1
|
Filippopoulou K, Konstantinides N. Evolution of patterning. FEBS J 2024; 291:663-671. [PMID: 37943156 DOI: 10.1111/febs.16995] [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: 06/19/2023] [Revised: 09/28/2023] [Accepted: 11/07/2023] [Indexed: 11/10/2023]
Abstract
Developing tissues are patterned in space and time; this enables them to differentiate their cell types and form complex structures to support different body plans. Although space and time are two independent entities, there are many examples of spatial patterns that originate from temporal ones. The most prominent example is the expression of the genes hunchback, Krüppel, pdm, and castor, which are expressed temporally in the neural stem cells of the Drosophila ventral nerve cord and spatially along the anteroposterior axis of the blastoderm stage embryo. In this Viewpoint, we investigate the relationship between space and time in specific examples of spatial and temporal patterns with the aim of gaining insight into the evolutionary history of patterning.
Collapse
|
2
|
Hamid A, Gutierrez A, Munroe J, Syed MH. The Drivers of Diversity: Integrated genetic and hormonal cues regulate neural diversity. Semin Cell Dev Biol 2023; 142:23-35. [PMID: 35915026 DOI: 10.1016/j.semcdb.2022.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/06/2022] [Accepted: 07/17/2022] [Indexed: 11/17/2022]
Abstract
Proper functioning of the nervous system relies not only on the generation of a vast repertoire of distinct neural cell types but also on the precise neural circuitry within them. How the generation of highly diverse neural populations is regulated during development remains a topic of interest. Landmark studies in Drosophila have identified the genetic and temporal cues regulating neural diversity and thus have provided valuable insights into our understanding of temporal patterning of the central nervous system. The development of the Drosophila central complex, which is mostly derived from type II neural stem cell (NSC) lineages, showcases how a small pool of NSCs can give rise to vast and distinct progeny. Similar to the human outer subventricular zone (OSVZ) neural progenitors, type II NSCs generate intermediate neural progenitors (INPs) to expand and diversify lineages that populate higher brain centers. Each type II NSC has a distinct spatial identity and timely regulated expression of many transcription factors and mRNA binding proteins. Additionally, INPs derived from them show differential expression of genes depending on their birth order. Together type II NSCs and INPs display a combinatorial temporal patterning that expands neural diversity of the central brain lineages. We cover advances in current understanding of type II NSC temporal patterning and discuss similarities and differences in temporal patterning mechanisms of various NSCs with a focus on how cell-intrinsic and extrinsic hormonal cues regulate temporal transitions in NSCs during larval development. Cell extrinsic ligands activate conserved signaling pathways and extrinsic hormonal cues act as a temporal switch that regulate temporal progression of the NSCs. We conclude by elaborating on how a progenitor's temporal code regulates the fate specification and identity of distinct neural types. At the end, we also discuss open questions in linking developmental cues to neural identity, circuits, and underlying behaviors in the adult fly.
Collapse
Affiliation(s)
- Aisha Hamid
- Department of Biology, University of New Mexico, Albuquerque, NM 87113, USA
| | - Andrew Gutierrez
- Department of Biology, University of New Mexico, Albuquerque, NM 87113, USA
| | - Jordan Munroe
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | | |
Collapse
|
3
|
Sun H, Hobert O. Temporal transitions in the postembryonic nervous system of the nematode Caenorhabditis elegans: Recent insights and open questions. Semin Cell Dev Biol 2023; 142:67-80. [PMID: 35688774 DOI: 10.1016/j.semcdb.2022.05.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
After the generation, differentiation and integration into functional circuitry, post-mitotic neurons continue to change certain phenotypic properties throughout postnatal juvenile stages until an animal has reached a fully mature state in adulthood. We will discuss such changes in the context of the nervous system of the nematode C. elegans, focusing on recent descriptions of anatomical and molecular changes that accompany postembryonic maturation of neurons. We summarize the characterization of genetic timer mechanisms that control these temporal transitions or maturational changes, and discuss that many but not all of these transitions relate to sexual maturation of the animal. We describe how temporal, spatial and sex-determination pathways are intertwined to sculpt the emergence of cell-type specific maturation events. Finally, we lay out several unresolved questions that should be addressed to move the field forward, both in C. elegans and in vertebrates.
Collapse
Affiliation(s)
- Haosheng Sun
- Department of Cell, Developmental, and Integrative Biology. University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, New York, USA
| |
Collapse
|
4
|
Early Neurogenesis and Gliogenesis in Drosophila. Neurogenetics 2023. [DOI: 10.1007/978-3-031-07793-7_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
5
|
Guo X, Zhang Y, Huang H, Xi R. A hierarchical transcription factor cascade regulates enteroendocrine cell diversity and plasticity in Drosophila. Nat Commun 2022; 13:6525. [PMID: 36316343 PMCID: PMC9622890 DOI: 10.1038/s41467-022-34270-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 10/19/2022] [Indexed: 11/07/2022] Open
Abstract
Enteroendocrine cells (EEs) represent a heterogeneous cell population in intestine and exert endocrine functions by secreting a diverse array of neuropeptides. Although many transcription factors (TFs) required for specification of EEs have been identified in both mammals and Drosophila, it is not understood how these TFs work together to generate this considerable subtype diversity. Here we show that EE diversity in adult Drosophila is generated via an "additive hierarchical TF cascade". Specifically, a combination of a master TF, a secondary-level TF and a tertiary-level TF constitute a "TF code" for generating EE diversity. We also discover a high degree of post-specification plasticity of EEs, as changes in the code-including as few as one distinct TF-allow efficient switching of subtype identities. Our study thus reveals a hierarchically-organized TF code that underlies EE diversity and plasticity in Drosophila, which can guide investigations of EEs in mammals and inform their application in medicine.
Collapse
Affiliation(s)
- Xingting Guo
- grid.410717.40000 0004 0644 5086National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China ,grid.12527.330000 0001 0662 3178Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| | - Yongchao Zhang
- grid.410717.40000 0004 0644 5086National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China ,grid.12527.330000 0001 0662 3178Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| | - Huanwei Huang
- grid.410717.40000 0004 0644 5086National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China ,grid.12527.330000 0001 0662 3178Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| | - Rongwen Xi
- grid.410717.40000 0004 0644 5086National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, 102206 Beijing, China ,grid.12527.330000 0001 0662 3178Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| |
Collapse
|
6
|
Rowton M, Perez-Cervantes C, Hur S, Jacobs-Li J, Lu E, Deng N, Guzzetta A, Hoffmann AD, Stocker M, Steimle JD, Lazarevic S, Oubaha S, Yang XH, Kim C, Yu S, Eckart H, Koska M, Hanson E, Chan SSK, Garry DJ, Kyba M, Basu A, Ikegami K, Pott S, Moskowitz IP. Hedgehog signaling activates a mammalian heterochronic gene regulatory network controlling differentiation timing across lineages. Dev Cell 2022; 57:2181-2203.e9. [PMID: 36108627 PMCID: PMC10506397 DOI: 10.1016/j.devcel.2022.08.009] [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: 01/14/2022] [Revised: 06/24/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022]
Abstract
Many developmental signaling pathways have been implicated in lineage-specific differentiation; however, mechanisms that explicitly control differentiation timing remain poorly defined in mammals. We report that murine Hedgehog signaling is a heterochronic pathway that determines the timing of progenitor differentiation. Hedgehog activity was necessary to prevent premature differentiation of second heart field (SHF) cardiac progenitors in mouse embryos, and the Hedgehog transcription factor GLI1 was sufficient to delay differentiation of cardiac progenitors in vitro. GLI1 directly activated a de novo progenitor-specific network in vitro, akin to that of SHF progenitors in vivo, which prevented the onset of the cardiac differentiation program. A Hedgehog signaling-dependent active-to-repressive GLI transition functioned as a differentiation timer, restricting the progenitor network to the SHF. GLI1 expression was associated with progenitor status across germ layers, and it delayed the differentiation of neural progenitors in vitro, suggesting a broad role for Hedgehog signaling as a heterochronic pathway.
Collapse
Affiliation(s)
- Megan Rowton
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Carlos Perez-Cervantes
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Suzy Hur
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Jessica Jacobs-Li
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Emery Lu
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Nikita Deng
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Alexander Guzzetta
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Andrew D Hoffmann
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Matthew Stocker
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Jeffrey D Steimle
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Sonja Lazarevic
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Sophie Oubaha
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Xinan H Yang
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Chul Kim
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Shuhan Yu
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Heather Eckart
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Mervenaz Koska
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Erika Hanson
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Sunny S K Chan
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Daniel J Garry
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN 55455, USA; Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Anindita Basu
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Kohta Ikegami
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Sebastian Pott
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA
| | - Ivan P Moskowitz
- Departments of Pediatrics, Pathology, Human Genetics, and Genetic Medicine, The University of Chicago, Chicago, IL, USA.
| |
Collapse
|
7
|
Ray A, Li X. A Notch-dependent transcriptional mechanism controls expression of temporal patterning factors in Drosophila medulla. eLife 2022; 11:e75879. [PMID: 36040415 PMCID: PMC9427115 DOI: 10.7554/elife.75879] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 07/19/2022] [Indexed: 11/24/2022] Open
Abstract
Temporal patterning is an important mechanism for generating a great diversity of neuron subtypes from a seemingly homogenous progenitor pool in both vertebrates and invertebrates. Drosophila neuroblasts are temporally patterned by sequentially expressed Temporal Transcription Factors (TTFs). These TTFs are proposed to form a transcriptional cascade based on mutant phenotypes, although direct transcriptional regulation between TTFs has not been verified in most cases. Furthermore, it is not known how the temporal transitions are coupled with the generation of the appropriate number of neurons at each stage. We use neuroblasts of the Drosophila optic lobe medulla to address these questions and show that the expression of TTFs Sloppy-paired 1/2 (Slp1/2) is directly regulated at the transcriptional level by two other TTFs and the cell-cycle dependent Notch signaling through two cis-regulatory elements. We also show that supplying constitutively active Notch can rescue the delayed transition into the Slp stage in cell cycle arrested neuroblasts. Our findings reveal a novel Notch-pathway dependent mechanism through which the cell cycle progression regulates the timing of a temporal transition within a TTF transcriptional cascade.
Collapse
Affiliation(s)
- Alokananda Ray
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Xin Li
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| |
Collapse
|
8
|
Konstantinides N, Holguera I, Rossi AM, Escobar A, Dudragne L, Chen YC, Tran TN, Martínez Jaimes AM, Özel MN, Simon F, Shao Z, Tsankova NM, Fullard JF, Walldorf U, Roussos P, Desplan C. A complete temporal transcription factor series in the fly visual system. Nature 2022; 604:316-322. [PMID: 35388222 PMCID: PMC9074256 DOI: 10.1038/s41586-022-04564-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 02/18/2022] [Indexed: 01/17/2023]
Abstract
The brain consists of thousands of neuronal types that are generated by stem cells producing different neuronal types as they age. In Drosophila, this temporal patterning is driven by the successive expression of temporal transcription factors (tTFs)1-6. Here we used single-cell mRNA sequencing to identify the complete series of tTFs that specify most Drosophila optic lobe neurons. We verify that tTFs regulate the progression of the series by activating the next tTF(s) and repressing the previous one(s), and also identify more complex mechanisms of regulation. Moreover, we establish the temporal window of origin and birth order of each neuronal type in the medulla and provide evidence that these tTFs are sufficient to explain the generation of all of the neuronal diversity in this brain region. Finally, we describe the first steps of neuronal differentiation and show that these steps are conserved in humans. We find that terminal differentiation genes, such as neurotransmitter-related genes, are present as transcripts, but not as proteins, in immature larval neurons. This comprehensive analysis of a temporal series of tTFs in the optic lobe offers mechanistic insights into how tTF series are regulated, and how they can lead to the generation of a complete set of neurons.
Collapse
Affiliation(s)
- Nikolaos Konstantinides
- Department of Biology, New York University, New York, NY, USA.
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France.
| | - Isabel Holguera
- Department of Biology, New York University, New York, NY, USA
| | - Anthony M Rossi
- Department of Biology, New York University, New York, NY, USA
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | | | | | - Yen-Chung Chen
- Department of Biology, New York University, New York, NY, USA
| | - Thinh N Tran
- Department of Biology, New York University, New York, NY, USA
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | | | | | - Félix Simon
- Department of Biology, New York University, New York, NY, USA
| | - Zhiping Shao
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, New York, NY, USA
| | - Nadejda M Tsankova
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - John F Fullard
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Homburg, Germany
| | - Panos Roussos
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, Institute for Genomics and Multiscale Biology, New York, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mental Illness Research, Education and Clinical Center (VISN 2 South), James J. Peters VA Medical Center, New York, NY, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY, USA.
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
9
|
Temporal transitions in the post-mitotic nervous system of Caenorhabditis elegans. Nature 2021; 600:93-99. [PMID: 34759317 PMCID: PMC8785361 DOI: 10.1038/s41586-021-04071-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 09/29/2021] [Indexed: 01/03/2023]
Abstract
In most animals, the majority of the nervous system is generated and assembled into neuronal circuits during embryonic development1. However, during juvenile stages, nervous systems still undergo extensive anatomical and functional changes to eventually form a fully mature nervous system by the adult stage2,3. The molecular changes in post-mitotic neurons across post-embryonic development and the genetic programs that control these temporal transitions are not well understood4,5. Here, using the model system Caenorhabditis elegans, we comprehensively characterized the distinct functional states (locomotor behaviour) and the corresponding distinct molecular states (transcriptome) of the post-mitotic nervous system across temporal transitions during post-embryonic development. We observed pervasive, neuron-type-specific changes in gene expression, many of which are controlled by the developmental upregulation of the conserved heterochronic microRNA LIN-4 and the subsequent promotion of a mature neuronal transcriptional program through the repression of its target, the transcription factor lin-14. The functional relevance of these molecular transitions are exemplified by a temporally regulated target gene of the LIN-14 transcription factor, nlp-45, a neuropeptide-encoding gene, which we find is required for several distinct temporal transitions in exploratory activity during post-embryonic development. Our study provides insights into regulatory strategies that control neuron-type-specific gene batteries to modulate distinct behavioural states across temporal, sexual and environmental dimensions of post-embryonic development.
Collapse
|
10
|
Transcriptional and epigenetic regulation of temporal patterning in neural progenitors. Dev Biol 2021; 481:116-128. [PMID: 34666024 DOI: 10.1016/j.ydbio.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/05/2021] [Accepted: 10/12/2021] [Indexed: 12/15/2022]
Abstract
During development, neural progenitors undergo temporal patterning as they age to sequentially generate differently fated progeny. Temporal patterning of neural progenitors is relatively well-studied in Drosophila. Temporal cascades of transcription factors or opposing temporal gradients of RNA-binding proteins are expressed in neural progenitors as they age to control the fates of the progeny. The temporal progression is mostly driven by intrinsic mechanisms including cross-regulations between temporal genes, but environmental cues also play important roles in certain transitions. Vertebrate neural progenitors demonstrate greater plasticity in response to extrinsic cues. Recent studies suggest that vertebrate neural progenitors are also temporally patterned by a combination of transcriptional and post-transcriptional mechanisms in response to extracellular signaling to regulate neural fate specification. In this review, we summarize recent advances in the study of temporal patterning of neural progenitors in Drosophila and vertebrates. We also discuss the involvement of epigenetic mechanisms, specifically the Polycomb group complexes and ATP-dependent chromatin remodeling complexes, in the temporal patterning of neural progenitors.
Collapse
|
11
|
Wang M, Du L, Lee AC, Li Y, Qin H, He J. Different lineage contexts direct common pro-neural factors to specify distinct retinal cell subtypes. J Cell Biol 2021; 219:151968. [PMID: 32699896 PMCID: PMC7480095 DOI: 10.1083/jcb.202003026] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 05/13/2020] [Accepted: 06/04/2020] [Indexed: 02/08/2023] Open
Abstract
How astounding neuronal diversity arises from variable cell lineages in vertebrates remains mostly elusive. By in vivo lineage tracing of ∼1,000 single zebrafish retinal progenitors, we identified a repertoire of subtype-specific stereotyped neurogenic lineages. Remarkably, within these stereotyped lineages, GABAergic amacrine cells were born with photoreceptor cells, whereas glycinergic amacrine cells were born with OFF bipolar cells. More interestingly, post-mitotic differentiation blockage of GABAergic and glycinergic amacrine cells resulted in their respecification into photoreceptor and bipolar cells, respectively, suggesting lineage constraint in cell subtype specification. Using single-cell RNA-seq and ATAC-seq analyses, we further identified lineage-specific progenitors, each defined by specific transcription factors that exhibited characteristic chromatin accessibility dynamics. Finally, single pro-neural factors could specify different neuron types/subtypes in a lineage-dependent manner. Our findings reveal the importance of lineage context in defining neuronal subtypes and provide a demonstration of in vivo lineage-dependent induction of unique retinal neuron subtypes for treatment purposes.
Collapse
Affiliation(s)
- Mei Wang
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Lei Du
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Aih Cheun Lee
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yan Li
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Huiwen Qin
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| | - Jie He
- State Key Laboratory of Neuroscience, Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China
| |
Collapse
|
12
|
Oproescu AM, Han S, Schuurmans C. New Insights Into the Intricacies of Proneural Gene Regulation in the Embryonic and Adult Cerebral Cortex. Front Mol Neurosci 2021; 14:642016. [PMID: 33658912 PMCID: PMC7917194 DOI: 10.3389/fnmol.2021.642016] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/26/2021] [Indexed: 12/21/2022] Open
Abstract
Historically, the mammalian brain was thought to lack stem cells as no new neurons were found to be made in adulthood. That dogma changed ∼25 years ago with the identification of neural stem cells (NSCs) in the adult rodent forebrain. However, unlike rapidly self-renewing mature tissues (e.g., blood, intestinal crypts, skin), the majority of adult NSCs are quiescent, and those that become 'activated' are restricted to a few neurogenic zones that repopulate specific brain regions. Conversely, embryonic NSCs are actively proliferating and neurogenic. Investigations into the molecular control of the quiescence-to-proliferation-to-differentiation continuum in the embryonic and adult brain have identified proneural genes encoding basic-helix-loop-helix (bHLH) transcription factors (TFs) as critical regulators. These bHLH TFs initiate genetic programs that remove NSCs from quiescence and drive daughter neural progenitor cells (NPCs) to differentiate into specific neural cell subtypes, thereby contributing to the enormous cellular diversity of the adult brain. However, new insights have revealed that proneural gene activities are context-dependent and tightly regulated. Here we review how proneural bHLH TFs are regulated, with a focus on the murine cerebral cortex, drawing parallels where appropriate to other organisms and neural tissues. We discuss upstream regulatory events, post-translational modifications (phosphorylation, ubiquitinylation), protein-protein interactions, epigenetic and metabolic mechanisms that govern bHLH TF expression, stability, localization, and consequent transactivation of downstream target genes. These tight regulatory controls help to explain paradoxical findings of changes to bHLH activity in different cellular contexts.
Collapse
Affiliation(s)
- Ana-Maria Oproescu
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Sisu Han
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Carol Schuurmans
- Sunnybrook Research Institute, Biological Sciences Platform, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
13
|
Sox2 knockdown in the neonatal retina causes cell fate to switch from amacrine to bipolar. Brain Res 2021; 1752:147265. [PMID: 33422527 DOI: 10.1016/j.brainres.2020.147265] [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: 10/09/2020] [Revised: 12/18/2020] [Accepted: 12/26/2020] [Indexed: 11/20/2022]
Abstract
Transcription factor Sox2 is widely recognized for its critical roles in the nervous system, including the neural retina. Here, we aimed to reveal the function of Sox2 in the process of mouse postnatal development. After the suppression of Sox2 at P0, there was an increase number in bipolar cells but a decrease in amacrine cells. Inhibited Sox2 expression also led to decreased visual function. Furthermore, we found a distinctive type of retinal cells expressing the characteristic proteins of both bipolar cells and amacrine cells at P6, which may be an intermediate state in which amacrine cells were transforming into bipolar cells. Transcription factors associated with the development of bipolar cells and amacrine cells also support those changes. Our work indicated that inhibition of Sox2 could change cell fate by affecting transcription factors in the development of bipolar cells and amacrine cells, may provide new directions for the study and treatment of retinal genetic diseases and retinal dysplasia.
Collapse
|
14
|
Development of motor circuits: From neuronal stem cells and neuronal diversity to motor circuit assembly. Curr Top Dev Biol 2020; 142:409-442. [PMID: 33706923 DOI: 10.1016/bs.ctdb.2020.11.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this review, we discuss motor circuit assembly starting from neuronal stem cells. Until recently, studies of neuronal stem cells focused on how a relatively small pool of stem cells could give rise to a large diversity of different neuronal identities. Historically, neuronal identity has been assayed in embryos by gene expression, gross anatomical features, neurotransmitter expression, and physiological properties. However, these definitions of identity are largely unlinked to mature functional neuronal features relevant to motor circuits. Such mature neuronal features include presynaptic and postsynaptic partnerships, dendrite morphologies, as well as neuronal firing patterns and roles in behavior. This review focuses on recent work that links the specification of neuronal molecular identity in neuronal stem cells to mature, circuit-relevant identity specification. Specifically, these studies begin to address the question: to what extent are the decisions that occur during motor circuit assembly controlled by the same genetic information that generates diverse embryonic neuronal diversity? Much of the research addressing this question has been conducted using the Drosophila larval motor system. Here, we focus largely on Drosophila motor circuits and we point out parallels to other systems. And we highlight outstanding questions in the field. The main concepts addressed in this review are: (1) the description of temporal cohorts-novel units of developmental organization that link neuronal stem cell lineages to motor circuit configuration and (2) the discovery that temporal transcription factors expressed in neuronal stem cells control aspects of circuit assembly by controlling the size of temporal cohorts and influencing synaptic partner choice.
Collapse
|
15
|
Myasnikova E, Spirov A. Gene regulatory networks in Drosophila early embryonic development as a model for the study of the temporal identity of neuroblasts. Biosystems 2020; 197:104192. [PMID: 32619531 DOI: 10.1016/j.biosystems.2020.104192] [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: 01/07/2020] [Revised: 04/30/2020] [Accepted: 06/21/2020] [Indexed: 11/27/2022]
Abstract
Genes belonging to the "gap" and "gap-like" family constitute the best-studied gene regulatory networks (GRNs) in Drosophila embryogenesis. Gap genes are a core of two subnetworks controlling embryonic segmentation: (hunchback, hb; Krüppel, Kr; giant, gt; and knirps, kni) and (hb; Kr; pou-domain, pdm; and, probably, castor, cas). Of particular interest is that (hb, Kr, pdm, cas) also specifies the temporal identity of stem cells, neuroblasts, in Drosophila neurogenesis. This GRN controls the sequential differentiation of neuroblasts during the asymmetric cell division. In the last decades, modeling of the patterning of gene ensemble (hb, Kr, gt, kni) in segmentation was in the center of attention. We show that our previously published and extensively studied model at a certain level of external factors is able to reproduce temporal patterns of (hb, Kr, pdm, cas) in neurogenesis with minor evolutionary explicable modifications. This result testifies in favor of a hypothesis that the similarity of two gene ensembles active in segmentation and neurogenesis is a result of co-option of the network architecture in evolution from the common ancestral form. By means of the model dynamical analysis, it is shown that the establishment of the robust patterns in both systems could be explained in terms of the action of attractors in the gap gene dynamical system. We formulate the common principles underlying the robustness of both GRNs in segmentation and neurogenesis due to the similar functional organization of the gene ensembles as having the same evolutionary origin.
Collapse
Affiliation(s)
- Ekaterina Myasnikova
- Peter the Great Saint-Petersburg Polytechnical University, 29 Politekhnicheskaya str, St. Petersburg, 195251, Russia.
| | - Alexander Spirov
- I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry Russian Academy of Sciences, 44 Thorez Pr, St.Petersburg, 194223, Russia; Computer Science and CEWIT, SUNY Stony Brook, Stony Brook, 1500 Stony Brook Road, Stony Brook, 11794, NY, USA
| |
Collapse
|
16
|
Sizemore Blevins A, Bassett DS. Reorderability of node-filtered order complexes. Phys Rev E 2020; 101:052311. [PMID: 32575295 DOI: 10.1103/physreve.101.052311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 02/19/2020] [Indexed: 06/11/2023]
Abstract
Growing graphs describe a multitude of developing processes from maturing brains to expanding vocabularies to burgeoning public transit systems. Each of these growing processes likely adheres to proliferation rules that establish an effective order of node and connection emergence. When followed, such proliferation rules allow the system to properly develop along a predetermined trajectory. But rules are rarely followed. Here we ask what topological changes in the growing graph trajectories might occur after the specific but basic perturbation of permuting the node emergence order. Specifically, we harness applied topological methods to determine which of six growing graph models exhibit topology that is robust to randomizing node order, termed global reorderability, and robust to temporally local node swaps, termed local reorderability. We find that the six graph models fall upon a spectrum of both local and global reorderability, and furthermore we provide theoretical connections between robustness to node pair ordering and robustness to arbitrary node orderings. Finally, we discuss real-world applications of reorderability analyses and suggest possibilities for designing reorderable networks.
Collapse
Affiliation(s)
- Ann Sizemore Blevins
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Danielle S Bassett
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Physics and Astronomy, College of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Electrical and Systems Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Santa Fe Institute, Santa Fe, New Mexico 87501, USA
| |
Collapse
|
17
|
Hartenstein V, Omoto JJ, Lovick JK. The role of cell lineage in the development of neuronal circuitry and function. Dev Biol 2020; 475:165-180. [PMID: 32017903 DOI: 10.1016/j.ydbio.2020.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 01/23/2020] [Accepted: 01/23/2020] [Indexed: 12/13/2022]
Abstract
Complex nervous systems have a modular architecture, whereby reiterative groups of neurons ("modules") that share certain structural and functional properties are integrated into large neural circuits. Neurons develop from proliferating progenitor cells that, based on their location and time of appearance, are defined by certain genetic programs. Given that genes expressed by a given progenitor play a fundamental role in determining the properties of its lineage (i.e., the neurons descended from that progenitor), one efficient developmental strategy would be to have lineages give rise to the structural modules of the mature nervous system. It is clear that this strategy plays an important role in neural development of many invertebrate animals, notably insects, where the availability of genetic techniques has made it possible to analyze the precise relationship between neuronal origin and differentiation since several decades. Similar techniques, developed more recently in the vertebrate field, reveal that functional modules of the mammalian cerebral cortex are also likely products of developmentally defined lineages. We will review studies that relate cell lineage to circuitry and function from a comparative developmental perspective, aiming at enhancing our understanding of neural progenitors and their lineages, and translating findings acquired in different model systems into a common conceptual framework.
Collapse
Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA.
| | - Jaison J Omoto
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Jennifer K Lovick
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| |
Collapse
|
18
|
Cembran A, Bruggeman KF, Williams RJ, Parish CL, Nisbet DR. Biomimetic Materials and Their Utility in Modeling the 3-Dimensional Neural Environment. iScience 2020; 23:100788. [PMID: 31954980 PMCID: PMC6970178 DOI: 10.1016/j.isci.2019.100788] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/30/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023] Open
Abstract
The brain is a complex 3-dimensional structure, the organization of which provides a local environment that directly influences the survival, proliferation, differentiation, migration, and plasticity of neurons. To probe the effects of damage and disease on these cells, a synthetic environment is needed. Three-dimensional culturing of stem cells, neural progenitors, and neurons within fabricated biomaterials has demonstrated superior biomimetic properties over conventional 2-dimensional cultureware, offering direct recapitulation of both cell-cell and cell-extracellular matrix interactions. Within this review we address the benefits of deploying biomaterials as advanced cell culture tools capable of influencing neuronal fate and as in vitro models of the native in vivo microenvironment. We highlight recent and promising biomaterials approaches toward understanding neural network and their function relevant to neurodevelopment and provide our perspective on how these materials can be engineered and programmed to study both the healthy and diseased nervous system.
Collapse
Affiliation(s)
- Arianna Cembran
- Laboratory of Advanced Biomaterials, Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2600, Australia
| | - Kiara F Bruggeman
- Laboratory of Advanced Biomaterials, Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2600, Australia
| | | | - Clare L Parish
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Melbourne, VIC 3010, Australia.
| | - David R Nisbet
- Laboratory of Advanced Biomaterials, Research School of Electrical, Energy and Materials Engineering, The Australian National University, Canberra, ACT 2600, Australia.
| |
Collapse
|
19
|
Meng JL, Wang Y, Carrillo RA, Heckscher ES. Temporal transcription factors determine circuit membership by permanently altering motor neuron-to-muscle synaptic partnerships. eLife 2020; 9:56898. [PMID: 32391795 PMCID: PMC7242025 DOI: 10.7554/elife.56898] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/09/2020] [Indexed: 01/01/2023] Open
Abstract
How circuit wiring is specified is a key question in developmental neurobiology. Previously, using the Drosophila motor system as a model, we found the classic temporal transcription factor Hunchback acts in NB7-1 neuronal stem cells to control the number of NB7-1 neuronal progeny form functional synapses on dorsal muscles (Meng et al., 2019). However, it is unknown to what extent control of motor neuron-to-muscle synaptic partnerships is a general feature of temporal transcription factors. Here, we perform additional temporal transcription factor manipulations-prolonging expression of Hunchback in NB3-1, as well as precociously expressing Pdm and Castor in NB7-1. We use confocal microscopy, calcium imaging, and electrophysiology to show that in every manipulation there are permanent alterations in neuromuscular synaptic partnerships. Our data show temporal transcription factors, as a group of molecules, are potent determinants of synaptic partner choice and therefore ultimately control circuit membership.
Collapse
Affiliation(s)
- Julia L Meng
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicagoUnited States,Program in Cell and Molecular Biology, University of ChicagoChicagoUnited States
| | - Yupu Wang
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicagoUnited States,Committee on Development, Regeneration, and Stem Cell Biology, University of ChicagoChicagoUnited States
| | - Robert A Carrillo
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicagoUnited States,Program in Cell and Molecular Biology, University of ChicagoChicagoUnited States,Committee on Development, Regeneration, and Stem Cell Biology, University of ChicagoChicagoUnited States,Grossman Institute for Neuroscience, University of ChicagoChicagoUnited States
| | - Ellie S Heckscher
- Department of Molecular Genetics and Cell Biology, University of ChicagoChicagoUnited States,Program in Cell and Molecular Biology, University of ChicagoChicagoUnited States,Committee on Development, Regeneration, and Stem Cell Biology, University of ChicagoChicagoUnited States,Grossman Institute for Neuroscience, University of ChicagoChicagoUnited States
| |
Collapse
|
20
|
Li X, Zhou W, Li X, Gao M, Ji S, Tian W, Ji G, Du J, Hao A. SOX19b regulates the premature neuronal differentiation of neural stem cells through EZH2-mediated histone methylation in neural tube development of zebrafish. Stem Cell Res Ther 2019; 10:389. [PMID: 31842983 PMCID: PMC6915949 DOI: 10.1186/s13287-019-1495-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/29/2019] [Accepted: 11/14/2019] [Indexed: 12/15/2022] Open
Abstract
Objective Neural tube defects (NTDs) are the most serious and common birth defects in the clinic. The SRY-related HMG box B1 (SoxB1) gene family has been implicated in different processes of early embryogenesis. Sox19b is a maternally expressed gene in the SoxB1 family that is found in the region of the presumptive central nervous system (CNS), but its role and mechanism in embryonic neural stem cells (NSCs) during neural tube development have not yet been explored. Considering that Sox19b is specific to bony fish, we intended to investigate the role and mechanism of Sox19b in neural tube development in zebrafish embryos. Material and methods Morpholino (MO) antisense oligonucleotides were used to construct a Sox19b loss-of-function zebrafish model. The phenotype and the expression of related genes were analysed by in situ hybridization and immunolabelling. Epigenetic modifications were detected by western blot and chromatin immunoprecipitation. Results In this study, we found that zebrafish embryos exhibited a reduced or even deleted forebrain phenotype after the expression of the Sox19b gene was inhibited. Moreover, we found for the first time that knockdown of Sox19b reduced the proliferation of NSCs; increased the transcription levels of Ngn1, Ascl1, HuC, Islet1, and cyclin-dependent kinase (CDK) inhibitors; and led to premature differentiation of NSCs. Finally, we found that knockdown of Sox19b decreased the levels of EZH2/H3K27me3 and decreased the level of H3K27me3 at the promoters of Ngn1 and ascl1a. Conclusion Together, our data demonstrate that Sox19b plays an essential role in early NSC proliferation and differentiation through EZH2-mediated histone methylation in neural tube development. This study established the role of transcription factor Sox19b and epigenetic factor EZH2 regulatory network on NSC development, which provides new clues and theoretical guidance for the clinical treatment of neural tube defects.
Collapse
Affiliation(s)
- Xian Li
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.,Foot and Ankle Surgery Center of Shandong University and Department of Hand and Foot Surgery, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Wenjuan Zhou
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Xinyue Li
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Ming Gao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Center for Reproductive Medicine, Shandong University, Jinan, China
| | - Shufang Ji
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Wenyu Tian
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Guangyu Ji
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Jingyi Du
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.
| |
Collapse
|
21
|
Analysis of Complete Neuroblast Cell Lineages in the Drosophila Embryonic Brain via DiI Labeling. Methods Mol Biol 2019. [PMID: 31552652 DOI: 10.1007/978-1-4939-9732-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Proper functioning of the brain relies on an enormous diversity of neural cells generated by neural stem cell-like neuroblasts (NBs). Each of the about 100 NBs in each side of brain generates a nearly invariant and unique cell lineage, consisting of specific neural cell types that develop in defined time periods. In this chapter we describe a method that labels entire NB lineages in the embryonic brain. Clonal DiI labeling allows us to follow the development of an NB lineage starting from the neuroectodermal precursor cell up to the fully developed cell clone in the first larval instar brain. We also show how to ablate individual cells within an NB clone, which reveals information about the temporal succession in which daughter cells are generated. Finally, we describe how to combine clonal DiI labeling with fluorescent antibody staining that permits relating protein expression to individual cells within a labeled NB lineage. These protocols make it feasible to uncover precise lineage relationships between a brain NB and its daughter cells, and to assign gene expression to individual clonal cells. Such lineage-based information is a critical key for understanding the cellular and molecular mechanisms that underlie specification of cell fates in spatial and temporal dimension in the embryonic brain.
Collapse
|
22
|
Catela C, Kratsios P. Transcriptional mechanisms of motor neuron development in vertebrates and invertebrates. Dev Biol 2019; 475:193-204. [PMID: 31479648 DOI: 10.1016/j.ydbio.2019.08.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 07/08/2019] [Accepted: 08/29/2019] [Indexed: 02/04/2023]
Abstract
Across phylogeny, motor neurons (MNs) represent a single but often remarkably diverse neuronal class composed of a multitude of subtypes required for vital behaviors, such as eating and locomotion. Over the past decades, seminal studies in multiple model organisms have advanced our molecular understanding of the early steps of MN development, such as progenitor specification and acquisition of MN subtype identity, by revealing key roles for several evolutionarily conserved transcription factors. However, very little is known about the molecular strategies that allow distinct MN subtypes to maintain their identity- and function-defining features during the late steps of development and postnatal life. Here, we provide an overview of invertebrate and vertebrate studies on transcription factor-based strategies that control early and late steps of MN development, aiming to highlight evolutionarily conserved gene regulatory principles necessary for establishment and maintenance of neuronal identity.
Collapse
Affiliation(s)
- Catarina Catela
- Department of Neurobiology, University of Chicago, Chicago, IL, 60637, USA; The Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL, 60637, USA; The Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, The University of Chicago, Chicago, IL, USA.
| |
Collapse
|
23
|
Spirov AV, Myasnikova EM. Evolutionary Stability of Gene Regulatory Networks That Define the Temporal Identity of Neuroblasts. Mol Biol 2019. [DOI: 10.1134/s0026893319020158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
24
|
Seroka AQ, Doe CQ. The Hunchback temporal transcription factor determines motor neuron axon and dendrite targeting in Drosophila. Development 2019; 146:dev175570. [PMID: 30890568 PMCID: PMC6467472 DOI: 10.1242/dev.175570] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 03/11/2019] [Indexed: 12/14/2022]
Abstract
The generation of neuronal diversity is essential for circuit formation and behavior. Morphological differences in sequentially born neurons could be due to intrinsic molecular identity specified by temporal transcription factors (henceforth called intrinsic temporal identity) or due to changing extrinsic cues. Here, we have used the Drosophila NB7-1 lineage to address this issue. NB7-1 generates the U1-U5 motor neurons sequentially; each has a distinct intrinsic temporal identity due to inheritance of different temporal transcription factors at its time of birth. We show that the U1-U5 neurons project axons sequentially, followed by sequential dendrite extension. We misexpressed the earliest temporal transcription factor, Hunchback, to create 'ectopic' U1 neurons with an early intrinsic temporal identity but later birth-order. These ectopic U1 neurons have axon muscle targeting and dendrite neuropil targeting that are consistent with U1 intrinsic temporal identity, rather than with their time of birth or differentiation. We conclude that intrinsic temporal identity plays a major role in establishing both motor axon muscle targeting and dendritic arbor targeting, which are required for proper motor circuit development.
Collapse
Affiliation(s)
- Austin Q Seroka
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| | - Chris Q Doe
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| |
Collapse
|
25
|
Averbukh I, Lai SL, Doe CQ, Barkai N. A repressor-decay timer for robust temporal patterning in embryonic Drosophila neuroblast lineages. eLife 2018; 7:38631. [PMID: 30526852 PMCID: PMC6303102 DOI: 10.7554/elife.38631] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 12/10/2018] [Indexed: 11/13/2022] Open
Abstract
Biological timers synchronize patterning processes during embryonic development. In the Drosophila embryo, neural progenitors (neuroblasts; NBs) produce a sequence of unique neurons whose identities depend on the sequential expression of temporal transcription factors (TTFs). The stereotypy and precision of NB lineages indicate reproducible TTF timer progression. We combine theory and experiments to define the timer mechanism. The TTF timer is commonly described as a relay of activators, but its regulatory circuit is also consistent with a repressor-decay timer, where TTF expression begins when its repressor decays. Theory shows that repressor-decay timers are more robust to parameter variations than activator-relay timers. This motivated us to experimentally compare the relative importance of the relay and decay interactions in vivo. Comparing WT and mutant NBs at high temporal resolution, we show that the TTF sequence progresses primarily by repressor-decay. We suggest that need for robust performance shapes the evolutionary-selected designs of biological circuits.
Collapse
Affiliation(s)
- Inna Averbukh
- Department of Molecular Genetics, Weizmann institute of science, Rehovot, Israel
| | - Sen-Lin Lai
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Chris Q Doe
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, United States
| | - Naama Barkai
- Department of Molecular Genetics, Weizmann institute of science, Rehovot, Israel
| |
Collapse
|
26
|
Pérez Saturnino A, Lust K, Wittbrodt J. Notch signalling patterns retinal composition by regulating atoh7 during post-embryonic growth. Development 2018; 145:dev.169698. [PMID: 30337377 PMCID: PMC6240314 DOI: 10.1242/dev.169698] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/09/2018] [Indexed: 01/01/2023]
Abstract
Patterning of a continuously growing naive field in the context of a life-long growing organ such as the teleost eye is of high functional relevance. Intrinsic and extrinsic signals have been proposed to regulate lineage specification in progenitors that exit the stem cell niche in the ciliary marginal zone (CMZ). The proper cell-type composition arising from those progenitors is a prerequisite for retinal function. Our findings in the teleost medaka (Oryzias latipes) uncover that the Notch-Atoh7 axis continuously patterns the CMZ. The complement of cell types originating from the two juxtaposed progenitors marked by Notch or Atoh7 activity contains all constituents of a retinal column. Modulation of Notch signalling specifically in Atoh7-expressing cells demonstrates the crucial role of this axis in generating the correct cell-type proportions. After transiently blocking Notch signalling, retinal patterning and differentiation is re-initiated de novo. Taken together, our data show that Notch activity in the CMZ continuously structures the growing retina by juxtaposing Notch and Atoh7 progenitors that give rise to distinct complementary lineages, revealing coupling of de novo patterning and cell-type specification in the respective lineages. Summary: Mutually exclusive activity of Notch and Atoh7 in the ciliary marginal zone gives rise to two distinct lineages resulting in specification of the full complement of cell types in medaka retina.
Collapse
Affiliation(s)
- Alicia Pérez Saturnino
- Centre for Organismal Studies, Heidelberg University, Heidelberg 69120, Germany.,Heidelberg Biosciences International Graduate School (HBIGS), Heidelberg 69120, Germany
| | - Katharina Lust
- Centre for Organismal Studies, Heidelberg University, Heidelberg 69120, Germany
| | - Joachim Wittbrodt
- Centre for Organismal Studies, Heidelberg University, Heidelberg 69120, Germany
| |
Collapse
|
27
|
Han S, Dennis DJ, Balakrishnan A, Dixit R, Britz O, Zinyk D, Touahri Y, Olender T, Brand M, Guillemot F, Kurrasch D, Schuurmans C. A non-canonical role for the proneural gene Neurog1 as a negative regulator of neocortical neurogenesis. Development 2018; 145:dev157719. [PMID: 30201687 PMCID: PMC6198467 DOI: 10.1242/dev.157719] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 08/31/2018] [Indexed: 02/05/2023]
Abstract
Neural progenitors undergo temporal identity transitions to sequentially generate the neuronal and glial cells that make up the mature brain. Proneural genes have well-characterised roles in promoting neural cell differentiation and subtype specification, but they also regulate the timing of identity transitions through poorly understood mechanisms. Here, we investigated how the highly related proneural genes Neurog1 and Neurog2 interact to control the timing of neocortical neurogenesis. We found that Neurog1 acts in an atypical fashion as it is required to suppress rather than promote neuronal differentiation in early corticogenesis. In Neurog1-/- neocortices, early born neurons differentiate in excess, whereas, in vitro, Neurog1-/- progenitors have a decreased propensity to proliferate and form neurospheres. Instead, Neurog1-/- progenitors preferentially generate neurons, a phenotype restricted to the Neurog2+ progenitor pool. Mechanistically, Neurog1 and Neurog2 heterodimerise, and while Neurog1 and Neurog2 individually promote neurogenesis, misexpression together blocks this effect. Finally, Neurog1 is also required to induce the expression of neurogenic factors (Dll1 and Hes5) and to repress the expression of neuronal differentiation genes (Fezf2 and Neurod6). Neurog1 thus employs different mechanisms to temper the pace of early neocortical neurogenesis.
Collapse
Affiliation(s)
- Sisu Han
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Daniel J Dennis
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
- Department of Molecular Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Anjali Balakrishnan
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Rajiv Dixit
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Olivier Britz
- The Francis Crick Institute-Mill Hill Laboratory, London NW7 1AA, UK
| | - Dawn Zinyk
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Yacine Touahri
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
| | - Thomas Olender
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Marjorie Brand
- Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | | | - Deborah Kurrasch
- Department of Molecular Genetics, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Carol Schuurmans
- Biological Sciences Platform, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
- Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| |
Collapse
|
28
|
Kuzin A, Smith S, Brody T, Odenwald WF. Structure and cis-regulatory analysis of a Drosophila grainyhead neuroblast enhancer. Genesis 2018; 56:e23094. [PMID: 29417712 DOI: 10.1002/dvg.23094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 02/06/2023]
Abstract
Evolutionary analysis of cis-regulatory DNA reveals that enhancers consist of clusters of conserved sequence blocks (CSBs) that are made up of both unique and repeated sequence elements. This study seeks to address the basis for spatial and temporal regulation of neuroblas. A search for temporally restricted CNS NB enhancers identified one within the transcription factor grainyhead (grh) gene locus. The intronic enhancer, grh-15, contains two separable semi-autonomous activities, one that drives expression predominantly within the developing brain NBs and another in ventral cord NBs. To gain insight into the function of the CSBs constituting the brain-specific enhancer, we have systematically deleted each CSB and compared the activity of the altered enhancer to that of the full brain-specific enhancer. While our results indicate that information regulating enhancer activity is highly redundant, we have found that individual CSBs convey expression in subsets of larval lineages that are generated from either Type I or Type II NBs. These studies also highlight how evolutionary sequence conservation can be used as a guide the functional analysis of cis-regulatory DNA.
Collapse
Affiliation(s)
- Alexander Kuzin
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Svetlana Smith
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Thomas Brody
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Ward F Odenwald
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| |
Collapse
|
29
|
Abstract
A small pool of neural progenitors generates the vast diversity of cell types in the CNS. Spatial patterning specifies progenitor identity, followed by temporal patterning within progenitor lineages to expand neural diversity. Recent work has shown that in Drosophila, all neural progenitors (neuroblasts) sequentially express temporal transcription factors (TTFs) that generate molecular and cellular diversity. Embryonic neuroblasts use a lineage-intrinsic cascade of five TTFs that switch nearly every neuroblast cell division; larval optic lobe neuroblasts also use a rapid cascade of five TTFs, but the factors are completely different. In contrast, larval central brain neuroblasts undergo a major molecular transition midway through larval life, and this transition is regulated by a lineage-extrinsic cue (ecdysone hormone signaling). Overall, every neuroblast lineage uses a TTF cascade to generate diversity, illustrating the widespread importance of temporal patterning.
Collapse
Affiliation(s)
- Chris Q Doe
- Institute of Neuroscience, Institute of Molecular Biology, and Howard Hughes Medical Institute (HHMI), University of Oregon, Eugene, Oregon 97403;
| |
Collapse
|
30
|
Bertacchi M, Parisot J, Studer M. The pleiotropic transcriptional regulator COUP-TFI plays multiple roles in neural development and disease. Brain Res 2018; 1705:75-94. [PMID: 29709504 DOI: 10.1016/j.brainres.2018.04.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 12/23/2022]
Abstract
Transcription factors are expressed in a dynamic fashion both in time and space during brain development, and exert their roles by activating a cascade of multiple target genes. This implies that understanding the precise function of a transcription factor becomes a challenging task. In this review, we will focus on COUP-TFI (or NR2F1), a nuclear receptor belonging to the superfamily of the steroid/thyroid hormone receptors, and considered to be one of the major transcriptional regulators orchestrating cortical arealization, cell-type specification and maturation. Recent data have unraveled the multi-faceted functions of COUP-TFI in the development of several mouse brain structures, including the neocortex, hippocampus and ganglionic eminences. Despite NR2F1 mutations and deletions in humans have been linked to a complex neurodevelopmental disease mainly associated to optic atrophy and intellectual disability, its role during the formation of the retina and optic nerve remains unclear. In light of its major influence in cortical development, we predict that its haploinsufficiency might be the cause of other cognitive diseases, not identified so far. Mouse models offer a unique opportunity of dissecting COUP-TFI function in different regions during brain assembly; hence, the importance of comparing and discussing common points linking mouse models to human patients' symptoms.
Collapse
Affiliation(s)
- Michele Bertacchi
- Université Côte d'Azur, CNRS, Inserm, iBV - Institut de Biologie Valrose, 06108 Nice, France.
| | - Josephine Parisot
- Université Côte d'Azur, CNRS, Inserm, iBV - Institut de Biologie Valrose, 06108 Nice, France
| | - Michèle Studer
- Université Côte d'Azur, CNRS, Inserm, iBV - Institut de Biologie Valrose, 06108 Nice, France.
| |
Collapse
|
31
|
Adnani L, Han S, Li S, Mattar P, Schuurmans C. Mechanisms of Cortical Differentiation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 336:223-320. [DOI: 10.1016/bs.ircmb.2017.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
32
|
Hartenstein V, Omoto JJ, Ngo KT, Wong D, Kuert PA, Reichert H, Lovick JK, Younossi-Hartenstein A. Structure and development of the subesophageal zone of the Drosophila brain. I. Segmental architecture, compartmentalization, and lineage anatomy. J Comp Neurol 2018; 526:6-32. [PMID: 28730682 PMCID: PMC5963519 DOI: 10.1002/cne.24287] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/13/2017] [Accepted: 07/17/2017] [Indexed: 02/03/2023]
Abstract
The subesophageal zone (SEZ) of the Drosophila brain houses the circuitry underlying feeding behavior and is involved in many other aspects of sensory processing and locomotor control. Formed by the merging of four neuromeres, the internal architecture of the SEZ can be best understood by identifying segmentally reiterated landmarks emerging in the embryo and larva, and following the gradual changes by which these landmarks become integrated into the mature SEZ during metamorphosis. In previous works, the system of longitudinal fibers (connectives) and transverse axons (commissures) has been used as a scaffold that provides internal landmarks for the neuromeres of the larval ventral nerve cord. We have extended the analysis of this scaffold to the SEZ and, in addition, reconstructed the tracts formed by lineages and nerves in relationship to the connectives and commissures. As a result, we establish reliable criteria that define boundaries between the four neuromeres (tritocerebrum, mandibular neuromere, maxillary neuromere, labial neuromere) of the SEZ at all stages of development. Fascicles and lineage tracts also demarcate seven columnar neuropil domains (ventromedial, ventro-lateral, centromedial, central, centrolateral, dorsomedial, dorsolateral) identifiable throughout development. These anatomical subdivisions, presented in the form of an atlas including confocal sections and 3D digital models for the larval, pupal and adult stage, allowed us to describe the morphogenetic changes shaping the adult SEZ. Finally, we mapped MARCM-labeled clones of all secondary lineages of the SEZ to the newly established neuropil subdivisions. Our work will facilitate future studies of function and comparative anatomy of the SEZ.
Collapse
Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Jaison J. Omoto
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Kathy T. Ngo
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Darren Wong
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | | | | | - Jennifer K. Lovick
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Amelia Younossi-Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
33
|
Bonneaud N, Layalle S, Colomb S, Jourdan C, Ghysen A, Severac D, Dantec C, Nègre N, Maschat F. Control of nerve cord formation by Engrailed and Gooseberry-Neuro: A multi-step, coordinated process. Dev Biol 2017; 432:273-285. [PMID: 29097190 DOI: 10.1016/j.ydbio.2017.10.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 10/06/2017] [Accepted: 10/24/2017] [Indexed: 01/05/2023]
Abstract
One way to better understand the molecular mechanisms involved in the construction of a nervous system is to identify the downstream effectors of major regulatory proteins. We previously showed that Engrailed (EN) and Gooseberry-Neuro (GsbN) transcription factors act in partnership to drive the formation of posterior commissures in the central nervous system of Drosophila. In this report, we identified genes regulated by both EN and GsbN through chromatin immunoprecipitation ("ChIP on chip") and transcriptome experiments, combined to a genetic screen relied to the gene dose titration method. The genomic-scale approaches allowed us to define 175 potential targets of EN-GsbN regulation. We chose a subset of these genes to examine ventral nerve cord (VNC) defects and found that half of the mutated targets show clear VNC phenotypes when doubly heterozygous with en or gsbn mutations, or when homozygous. This strategy revealed new groups of genes never described for their implication in the construction of the nerve cord. Their identification suggests that, to construct the nerve cord, EN-GsbN may act at three levels, in: (i) sequential control of the attractive-repulsive signaling that ensures contralateral projection of the commissural axons, (ii) temporal control of the translation of some mRNAs, (iii) regulation of the capability of glial cells to act as commissural guideposts for developing axons. These results illustrate how an early, coordinated transcriptional control may orchestrate the various mechanisms involved in the formation of stereotyped neuronal networks. They also validate the overall strategy to identify genes that play crucial role in axonal pathfinding.
Collapse
Affiliation(s)
- Nathalie Bonneaud
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France; CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France
| | - Sophie Layalle
- CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France; CNRS - INSERM - Université de Montpellier, UMR-5203, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Sophie Colomb
- CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France
| | - Christophe Jourdan
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France
| | - Alain Ghysen
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France
| | - Dany Severac
- MGX - Montpellier GenomiX, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Christelle Dantec
- MGX - Montpellier GenomiX, Institut de Génomique Fonctionnelle, Montpellier F-34094, France
| | - Nicolas Nègre
- DGIMI, INRA, Université de Montpellier, 34095 Montpellier, France; Institut Universitaire de France (IUF), Paris, France
| | - Florence Maschat
- MMDN, Univ. Montpellier, EPHE, INSERM, U1198, Montpellier, F-34095 France; CNRS,UPR1142, Institut de Génétique Humaine, Montpellier, F-34094, France.
| |
Collapse
|
34
|
Saraiva C, Esteves M, Bernardino L. MicroRNA: Basic concepts and implications for regeneration and repair of neurodegenerative diseases. Biochem Pharmacol 2017; 141:118-131. [DOI: 10.1016/j.bcp.2017.07.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/07/2017] [Indexed: 12/25/2022]
|
35
|
Pten Regulates Retinal Amacrine Cell Number by Modulating Akt, Tgfβ, and Erk Signaling. J Neurosci 2017; 36:9454-71. [PMID: 27605619 DOI: 10.1523/jneurosci.0936-16.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/18/2016] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED All tissues are genetically programmed to acquire an optimal size that is defined by total cell number and individual cellular dimensions. The retina contains stereotyped proportions of one glial and six neuronal cell types that are generated in overlapping waves. How multipotent retinal progenitors know when to switch from making one cell type to the next so that appropriate numbers of each cell type are generated is poorly understood. Pten is a phosphatase that controls progenitor cell proliferation and differentiation in several lineages. Here, using a conditional loss-of-function strategy, we found that Pten regulates retinal cell division and is required to produce the full complement of rod photoreceptors and amacrine cells in mouse. We focused on amacrine cell number control, identifying three downstream Pten effector pathways. First, phosphoinositide 3-kinase/Akt signaling is hyperactivated in Pten conditional knock-out (cKO) retinas, and misexpression of constitutively active Akt (Akt-CA) in retinal explants phenocopies the reduction in amacrine cell production observed in Pten cKOs. Second, Akt-CA activates Tgfβ signaling in retinal explants, which is a negative feedback pathway for amacrine cell production. Accordingly, Tgfβ signaling is elevated in Pten cKO retinas, and epistatic analyses placed Pten downstream of TgfβRII in amacrine cell number control. Finally, Pten regulates Raf/Mek/Erk signaling levels to promote the differentiation of all amacrine cell subtypes, which are each reduced in number in Pten cKOs. Pten is thus a positive regulator of amacrine cell production, acting via multiple downstream pathways, highlighting its diverse actions as a mediator of cell number control. SIGNIFICANCE STATEMENT Despite the importance of size for optimal organ function, how individual cell types are generated in correct proportions is poorly understood. There are several ways to control cell number, including readouts of organ function (e.g., secreted hormones reach functional levels when enough cells are made) or counting of cell divisions or cell number. The latter applies to the retina, where cell number is regulated by negative feedback signals, which arrest differentiation of particular cell types at threshold levels. Herein, we show that Pten is a critical regulator of amacrine cell number in the retina, acting via multiple downstream pathways. Our studies provide molecular insights into how PTEN loss in humans may lead to uncontrolled cell division in several pathological conditions.
Collapse
|
36
|
Oliveira MAP, Balling R, Smidt MP, Fleming RMT. Embryonic development of selectively vulnerable neurons in Parkinson's disease. NPJ Parkinsons Dis 2017; 3:21. [PMID: 28685157 PMCID: PMC5484687 DOI: 10.1038/s41531-017-0022-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 05/24/2017] [Accepted: 06/01/2017] [Indexed: 02/07/2023] Open
Abstract
A specific set of brainstem nuclei are susceptible to degeneration in Parkinson's disease. We hypothesise that neuronal vulnerability reflects shared phenotypic characteristics that confer selective vulnerability to degeneration. Neuronal phenotypic specification is mainly the cumulative result of a transcriptional regulatory program that is active during the development. By manual curation of the developmental biology literature, we comprehensively reconstructed an anatomically resolved cellular developmental lineage for the adult neurons in five brainstem regions that are selectively vulnerable to degeneration in prodromal or early Parkinson's disease. We synthesised the literature on transcription factors that are required to be active, or required to be inactive, in the development of each of these five brainstem regions, and at least two differentially vulnerable nuclei within each region. Certain transcription factors, e.g., Ascl1 and Lmx1b, seem to be required for specification of many brainstem regions that are susceptible to degeneration in early Parkinson's disease. Some transcription factors can even distinguish between differentially vulnerable nuclei within the same brain region, e.g., Pitx3 is required for specification of the substantia nigra pars compacta, but not the ventral tegmental area. We do not suggest that Parkinson's disease is a developmental disorder. In contrast, we consider identification of shared developmental trajectories as part of a broader effort to identify the molecular mechanisms that underlie the phenotypic features that are shared by selectively vulnerable neurons. Systematic in vivo assessment of fate determining transcription factors should be completed for all neuronal populations vulnerable to degeneration in early Parkinson's disease.
Collapse
Affiliation(s)
- Miguel A. P. Oliveira
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
| | - Marten P. Smidt
- Department of Molecular Neuroscience, Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands
| | - Ronan M. T. Fleming
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 Avenue du Swing, Belvaux, L-4362 Luxembourg
| |
Collapse
|
37
|
Temporal profiling of photoreceptor lineage gene expression during murine retinal development. Gene Expr Patterns 2017; 23-24:32-44. [PMID: 28288836 DOI: 10.1016/j.gep.2017.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/03/2017] [Accepted: 03/07/2017] [Indexed: 02/08/2023]
Abstract
Rod and cone photoreceptors are photosensitive cells in the retina that convert light to electrical signals that are transmitted to visual processing centres in the brain. During development, cones and rods are generated from a common pool of multipotent retinal progenitor cells (RPCs) that also give rise to other retinal cell types. Cones and rods differentiate in two distinct waves, peaking in mid-embryogenesis and the early postnatal period, respectively. As RPCs transition from making cones to generating rods, there are changes in the expression profiles of genes involved in photoreceptor cell fate specification and differentiation. To better understand the temporal transition from cone to rod genesis, we assessed the timing of onset and offset of expression of a panel of 11 transcription factors and 7 non-transcription factors known to function in photoreceptor development, examining their expression between embryonic day (E) 12.5 and postnatal day (P) 60. Transcription factor expression in the photoreceptor layer was observed as early as E12.5, beginning with Crx, Otx2, Rorb, Neurod1 and Prdm1 expression, followed at E15.5 with the expression of Thrb, Neurog1, Sall3 and Rxrg expression, and at P0 by Nrl and Nr2e3 expression. Of the non-transcription factors, peanut agglutinin lectin staining and cone arrestin protein were observed as early as E15.5 in the developing outer nuclear layer, while transcripts for the cone opsins Opn1mw and Opn1sw and Recoverin protein were detected in photoreceptors by P0. In contrast, Opn1mw and Opn1sw protein were not observed in cones until P7, when rod-specific Gnat1 transcripts and rhodopsin protein were also detected. We have thus identified four transitory stages during murine retina photoreceptor differentiation marked by the period of onset of expression of new photoreceptor lineage genes. By characterizing these stages, we have clarified the dynamic nature of gene expression during the period when photoreceptor identities are progressively acquired during development.
Collapse
|
38
|
Sweeney NT, James KN, Nistorica A, Lorig-Roach RM, Feldheim DA. Expression of transcription factors divides retinal ganglion cells into distinct classes. J Comp Neurol 2017; 527:225-235. [PMID: 28078709 DOI: 10.1002/cne.24172] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 12/16/2016] [Accepted: 12/23/2016] [Indexed: 12/12/2022]
Abstract
Retinal ganglion cells (RGCs) are tasked with transmitting all light information from the eye to the retinal recipient areas of the brain. RGCs can be classified into many different types by morphology, gene expression, axonal projections, and functional responses to different light stimuli. Ultimately, these classification systems should be unified into an all-encompassing taxonomy. Toward that end, we show here that nearly all RGCs express either Islet-2 (Isl2), Tbr2, or a combination of Satb1 and Satb2. We present gene expression data supporting the hypothesis that Satb1 and Satb2 are expressed in ON-OFF direction-selective (DS) RGCs, complementing our previous work demonstrating that RGCs that express Isl2 and Tbr2 are non-DS and non-image-forming, respectively. Expression of these transcription factors emerges at distinct embryonic ages and only in postmitotic cells. Finally, we demonstrate that these transcription factor-defined RGC classes are born throughout RGC genesis.
Collapse
Affiliation(s)
- Neal T Sweeney
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, California
| | - Kiely N James
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, California
| | - Andreea Nistorica
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, California
| | - Ryan M Lorig-Roach
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, California
| | - David A Feldheim
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, California
| |
Collapse
|
39
|
Hirono K, Kohwi M, Clark MQ, Heckscher ES, Doe CQ. The Hunchback temporal transcription factor establishes, but is not required to maintain, early-born neuronal identity. Neural Dev 2017; 12:1. [PMID: 28137283 PMCID: PMC5282720 DOI: 10.1186/s13064-017-0078-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 01/26/2017] [Indexed: 01/01/2023] Open
Abstract
Background Drosophila and mammalian neural progenitors typically generate a diverse family of neurons in a stereotyped order. Neuronal diversity can be generated by the sequential expression of temporal transcription factors. In Drosophila, neural progenitors (neuroblasts) sequentially express the temporal transcription factors Hunchback (Hb), Kruppel, Pdm, and Castor. Hb is necessary and sufficient to specify early-born neuronal identity in multiple lineages, and is maintained in the post-mitotic neurons produced during each neuroblast expression window. Surprisingly, nothing is currently known about whether Hb acts in neuroblasts or post-mitotic neurons (or both) to specify first-born neuronal identity. Methods Here we selectively remove Hb from post-mitotic neurons, and assay the well-characterized NB7-1 and NB1-1 lineages for defects in neuronal identity and function. Results We find that loss of Hb from embryonic and larval post-mitotic neurons does not affect neuronal identity. Furthermore, removing Hb from post-mitotic neurons throughout the entire CNS has no effect on larval locomotor velocity, a sensitive assay for motor neuron and pre-motor neuron function. Conclusions We conclude that Hb functions in progenitors (neuroblasts/GMCs) to establish heritable neuronal identity that is maintained by a Hb-independent mechanism. We suggest that Hb acts in neuroblasts to establish an epigenetic state that is permanently maintained in early-born neurons. Electronic supplementary material The online version of this article (doi:10.1186/s13064-017-0078-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Keiko Hirono
- Howard Hughes Medical Institute, Eugene, 97403, USA.,Institute of Molecular Biology, Eugene, 97403, USA.,Institute of Neuroscience, University of Oregon, Eugene, 97403, USA
| | - Minoree Kohwi
- Department of Neuroscience, Columbia University Medical Center, New York, NY, 10032, USA
| | - Matt Q Clark
- Howard Hughes Medical Institute, Eugene, 97403, USA.,Institute of Molecular Biology, Eugene, 97403, USA.,Institute of Neuroscience, University of Oregon, Eugene, 97403, USA
| | - Ellie S Heckscher
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Chris Q Doe
- Howard Hughes Medical Institute, Eugene, 97403, USA. .,Institute of Molecular Biology, Eugene, 97403, USA. .,Institute of Neuroscience, University of Oregon, Eugene, 97403, USA.
| |
Collapse
|
40
|
Rossi AM, Fernandes VM, Desplan C. Timing temporal transitions during brain development. Curr Opin Neurobiol 2016; 42:84-92. [PMID: 27984764 DOI: 10.1016/j.conb.2016.11.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 01/05/2023]
Abstract
During development a limited number of progenitors generate diverse cell types that comprise the nervous system. Neuronal diversity, which arises largely at the level of neural stem cells, is critical for brain function. Often these cells exhibit temporal patterning: they sequentially produce neurons of distinct cell fates as a consequence of intrinsic and/or extrinsic cues. Here, we review recent advances in temporal patterning during neuronal specification, focusing on conserved players and mechanisms in invertebrate and vertebrate models. These studies underscore temporal patterning as an evolutionarily conserved strategy to generate neuronal diversity. Understanding the general principles governing temporal patterning and the molecular players involved will improve our ability to direct neural progenitors towards specific neuronal fates for brain repair.
Collapse
Affiliation(s)
- Anthony M Rossi
- Department of Biology, New York University, New York, NY 10003, USA
| | | | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA; CGSB, NYU Abu Dhabi, United Arab Emirates.
| |
Collapse
|
41
|
Stratmann J, Gabilondo H, Benito-Sipos J, Thor S. Neuronal cell fate diversification controlled by sub-temporal action of Kruppel. eLife 2016; 5. [PMID: 27740908 PMCID: PMC5065313 DOI: 10.7554/elife.19311] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/09/2016] [Indexed: 01/09/2023] Open
Abstract
During Drosophila embryonic nervous system development, neuroblasts express a programmed cascade of five temporal transcription factors that govern the identity of cells generated at different time-points. However, these five temporal genes fall short of accounting for the many distinct cell types generated in large lineages. Here, we find that the late temporal gene castor sub-divides its large window in neuroblast 5–6 by simultaneously activating two cell fate determination cascades and a sub-temporal regulatory program. The sub-temporal program acts both upon itself and upon the determination cascades to diversify the castor window. Surprisingly, the early temporal gene Kruppel acts as one of the sub-temporal genes within the late castor window. Intriguingly, while the temporal gene castor activates the two determination cascades and the sub-temporal program, spatial cues controlling cell fate in the latter part of the 5–6 lineage exclusively act upon the determination cascades. DOI:http://dx.doi.org/10.7554/eLife.19311.001 As a nervous system develops, stem cells generate different types of nerve cells at different times. This series of events follows a fixed schedule in developing embryos, and even a single stem cell that is removed and then grown outside the body will follow the same schedule. This strongly suggests that stem cells have a built-in clock that controls their development. Studies of the developing nervous system of fruit flies reveal that this clock works by switching genes on in specific sequences, which defines which nerve cells are produced at different stages of development. However, a clock built from the genes that are currently known to be involved in the process is simply not fine-tuned enough to explain how so many different types of nerve cell develop at such precise times. This implies that scientists do not yet know all of the genes that are involved. Using genetic experiments in stem cells from fruit flies, Stratmann, Gabilondo et al. now identify additional clock genes that act to divide broad windows of time during development into smaller, more precise ones. Genes that define broad windows of time switch on the “small window” genes at specific times – a bit like large cogs turning small cogs in a clock. One small window gene, called Kruppel, works at different stages of development and it is possible that other small window genes multi-task in similar ways in other developmental clocks, such as those found in more complex organisms like humans. It is clear that many genes work in sequence in the developing nervous system to ensure that developmental stages happen at precise times. Stratmann, Gabilondo et al. will next investigate the molecular details of this timing, specifically how genes in sequential time windows connect together like cogs in the developmental clock. DOI:http://dx.doi.org/10.7554/eLife.19311.002
Collapse
Affiliation(s)
- Johannes Stratmann
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Hugo Gabilondo
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.,Departamento de Biología, Universidad Autónoma de Madrid, Madrid, Spain
| | | | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| |
Collapse
|
42
|
Liu B, Bossing T. Single neuron transcriptomics identify SRSF/SR protein B52 as a regulator of axon growth and Choline acetyltransferase splicing. Sci Rep 2016; 6:34952. [PMID: 27725692 PMCID: PMC5057162 DOI: 10.1038/srep34952] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 09/21/2016] [Indexed: 01/14/2023] Open
Abstract
We removed single identified neurons from living Drosophila embryos to gain insight into the transcriptional control of developing neuronal networks. The microarray analysis of the transcriptome of two sibling neurons revealed seven differentially expressed transcripts between both neurons (threshold: log21.4). One transcript encodes the RNA splicing factor B52. Loss of B52 increases growth of axon branches. B52 function is also required for Choline acetyltransferase (ChAT ) splicing. At the end of embryogenesis, loss of B52 function impedes splicing of ChAT, reduces acetylcholine synthesis, and extends the period of uncoordinated muscle twitches during larval hatching. ChAT regulation by SRSF proteins may be a conserved feature since changes in SRSF5 expression and increased acetylcholine levels in brains of bipolar disease patients have been reported recently.
Collapse
Affiliation(s)
- Boyin Liu
- School of Biological Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, U.K
| | - Torsten Bossing
- School of Biomedical and Healthcare Sciences, Plymouth University, John Bull Building, Plymouth, PL6 8BU, U.K
| |
Collapse
|
43
|
Bailey AP, Koster G, Guillermier C, Hirst EMA, MacRae JI, Lechene CP, Postle AD, Gould AP. Antioxidant Role for Lipid Droplets in a Stem Cell Niche of Drosophila. Cell 2016; 163:340-53. [PMID: 26451484 PMCID: PMC4601084 DOI: 10.1016/j.cell.2015.09.020] [Citation(s) in RCA: 418] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 06/15/2015] [Accepted: 08/12/2015] [Indexed: 12/19/2022]
Abstract
Stem cells reside in specialized microenvironments known as niches. During Drosophila development, glial cells provide a niche that sustains the proliferation of neural stem cells (neuroblasts) during starvation. We now find that the glial cell niche also preserves neuroblast proliferation under conditions of hypoxia and oxidative stress. Lipid droplets that form in niche glia during oxidative stress limit the levels of reactive oxygen species (ROS) and inhibit the oxidation of polyunsaturated fatty acids (PUFAs). These droplets protect glia and also neuroblasts from peroxidation chain reactions that can damage many types of macromolecules. The underlying antioxidant mechanism involves diverting PUFAs, including diet-derived linoleic acid, away from membranes to the core of lipid droplets, where they are less vulnerable to peroxidation. This study reveals an antioxidant role for lipid droplets that could be relevant in many different biological contexts. Oxidative stress stimulates lipid droplet biosynthesis in a neural stem cell niche Lipid droplets protect niche and neural stem cells from damaging PUFA peroxidation PUFAs are less vulnerable to peroxidation in lipid droplets than in cell membranes
Collapse
Affiliation(s)
- Andrew P Bailey
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Grielof Koster
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, Sir Henry Wellcome Laboratories, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Christelle Guillermier
- National Resource for Imaging Mass Spectroscopy, Harvard Medical School and Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | - Elizabeth M A Hirst
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - James I MacRae
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK
| | - Claude P Lechene
- National Resource for Imaging Mass Spectroscopy, Harvard Medical School and Brigham and Women's Hospital, Cambridge, MA 02139, USA
| | - Anthony D Postle
- Academic Unit of Clinical & Experimental Sciences, Faculty of Medicine, Sir Henry Wellcome Laboratories, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Alex P Gould
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, Mill Hill, London NW7 1AA, UK.
| |
Collapse
|
44
|
Phillips NE, Manning CS, Pettini T, Biga V, Marinopoulou E, Stanley P, Boyd J, Bagnall J, Paszek P, Spiller DG, White MRH, Goodfellow M, Galla T, Rattray M, Papalopulu N. Stochasticity in the miR-9/Hes1 oscillatory network can account for clonal heterogeneity in the timing of differentiation. eLife 2016; 5:e16118. [PMID: 27700985 PMCID: PMC5050025 DOI: 10.7554/elife.16118] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/24/2016] [Indexed: 01/27/2023] Open
Abstract
Recent studies suggest that cells make stochastic choices with respect to differentiation or division. However, the molecular mechanism underlying such stochasticity is unknown. We previously proposed that the timing of vertebrate neuronal differentiation is regulated by molecular oscillations of a transcriptional repressor, HES1, tuned by a post-transcriptional repressor, miR-9. Here, we computationally model the effects of intrinsic noise on the Hes1/miR-9 oscillator as a consequence of low molecular numbers of interacting species, determined experimentally. We report that increased stochasticity spreads the timing of differentiation in a population, such that initially equivalent cells differentiate over a period of time. Surprisingly, inherent stochasticity also increases the robustness of the progenitor state and lessens the impact of unequal, random distribution of molecules at cell division on the temporal spread of differentiation at the population level. This advantageous use of biological noise contrasts with the view that noise needs to be counteracted.
Collapse
Affiliation(s)
- Nick E Phillips
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Cerys S Manning
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Tom Pettini
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Veronica Biga
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Elli Marinopoulou
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Peter Stanley
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - James Boyd
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - James Bagnall
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Pawel Paszek
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - David G Spiller
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michael RH White
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Marc Goodfellow
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom,Centre for Biomedical Modelling and Analysis, University of Exeter, Exeter, United Kingdom,EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter, United Kingdom
| | - Tobias Galla
- Theoretical Physics, School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom
| | - Magnus Rattray
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Nancy Papalopulu
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom,
| |
Collapse
|
45
|
Abstract
Photoreceptors have been the most intensively studied retinal cell type. Early lineage studies showed that photoreceptors are produced by retinal progenitor cells (RPCs) that produce only photoreceptor cells and by RPCs that produce both photoreceptor cells and other retinal cell types. More recent lineage studies have shown that there are intrinsic, molecular differences among these RPCs and that these molecular differences operate in gene regulatory networks (GRNs) that lead to the choice of the rod versus the cone fate. In addition, there are GRNs that lead to the choice of a photoreceptor fate and that of another retinal cell type. An example of such a GRN is one that drives the binary fate choice between a rod photoreceptor and bipolar cell. This GRN has many elements, including both feedforward and feedback regulatory loops, highlighting the complexity of such networks. This and other examples of retinal cell fate determination are reviewed here, focusing on the events that direct the choice of rod and cone photoreceptor fate.
Collapse
Affiliation(s)
- Constance L Cepko
- Departments of Genetics and Ophthalmology, Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115;
| |
Collapse
|
46
|
Farnsworth DR, Bayraktar OA, Doe CQ. Aging Neural Progenitors Lose Competence to Respond to Mitogenic Notch Signaling. Curr Biol 2015; 25:3058-68. [PMID: 26585279 DOI: 10.1016/j.cub.2015.10.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 10/07/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022]
Abstract
Drosophila neural stem cells (neuroblasts) are a powerful model system for investigating stem cell self-renewal, specification of temporal identity, and progressive restriction in competence. Notch signaling is a conserved cue that is an important determinant of cell fate in many contexts across animal development; for example, mammalian T cell differentiation in the thymus and neuroblast specification in Drosophila are both regulated by Notch signaling. However, Notch also functions as a mitogen, and constitutive Notch signaling potentiates T cell leukemia as well as Drosophila neuroblast tumors. While the role of Notch signaling has been studied in these and other cell types, it remains unclear how stem cells and progenitors change competence to respond to Notch over time. Notch is required in type II neuroblasts for normal development of their transit amplifying progeny, intermediate neural progenitors (INPs). Here, we find that aging INPs lose competence to respond to constitutively active Notch signaling. Moreover, we show that reducing the levels of the old INP temporal transcription factor Eyeless/Pax6 allows Notch signaling to promote the de-differentiation of INP progeny into ectopic INPs, thereby creating a proliferative mass of ectopic progenitors in the brain. These findings provide a new system for studying progenitor competence and identify a novel role for the conserved transcription factor Eyeless/Pax6 in blocking Notch signaling during development.
Collapse
Affiliation(s)
- Dylan R Farnsworth
- Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Omer Ali Bayraktar
- Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Chris Q Doe
- Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
| |
Collapse
|
47
|
Seto Y, Nakatani T, Masuyama N, Taya S, Kumai M, Minaki Y, Hamaguchi A, Inoue YU, Inoue T, Miyashita S, Fujiyama T, Yamada M, Chapman H, Campbell K, Magnuson MA, Wright CV, Kawaguchi Y, Ikenaka K, Takebayashi H, Ishiwata S, Ono Y, Hoshino M. Temporal identity transition from Purkinje cell progenitors to GABAergic interneuron progenitors in the cerebellum. Nat Commun 2015; 5:3337. [PMID: 24535035 DOI: 10.1038/ncomms4337] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 01/29/2014] [Indexed: 11/09/2022] Open
Abstract
In the cerebellum, all GABAergic neurons are generated from the Ptf1a-expressing ventricular zone (Ptf1a domain). However, the machinery to produce different types of GABAergic neurons remains elusive. Here we show temporal regulation of distinct GABAergic neuron progenitors in the cerebellum. Within the Ptf1a domain at early stages, we find two subpopulations; dorsally and ventrally located progenitors that express Olig2 and Gsx1, respectively. Lineage tracing reveals the former are exclusively Purkinje cell progenitors (PCPs) and the latter Pax2-positive interneuron progenitors (PIPs). As development proceeds, PCPs gradually become PIPs starting from ventral to dorsal. In gain- and loss-of-function mutants for Gsx1 and Olig1/2, we observe abnormal transitioning from PCPs to PIPs at inappropriate developmental stages. Our findings suggest that the temporal identity transition of cerebellar GABAergic neuron progenitors from PCPs to PIPs is negatively regulated by Olig2 and positively by Gsx1, and contributes to understanding temporal control of neuronal progenitor identities.
Collapse
Affiliation(s)
- Yusuke Seto
- 1] Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan [2] Department of Physics, Major in Integrative Bioscience and Biomedical Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Tomoya Nakatani
- KAN Research Institute Inc., 3F, Kobe MI R&D Center, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Norihisa Masuyama
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Shinichiro Taya
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Minoru Kumai
- KAN Research Institute Inc., 3F, Kobe MI R&D Center, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Yasuko Minaki
- 1] KAN Research Institute Inc., 3F, Kobe MI R&D Center, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan [2]
| | - Akiko Hamaguchi
- KAN Research Institute Inc., 3F, Kobe MI R&D Center, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Yukiko U Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Satoshi Miyashita
- 1] Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan [2] Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Tomoyuki Fujiyama
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Mayumi Yamada
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| | - Heather Chapman
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3026, USA
| | - Kenneth Campbell
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, Ohio 45229-3026, USA
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics and Center for Stem Cell Biology, Vanderbilt University School of Medicine, 2213 Garland Avenue, 9465 MRB IV, Nashville, Tennessee 37232-0494, USA
| | - Christopher V Wright
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University Medical Center, 2213 Garland Avenue, 9465 MRB IV, Nashville, Tennessee 37232-0494, USA
| | - Yoshiya Kawaguchi
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kazuhiro Ikenaka
- 1] Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan [2] Department of Physiological Sciences, School of Life Sciences, Graduate University for Advanced Studies, Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Hirohide Takebayashi
- 1] Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan [2] Department of Physiological Sciences, School of Life Sciences, Graduate University for Advanced Studies, Shonan Village, Hayama, Kanagawa 240-0193, Japan [3] Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi, Chuo-ku, Niigata 951-8510, Japan
| | - Shin'ichi Ishiwata
- 1] Department of Physics, Major in Integrative Bioscience and Biomedical Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan [2] Waseda Bioscience Research Institute in Singapore, Waseda University, 11 Biopolis Way, #05-01/02, Helios, Singapore 138667, Republic of Singapore
| | - Yuichi Ono
- KAN Research Institute Inc., 3F, Kobe MI R&D Center, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan
| |
Collapse
|
48
|
Altenhein B, Cattenoz PB, Giangrande A. The early life of a fly glial cell. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015. [DOI: 10.1002/wdev.200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Angela Giangrande
- Department of Functional Genomics and Cancer; IGBMC; Illkirch France
| |
Collapse
|
49
|
Hartenstein V, Younossi-Hartenstein A, Lovick JK, Kong A, Omoto JJ, Ngo KT, Viktorin G. Lineage-associated tracts defining the anatomy of the Drosophila first instar larval brain. Dev Biol 2015; 406:14-39. [PMID: 26141956 DOI: 10.1016/j.ydbio.2015.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/25/2015] [Accepted: 06/27/2015] [Indexed: 11/15/2022]
Abstract
Fixed lineages derived from unique, genetically specified neuroblasts form the anatomical building blocks of the Drosophila brain. Neurons belonging to the same lineage project their axons in a common tract, which is labeled by neuronal markers. In this paper, we present a detailed atlas of the lineage-associated tracts forming the brain of the early Drosophila larva, based on the use of global markers (anti-Neuroglian, anti-Neurotactin, inscuteable-Gal4>UAS-chRFP-Tub) and lineage-specific reporters. We describe 68 discrete fiber bundles that contain axons of one lineage or pairs/small sets of adjacent lineages. Bundles enter the neuropil at invariant locations, the lineage tract entry portals. Within the neuropil, these fiber bundles form larger fascicles that can be classified, by their main orientation, into longitudinal, transverse, and vertical (ascending/descending) fascicles. We present 3D digital models of lineage tract entry portals and neuropil fascicles, set into relationship to commonly used, easily recognizable reference structures such as the mushroom body, the antennal lobe, the optic lobe, and the Fasciclin II-positive fiber bundles that connect the brain and ventral nerve cord. Correspondences and differences between early larval tract anatomy and the previously described late larval and adult lineage patterns are highlighted. Our L1 neuro-anatomical atlas of lineages constitutes an essential step towards following morphologically defined lineages to the neuroblasts of the early embryo, which will ultimately make it possible to link the structure and connectivity of a lineage to the expression of genes in the particular neuroblast that gives rise to that lineage. Furthermore, the L1 atlas will be important for a host of ongoing work that attempts to reconstruct neuronal connectivity at the level of resolution of single neurons and their synapses.
Collapse
Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA.
| | - Amelia Younossi-Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA
| | - Jennifer K Lovick
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA
| | - Angel Kong
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA
| | - Jaison J Omoto
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA
| | - Kathy T Ngo
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, 610 Charles E. Young Drive, 5009 Terasaki Life Sciences Building, Los Angeles, CA 90095, USA
| | | |
Collapse
|
50
|
Novel Genes Involved in Controlling Specification of Drosophila FMRFamide Neuropeptide Cells. Genetics 2015; 200:1229-44. [PMID: 26092715 DOI: 10.1534/genetics.115.178483] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/16/2015] [Indexed: 01/28/2023] Open
Abstract
The expression of neuropeptides is often extremely restricted in the nervous system, making them powerful markers for addressing cell specification . In the developing Drosophila ventral nerve cord, only six cells, the Ap4 neurons, of some 10,000 neurons, express the neuropeptide FMRFamide (FMRFa). Each Ap4/FMRFa neuron is the last-born cell generated by an identifiable and well-studied progenitor cell, neuroblast 5-6 (NB5-6T). The restricted expression of FMRFa and the wealth of information regarding its gene regulation and Ap4 neuron specification makes FMRFa a valuable readout for addressing many aspects of neural development, i.e., spatial and temporal patterning cues, cell cycle control, cell specification, axon transport, and retrograde signaling. To this end, we have conducted a forward genetic screen utilizing an Ap4-specific FMRFa-eGFP transgenic reporter as our readout. A total of 9781 EMS-mutated chromosomes were screened for perturbations in FMRFa-eGFP expression, and 611 mutants were identified. Seventy-nine of the strongest mutants were mapped down to the affected gene by deficiency mapping or whole-genome sequencing. We isolated novel alleles for previously known FMRFa regulators, confirming the validity of the screen. In addition, we identified novel essential genes, including several with previously undefined functions in neural development. Our identification of genes affecting most major steps required for successful terminal differentiation of Ap4 neurons provides a comprehensive view of the genetic flow controlling the generation of highly unique neuronal cell types in the developing nervous system.
Collapse
|