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Lavin R, Rathore S, Bauer B, Disalvo J, Mosley N, Shearer E, Elia Z, Cook TA, Buschbeck EK. EyeVolve, a modular PYTHON based model for simulating developmental eye type diversification. Front Cell Dev Biol 2022; 10:964746. [PMID: 36092740 PMCID: PMC9459020 DOI: 10.3389/fcell.2022.964746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Vision is among the oldest and arguably most important sensory modalities for animals to interact with their external environment. Although many different eye types exist within the animal kingdom, mounting evidence indicates that the genetic networks required for visual system formation and function are relatively well conserved between species. This raises the question as to how common developmental programs are modified in functionally different eye types. Here, we approached this issue through EyeVolve, an open-source PYTHON-based model that recapitulates eye development based on developmental principles originally identified in Drosophila melanogaster. Proof-of-principle experiments showed that this program’s animated timeline successfully simulates early eye tissue expansion, neurogenesis, and pigment cell formation, sequentially transitioning from a disorganized pool of progenitor cells to a highly organized lattice of photoreceptor clusters wrapped with support cells. Further, tweaking just five parameters (precursor pool size, founder cell distance and placement from edge, photoreceptor subtype number, and cell death decisions) predicted a multitude of visual system layouts, reminiscent of the varied eye types found in larval and adult arthropods. This suggests that there are universal underlying mechanisms that can explain much of the existing arthropod eye diversity. Thus, EyeVolve sheds light on common principles of eye development and provides a new computational system for generating specific testable predictions about how development gives rise to diverse visual systems from a commonly specified neuroepithelial ground plan.
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Affiliation(s)
- Ryan Lavin
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Shubham Rathore
- Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Brian Bauer
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Joe Disalvo
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Nick Mosley
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Evan Shearer
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Zachary Elia
- Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States
| | - Tiffany A. Cook
- Center of Molecular Medicine and Genomics, Wayne State University School of Medicine, Detroit, MI, United States
| | - Elke K. Buschbeck
- Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
- *Correspondence: Elke K. Buschbeck,
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Ji W, Wu LF, Altschuler SJ. Analysis of growth cone extension in standardized coordinates highlights self-organization rules during wiring of the Drosophila visual system. PLoS Genet 2021; 17:e1009857. [PMID: 34731164 PMCID: PMC8565740 DOI: 10.1371/journal.pgen.1009857] [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: 09/20/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
A fascinating question in neuroscience is how ensembles of neurons, originating from different locations, extend to the proper place and by the right time to create precise circuits. Here, we investigate this question in the Drosophila visual system, where photoreceptors re-sort in the lamina to form the crystalline-like neural superposition circuit. The repeated nature of this circuit allowed us to establish a data-driven, standardized coordinate system for quantitative comparison of sparsely perturbed growth cones within and across specimens. Using this common frame of reference, we investigated the extension of the R3 and R4 photoreceptors, which is the only pair of symmetrically arranged photoreceptors with asymmetric target choices. Specifically, we found that extension speeds of the R3 and R4 growth cones are inherent to their cell identities. The ability to parameterize local regularity in tissue organization facilitated the characterization of ensemble cellular behaviors and dissection of mechanisms governing neural circuit formation.
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Affiliation(s)
- Weiyue Ji
- Biophysics Graduate Group, University of California, San Francisco, San Francisco, California, United States of America
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
| | - Lani F. Wu
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
| | - Steven J. Altschuler
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
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Charlton-Perkins MA, Friedrich M, Cook TA. Semper's cells in the insect compound eye: Insights into ocular form and function. Dev Biol 2021; 479:126-138. [PMID: 34343526 PMCID: PMC8410683 DOI: 10.1016/j.ydbio.2021.07.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/28/2022]
Abstract
The arthropod compound eye represents one of two major eye types in the animal kingdom and has served as an essential experimental paradigm for defining fundamental mechanisms underlying sensory organ formation, function, and maintenance. One of the most distinguishing features of the compound eye is the highly regular array of lens facets that define individual eye (ommatidial) units. These lens facets are produced by a deeply conserved quartet of cuticle-secreting cells, called Semper cells (SCs). Also widely known as cone cells, SCs were originally identified for their secretion of the dioptric system, i.e. the corneal lens and underlying crystalline cones. Additionally, SCs are now known to execute a diversity of patterning and glial functions in compound eye development and maintenance. Here, we present an integrated account of our current knowledge of SC multifunctionality in the Drosophila compound eye, highlighting emerging gene regulatory modules that may drive the diverse roles for these cells. Drawing comparisons with other deeply conserved retinal glia in the vertebrate single lens eye, this discussion speaks to glial cell origins and opens new avenues for understanding sensory system support programs.
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Affiliation(s)
- Mark A Charlton-Perkins
- Department of Paediatrics, Wellcome-MRC Stem Cell Institute, Jeffrey Cheah Biomedical Centre, University of Cambridge, Puddicombe Way, Cambridge, CB2 0AW, United Kingdom
| | - Markus Friedrich
- Department of Biological Sciences, Wayne State University, 5047 Gullen Mall, Detroit, MI, 48202, USA; Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA
| | - Tiffany A Cook
- Department of Ophthalmological, Visual, and Anatomical Sciences, Wayne State University, School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA; Center of Molecular Medicine and Genetics, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, MI, 48201, USA.
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Abstract
For centuries, the eye has fascinated scientists and philosophers alike, and as a result the visual system has always been at the forefront of integrating cutting-edge technology in research. We are again at a turning point at which technical advances have expanded the range of organisms we can study developmentally and deepened what we can learn. In this new era, we are finally able to understand eye development in animals across the phylogenetic tree. In this Review, we highlight six areas in comparative visual system development that address questions that are important for understanding the developmental basis of evolutionary change. We focus on the opportunities now available to biologists to study the developmental genetics, cell biology and morphogenesis that underlie the incredible variation of visual organs found across the Metazoa. Although decades of important work focused on gene expression has suggested homologies and potential evolutionary relationships between the eyes of diverse animals, it is time for developmental biologists to move away from this reductive approach. We now have the opportunity to celebrate the differences and diversity in visual organs found across animal development, and to learn what it can teach us about the fundamental principles of biological systems and how they are built.
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Affiliation(s)
- Kristen M Koenig
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey M Gross
- Departments of Ophthalmology and Developmental Biology, Louis J. Fox Center for Vision Restoration, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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5
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Neal SJ, Zhou Q, Pignoni F. STRIPAK-PP2A regulates Hippo-Yorkie signaling to suppress retinal fate in the Drosophila eye disc peripodial epithelium. J Cell Sci 2020; 133:jcs237834. [PMID: 32184260 PMCID: PMC7272332 DOI: 10.1242/jcs.237834] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 03/09/2020] [Indexed: 12/30/2022] Open
Abstract
The specification of organs, tissues and cell types results from cell fate restrictions enacted by nuclear transcription factors under the control of conserved signaling pathways. The progenitor epithelium of the Drosophila compound eye, the eye imaginal disc, is a premier model for the study of such processes. Early in development, apposing cells of the eye disc are established as either retinal progenitors or support cells of the peripodial epithelium (PE), in a process whose genetic and mechanistic determinants are poorly understood. We have identified protein phosphatase 2A (PP2A), and specifically a STRIPAK-PP2A complex that includes the scaffolding and substrate-specificity components Cka, Strip and SLMAP, as a critical player in the retina-PE fate choice. We show that these factors suppress ectopic retina formation in the presumptive PE and do so via the Hippo signaling axis. STRIPAK-PP2A negatively regulates Hippo kinase, and consequently its substrate Warts, to release the transcriptional co-activator Yorkie into the nucleus. Thus, a modular higher-order PP2A complex refines the activity of this general phosphatase to act in a precise specification of cell fate.
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Affiliation(s)
- Scott J Neal
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Qingxiang Zhou
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
| | - Francesca Pignoni
- Department of Ophthalmology and Visual Sciences, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
- Department of Neuroscience and Physiology; Department of Biochemistry and Molecular Biology; Department of Cell and Developmental Biology, Upstate Medical University, 505 Irving Avenue, NRB 4610, Syracuse, NY 13210, USA
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6
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Sancer G, Kind E, Plazaola-Sasieta H, Balke J, Pham T, Hasan A, Münch LO, Courgeon M, Mathejczyk TF, Wernet MF. Modality-Specific Circuits for Skylight Orientation in the Fly Visual System. Curr Biol 2019; 29:2812-2825.e4. [DOI: 10.1016/j.cub.2019.07.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 07/02/2019] [Accepted: 07/09/2019] [Indexed: 01/17/2023]
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Mellough CB, Bauer R, Collin J, Dorgau B, Zerti D, Dolan DWP, Jones CM, Izuogu OG, Yu M, Hallam D, Steyn JS, White K, Steel DH, Santibanez-Koref M, Elliott DJ, Jackson MS, Lindsay S, Grellscheid S, Lako M. An integrated transcriptional analysis of the developing human retina. Development 2019; 146:146/2/dev169474. [PMID: 30696714 PMCID: PMC6361134 DOI: 10.1242/dev.169474] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/24/2018] [Indexed: 12/11/2022]
Abstract
The scarcity of embryonic/foetal material as a resource for direct study means that there is still limited understanding of human retina development. Here, we present an integrated transcriptome analysis combined with immunohistochemistry in human eye and retinal samples from 4 to 19 post-conception weeks. This analysis reveals three developmental windows with specific gene expression patterns that informed the sequential emergence of retinal cell types and enabled identification of stage-specific cellular and biological processes, and transcriptional regulators. Each stage is characterised by a specific set of alternatively spliced transcripts that code for proteins involved in the formation of the photoreceptor connecting cilium, pre-mRNA splicing and epigenetic modifiers. Importantly, our data show that the transition from foetal to adult retina is characterised by a large increase in the percentage of mutually exclusive exons that code for proteins involved in photoreceptor maintenance. The circular RNA population is also defined and shown to increase during retinal development. Collectively, these data increase our understanding of human retinal development and the pre-mRNA splicing process, and help to identify new candidate disease genes.
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Affiliation(s)
- Carla B. Mellough
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK,Lions Eye Institute, 2 Verdun Street, Nedlands, Perth, WA 6009, Australia
| | - Roman Bauer
- School of Computing, Newcastle University, Newcastle NE4 5TG, UK
| | - Joseph Collin
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Birthe Dorgau
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Darin Zerti
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - David W. P. Dolan
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Carl M. Jones
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Osagie G. Izuogu
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK,European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Cambridge CB10 1SD, UK
| | - Min Yu
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Dean Hallam
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Jannetta S. Steyn
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Kathryn White
- EM Research Services, Newcastle University, Newcastle NE2 4HH, UK
| | - David H. Steel
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | | | - David J. Elliott
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Michael S. Jackson
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Susan Lindsay
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
| | - Sushma Grellscheid
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, Newcastle NE1 3BZ, UK
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8
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Mechanisms of Photoreceptor Patterning in Vertebrates and Invertebrates. Trends Genet 2017; 32:638-659. [PMID: 27615122 DOI: 10.1016/j.tig.2016.07.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 11/22/2022]
Abstract
Across the animal kingdom, visual systems have evolved to be uniquely suited to the environments and behavioral patterns of different species. Visual acuity and color perception depend on the distribution of photoreceptor (PR) subtypes within the retina. Retinal mosaics can be organized into three broad categories: stochastic/regionalized, regionalized, and ordered. We describe here the retinal mosaics of flies, zebrafish, chickens, mice, and humans, and the gene regulatory networks controlling proper PR specification in each. By drawing parallels in eye development between these divergent species, we identify a set of conserved organizing principles and transcriptional networks that govern PR subtype differentiation.
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Quan XJ, Yuan L, Tiberi L, Claeys A, De Geest N, Yan J, van der Kant R, Xie W, Klisch T, Shymkowitz J, Rousseau F, Bollen M, Beullens M, Zoghbi H, Vanderhaeghen P, Hassan B. Post-translational Control of the Temporal Dynamics of Transcription Factor Activity Regulates Neurogenesis. Cell 2016; 164:460-75. [DOI: 10.1016/j.cell.2015.12.048] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 10/12/2015] [Accepted: 12/22/2015] [Indexed: 11/28/2022]
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10
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Wernet MF, Perry MW, Desplan C. The evolutionary diversity of insect retinal mosaics: common design principles and emerging molecular logic. Trends Genet 2015; 31:316-28. [PMID: 26025917 PMCID: PMC4458154 DOI: 10.1016/j.tig.2015.04.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 04/13/2015] [Accepted: 04/14/2015] [Indexed: 12/21/2022]
Abstract
Independent evolution has resulted in a vast diversity of eyes. Despite the lack of a common Bauplan or ancestral structure, similar developmental strategies are used. For instance, different classes of photoreceptor cells (PRs) are distributed stochastically and/or localized in different regions of the retina. Here, we focus on recent progress made towards understanding the molecular principles behind patterning retinal mosaics of insects, one of the most diverse groups of animals adapted to life on land, in the air, under water, or on the water surface. Morphological, physiological, and behavioral studies from many species provide detailed descriptions of the vast variation in retinal design and function. By integrating this knowledge with recent progress in the characterization of insect Rhodopsins as well as insight from the model organism Drosophila melanogaster, we seek to identify the molecular logic behind the adaptation of retinal mosaics to the habitat and way of life of an animal.
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Affiliation(s)
- Mathias F Wernet
- New York University Abu Dhabi, Abu Dhabi, 129188 Saadiyat Island, United Arab Emirates
| | - Michael W Perry
- Department of Biology, New York University, New York, NY 10003, USA
| | - Claude Desplan
- New York University Abu Dhabi, Abu Dhabi, 129188 Saadiyat Island, United Arab Emirates; Department of Biology, New York University, New York, NY 10003, USA.
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11
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Davie K, Jacobs J, Atkins M, Potier D, Christiaens V, Halder G, Aerts S. Discovery of transcription factors and regulatory regions driving in vivo tumor development by ATAC-seq and FAIRE-seq open chromatin profiling. PLoS Genet 2015; 11:e1004994. [PMID: 25679813 PMCID: PMC4334524 DOI: 10.1371/journal.pgen.1004994] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 01/08/2015] [Indexed: 01/24/2023] Open
Abstract
Genomic enhancers regulate spatio-temporal gene expression by recruiting specific combinations of transcription factors (TFs). When TFs are bound to active regulatory regions, they displace canonical nucleosomes, making these regions biochemically detectable as nucleosome-depleted regions or accessible/open chromatin. Here we ask whether open chromatin profiling can be used to identify the entire repertoire of active promoters and enhancers underlying tissue-specific gene expression during normal development and oncogenesis in vivo. To this end, we first compare two different approaches to detect open chromatin in vivo using the Drosophila eye primordium as a model system: FAIRE-seq, based on physical separation of open versus closed chromatin; and ATAC-seq, based on preferential integration of a transposon into open chromatin. We find that both methods reproducibly capture the tissue-specific chromatin activity of regulatory regions, including promoters, enhancers, and insulators. Using both techniques, we screened for regulatory regions that become ectopically active during Ras-dependent oncogenesis, and identified 3778 regions that become (over-)activated during tumor development. Next, we applied motif discovery to search for candidate transcription factors that could bind these regions and identified AP-1 and Stat92E as key regulators. We validated the importance of Stat92E in the development of the tumors by introducing a loss of function Stat92E mutant, which was sufficient to rescue the tumor phenotype. Additionally we tested if the predicted Stat92E responsive regulatory regions are genuine, using ectopic induction of JAK/STAT signaling in developing eye discs, and observed that similar chromatin changes indeed occurred. Finally, we determine that these are functionally significant regulatory changes, as nearby target genes are up- or down-regulated. In conclusion, we show that FAIRE-seq and ATAC-seq based open chromatin profiling, combined with motif discovery, is a straightforward approach to identify functional genomic regulatory regions, master regulators, and gene regulatory networks controlling complex in vivo processes.
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Affiliation(s)
- Kristofer Davie
- Laboratory of Computational Biology, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Jelle Jacobs
- Laboratory of Computational Biology, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Mardelle Atkins
- Laboratory of Growth Control and Cancer Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
- VIB Center for the Biology of Disease, Laboratory for Molecular Cancer Biology, Leuven, Belgium
| | - Delphine Potier
- Laboratory of Computational Biology, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Valerie Christiaens
- Laboratory of Computational Biology, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Georg Halder
- Laboratory of Growth Control and Cancer Research, Center for Human Genetics, KU Leuven, Leuven, Belgium
- VIB Center for the Biology of Disease, Laboratory for Molecular Cancer Biology, Leuven, Belgium
| | - Stein Aerts
- Laboratory of Computational Biology, Center for Human Genetics, KU Leuven, Leuven, Belgium
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Mapping Gene Regulatory Networks in Drosophila Eye Development by Large-Scale Transcriptome Perturbations and Motif Inference. Cell Rep 2014; 9:2290-303. [DOI: 10.1016/j.celrep.2014.11.038] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/24/2014] [Accepted: 11/22/2014] [Indexed: 11/20/2022] Open
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13
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Oliva C, Choi CM, Nicolai LJJ, Mora N, De Geest N, Hassan BA. Proper connectivity of Drosophila motion detector neurons requires Atonal function in progenitor cells. Neural Dev 2014; 9:4. [PMID: 24571981 PMCID: PMC3941608 DOI: 10.1186/1749-8104-9-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Accepted: 02/13/2014] [Indexed: 01/15/2023] Open
Abstract
Background Vertebrates and invertebrates obtain visual motion information by channeling moving visual cues perceived by the retina through specific motion sensitive synaptic relays in the brain. In Drosophila, the series of synaptic relays forming the optic lobe are known as the lamina, medulla, lobula and lobula plate neuropiles. The fly’s motion detection output neurons, called the T4 and T5 cells, reside in the lobula plate. Adult optic lobe neurons are derived from larval neural progenitors in two proliferating compartments known as the outer and inner proliferation centers (OPC and IPC). Important insight has been gained into molecular mechanisms involved in the development of the lamina and medulla from the OPC, though less is known about the development of the lobula and lobula plate. Results Here we show that the proneural gene Atonal is expressed in a subset of IPC progenitors that give rise to the higher order motion detection neurons, T4 and T5, of the lobula plate. We also show that Atonal does not act as a proneural gene in this context. Rather, it is required specifically in IPC neural progenitors to regulate neurite outgrowth in the neuronal progeny. Conclusions Our findings reveal that a proneural gene is expressed in progenitors but is required for neurite development of their progeny neurons. This suggests that transcriptional programs initiated specifically in progenitors are necessary for subsequent neuronal morphogenesis.
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Affiliation(s)
| | | | | | | | | | - Bassem A Hassan
- VIB Center for Biology of Disease, VIB, 3000 Leuven, Belgium.
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