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Lago-Baldaia I, Cooper M, Seroka A, Trivedi C, Powell GT, Wilson SW, Ackerman SD, Fernandes VM. A Drosophila glial cell atlas reveals a mismatch between transcriptional and morphological diversity. PLoS Biol 2023; 21:e3002328. [PMID: 37862379 PMCID: PMC10619882 DOI: 10.1371/journal.pbio.3002328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 11/01/2023] [Accepted: 09/08/2023] [Indexed: 10/22/2023] Open
Abstract
Morphology is a defining feature of neuronal identity. Like neurons, glia display diverse morphologies, both across and within glial classes, but are also known to be morphologically plastic. Here, we explored the relationship between glial morphology and transcriptional signature using the Drosophila central nervous system (CNS), where glia are categorised into 5 main classes (outer and inner surface glia, cortex glia, ensheathing glia, and astrocytes), which show within-class morphological diversity. We analysed and validated single-cell RNA sequencing data of Drosophila glia in 2 well-characterised tissues from distinct developmental stages, containing distinct circuit types: the embryonic ventral nerve cord (VNC) (motor) and the adult optic lobes (sensory). Our analysis identified a new morphologically and transcriptionally distinct surface glial population in the VNC. However, many glial morphological categories could not be distinguished transcriptionally, and indeed, embryonic and adult astrocytes were transcriptionally analogous despite differences in developmental stage and circuit type. While we did detect extensive within-class transcriptomic diversity for optic lobe glia, this could be explained entirely by glial residence in the most superficial neuropil (lamina) and an associated enrichment for immune-related gene expression. In summary, we generated a single-cell transcriptomic atlas of glia in Drosophila, and our extensive in vivo validation revealed that glia exhibit more diversity at the morphological level than was detectable at the transcriptional level. This atlas will serve as a resource for the community to probe glial diversity and function.
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Affiliation(s)
- Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Maia Cooper
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Austin Seroka
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Chintan Trivedi
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Gareth T. Powell
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Stephen W. Wilson
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sarah D. Ackerman
- Department of Pathology and Immunology, Brain Immunology and Glia Center, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Vilaiwan M. Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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Tse J, Li TH, Zhang J, Lee ACK, Lee I, Qu Z, Lin X, Hui J, Chan TF. Single-Cell Atlas of the Drosophila Leg Disc Identifies a Long Non-Coding RNA in Late Development. Int J Mol Sci 2022; 23:ijms23126796. [PMID: 35743238 PMCID: PMC9224501 DOI: 10.3390/ijms23126796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 02/05/2023] Open
Abstract
The Drosophila imaginal disc has been an excellent model for the study of developmental gene regulation. In particular, long non-coding RNAs (lncRNAs) have gained widespread attention in recent years due to their important role in gene regulation. Their specific spatiotemporal expressions further support their role in developmental processes and diseases. In this study, we explored the role of a novel lncRNA in Drosophila leg development by dissecting and dissociating w1118 third-instar larval third leg (L3) discs into single cells and single nuclei, and performing single-cell RNA-sequencing (scRNA-seq) and single-cell assays for transposase-accessible chromatin (scATAC-seq). Single-cell transcriptomics analysis of the L3 discs across three developmental timepoints revealed different cell types and identified lncRNA:CR33938 as a distal specific gene with high expression in late development. This was further validated by fluorescence in-situ hybridization (FISH). The scATAC-seq results reproduced the single-cell transcriptomics landscape and elucidated the distal cell functions at different timepoints. Furthermore, overexpression of lncRNA:CR33938 in the S2 cell line increased the expression of leg development genes, further elucidating its potential role in development.
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Affiliation(s)
- Joyce Tse
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Tsz Ho Li
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Jizhou Zhang
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Alan Chun Kit Lee
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Ivy Lee
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Zhe Qu
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Xiao Lin
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Jerome Hui
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong; (J.T.); (T.H.L.); (J.Z.); (A.C.K.L.); (I.L.); (Z.Q.); (X.L.); (J.H.)
- State Key Lab of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
- Correspondence:
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Contreras EG, Sierralta J. The Fly Blood-Brain Barrier Fights Against Nutritional Stress. Neurosci Insights 2022; 17:26331055221120252. [PMID: 36225749 PMCID: PMC9549514 DOI: 10.1177/26331055221120252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/01/2022] [Indexed: 11/17/2022] Open
Abstract
In the wild, animals face different challenges including multiple events of food
scarcity. How they overcome these conditions is essential for survival. Thus,
adaptation mechanisms evolved to allow the development and survival of an
organism during nutrient restriction periods. Given the high energy demand of
the nervous system, the molecular mechanisms of adaptation to malnutrition are
of great relevance to fuel the brain. The blood-brain barrier (BBB) is the
interface between the central nervous system (CNS) and the circulatory system.
The BBB mediates the transport of macromolecules in and out of the CNS, and
therefore, it can buffer changes in nutrient availability. In this review, we
collect the current evidence using the fruit fly, Drosophila
melanogaster, as a model of the role of the BBB in the adaptation
to starvation. We discuss the role of the Drosophila BBB during
nutrient deprivation as a potential sensor for circulating nutrients, and
transient nutrient storage as a regulator of the CNS neurogenic niche.
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Affiliation(s)
- Esteban G Contreras
- Institute of Neuro- and Behavioral Biology, University of Münster, Münster, Germany
| | - Jimena Sierralta
- Biomedical Neuroscience Institute and Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile
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Rhee JE, Choi JH, Park JH, Lee G, Pak B, Kwon SH, Jeon SH. CG11426 gene product negatively regulates glial population size in the Drosophila eye imaginal disc. Dev Neurobiol 2021; 81:805-816. [PMID: 34047015 DOI: 10.1002/dneu.22838] [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: 09/01/2020] [Revised: 05/03/2021] [Accepted: 05/16/2021] [Indexed: 11/09/2022]
Abstract
Glial cells play essential roles in the nervous system. Although glial populations are tightly regulated, the mechanisms regulating the population size remain poorly understood. Since Drosophila glial cells are similar to the human counterparts in their functions and shapes, rendering them an excellent model system to understand the human glia biology. Lipid phosphate phosphatases (LPPs) are important for regulating bioactive lipids. In Drosophila, there are three known LPP-encoding genes: wunen, wunen-2, and lazaro. The wunens are important for germ cell migration and survival and septate junction formation during tracheal development. Lazaro is involved in phototransduction. In the present study, we characterized a novel Drosophila LPP-encoding gene, CG11426. Suppression of CG11426 increased glial cell number in the eye imaginal disc during larval development, while ectopic CG11426 expression decreased it. Both types of mutation also caused defects in axon projection to the optic lobe in larval eye-brain complexes. Moreover, CG11426 promoted apoptosis via inhibiting ERK signaling in the eye imaginal disc. Taken together, these findings demonstrated that CG11426 gene product negatively regulates ERK signaling to promote apoptosis for proper maintenance of the glial population in the developing eye disc.
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Affiliation(s)
- Jong-Eun Rhee
- Department of Biology Education, Seoul National University, Seoul, Republic of Korea
| | - Jin-Hyeon Choi
- Department of Biology Education, Seoul National University, Seoul, Republic of Korea
| | - Jae H Park
- Department of Biochemistry & Cellular and Molecular Biology, and Neuronet Research Center, University of Tennessee, Knoxville, Tennessee, USA
| | - Gyunghee Lee
- Department of Biochemistry & Cellular and Molecular Biology, and Neuronet Research Center, University of Tennessee, Knoxville, Tennessee, USA
| | - Banya Pak
- Department of Biology Education, Seoul National University, Seoul, Republic of Korea
| | - Seung-Hae Kwon
- Korea Basic Science Institute, Seoul Center, Seoul, Korea
| | - Sang-Hak Jeon
- Department of Biology Education, Seoul National University, Seoul, Republic of Korea
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Hertenstein H, McMullen E, Weiler A, Volkenhoff A, Becker HM, Schirmeier S. Starvation-induced regulation of carbohydrate transport at the blood-brain barrier is TGF-β-signaling dependent. eLife 2021; 10:e62503. [PMID: 34032568 PMCID: PMC8149124 DOI: 10.7554/elife.62503] [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: 08/26/2020] [Accepted: 04/13/2021] [Indexed: 12/15/2022] Open
Abstract
During hunger or malnutrition, animals prioritize alimentation of the brain over other organs to ensure its function and, thus, their survival. This protection, also-called brain sparing, is described from Drosophila to humans. However, little is known about the molecular mechanisms adapting carbohydrate transport. Here, we used Drosophila genetics to unravel the mechanisms operating at the blood-brain barrier (BBB) under nutrient restriction. During starvation, expression of the carbohydrate transporter Tret1-1 is increased to provide more efficient carbohydrate uptake. Two mechanisms are responsible for this increase. Similar to the regulation of mammalian GLUT4, Rab-dependent intracellular shuttling is needed for Tret1-1 integration into the plasma membrane; even though Tret1-1 regulation is independent of insulin signaling. In addition, starvation induces transcriptional upregulation that is controlled by TGF-β signaling. Considering TGF-β-dependent regulation of the glucose transporter GLUT1 in murine chondrocytes, our study reveals an evolutionarily conserved regulatory paradigm adapting the expression of sugar transporters at the BBB.
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Affiliation(s)
- Helen Hertenstein
- Department of Biology, Institute of Zoology, Technische Universität DresdenDresdenGermany
| | - Ellen McMullen
- Institut für Neuro- und Verhaltensbiologie, WWU MünsterMünsterGermany
| | - Astrid Weiler
- Department of Biology, Institute of Zoology, Technische Universität DresdenDresdenGermany
| | - Anne Volkenhoff
- Department of Biology, Institute of Zoology, Technische Universität DresdenDresdenGermany
| | - Holger M Becker
- Department of Biology, Institute of Zoology, Technische Universität DresdenDresdenGermany
- Division of General Zoology, Department of Biology, University of KaiserslauternKaiserslauternGermany
| | - Stefanie Schirmeier
- Department of Biology, Institute of Zoology, Technische Universität DresdenDresdenGermany
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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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