1
|
Identification of the Time Period during Which BMP Signaling Regulates Proliferation of Neural Progenitor Cells in Zebrafish. Int J Mol Sci 2023; 24:ijms24021733. [PMID: 36675251 PMCID: PMC9863262 DOI: 10.3390/ijms24021733] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Bone morphogenetic protein (BMP) signaling regulates neural induction, neuronal specification, and neuronal differentiation. However, the role of BMP signaling in neural progenitors remains unclear. This is because interruption of BMP signaling before or during neural induction causes severe effects on subsequent neural developmental processes. To examine the role of BMP signaling in the development of neural progenitors in zebrafish, we bypassed the effect of BMP signaling on neural induction and suppressed BMP signaling at different time points during gastrulation using a temporally controlled transgenic line carrying a dominant-negative form of Bmp receptor type 1aa and a chemical inhibitor of BMP signaling, DMH1. Inhibiting BMP signaling from 8 hpf could bypass BMP regulation on neural induction, induce the number of proliferating neural progenitors, and reduce the number of neuronal precursors. Inhibiting BMP signaling upregulates the expression of the Notch downstream gene hairy/E(spl)-related 2 (her2). Inhibiting Notch signaling or knocking down the Her2 function reduced neural progenitor proliferation, whereas inactivating BMP signaling in Notch-Her2 deficient background restored the number of proliferating neural progenitors. These results reveal the time window for the proliferation of neural progenitors during zebrafish development and a fine balance between BMP and Notch signaling in regulating the proliferation of neural progenitor cells.
Collapse
|
2
|
Vuilleumier R, Miao M, Medina-Giro S, Ell CM, Flibotte S, Lian T, Kauwe G, Collins A, Ly S, Pyrowolakis G, Haghighi AP, Allan DW. Dichotomous cis-regulatory motifs mediate the maturation of the neuromuscular junction by retrograde BMP signaling. Nucleic Acids Res 2022; 50:9748-9764. [PMID: 36029115 PMCID: PMC9508838 DOI: 10.1093/nar/gkac730] [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: 02/12/2022] [Revised: 07/20/2022] [Accepted: 08/19/2022] [Indexed: 11/26/2022] Open
Abstract
Retrograde bone morphogenetic protein (BMP) signaling at the Drosophila neuromuscular junction (NMJ) has served as a paradigm to study TGF-β-dependent synaptic function and maturation. Yet, how retrograde BMP signaling transcriptionally regulates these functions remains unresolved. Here, we uncover a gene network, enriched for neurotransmission-related genes, that is controlled by retrograde BMP signaling in motor neurons through two Smad-binding cis-regulatory motifs, the BMP-activating (BMP-AE) and silencer (BMP-SE) elements. Unpredictably, both motifs mediate direct gene activation, with no involvement of the BMP derepression pathway regulators Schnurri and Brinker. Genome editing of candidate BMP-SE and BMP-AE within the locus of the active zone gene bruchpilot, and a novel Ly6 gene witty, demonstrated the role of these motifs in upregulating genes required for the maturation of pre- and post-synaptic NMJ compartments. Our findings uncover how Smad-dependent transcriptional mechanisms specific to motor neurons directly orchestrate a gene network required for synaptic maturation by retrograde BMP signaling.
Collapse
Affiliation(s)
- Robin Vuilleumier
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Mo Miao
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Sonia Medina-Giro
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Clara-Maria Ell
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, 79104, Germany.,CIBSS - Centre for Integrative Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Hilde Mangold Haus, Habsburgerstrasse 49, University of Freiburg, Freiburg, 79104, Germany
| | - Stephane Flibotte
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Tianshun Lian
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Grant Kauwe
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Annie Collins
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Sophia Ly
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - George Pyrowolakis
- CIBSS - Centre for Integrative Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Hilde Mangold Haus, Habsburgerstrasse 49, University of Freiburg, Freiburg, 79104, Germany
| | | | - Douglas W Allan
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| |
Collapse
|
3
|
Coulcher JF, Roure A, Chowdhury R, Robert M, Lescat L, Bouin A, Carvajal Cadavid J, Nishida H, Darras S. Conservation of peripheral nervous system formation mechanisms in divergent ascidian embryos. eLife 2020; 9:e59157. [PMID: 33191918 PMCID: PMC7710358 DOI: 10.7554/elife.59157] [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: 05/21/2020] [Accepted: 11/13/2020] [Indexed: 01/23/2023] Open
Abstract
Ascidians with very similar embryos but highly divergent genomes are thought to have undergone extensive developmental system drift. We compared, in four species (Ciona and Phallusia for Phlebobranchia, Molgula and Halocynthia for Stolidobranchia), gene expression and gene regulation for a network of six transcription factors regulating peripheral nervous system (PNS) formation in Ciona. All genes, but one in Molgula, were expressed in the PNS with some differences correlating with phylogenetic distance. Cross-species transgenesis indicated strong levels of conservation, except in Molgula, in gene regulation despite lack of sequence conservation of the enhancers. Developmental system drift in ascidians is thus higher for gene regulation than for gene expression and is impacted not only by phylogenetic distance, but also in a clade-specific manner and unevenly within a network. Finally, considering that Molgula is divergent in our analyses, this suggests deep conservation of developmental mechanisms in ascidians after 390 My of separate evolution.
Collapse
Affiliation(s)
- Joshua F Coulcher
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Agnès Roure
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Rafath Chowdhury
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Méryl Robert
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Laury Lescat
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Aurélie Bouin
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Juliana Carvajal Cadavid
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka UniversityToyonakaJapan
| | - Sébastien Darras
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| |
Collapse
|
4
|
Berndt AJ, Othonos KM, Lian T, Flibotte S, Miao M, Bhuiyan SA, Cho RY, Fong JS, Hur SA, Pavlidis P, Allan DW. A low affinity cis-regulatory BMP response element restricts target gene activation to subsets of Drosophila neurons. eLife 2020; 9:59650. [PMID: 33124981 PMCID: PMC7669266 DOI: 10.7554/elife.59650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/29/2020] [Indexed: 11/19/2022] Open
Abstract
Retrograde BMP signaling and canonical pMad/Medea-mediated transcription regulate diverse target genes across subsets of Drosophila efferent neurons, to differentiate neuropeptidergic neurons and promote motor neuron terminal maturation. How a common BMP signal regulates diverse target genes across many neuronal subsets remains largely unresolved, although available evidence implicates subset-specific transcription factor codes rather than differences in BMP signaling. Here we examine the cis-regulatory mechanisms restricting BMP-induced FMRFa neuropeptide expression to Tv4-neurons. We find that pMad/Medea bind at an atypical, low affinity motif in the FMRFa enhancer. Converting this motif to high affinity caused ectopic enhancer activity and eliminated Tv4-neuron expression. In silico searches identified additional motif instances functional in other efferent neurons, implicating broader functions for this motif in BMP-dependent enhancer activity. Thus, differential interpretation of a common BMP signal, conferred by low affinity pMad/Medea binding motifs, can contribute to the specification of BMP target genes in efferent neuron subsets.
Collapse
Affiliation(s)
- Anthony Je Berndt
- Department of Food & Fuel for the 21st Century, University of California San Diego, San Diego, United States
| | - Katerina M Othonos
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Tianshun Lian
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Stephane Flibotte
- UBC/LSI Bioinformatics Facility, University of British Columbia, Vancouver, Canada
| | - Mo Miao
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | | | - Raymond Y Cho
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Justin S Fong
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Seo Am Hur
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| | - Paul Pavlidis
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Douglas W Allan
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, Canada
| |
Collapse
|
5
|
Crews ST. Drosophila Embryonic CNS Development: Neurogenesis, Gliogenesis, Cell Fate, and Differentiation. Genetics 2019; 213:1111-1144. [PMID: 31796551 PMCID: PMC6893389 DOI: 10.1534/genetics.119.300974] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/26/2019] [Indexed: 01/04/2023] Open
Abstract
The Drosophila embryonic central nervous system (CNS) is a complex organ consisting of ∼15,000 neurons and glia that is generated in ∼1 day of development. For the past 40 years, Drosophila developmental neuroscientists have described each step of CNS development in precise molecular genetic detail. This has led to an understanding of how an intricate nervous system emerges from a single cell. These studies have also provided important, new concepts in developmental biology, and provided an essential model for understanding similar processes in other organisms. In this article, the key genes that guide Drosophila CNS development and how they function is reviewed. Features of CNS development covered in this review are neurogenesis, gliogenesis, cell fate specification, and differentiation.
Collapse
Affiliation(s)
- Stephen T Crews
- Department of Biochemistry and Biophysics, Integrative Program for Biological and Genome Sciences, School of Medicine, The University of North Carolina at Chapel Hill, North Carolina 27599
| |
Collapse
|
6
|
Vuilleumier R, Lian T, Flibotte S, Khan ZN, Fuchs A, Pyrowolakis G, Allan DW. Retrograde BMP signaling activates neuronal gene expression through widespread deployment of a conserved BMP-responsive cis-regulatory activation element. Nucleic Acids Res 2019; 47:679-699. [PMID: 30476189 PMCID: PMC6344883 DOI: 10.1093/nar/gky1135] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 10/25/2018] [Indexed: 12/29/2022] Open
Abstract
Retrograde Bone Morphogenetic Protein (BMP) signaling in neurons is essential for the differentiation and synaptic function of many neuronal subtypes. BMP signaling regulates these processes via Smad transcription factor activity, yet the scope and nature of Smad-dependent gene regulation in neurons are mostly unknown. Here, we applied a computational approach to predict Smad-binding cis-regulatory BMP-Activating Elements (BMP-AEs) in Drosophila, followed by transgenic in vivo reporter analysis to test their neuronal subtype enhancer activity in the larval central nervous system (CNS). We identified 34 BMP-AE-containing genomic fragments that are responsive to BMP signaling in neurons, and showed that the embedded BMP-AEs are required for this activity. RNA-seq analysis identified BMP-responsive genes in the CNS and revealed that BMP-AEs selectively enrich near BMP-activated genes. These data suggest that functional BMP-AEs control nearby BMP-activated genes, which we validated experimentally. Finally, we demonstrated that the BMP-AE motif mediates a conserved Smad-responsive function in the Drosophila and vertebrate CNS. Our results provide evidence that BMP signaling controls neuronal function by directly coordinating the expression of a battery of genes through widespread deployment of a conserved Smad-responsive cis-regulatory motif.
Collapse
Affiliation(s)
- Robin Vuilleumier
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tianshun Lian
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephane Flibotte
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zaynah N Khan
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alisa Fuchs
- BIOSS, Centre for Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Albert-Ludwigs University of Freiburg, Freiburg, Germany.,Max-Planck Institute for Molecular Genetics, Berlin, Germany
| | - George Pyrowolakis
- BIOSS, Centre for Biological Signaling Studies and Institute for Biology I, Faculty of Biology, Albert-Ludwigs University of Freiburg, Freiburg, Germany
| | - Douglas W Allan
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
7
|
Chayengia M, Veikkolainen V, Jevtic M, Pyrowolakis G. Sequence environment of BMP-dependent activating elements controls transcriptional responses to Dpp signaling in Drosophila. Development 2019; 146:dev.176107. [PMID: 31110028 DOI: 10.1242/dev.176107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/14/2019] [Indexed: 11/20/2022]
Abstract
Intercellular signaling pathways activate transcription factors, which, along with tissue-specific co-factors, regulate expression of target genes. Responses to TGFβ/BMP signals are mediated by Smad proteins, which form complexes and accumulate in the nucleus to directly bind and regulate enhancers of BMP targets upon signaling. In Drosophila, gene activation by BMP signaling often requires, in addition to direct input by Smads, the signal-dependent removal of the transcriptional repressor Brk. Previous studies on enhancers of BMP-activated genes have defined a BMP-responsive motif, the AE, which integrates activatory and repressive input by the Smad complex and Brk, respectively. Here, we address whether sequence variations within the core AE sequences might endow the motif with additional properties accounting for qualitative and quantitative differences in BMP responses, including tissue specificity of transcriptional activation and differential sensitivity to Smad and Brk inputs. By analyzing and cross-comparing three distinct BMP-responsive enhancers from the genes wit and D ad in two different epithelia, the wing imaginal disc and the follicular epithelium, we demonstrate that differences in the AEs contribute neither to the observed tissue-restriction of BMP responses nor to differences in the utilization of the Smad and Brk branches for transcriptional activation. Rather, our results suggest that the cis-environment of the BMP-response elements not only dictates tissue specificity but also differential sensitivity to the two BMP mediators.
Collapse
Affiliation(s)
- Mrinal Chayengia
- Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany.,Research Training Program GRK 1104, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany.,Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Germany
| | - Ville Veikkolainen
- Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany.,Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Germany
| | - Milica Jevtic
- Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany
| | - George Pyrowolakis
- Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany .,Institute for Biology I, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Germany.,Center for Biological Systems Analysis, Albert-Ludwigs-University of Freiburg, Habsburgerstr. 49, 79104 Freiburg, Germany
| |
Collapse
|
8
|
A Notch-mediated, temporal asymmetry in BMP pathway activation promotes photoreceptor subtype diversification. PLoS Biol 2019; 17:e2006250. [PMID: 30703098 PMCID: PMC6372210 DOI: 10.1371/journal.pbio.2006250] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 02/12/2019] [Accepted: 01/22/2019] [Indexed: 11/19/2022] Open
Abstract
Neural progenitors produce neurons whose identities can vary as a function of the time that specification occurs. Here, we describe the heterochronic specification of two photoreceptor (PhR) subtypes in the zebrafish pineal gland. We find that accelerating PhR specification by impairing Notch signaling favors the early fate at the expense of the later fate. Using in vivo lineage tracing, we show that most pineal PhRs are born from a fate-restricted progenitor. Furthermore, sister cells derived from the division of PhR-restricted progenitors activate the bone morphogenetic protein (BMP) signaling pathway at different times after division, and this heterochrony requires Notch activity. Finally, we demonstrate that PhR identity is established as a function of when the BMP pathway is activated. We propose a novel model in which division of a progenitor with restricted potential generates sister cells with distinct identities via a temporal asymmetry in the activation of a signaling pathway. A major goal in the field of developmental neurobiology is to identify the mechanisms that underly the diversification of the subtypes of neurons that are needed for the function of the nervous system. When investigating these mechanisms, time is an often-overlooked variable. Here, we show that in the zebrafish pineal gland—a neuroendocrine organ containing mostly photoreceptors (PhRs) and projection neurons—different classes of PhRs appear in a temporal sequence. In this simple system, the decision to adopt a PhR fate is driven by the activation of the bone morphogenetic protein (BMP) signaling pathway. Following the final cell division of a PhR progenitor, the sister cells normally activate the BMP pathway at different times. When Notch signaling activity is abrogated, activation of the BMP pathway occurs earlier and synchronously, which in turn favors the development of early PhR fates at the expense of later fates. We propose a model in which preventing sister cells from activating a signaling pathway in a synchronous fashion after their final division allows diversification of cell fates.
Collapse
|
9
|
Zhao D, Chen S, Liu X. Lateral neural borders as precursors of peripheral nervous systems: A comparative view across bilaterians. Dev Growth Differ 2018; 61:58-72. [DOI: 10.1111/dgd.12585] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 11/14/2018] [Accepted: 11/14/2018] [Indexed: 01/13/2023]
Affiliation(s)
- Di Zhao
- School of Life Sciences; Capital Normal University; Beijing China
- Ministry of Education Key Laboratory of Bioinformatics; Center for Synthetic and Systems Biology; School of Life Sciences; Tsinghua University; Beijing China
| | - Siyu Chen
- Ministry of Education Key Laboratory of Bioinformatics; Center for Synthetic and Systems Biology; School of Life Sciences; Tsinghua University; Beijing China
| | - Xiao Liu
- School of Life Sciences; Capital Normal University; Beijing China
- Ministry of Education Key Laboratory of Bioinformatics; Center for Synthetic and Systems Biology; School of Life Sciences; Tsinghua University; Beijing China
| |
Collapse
|
10
|
Abstract
TGF-β family ligands function in inducing and patterning many tissues of the early vertebrate embryonic body plan. Nodal signaling is essential for the specification of mesendodermal tissues and the concurrent cellular movements of gastrulation. Bone morphogenetic protein (BMP) signaling patterns tissues along the dorsal-ventral axis and simultaneously directs the cell movements of convergence and extension. After gastrulation, a second wave of Nodal signaling breaks the symmetry between the left and right sides of the embryo. During these processes, elaborate regulatory feedback between TGF-β ligands and their antagonists direct the proper specification and patterning of embryonic tissues. In this review, we summarize the current knowledge of the function and regulation of TGF-β family signaling in these processes. Although we cover principles that are involved in the development of all vertebrate embryos, we focus specifically on three popular model organisms: the mouse Mus musculus, the African clawed frog of the genus Xenopus, and the zebrafish Danio rerio, highlighting the similarities and differences between these species.
Collapse
Affiliation(s)
- Joseph Zinski
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Benjamin Tajer
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Mary C Mullins
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| |
Collapse
|
11
|
Ricci L, Srivastava M. Wound-induced cell proliferation during animal regeneration. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e321. [PMID: 29719123 DOI: 10.1002/wdev.321] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 12/19/2022]
Abstract
Many animal species are capable of replacing missing tissues that are lost upon injury or amputation through the process of regeneration. Although the extent of regeneration is variable across animals, that is, some animals can regenerate any missing cell type whereas some can only regenerate certain organs or tissues, regulated cell proliferation underlies the formation of new tissues in most systems. Notably, many species display an increase in proliferation within hours or days upon wounding. While different cell types proliferate in response to wounding in various animal taxa, comparative molecular data are beginning to point to shared wound-induced mechanisms that regulate cell division during regeneration. Here, we synthesize current insights about early molecular pathways of regeneration from diverse model and emerging systems by considering these species in their evolutionary contexts. Despite the great diversity of mechanisms underlying injury-induced cell proliferation across animals, and sometimes even in the same species, similar pathways for proliferation have been implicated in distantly related species (e.g., small diffusible molecules, signaling from apoptotic cells, growth factor signaling, mTOR and Hippo signaling, and Wnt and Bmp pathways). Studies that explicitly interrogate molecular and cellular regenerative mechanisms in understudied animal phyla will reveal the extent to which early pathways in the process of regeneration are conserved or independently evolved. This article is categorized under: Comparative Development and Evolution > Body Plan Evolution Adult Stem Cells, Tissue Renewal, and Regeneration > Regeneration Comparative Development and Evolution > Model Systems.
Collapse
Affiliation(s)
- Lorenzo Ricci
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Mansi Srivastava
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| |
Collapse
|
12
|
Karaiskos N, Wahle P, Alles J, Boltengagen A, Ayoub S, Kipar C, Kocks C, Rajewsky N, Zinzen RP. The Drosophila embryo at single-cell transcriptome resolution. Science 2017; 358:194-199. [PMID: 28860209 DOI: 10.1126/science.aan3235] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/24/2017] [Indexed: 01/22/2023]
Abstract
By the onset of morphogenesis, Drosophila embryos consist of about 6000 cells that express distinct gene combinations. Here, we used single-cell sequencing of precisely staged embryos and devised DistMap, a computational mapping strategy to reconstruct the embryo and to predict spatial gene expression approaching single-cell resolution. We produced a virtual embryo with about 8000 expressed genes per cell. Our interactive Drosophila Virtual Expression eXplorer (DVEX) database generates three-dimensional virtual in situ hybridizations and computes gene expression gradients. We used DVEX to uncover patterned expression of transcription factors and long noncoding RNAs, as well as signaling pathway components. Spatial regulation of Hippo signaling during early embryogenesis suggests a mechanism for establishing asynchronous cell proliferation. Our approach is suitable to generate transcriptomic blueprints for other complex tissues.
Collapse
Affiliation(s)
- Nikos Karaiskos
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Philipp Wahle
- Systems Biology of Neural Tissue Differentiation, BIMSB, MDC, 13125 Berlin, Germany
| | - Jonathan Alles
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Anastasiya Boltengagen
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Salah Ayoub
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Claudia Kipar
- Systems Biology of Neural Tissue Differentiation, BIMSB, MDC, 13125 Berlin, Germany
| | - Christine Kocks
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 13125 Berlin, Germany.
| | - Robert P Zinzen
- Systems Biology of Neural Tissue Differentiation, BIMSB, MDC, 13125 Berlin, Germany.
| |
Collapse
|
13
|
Aguillon R, Blader P, Batut J. Patterning, morphogenesis, and neurogenesis of zebrafish cranial sensory placodes. Methods Cell Biol 2016; 134:33-67. [PMID: 27312490 DOI: 10.1016/bs.mcb.2016.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Peripheral sensory organs and ganglia found in the vertebrate head arise during embryonic development from distinct ectodermal thickenings, called cranial sensory placodes (adenohypophyseal, olfactory, lens, trigeminal, epibranchial, and otic). A series of patterning events leads to the establishment of these placodes. Subsequently, these placodes undergo specific morphogenetic movements and cell-type specification in order to shape the final placodal derivatives and to produce differentiated cell types necessary for their function. In this chapter, we will focus on recent studies in the zebrafish that have advanced our understanding of cranial sensory placode development. We will summarize the signaling events and their molecular effectors guiding the formation of the so-called preplacodal region, and the subsequent subdivision of this region along the anteroposterior axis that gives rise to specific placode identities as well as those controlling morphogenesis and neurogenesis. Finally, we will highlight the approaches used in zebrafish that have been established to precisely label cell populations, to follow their development, and/or to characterize cell fates within a specific placode.
Collapse
Affiliation(s)
- R Aguillon
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - P Blader
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - J Batut
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| |
Collapse
|
14
|
Bier E, De Robertis EM. BMP gradients: A paradigm for morphogen-mediated developmental patterning. Science 2015; 348:aaa5838. [DOI: 10.1126/science.aaa5838] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
15
|
Abstract
Evolutionary modifications in nervous systems enabled organisms to adapt to their specific environments and underlie the remarkable diversity of behaviors expressed by animals. Resolving the pathways that shaped and modified neural circuits during evolution remains a significant challenge. Comparative studies have revealed a surprising conservation in the intrinsic signaling systems involved in early patterning of bilaterian nervous systems but also raise the question of how neural circuit compositions and architectures evolved within specific animal lineages. In this review, we discuss the mechanisms that contributed to the emergence and diversity of animal nervous systems, focusing on the circuits governing vertebrate locomotion.
Collapse
Affiliation(s)
- Heekyung Jung
- Howard Hughes Medical Institute (HHMI), NYU Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA
| | - Jeremy S Dasen
- Howard Hughes Medical Institute (HHMI), NYU Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
16
|
BMP-dependent gene repression cascade in Drosophila eggshell patterning. Dev Biol 2015; 400:258-65. [PMID: 25704512 DOI: 10.1016/j.ydbio.2015.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 01/19/2015] [Accepted: 02/10/2015] [Indexed: 12/17/2022]
Abstract
Bone Morphogenetic Proteins (BMPs) signal by activating Smad transcription factors to control a number of decisions during animal development. In Drosophila, signaling by the BMP ligand Decapentaplegic (Dpp) involves the activity of brinker (brk) which, in most contexts, is repressed by Dpp. Brk encodes a transcription factor which represses BMP signaling output by antagonizing Smad-dependent target gene activation. Here, we study BMP-dependent gene regulation during Drosophila oogenesis by following the signal transmission from Dpp to its target broad (br), a gene with a crucial function in eggshell patterning. We identify regulatory sequences that account for expression of both brk and br, and connect these to the transcription factors of the pathway. We show that Dpp directly regulates brk transcription through Smad- and Schnurri (Shn)-dependent repression. Brk is epistatic to Dpp in br expression and activates br indirectly, through removal of a repressor, which is yet to be identified. Our work provides first cis-regulatory insights into transcriptional interpretation of BMP signaling in eggshell morphogenesis and defines a transcriptional cascade that connects Dpp to target gene regulation.
Collapse
|