the glutamate/GABA/glutamine cycle in glia to control neurotransmitter levels in neurons and their behavioral output. The mechanism identified here in Drosophila exemplifies how adult functions can be modulated at the transcriptional level and suggest an active synchronized regulation of genes involved in the same pathway. The process of neurotransmitter recycling is of essential importance in human epileptic and psychiatric disorders and our findings may thus have important consequences for the understanding of the role that transcriptional regulation of neurotransmitter recycling in astrocytes has in human disease. SIGNIFICANCE STATEMENT Glial cells are an essential support to neurons in adult life and have been involved in a number of neurological disorders. What controls the maintenance and modulation of glial functions in adult life is not fully characterized. Through a miR overexpression screen in adult glia in Drosophila, we identify an essential role in adult glia of repo, which directs glial differentiation during embryonic development. Repo levels modulate, via transcriptional regulation, the ability of glial cells to support neurons in the glutamate/GABA/glutamine cycle. This leads to significant abnormalities in motor behavior as assessed through a novel automated paradigm. Our work points to the importance of transcriptional regulation in adult glia for neurotransmitter recycling, a key process in several human neurological disorders.
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37
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Matsuno M, Horiuchi J, Ofusa K, Masuda T, Saitoe M. Inhibiting Glutamate Activity during Consolidation Suppresses Age-Related Long-Term Memory Impairment in Drosophila. iScience 2019; 15:55-65. [PMID: 31030182 PMCID: PMC6487374 DOI: 10.1016/j.isci.2019.04.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/24/2018] [Accepted: 04/08/2019] [Indexed: 01/17/2023] Open
Abstract
In Drosophila, long-term memory (LTM) formation requires increases in glial gene expression. Klingon (Klg), a cell adhesion molecule expressed in both neurons and glia, induces expression of the glial transcription factor, Repo. However, glial signaling downstream of Repo has been unclear. Here we demonstrate that Repo increases expression of the glutamate transporter, EAAT1, and EAAT1 is required during consolidation of LTM. The expressions of Klg, Repo, and EAAT1 decrease upon aging, suggesting that age-related impairments in LTM are caused by dysfunction of the Klg-Repo-EAAT1 pathway. Supporting this idea, overexpression of Repo or EAAT1 rescues age-associated impairments in LTM. Pharmacological inhibition of glutamate activity during consolidation improves LTM in klg mutants and aged flies. Altogether, our results indicate that LTM formation requires glial-dependent inhibition of glutamate signaling during memory consolidation, and aging disrupts this process by inhibiting the Klg-Repo-EAAT1 pathway.
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Affiliation(s)
- Motomi Matsuno
- Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8502, Japan
| | - Junjiro Horiuchi
- Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8502, Japan
| | - Kyoko Ofusa
- Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8502, Japan
| | - Tomoko Masuda
- Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8502, Japan
| | - Minoru Saitoe
- Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-8502, Japan.
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38
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Yeh PA, Liu YH, Chu WC, Liu JY, Sun YH. Glial expression of disease-associated poly-glutamine proteins impairs the blood-brain barrier in Drosophila. Hum Mol Genet 2019; 27:2546-2562. [PMID: 29726932 DOI: 10.1093/hmg/ddy160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/25/2018] [Indexed: 12/25/2022] Open
Abstract
Expansion of poly-glutamine (polyQ) stretches in several proteins has been linked to neurodegenerative diseases. The effects of polyQ-expanded proteins on neurons have been extensively studied, but their effects on glia remain unclear. We found that expression of distinct polyQ proteins exclusively in all glia or specifically in the blood-brain barrier (BBB) and blood-retina barrier (BRB) glia caused cell-autonomous impairment of BBB/BRB integrity, suggesting that BBB/BRB glia are most vulnerable to polyQ-expanded proteins. Furthermore, we also found that BBB/BRB leakage in Drosophila is reflected in reversed waveform polarity on the basis of electroretinography (ERG), making ERG a sensitive method to detect BBB/BRB leakage. The polyQ-expanded protein Atxn3-84Q forms aggregates, induces BBB/BRB leakage, restricts Drosophila lifespan and reduces the level of Repo (a pan-glial transcriptional factor required for glial differentiation). Expression of Repo in BBB/BRB glia can rescue BBB/BRB leakage, suggesting that the reduced expression of Repo is important for the effect of polyQ on BBB/BRB impairment. Coexpression of the chaperon HSP40 and HSP70 effectively rescues the effects of Atxn3-84Q, indicating that polyQ protein aggregation in glia is deleterious. Intriguingly, coexpression of wild-type Atxn3-27Q can also rescue BBB/BRB impairment, suggesting that normal polyQ protein may have a protective function.
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Affiliation(s)
- Po-An Yeh
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.,Department of Bioscience Technology, Chung Yuan Christian University, Chung Li, Taiwan
| | - Ya-Hsin Liu
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Chen Chu
- Laboratory for Morphogenetic Signaling, RIKEN Center for Biosystems Dynamics Research (BDR), Chuou-ku, Kobe, Japan
| | - Jia-Yu Liu
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
| | - Y Henry Sun
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
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39
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Xiao C, Qiu S. Downregulation of EDTP in glial cells suppresses polyglutamine protein aggregates and extends lifespan in Drosophila melanogaster. Neurosci Lett 2019; 694:168-175. [PMID: 30528881 DOI: 10.1016/j.neulet.2018.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/13/2018] [Accepted: 12/04/2018] [Indexed: 01/26/2023]
Abstract
Drosophila egg-derived tyrosine phosphatase (EDTP) is a lipid phosphatase essential for oogenesis and muscle function. Loss-of-EDTP is lethal at early developmental stages. Hypomorphic mutation of EDTP causes impaired muscle performance and shortened lifespan. Mutation of MTMR14, a mammalian homolog to EDTP, is associated with muscle fatigue in rodents and a rare genetic disease called centronuclear myopathy in humans. Despite the deleterious consequences, downregulation of MTMR14 promotes autophagy. It is proposed that selective downregulation of EDTP/MTMR14 in non-muscle tissues improves the survivorship to cellular wastes and extends lifespan. Here, we show that downregulation of EDTP in glial cells suppressed the expression of polyglutamine (polyQ) protein aggregates and improved survival. Downregulation of EDTP in glial cells also extended lifespan. These effects were not observed by targeting pan-neurons in the nervous system, suggesting the significance of tissue-specificity. Additionally, flies carrying an EDTP mutant had increased survival to prolonged anoxia and altered dynamics of polyQ expression. These data supported the proposal that selective downregulation of EDTP in non-muscle tissues improved survivorship to cellular protein aggregates and extended lifespan. Our findings suggest that EDTP/MTMR14 could be a novel molecular target for the treatment of neurodegeneration.
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Affiliation(s)
- Chengfeng Xiao
- Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
| | - Shuang Qiu
- Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing, 210094, Jiangsu, PR China
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40
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Abstract
As the nervous system evolved from the diffused to centralised form, the neurones were joined by the appearance of the supportive cells, the neuroglia. Arguably, these non-neuronal cells evolve into a more diversified cell family than the neurones are. The first ancestral neuroglia appeared in flatworms being mesenchymal in origin. In the nematode C. elegans proto-astrocytes/supportive glia of ectodermal origin emerged, albeit the ensheathment of axons by glial cells occurred later in prawns. The multilayered myelin occurred by convergent evolution of oligodendrocytes and Schwann cells in vertebrates above the jawless fishes. Nutritive partitioning of the brain from the rest of the body appeared in insects when the hemolymph-brain barrier, a predecessor of the blood-brain barrier was formed. The defensive cellular mechanism required specialisation of bona fide immune cells, microglia, a process that occurred in the nervous system of leeches, bivalves, snails, insects and above. In ascending phylogeny, new type of glial cells, such as scaffolding radial glia, appeared and as the bran sizes enlarged, the glia to neurone ratio increased. Humans possess some unique glial cells not seen in other animals.
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41
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The Repo Homeodomain Transcription Factor Suppresses Hematopoiesis in Drosophila and Preserves the Glial Fate. J Neurosci 2018; 39:238-255. [PMID: 30504274 DOI: 10.1523/jneurosci.1059-18.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 01/12/2023] Open
Abstract
Despite their different origins, Drosophila glia and hemocytes are related cell populations that provide an immune function. Drosophila hemocytes patrol the body cavity and act as macrophages outside the nervous system, whereas glia originate from the neuroepithelium and provide the scavenger population of the nervous system. Drosophila glia are hence the functional orthologs of vertebrate microglia, even though the latter are cells of immune origin that subsequently move into the brain during development. Interestingly, the Drosophila immune cells within (glia) and outside (hemocytes) the nervous system require the same transcription factor glial cells deficient/glial cells missing (Glide/Gcm) for their development. This raises the issue of how do glia specifically differentiate in the nervous system, and hemocytes in the procephalic mesoderm. The Repo homeodomain transcription factor and panglial direct target of Glide/Gcm is known to ensure glial terminal differentiation. Here we show that Repo also takes center stage in the process that discriminates between glia and hemocytes. First, Repo expression is repressed in the hemocyte anlagen by mesoderm-specific factors. Second, Repo ectopic activation in the procephalic mesoderm is sufficient to repress the expression of hemocyte-specific genes. Third, the lack of Repo triggers the expression of hemocyte markers in glia. Thus, a complex network of tissue-specific cues biases the potential of Glide/Gcm. These data allow us to revise the concept of fate determinants and help us to understand the bases of cell specification. Both sexes were analyzed.SIGNIFICANCE STATEMENT Distinct cell types often require the same pioneer transcription factor, raising the issue of how one factor triggers different fates. In Drosophila, glia and hemocytes provide a scavenger activity within and outside the nervous system, respectively. While they both require the glial cells deficient/glial cells missing (Glide/Gcm) transcription factor, glia originate from the ectoderm, and hemocytes from the mesoderm. Here we show that tissue-specific factors inhibit the gliogenic potential of Glide/Gcm in the mesoderm by repressing the expression of the homeodomain protein Repo, a major glial-specific target of Glide/Gcm. Repo expression in turn inhibits the expression of hemocyte-specific genes in the nervous system. These cell-specific networks secure the establishment of the glial fate only in the nervous system and allow cell diversification.
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Yildirim K, Petri J, Kottmeier R, Klämbt C. Drosophila glia: Few cell types and many conserved functions. Glia 2018; 67:5-26. [DOI: 10.1002/glia.23459] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/25/2018] [Accepted: 05/04/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Kerem Yildirim
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Johanna Petri
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Rita Kottmeier
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Christian Klämbt
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
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43
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Bason M, Meister-Broekema M, Alberts N, Dijkers P, Bergink S, Sibon OCM, Kampinga HH. Astrocytic expression of the chaperone DNAJB6 results in non-cell autonomous protection in Huntington's disease. Neurobiol Dis 2018; 124:108-117. [PMID: 30408590 DOI: 10.1016/j.nbd.2018.10.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 10/02/2018] [Accepted: 10/28/2018] [Indexed: 01/02/2023] Open
Abstract
Several neurodegenerative diseases like Huntington's, a polyglutamine (PolyQ) disease, are initiated by protein aggregation in neurons. Furthermore, these diseases are also associated with a multitude of responses in non-neuronal cells in the brain, in particular glial cells, like astrocytes. These non-neuronal responses have repeatedly been suggested to play a disease-modulating role, but how these may be exploited to delay the progression of neurodegeneration has remained unclear. Interestingly, one of the molecular changes that astrocytes undergo includes the upregulation of certain Heat Shock Proteins (HSPs) that are classically considered to maintain protein homeostasis, thus resulting in cell autonomous protection. Previously, we discovered DNAJB6, a member of the human DNAJ family, as potent cell autonomous suppressor of PolyQ aggregation and related neurodegeneration. Using cell type specific expression systems in D. melanogaster, we show that exclusive expression of DNAJB6 in astrocytes (that do not express PolyQ protein) can delay neurodegeneration and expands lifespan when the PolyQ protein is exclusively expressed in neurons (that do not co-express DNAJB6 themselves). This provides direct evidence for a non-cell autonomous protective role of astrocytes in PolyQ diseases.
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Affiliation(s)
- Matteo Bason
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Melanie Meister-Broekema
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Niels Alberts
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Pascale Dijkers
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Steven Bergink
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Ody C M Sibon
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands
| | - Harm H Kampinga
- Department of Cell Biology, UMCG and University of Groningen, Ant. Deusinglaan 1, Groningen 9713AV, the Netherlands.
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44
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Widmer YF, Fritsch C, Jungo MM, Almeida S, Egger B, Sprecher SG. Multiple neurons encode CrebB dependent appetitive long-term memory in the mushroom body circuit. eLife 2018; 7:39196. [PMID: 30346271 PMCID: PMC6234028 DOI: 10.7554/elife.39196] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 10/19/2018] [Indexed: 11/28/2022] Open
Abstract
Lasting changes in gene expression are critical for the formation of long-term memories (LTMs), depending on the conserved CrebB transcriptional activator. While requirement of distinct neurons in defined circuits for different learning and memory phases have been studied in detail, only little is known regarding the gene regulatory changes that occur within these neurons. We here use the fruit fly as powerful model system to study the neural circuits of CrebB-dependent appetitive olfactory LTM. We edited the CrebB locus to create a GFP-tagged CrebB conditional knockout allele, allowing us to generate mutant, post-mitotic neurons with high spatial and temporal precision. Investigating CrebB-dependence within the mushroom body (MB) circuit we show that MB α/β and α’/β’ neurons as well as MBON α3, but not in dopaminergic neurons require CrebB for LTM. Thus, transcriptional memory traces occur in different neurons within the same neural circuit. Our brains can store different types of memories. You may have forgotten what you had for lunch yesterday, but still be able to remember a song from your childhood. Short-term memories and long-term memories form via different mechanisms. To establish long-term memories, the brain must produce new proteins, many of which are common to all members of the animal kingdom. By studying these proteins in organisms such as fruit flies, we can learn more about their role in our own memories. Widmer et al. used this approach to explore how a protein called CrebB helps fruit flies to remember for several days that a specific odor is associated with a sugary reward. These odor-reward memories form in a brain region called the mushroom body, which has three lobes. Input neurons supply information about the odor and the reward to the region, while output neurons pass on information to other parts of the fly brain. CrebB regulates the production of new proteins required to form these long-term odor-reward memories: but where exactly does CrebB act during this process? Using a gene editing technique called CRISPR, Widmer et al. generated mutant flies. In these insects CrebB could be easily deactivated ‘at will’ in either the entire brain, the whole mushroom body, each of the three lobes or in specific output neurons. The flies were then trained on the odor-reward task, and their memory tested 24 hours later. The results revealed that for the memories to form, CrebB is only required in two of the three lobes of the mushroom body, and in certain output neurons. Future studies can now focus on the cells shown to need CrebB to create long-term memories, and identify the other proteins involved in this process. In humans, defects in CrebB are associated with intellectual disability, addiction and depression. The mutant fly created by Widmer et al. could be a useful model in which to investigate how the protein may play a role in these conditions.
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Affiliation(s)
- Yves F Widmer
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Cornelia Fritsch
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Magali M Jungo
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Silvia Almeida
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Boris Egger
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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45
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Davie K, Janssens J, Koldere D, De Waegeneer M, Pech U, Kreft Ł, Aibar S, Makhzami S, Christiaens V, Bravo González-Blas C, Poovathingal S, Hulselmans G, Spanier KI, Moerman T, Vanspauwen B, Geurs S, Voet T, Lammertyn J, Thienpont B, Liu S, Konstantinides N, Fiers M, Verstreken P, Aerts S. A Single-Cell Transcriptome Atlas of the Aging Drosophila Brain. Cell 2018; 174:982-998.e20. [PMID: 29909982 PMCID: PMC6086935 DOI: 10.1016/j.cell.2018.05.057] [Citation(s) in RCA: 422] [Impact Index Per Article: 70.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 03/30/2018] [Accepted: 05/25/2018] [Indexed: 02/06/2023]
Abstract
The diversity of cell types and regulatory states in the brain, and how these change during aging, remains largely unknown. We present a single-cell transcriptome atlas of the entire adult Drosophila melanogaster brain sampled across its lifespan. Cell clustering identified 87 initial cell clusters that are further subclustered and validated by targeted cell-sorting. Our data show high granularity and identify a wide range of cell types. Gene network analyses using SCENIC revealed regulatory heterogeneity linked to energy consumption. During aging, RNA content declines exponentially without affecting neuronal identity in old brains. This single-cell brain atlas covers nearly all cells in the normal brain and provides the tools to study cellular diversity alongside other Drosophila and mammalian single-cell datasets in our unique single-cell analysis platform: SCope (http://scope.aertslab.org). These results, together with SCope, allow comprehensive exploration of all transcriptional states of an entire aging brain. A single-cell atlas of the adult fly brain during aging Network inference reveals regulatory states related to oxidative phosphorylation Cell identity is retained during aging despite exponential decline of gene expression SCope: An online tool to explore and compare single-cell datasets across species
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Affiliation(s)
- Kristofer Davie
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Jasper Janssens
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Duygu Koldere
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Maxime De Waegeneer
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Uli Pech
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Neurosciences, KU Leuven, Leuven 3000, Belgium
| | - Łukasz Kreft
- VIB Bioinformatics Core, VIB, Ghent 9052, Belgium
| | - Sara Aibar
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Valerie Christiaens
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Carmen Bravo González-Blas
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | | | - Gert Hulselmans
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Katina I Spanier
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Thomas Moerman
- ESAT, KU Leuven, Leuven 3001, Belgium; Smart Applications and Innovation Services, IMEC, Leuven 3001, Belgium
| | | | - Sarah Geurs
- Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | - Thierry Voet
- Department of Human Genetics KU Leuven, Leuven 3000, Belgium
| | | | | | - Sha Liu
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Neurosciences, KU Leuven, Leuven 3000, Belgium
| | | | - Mark Fiers
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Neurosciences, KU Leuven, Leuven 3000, Belgium
| | - Patrik Verstreken
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Neurosciences, KU Leuven, Leuven 3000, Belgium
| | - Stein Aerts
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium; Department of Human Genetics KU Leuven, Leuven 3000, Belgium.
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Identification of raw as a regulator of glial development. PLoS One 2018; 13:e0198161. [PMID: 29813126 PMCID: PMC5973607 DOI: 10.1371/journal.pone.0198161] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 05/15/2018] [Indexed: 12/18/2022] Open
Abstract
Glial cells perform numerous functions to support neuron development and function, including axon wrapping, formation of the blood brain barrier, and enhancement of synaptic transmission. We have identified a novel gene, raw, which functions in glia of the central and peripheral nervous systems in Drosophila. Reducing Raw levels in glia results in morphological defects in the brain and ventral nerve cord, as well as defects in neuron function, as revealed by decreased locomotion in crawling assays. Examination of the number of glia along peripheral nerves reveals a reduction in glial number upon raw knockdown. The reduced number of glia along peripheral nerves occurs as a result of decreased glial proliferation. As Raw has been shown to negatively regulate Jun N-terminal kinase (JNK) signaling in other developmental contexts, we examined the expression of a JNK reporter and the downstream JNK target, matrix metalloproteinase 1 (mmp1), and found that raw knockdown results in increased reporter activity and Mmp1 levels. These results are consistent with previous studies showing increased Mmp levels lead to nerve cord defects similar to those observed upon raw knockdown. In addition, knockdown of puckered, a negative feedback regulator of JNK signaling, also causes a decrease in glial number. Thus, our studies have resulted in the identification of a new regulator of gliogenesis, and demonstrate that increased JNK signaling negatively impacts glial development.
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Losada-Perez M. Glia: from 'just glue' to essential players in complex nervous systems: a comparative view from flies to mammals. J Neurogenet 2018; 32:78-91. [PMID: 29718753 DOI: 10.1080/01677063.2018.1464568] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the last years, glial cells have emerged as central players in the development and function of complex nervous systems. Therefore, the concept of glial cells has evolved from simple supporting cells to essential actors. The molecular mechanisms that govern glial functions are evolutionarily conserved from Drosophila to mammals, highlighting genetic similarities between these groups, as well as the great potential of Drosophila research for the understanding of human CNS. These similarities would imply a common phylogenetic origin of glia, even though there is a controversy at this point. This review addresses the existing literature on the evolutionary origin of glia and discusses whether or not insect and mammalian glia are homologous or analogous. Besides, this manuscript summarizes the main glial functions in the CNS and underscores the evolutionarily conserved molecular mechanisms between Drosophila and mammals. Finally, I also consider the current nomenclature and classification of glial cells to highlight the need for a consensus agreement and I propose an alternative nomenclature based on function that unifies Drosophila and mammalian glial types.
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Croset V, Treiber CD, Waddell S. Cellular diversity in the Drosophila midbrain revealed by single-cell transcriptomics. eLife 2018; 7:34550. [PMID: 29671739 PMCID: PMC5927767 DOI: 10.7554/elife.34550] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/18/2018] [Indexed: 12/12/2022] Open
Abstract
To understand the brain, molecular details need to be overlaid onto neural wiring diagrams so that synaptic mode, neuromodulation and critical signaling operations can be considered. Single-cell transcriptomics provide a unique opportunity to collect this information. Here we present an initial analysis of thousands of individual cells from Drosophila midbrain, that were acquired using Drop-Seq. A number of approaches permitted the assignment of transcriptional profiles to several major brain regions and cell-types. Expression of biosynthetic enzymes and reuptake mechanisms allows all the neurons to be typed according to the neurotransmitter or neuromodulator that they produce and presumably release. Some neuropeptides are preferentially co-expressed in neurons using a particular fast-acting transmitter, or monoamine. Neuromodulatory and neurotransmitter receptor subunit expression illustrates the potential of these molecules in generating complexity in neural circuit function. This cell atlas dataset provides an important resource to link molecular operations to brain regions and complex neural processes.
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Affiliation(s)
- Vincent Croset
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
| | - Christoph D Treiber
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
| | - Scott Waddell
- Centre for Neural Circuits and Behaviour, The University of Oxford, Oxford, United Kingdom
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49
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Krzeptowski W, Walkowicz L, Płonczyńska A, Górska-Andrzejak J. Different Levels of Expression of the Clock Protein PER and the Glial Marker REPO in Ensheathing and Astrocyte-Like Glia of the Distal Medulla of Drosophila Optic Lobe. Front Physiol 2018; 9:361. [PMID: 29695973 PMCID: PMC5904279 DOI: 10.3389/fphys.2018.00361] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 03/23/2018] [Indexed: 12/31/2022] Open
Abstract
Circadian plasticity of the visual system of Drosophila melanogaster depends on functioning of both the neuronal and glial oscillators. The clock function of the former is already quite well-recognized. The latter, however, is much less known and documented. In this study we focus on the glial oscillators that reside in the distal part of the second visual neuropil, medulla (dMnGl), in vicinity of the PIGMENT-DISPERSING FACTOR (PDF) releasing terminals of the circadian clock ventral Lateral Neurons (LNvs). We reveal the heterogeneity of the dMnGl, which express the clock protein PERIOD (PER) and the pan-glial marker REVERSED POLARITY (REPO) at higher (P1) or lower (P2) levels. We show that the cells with stronger expression of PER display also stronger expression of REPO, and that the number of REPO-P1 cells is bigger during the day than during the night. Using a combination of genetic markers and immunofluorescent labeling with anti PER and REPO Abs, we have established that the P1 and P2 cells can be associated with two different types of the dMnGl, the ensheathing (EnGl), and the astrocyte-like glia (ALGl). Surprisingly, the EnGl belong to the P1 cells, whereas the ALGl, previously reported to play the main role in the circadian rhythms, display the characteristics of the P2 cells (express very low level of PER and low level of REPO). Next to the EnGl and ALGl we have also observed another type of cells in the distal medulla that express PER and REPO, although at very low levels. Based on their morphology we have identified them as the T1 interneurons. Our study reveals the complexity of the distal medulla circadian network, which appears to consist of different types of glial and neuronal peripheral clocks, displaying molecular oscillations of higher (EnGl) and lower (ALGl and T1) amplitudes.
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Affiliation(s)
- Wojciech Krzeptowski
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Lucyna Walkowicz
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Alicja Płonczyńska
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
| | - Jolanta Górska-Andrzejak
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow, Poland
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50
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Zhang X, Li Q, Wang L, Liu ZJ, Zhong Y. Active Protection: Learning-Activated Raf/MAPK Activity Protects Labile Memory from Rac1-Independent Forgetting. Neuron 2018; 98:142-155.e4. [DOI: 10.1016/j.neuron.2018.02.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 12/20/2022]
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