1
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King HO, Owusu-Boaitey KE, Fincher CT, Reddien PW. A transcription factor atlas of stem cell fate in planarians. Cell Rep 2024; 43:113843. [PMID: 38401119 PMCID: PMC11232438 DOI: 10.1016/j.celrep.2024.113843] [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: 04/05/2023] [Revised: 12/05/2023] [Accepted: 02/06/2024] [Indexed: 02/26/2024] Open
Abstract
Whole-body regeneration requires the ability to produce the full repertoire of adult cell types. The planarian Schmidtea mediterranea contains over 125 cell types, which can be regenerated from a stem cell population called neoblasts. Neoblast fate choice can be regulated by the expression of fate-specific transcription factors (FSTFs). How fate choices are made and distributed across neoblasts versus their post-mitotic progeny remains unclear. We used single-cell RNA sequencing to systematically map fate choices made in S/G2/M neoblasts and, separately, in their post-mitotic progeny that serve as progenitors for all adult cell types. We defined transcription factor expression signatures associated with all detected fates, identifying numerous new progenitor classes and FSTFs that regulate them. Our work generates an atlas of stem cell fates with associated transcription factor signatures for most cell types in a complete adult organism.
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Affiliation(s)
- Hunter O King
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kwadwo E Owusu-Boaitey
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Harvard/MIT MD-PhD Program, Harvard Medical School, Boston, MA, USA
| | - Christopher T Fincher
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Chevy Chase, MD, USA; Whitehead Institute for Biomedical Research, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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2
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Stefanakis N, Jiang J, Liang Y, Shaham S. LET-381/FoxF and its target UNC-30/Pitx2 specify and maintain the molecular identity of C. elegans mesodermal glia that regulate motor behavior. EMBO J 2024; 43:956-992. [PMID: 38360995 PMCID: PMC10943081 DOI: 10.1038/s44318-024-00049-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/17/2024] Open
Abstract
While most glial cell types in the central nervous system (CNS) arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which envelop the brain neuropil and separate it from the circulatory system cavity. Transcriptome analysis shows that GLR glia combine astrocytic and endothelial characteristics, which are relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor also expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, the UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naive cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and promotes salt-induced paralysis, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neuronal differentiation, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.
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Affiliation(s)
- Nikolaos Stefanakis
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Jessica Jiang
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Yupu Liang
- Research Bioinformatics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
- Alexion Pharmaceuticals, Boston, MA, 02135, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
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3
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Lindsay-Mosher N, Lusk S, Pearson BJ. Planarians require ced-12/elmo-1 to clear dead cells by excretion through the gut. Cell Rep 2024; 43:113621. [PMID: 38165802 DOI: 10.1016/j.celrep.2023.113621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 10/13/2023] [Accepted: 12/08/2023] [Indexed: 01/04/2024] Open
Abstract
Cell corpse removal is a critical component of both development and homeostasis throughout the animal kingdom. Extensive research has revealed many of the mechanisms involved in corpse removal, typically involving engulfment and digestion by another cell; however, the dynamics of cell corpse clearance in adult tissues remain unclear. Here, we track cell death in the adult planarian Schmidtea mediterranea and find that, following light-induced cell death, pigment cell corpses transit to the gut and are excreted from the animal. Gut phagocytes, previously only known to phagocytose food, are required for pigment cells to enter the gut lumen. Finally, we show that the planarian ortholog of ced-12/engulfment and cell motility (ELMO) is required for corpse phagocytosis and removal through the gut. In total, we present a mechanism of cell clearance in an adult organism involving transit of dead cells to the gut, transport into the gut by phagocytes, and physical excretion of debris.
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Affiliation(s)
- Nicole Lindsay-Mosher
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON M5G0A4, Canada; University of Toronto, Department of Molecular Genetics, Toronto, ON, Canada
| | - Sarah Lusk
- Papé Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Bret J Pearson
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON M5G0A4, Canada; University of Toronto, Department of Molecular Genetics, Toronto, ON, Canada; Papé Research Institute, Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA.
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4
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Molina MD, Abduljabbar D, Guixeras A, Fraguas S, Cebrià F. LIM-HD transcription factors control axial patterning and specify distinct neuronal and intestinal cell identities in planarians. Open Biol 2023; 13:230327. [PMID: 38086422 PMCID: PMC10715919 DOI: 10.1098/rsob.230327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 11/01/2023] [Indexed: 12/18/2023] Open
Abstract
Adult planarians can regenerate the gut, eyes and even a functional brain. Proper identity and patterning of the newly formed structures require signals that guide and commit their adult stem cells. During embryogenesis, LIM-homeodomain (LIM-HD) transcription factors act in a combinatorial 'LIM code' to control cell fate determination and differentiation. However, our understanding about the role these genes play during regeneration and homeostasis is limited. Here, we report the full repertoire of LIM-HD genes in Schmidtea mediterranea. We found that lim homeobox (lhx) genes appear expressed in complementary patterns along the cephalic ganglia and digestive system of the planarian, with some of them being co-expressed in the same cell types. We have identified that Smed-islet1, -lhx1/5-1, -lhx2/9-3, -lhx6/8, -lmx1a/b-2 and -lmx1a/b-3 are essential to pattern and size the planarian brain as well as for correct regeneration of specific subpopulations of dopaminergic, serotonergic, GABAergic and cholinergic neurons, while Smed-lhx1/5.2 and -lhx2/9.2 are required for the proper expression of intestinal cell type markers, specifically the goblet subtype. LIM-HD are also involved in controlling axonal pathfinding (lhx6/8), axial patterning (islet1, lhx1/5-1, lmx1a/b-3), head/body proportions (islet2) and stem cell proliferation (lhx3/4, lhx2/9-3, lmx1a/b-2, lmx1a/b-3). Altogether, our results suggest that planarians might present a combinatorial LIM code that controls axial patterning and axonal growing and specifies distinct neuronal and intestinal cell identities.
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Affiliation(s)
- M. Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Dema Abduljabbar
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Anna Guixeras
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Susanna Fraguas
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
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5
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Stefanakis N, Jiang J, Liang Y, Shaham S. LET-381/FoxF and UNC-30/Pitx2 control the development of C. elegans mesodermal glia that regulate motor behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563501. [PMID: 37961181 PMCID: PMC10634723 DOI: 10.1101/2023.10.23.563501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
While most CNS glia arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which ensheath the brain neuropil and separate it from the circulatory-system cavity. Transcriptome analysis suggests GLR glia merge astrocytic and endothelial characteristics relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naïve cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and induces salt hypersensitivity, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neurons, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.
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6
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Wiggans M, Zhu SJ, Molinaro AM, Pearson BJ. The BAF chromatin remodeling complex licenses planarian stem cells access to ectodermal and mesodermal cell fates. BMC Biol 2023; 21:227. [PMID: 37864247 PMCID: PMC10589948 DOI: 10.1186/s12915-023-01730-y] [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: 02/09/2023] [Accepted: 10/10/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND The flatworm planarian, Schmidtea mediterranea, has a large population of adult stem cells (ASCs) that replace any cell type during tissue turnover or regeneration. How planarian ASCs (called neoblasts) manage self-renewal with the ability to produce daughter cells of different cell lineages (multipotency) is not well understood. Chromatin remodeling complexes ultimately control access to DNA regions of chromosomes and together with specific transcription factors determine whether a gene is transcribed in a given cell type. Previous work in planarians determined that RNAi of core components of the BAF chromatin remodeling complex, brg1 and smarcc2, caused increased ASCs and failed regeneration, but how these cellular defects arise at the level of gene regulation in neoblasts is unknown. RESULTS Here, we perform ATAC and RNA sequencing on purified neoblasts, deficient for the BAF complex subunits brg-1 and smarcc2. The data demonstrate that the BAF complex promotes chromatin accessibility and facilitates transcription at target loci, as in other systems. Interestingly, we find that the BAF complex enables access to genes known to be required for the generation of mesoderm- and ectoderm-derived lineages, including muscle, parenchymal cathepsin, neural, and epithelial lineages. BAF complex knockdowns result in disrupted differentiation into these cell lineages and functional consequences on planarian regeneration and tissue turnover. Notably, we did not detect a role for the BAF complex in neoblasts making endodermal lineages. CONCLUSIONS Our study provides functional insights into how the BAF complex contributes to cell fate decisions in planarian ASCs in vivo.
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Affiliation(s)
- Mallory Wiggans
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, M5G0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Shu Jun Zhu
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, M5G0A4, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Alyssa M Molinaro
- Present address: Oregon Health & Science University, Portland, OR, 97239, USA
| | - Bret J Pearson
- The Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, M5G0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada.
- Present address: Oregon Health & Science University, Portland, OR, 97239, USA.
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7
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Poulet A, Kratkiewicz AJ, Li D, van Wolfswinkel JC. Chromatin analysis of adult pluripotent stem cells reveals a unique stemness maintenance strategy. SCIENCE ADVANCES 2023; 9:eadh4887. [PMID: 37801496 PMCID: PMC10558129 DOI: 10.1126/sciadv.adh4887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 09/05/2023] [Indexed: 10/08/2023]
Abstract
Many highly regenerative organisms maintain adult pluripotent stem cells throughout their life, but how the long-term maintenance of pluripotency is accomplished is unclear. To decipher the regulatory logic of adult pluripotent stem cells, we analyzed the chromatin organization of stem cell genes in the planarian Schmidtea mediterranea. We identify a special chromatin state of stem cell genes, which is distinct from that of tissue-specific genes and resembles constitutive genes. Where tissue-specific promoters have detectable transcription factor binding sites, the promoters of stem cell-specific genes instead have sequence features that broadly decrease nucleosome binding affinity. This genic organization makes pluripotency-related gene expression the default state in these cells, which is maintained by the activity of chromatin remodelers ISWI and SNF2 in the stem cells.
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Affiliation(s)
- Axel Poulet
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Arcadia J. Kratkiewicz
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Danyan Li
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Josien C. van Wolfswinkel
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Yale Center for RNA Science and Medicine, Yale School of Medicine, New Haven, CT 06511, USA
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8
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Chen JJ, Lei K. The known, unknown, and unknown unknowns of cell-cell communication in planarian regeneration. Zool Res 2023; 44:981-992. [PMID: 37721107 PMCID: PMC10559094 DOI: 10.24272/j.issn.2095-8137.2023.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023] Open
Abstract
Planarians represent the most primitive bilateral triploblastic animals. Most planarian species exhibit mechanisms for whole-body regeneration, exemplified by the regeneration of their cephalic ganglion after complete excision. Given their robust whole-body regeneration capacity, planarians have been model organisms in regenerative research for more than 240 years. Advancements in research tools and techniques have progressively elucidated the mechanisms underlying planarian regeneration. Accurate cell-cell communication is recognized as a fundamental requirement for regeneration. In recent decades, mechanisms associated with such communication have been revealed at the cellular level. Notably, stem cells (neoblasts) have been identified as the source of all new cells during planarian homeostasis and regeneration. The interplay between neoblasts and somatic cells affects the identities and proportions of various tissues during homeostasis and regeneration. Here, this review outlines key discoveries regarding communication between stem cell compartments and other cell types in planarians, as well as the impact of communication on planarian regeneration. Additionally, this review discusses the challenges and potential directions of future planarian research, emphasizing the sustained impact of this field on our understanding of animal regeneration.
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Affiliation(s)
- Jia-Jia Chen
- School of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310030, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Kai Lei
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Growth Regulation and Translational Research of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310030, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China. E-mail:
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9
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Chandra B, Voas MG, Davies EL, Roberts-Galbraith RH. Ets-1 transcription factor regulates glial cell regeneration and function in planarians. Development 2023; 150:dev201666. [PMID: 37665145 PMCID: PMC10508700 DOI: 10.1242/dev.201666] [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: 02/01/2023] [Accepted: 08/15/2023] [Indexed: 09/05/2023]
Abstract
Glia play multifaceted roles in nervous systems in response to injury. Depending on the species, extent of injury and glial cell type in question, glia can help or hinder the regeneration of neurons. Studying glia in the context of successful regeneration could reveal features of pro-regenerative glia that could be exploited for new human therapies. Planarian flatworms completely regenerate their nervous systems after injury - including glia - and thus provide a strong model system for exploring glia in the context of regeneration. Here, we report that planarian glia regenerate after neurons, and that neurons are required for correct glial numbers and localization during regeneration. We also identify the planarian transcription factor-encoding gene ets-1 as a key regulator of glial cell maintenance and regeneration. Using ets-1 (RNAi) to perturb glia, we show that glial loss is associated with altered neuronal gene expression, impeded animal movement and impaired nervous system architecture - particularly within the neuropil. Importantly, our work reveals the inter-relationships of glia and neurons in the context of robust neural regeneration.
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Affiliation(s)
- Bidushi Chandra
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, USA
| | - Matthew G. Voas
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Erin L. Davies
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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10
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Fan Y, Chai C, Li P, Zou X, Ferrell JE, Wang B. Ultrafast distant wound response is essential for whole-body regeneration. Cell 2023; 186:3606-3618.e16. [PMID: 37480850 PMCID: PMC10957142 DOI: 10.1016/j.cell.2023.06.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 01/11/2023] [Accepted: 06/23/2023] [Indexed: 07/24/2023]
Abstract
Injury induces systemic responses, but their functions remain elusive. Mechanisms that can rapidly synchronize wound responses through long distances are also mostly unknown. Using planarian flatworms capable of whole-body regeneration, we report that injury induces extracellular signal-regulated kinase (Erk) activity waves to travel at a speed 10-100 times faster than those in other multicellular tissues. This ultrafast propagation requires longitudinal body-wall muscles, elongated cells forming dense parallel tracks running the length of the organism. The morphological properties of muscles allow them to act as superhighways for propagating and disseminating wound signals. Inhibiting Erk propagation prevents tissues distant to the wound from responding and blocks regeneration, which can be rescued by a second injury to distal tissues shortly after the first injury. Our findings provide a mechanism for long-range signal propagation in large, complex tissues to coordinate responses across cell types and highlight the function of feedback between spatially separated tissues during whole-body regeneration.
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Affiliation(s)
- Yuhang Fan
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Chew Chai
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Pengyang Li
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Xinzhi Zou
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - James E Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA, USA; Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Bo Wang
- Department of Bioengineering, Stanford University, Stanford, CA, USA.
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11
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Piovani L, Leite DJ, Yañez Guerra LA, Simpson F, Musser JM, Salvador-Martínez I, Marlétaz F, Jékely G, Telford MJ. Single-cell atlases of two lophotrochozoan larvae highlight their complex evolutionary histories. SCIENCE ADVANCES 2023; 9:eadg6034. [PMID: 37531419 PMCID: PMC10396302 DOI: 10.1126/sciadv.adg6034] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 06/30/2023] [Indexed: 08/04/2023]
Abstract
Pelagic larval stages are widespread across animals, yet it is unclear whether larvae were present in the last common ancestor of animals or whether they evolved multiple times due to common selective pressures. Many marine larvae are at least superficially similar; they are small, swim through the beating of bands of cilia, and sense the environment with an apical organ. To understand these similarities, we have generated single-cell atlases for marine larvae from two animal phyla and have compared their cell types. We found clear similarities among ciliary band cells and between neurons of the apical organ in the two larvae pointing to possible homology of these structures, suggesting a single origin of larvae within Spiralia. We also find several clade-specific innovations in each larva, including distinct myocytes and shell gland cells in the oyster larva. Oyster shell gland cells express many recently evolved genes that have made previous gene age estimates for the origin of trochophore larvae too young.
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Affiliation(s)
- Laura Piovani
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Daniel J. Leite
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | | | - Fraser Simpson
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Jacob M. Musser
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Irepan Salvador-Martínez
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Ferdinand Marlétaz
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, UK
| | - Maximilian J. Telford
- Centre for Life’s Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, London WC1E 6BT, UK
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12
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Cui G, Dong K, Zhou JY, Li S, Wu Y, Han Q, Yao B, Shen Q, Zhao YL, Yang Y, Cai J, Zhang S, Yang YG. Spatiotemporal transcriptomic atlas reveals the dynamic characteristics and key regulators of planarian regeneration. Nat Commun 2023; 14:3205. [PMID: 37268637 DOI: 10.1038/s41467-023-39016-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 05/25/2023] [Indexed: 06/04/2023] Open
Abstract
Whole-body regeneration of planarians is a natural wonder but how it occurs remains elusive. It requires coordinated responses from each cell in the remaining tissue with spatial awareness to regenerate new cells and missing body parts. While previous studies identified new genes essential to regeneration, a more efficient screening approach that can identify regeneration-associated genes in the spatial context is needed. Here, we present a comprehensive three-dimensional spatiotemporal transcriptomic landscape of planarian regeneration. We describe a pluripotent neoblast subtype, and show that depletion of its marker gene makes planarians more susceptible to sub-lethal radiation. Furthermore, we identified spatial gene expression modules essential for tissue development. Functional analysis of hub genes in spatial modules, such as plk1, shows their important roles in regeneration. Our three-dimensional transcriptomic atlas provides a powerful tool for deciphering regeneration and identifying homeostasis-related genes, and provides a publicly available online spatiotemporal analysis resource for planarian regeneration research.
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Affiliation(s)
- Guanshen Cui
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Kangning Dong
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jia-Yi Zhou
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
| | - Shang Li
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ying Wu
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Qinghua Han
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bofei Yao
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
| | - Qunlun Shen
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong-Liang Zhao
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ying Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China
- China National Center for Bioinformation, Beijing, 100101, China
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Cai
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, China.
| | - Shihua Zhang
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
| | - Yun-Gui Yang
- CAS Key Laboratory of Genomic and Precision Medicine, Collaborative Innovation Center of Genetics and Development, College of Future Technology, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, China.
- China National Center for Bioinformation, Beijing, 100101, China.
- Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 101408, China.
- Institute of Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
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13
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Hulett RE, Kimura JO, Bolaños DM, Luo YJ, Rivera-López C, Ricci L, Srivastava M. Acoel single-cell atlas reveals expression dynamics and heterogeneity of adult pluripotent stem cells. Nat Commun 2023; 14:2612. [PMID: 37147314 PMCID: PMC10163032 DOI: 10.1038/s41467-023-38016-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 04/11/2023] [Indexed: 05/07/2023] Open
Abstract
Adult pluripotent stem cell (aPSC) populations underlie whole-body regeneration in many distantly-related animal lineages, but how the underlying cellular and molecular mechanisms compare across species is unknown. Here, we apply single-cell RNA sequencing to profile transcriptional cell states of the acoel worm Hofstenia miamia during postembryonic development and regeneration. We identify cell types shared across stages and their associated gene expression dynamics during regeneration. Functional studies confirm that the aPSCs, also known as neoblasts, are the source of differentiated cells and reveal transcription factors needed for differentiation. Subclustering of neoblasts recovers transcriptionally distinct subpopulations, the majority of which are likely specialized to differentiated lineages. One neoblast subset, showing enriched expression of the histone variant H3.3, appears to lack specialization. Altogether, the cell states identified in this study facilitate comparisons to other species and enable future studies of stem cell fate potentials.
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Affiliation(s)
- Ryan E Hulett
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - Julian O Kimura
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - D Marcela Bolaños
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - Yi-Jyun Luo
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Carlos Rivera-López
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
- Department of Molecular and Cell Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Lorenzo Ricci
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA
| | - Mansi Srivastava
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 02138, USA.
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14
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Kaethner M, Epping K, Bernthaler P, Rudolf K, Thomann I, Leitschuh N, Bergmann M, Spiliotis M, Koziol U, Brehm K. Transforming growth factor-β signalling regulates protoscolex formation in the Echinococcus multilocularis metacestode. Front Cell Infect Microbiol 2023; 13:1153117. [PMID: 37033489 PMCID: PMC10073696 DOI: 10.3389/fcimb.2023.1153117] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 02/23/2023] [Indexed: 04/11/2023] Open
Abstract
The lethal zoonosis alveolar echinococcosis (AE) is caused by tumor-like, infiltrative growth of the metacestode larval stage of the tapeworm Echinococcus multilocularis. We previously showed that the metacestode is composed of posteriorized tissue and that the production of the subsequent larval stage, the protoscolex, depends on re-establishment of anterior identities within the metacestode germinative layer. It is, however, unclear so far how protoscolex differentiation in Echinococcus is regulated. We herein characterized the full complement of E. multilocularis TGFβ/BMP receptors, which is composed of one type II and three type I receptor serine/threonine kinases. Functional analyzes showed that all Echinococcus TGFβ/BMP receptors are enzymatically active and respond to host derived TGFβ/BMP ligands for activating downstream Smad transcription factors. In situ hybridization experiments demonstrated that the Echinococcus TGFβ/BMP receptors are mainly expressed by nerve and muscle cells within the germinative layer and in developing brood capsules. Interestingly, the production of brood capsules, which later give rise to protoscoleces, was strongly suppressed in the presence of inhibitors directed against TGFβ/BMP receptors, whereas protoscolex differentiation was accelerated in response to host BMP2 and TGFβ. Apart from being responsive to host TGFβ/BMP ligands, protoscolex production also correlated with the expression of a parasite-derived TGFβ-like ligand, EmACT, which is expressed in early brood capsules and which is strongly expressed in anterior domains during protoscolex development. Taken together, these data indicate an important role of TGFβ/BMP signalling in Echinococcus anterior pole formation and protoscolex development. Since TGFβ is accumulating around metacestode lesions at later stages of the infection, the host immune response could thus serve as a signal by which the parasite senses the time point at which protoscoleces must be produced. Overall, our data shed new light on molecular mechanisms of host-parasite interaction during AE and are relevant for the development of novel treatment strategies.
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Affiliation(s)
- Marc Kaethner
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Kerstin Epping
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Peter Bernthaler
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Kilian Rudolf
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Irena Thomann
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Nadine Leitschuh
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
- Laboratory of Microbiology and Biotechnology, Department of Food Technology, Fulda University of Applied Sciences, Fulda, Germany
| | - Monika Bergmann
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Markus Spiliotis
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Uriel Koziol
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Klaus Brehm
- Consultant Laboratory for Echinococcosis, Institute of Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
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15
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Planarians to schistosomes: an overview of flatworm cell-types and regulators. J Helminthol 2023; 97:e7. [PMID: 36644809 DOI: 10.1017/s0022149x22000621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Schistosomiasis remains a major neglected tropical disease that afflicts over 200 million people globally. Schistosomes, the aetiological agent of schistosomiasis, are parasitic flatworms that propagate between molluscan and mammalian hosts. Inside the mammalian host, schistosomes rapidly grow over 100-fold in size and develop into a sexually mature male or female that thrives in the bloodstream for several decades. Recent work has identified schistosome stem cells as the source that drives parasite transmission, reproduction and longevity. Moreover, studies have begun to uncover molecular programmes deployed by stem cells that are essential for tissue development and maintenance, parasite survival and immune evasion. Such programmes are reminiscent of neoblast-driven development and regeneration of planarians, the free-living flatworm relative of schistosomes. Over the last few decades, research in planarians has employed modern functional genomic tools that significantly enhanced our understanding of stem cell-driven animal development and regeneration. In this review, we take a broad stroke overview of major flatworm organ systems at the cellular and molecular levels. We summarize recent advances on genetic regulators that play critical roles in differentiation and maintenance of flatworm cell types. Finally, we provide perspectives on how investigation of basic parasite biology is critical to discovering new approaches to battle schistosomiasis.
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16
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Single-cell transcriptomics in planaria: new tools allow new insights into cellular and evolutionary features. Biochem Soc Trans 2022; 50:1237-1246. [DOI: 10.1042/bst20210825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 11/17/2022]
Abstract
Single-cell transcriptomics has revolutionised biology allowing the quantification of gene expression in individual cells. Since each single cell contains cell type specific mRNAs, these techniques enable the classification of cell identities. Therefore, single cell methods have been used to explore the repertoire of cell types (the single cell atlas) of different organisms, including freshwater planarians. Nowadays, planarians are one of the most prominent animal models in single cell biology. They have been studied at the single cell level for over a decade using most of the available single cell methodological approaches. These include plate-based methods, such as qPCR, nanodroplet methods and in situ barcoding methods. Because of these studies, we now have a very good picture of planarian cell types and their differentiation trajectories. Planarian regenerative properties and other characteristics, such as their developmental plasticity and their capacity to reproduce asexually, ensure that another decade of single cell biology in planarians is yet to come. Here, we review these characteristics, the new biological insights that have been obtained by single-cell transcriptomics and outline the perspectives for the future.
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17
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Janssen R, Schomburg C, Prpic NM, Budd GE. A comprehensive study of arthropod and onychophoran Fox gene expression patterns. PLoS One 2022; 17:e0270790. [PMID: 35802758 PMCID: PMC9269926 DOI: 10.1371/journal.pone.0270790] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/20/2022] [Indexed: 11/19/2022] Open
Abstract
Fox genes represent an evolutionary old class of transcription factor encoding genes that evolved in the last common ancestor of fungi and animals. They represent key-components of multiple gene regulatory networks (GRNs) that are essential for embryonic development. Most of our knowledge about the function of Fox genes comes from vertebrate research, and for arthropods the only comprehensive gene expression analysis is that of the fly Drosophila melanogaster. For other arthropods, only selected Fox genes have been investigated. In this study, we provide the first comprehensive gene expression analysis of arthropod Fox genes including representative species of all main groups of arthropods, Pancrustacea, Myriapoda and Chelicerata. We also provide the first comprehensive analysis of Fox gene expression in an onychophoran species. Our data show that many of the Fox genes likely retained their function during panarthropod evolution highlighting their importance in development. Comparison with published data from other groups of animals shows that this high degree of evolutionary conservation often dates back beyond the last common ancestor of Panarthropoda.
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Affiliation(s)
- Ralf Janssen
- Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden
- * E-mail:
| | - Christoph Schomburg
- AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Institut für Allgemeine Zoologie und Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
- Fachgebiet Botanik, Institut für Biologie, Universität Kassel, Kassel, Germany
| | - Nikola-Michael Prpic
- AG Zoologie mit dem Schwerpunkt Molekulare Entwicklungsbiologie, Institut für Allgemeine Zoologie und Entwicklungsbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Graham E. Budd
- Department of Earth Sciences, Palaeobiology, Uppsala University, Uppsala, Sweden
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18
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Reddien PW. Positional Information and Stem Cells Combine to Result in Planarian Regeneration. Cold Spring Harb Perspect Biol 2022; 14:a040717. [PMID: 34518341 PMCID: PMC9121904 DOI: 10.1101/cshperspect.a040717] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The capacity for regeneration is broad in the animal kingdom. Planarians are flatworms that can regenerate any missing body part and their regenerative powers have combined with ease of experimentation to make them a classic regeneration model for more than a century. Pluripotent stem cells called neoblasts generate missing planarian tissues. Fate specification happens in the neoblasts, and this can occur in response to regeneration instructions in the form of positional information. Fate specification can lead to differentiating cells in single steps rather than requiring a long lineage hierarchy. Planarians display constitutive expression of positional information from muscle cells, which is required for patterned maintenance of tissues in tissue turnover. Amputation leads to the rapid resetting of positional information in a process triggered by wound signaling and the resetting of positional information is required for regeneration. These findings suggest a model for planarian regeneration in which adult positional information resets after injury to regulate stem cells to bring about the replacement of missing parts.
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Affiliation(s)
- Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA
- Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
- Department of Biology, MIT, Cambridge, Massachusetts 02139, USA
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19
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Sarkar SR, Dubey VK, Jahagirdar A, Lakshmanan V, Haroon MM, Sowndarya S, Sowdhamini R, Palakodeti D. DDX24 is required for muscle fiber organization and the suppression of wound-induced Wnt activity necessary for pole re-establishment during planarian regeneration. Dev Biol 2022; 488:11-29. [PMID: 35523320 DOI: 10.1016/j.ydbio.2022.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/06/2022] [Accepted: 04/28/2022] [Indexed: 12/14/2022]
Abstract
Planarians have a remarkable ability to undergo whole-body regeneration. Successful regeneration outcome is determined by processes like polarity establishment at the wound site, which is followed by pole (organizer) specification. Interestingly, these determinants are almost exclusively expressed by muscles in these animals. However, the molecular toolkit that enables the functional versatility of planarian muscles remains poorly understood. Here we report that SMED_DDX24, a D-E-A-D Box RNA helicase, is necessary for planarian survival and regeneration. We found that DDX24 is enriched in muscles and its knockdown disrupts muscle fiber organization. This leads to defective pole specification, which in turn results in misregulation of many positional control genes specifically during regeneration. ddx24 RNAi also upregulates wound-induced Wnt signalling. Suppressing this ectopic Wnt activity rescues the knockdown phenotype by enabling better anterior pole regeneration. To summarize, our work highlights the role of an RNA helicase in muscle fiber organization, and modulating amputation-induced wnt levels, both of which seem critical for pole re-organization, thereby regulating whole-body regeneration.
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Affiliation(s)
- Souradeep R Sarkar
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bengaluru, 560065, India; Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India
| | - Vinay Kumar Dubey
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India; Manipal Academy of Higher Education, Manipal, 576104, India
| | - Anusha Jahagirdar
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India
| | - Vairavan Lakshmanan
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India
| | - Mohamed Mohamed Haroon
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India; SASTRA University, Thanjavur, 613401, India
| | - Sai Sowndarya
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India
| | - Ramanathan Sowdhamini
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), Bengaluru, 560065, India
| | - Dasaradhi Palakodeti
- Integrative Chemical Biology (ICB), Institute for Stem Cell Science and Regenerative Medicine (inStem), Bengaluru, 560065, India.
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20
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Coronel-Córdoba P, Molina MD, Cardona G, Fraguas S, Pascual-Carreras E, Saló E, Cebrià F, Adell T. FoxK1 is Required for Ectodermal Cell Differentiation During Planarian Regeneration. Front Cell Dev Biol 2022; 10:808045. [PMID: 35273960 PMCID: PMC8901602 DOI: 10.3389/fcell.2022.808045] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/24/2022] Open
Abstract
Forkhead box (Fox) genes belong to the “winged helix” transcription factor superfamily. The function of some Fox genes is well known, such as the role of foxO in controlling metabolism and longevity and foxA in controlling differentiation of endodermal tissues. However, the role of some Fox factors is not yet well characterized. Such is the case of FoxK genes, which are mainly studied in mammals and have been implicated in diverse processes including cell proliferation, tissue differentiation and carcinogenesis. Planarians are free-living flatworms, whose importance in biomedical research lies in their regeneration capacity. Planarians possess a wide population of pluripotent adult stem cells, called neoblasts, which allow them to regenerate any body part after injury. In a recent study, we identified three foxK paralogs in the genome of Schmidtea mediterranea. In this study, we demonstrate that foxK1 inhibition prevents regeneration of the ectodermal tissues, including the nervous system and the epidermis. These results correlate with foxK1 expression in neoblasts and in neural progenitors. Although the triggering of wound genes expression, polarity reestablishment and proliferation was not affected after foxK1 silencing, the apoptotic response was decreased. Altogether, these results suggest that foxK1 would be required for differentiation and maintenance of ectodermal tissues.
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Affiliation(s)
- Pablo Coronel-Córdoba
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - M Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Gemma Cardona
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Susanna Fraguas
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Eudald Pascual-Carreras
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Emili Saló
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
| | - Teresa Adell
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.,Institute of Biomedicine of the University of Barcelona (IBUB), Barcelona, Spain
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21
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Abstract
Over the past several decades, planarians have emerged as a powerful model system with which to study the cellular and molecular basis of whole-body regeneration. The best studied planarians belong to freshwater flatworm species that maintain their remarkable regenerative capacity partly through the deployment of a population of adult pluripotent stem cells. Assessment of gene function in planarian regeneration has primarily been achieved through RNA interference (RNAi), either through the feeding or injection of double-stranded RNA (dsRNA). RNAi treatment of planarians has several advantages, including ease of use, which allows for medium-throughput screens of hundreds of genes over the course of a single project. Here, I present methods for dsRNA synthesis and RNAi feeding, as well as strategies for follow-up assessment of both structural and functional regeneration of organ systems of planarians, with a special emphasis on neural regeneration.
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22
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Molina MD, Cebrià F. Decoding Stem Cells: An Overview on Planarian Stem Cell Heterogeneity and Lineage Progression. Biomolecules 2021; 11:1532. [PMID: 34680165 PMCID: PMC8533874 DOI: 10.3390/biom11101532] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 01/26/2023] Open
Abstract
Planarians are flatworms capable of whole-body regeneration, able to regrow any missing body part after injury or amputation. The extraordinary regenerative capacity of planarians is based upon the presence in the adult of a large population of somatic pluripotent stem cells. These cells, called neoblasts, offer a unique system to study the process of stem cell specification and differentiation in vivo. In recent years, FACS-based isolation of neoblasts, RNAi functional analyses as well as high-throughput approaches such as single-cell sequencing have allowed a rapid progress in our understanding of many different aspects of neoblast biology. Here, we summarize our current knowledge on the molecular signatures that define planarian neoblasts heterogeneity, which includes a percentage of truly pluripotent stem cells, and guide the commitment of pluripotent neoblasts into lineage-specific progenitor cells, as well as their differentiation into specific planarian cell types.
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Affiliation(s)
- M. Dolores Molina
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
| | - Francesc Cebrià
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute of Biomedicine of the University of Barcelona (IBUB), 08028 Barcelona, Spain
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23
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Ballarin L, Karahan A, Salvetti A, Rossi L, Manni L, Rinkevich B, Rosner A, Voskoboynik A, Rosental B, Canesi L, Anselmi C, Pinsino A, Tohumcu BE, Jemec Kokalj A, Dolar A, Novak S, Sugni M, Corsi I, Drobne D. Stem Cells and Innate Immunity in Aquatic Invertebrates: Bridging Two Seemingly Disparate Disciplines for New Discoveries in Biology. Front Immunol 2021; 12:688106. [PMID: 34276677 PMCID: PMC8278520 DOI: 10.3389/fimmu.2021.688106] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/31/2021] [Indexed: 12/12/2022] Open
Abstract
The scopes related to the interplay between stem cells and the immune system are broad and range from the basic understanding of organism's physiology and ecology to translational studies, further contributing to (eco)toxicology, biotechnology, and medicine as well as regulatory and ethical aspects. Stem cells originate immune cells through hematopoiesis, and the interplay between the two cell types is required in processes like regeneration. In addition, stem and immune cell anomalies directly affect the organism's functions, its ability to cope with environmental changes and, indirectly, its role in ecosystem services. However, stem cells and immune cells continue to be considered parts of two branches of biological research with few interconnections between them. This review aims to bridge these two seemingly disparate disciplines towards much more integrative and transformative approaches with examples deriving mainly from aquatic invertebrates. We discuss the current understanding of cross-disciplinary collaborative and emerging issues, raising novel hypotheses and comments. We also discuss the problems and perspectives of the two disciplines and how to integrate their conceptual frameworks to address basic equations in biology in a new, innovative way.
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Affiliation(s)
| | - Arzu Karahan
- Middle East Technical University, Institute of Marine Sciences, Erdemli, Mersin, Turkey
| | - Alessandra Salvetti
- Department of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Pisa, Italy
| | - Leonardo Rossi
- Department of Clinical and Experimental Medicine, Unit of Experimental Biology and Genetics, University of Pisa, Pisa, Italy
| | - Lucia Manni
- Department of Biology, University of Padua, Padua, Italy
| | - Baruch Rinkevich
- Department of Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel
| | - Amalia Rosner
- Department of Biology, Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel
| | - Ayelet Voskoboynik
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
- Department of Biology, Chan Zuckerberg Biohub, San Francisco, CA, United States
| | - Benyamin Rosental
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Center for Regenerative Medicine and Stem Cells, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Laura Canesi
- Department of Earth Environment and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
| | - Chiara Anselmi
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, United States
- Department of Biology, Stanford University, Hopkins Marine Station, Pacific Grove, CA, United States
| | - Annalisa Pinsino
- Institute for Biomedical Research and Innovation, National Research Council, Palermo, Italy
| | - Begüm Ece Tohumcu
- Middle East Technical University, Institute of Marine Sciences, Erdemli, Mersin, Turkey
| | - Anita Jemec Kokalj
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Andraž Dolar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Sara Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Michela Sugni
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Ilaria Corsi
- Department of Physical, Earth and Environmental Sciences, University of Siena, Siena, Italy
| | - Damjana Drobne
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
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24
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Raz AA, Wurtzel O, Reddien PW. Planarian stem cells specify fate yet retain potency during the cell cycle. Cell Stem Cell 2021; 28:1307-1322.e5. [PMID: 33882291 DOI: 10.1016/j.stem.2021.03.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 01/08/2021] [Accepted: 03/25/2021] [Indexed: 02/06/2023]
Abstract
Planarian whole-body regeneration is enabled by stem cells called neoblasts. At least some neoblasts are individually pluripotent. Neoblasts are also heterogeneous, with subpopulations of specialized neoblasts having different specified fates. Fate specification in neoblasts is regulated by fate-specific transcription factor (FSTF) expression. Here, we find that FSTF expression is common in neoblast S/G2/M cell-cycle phases but less common in G1. We find that specialized neoblasts can divide to produce progeny with asymmetric cell fates, suggesting that they could retain pluripotency. Furthermore, no known neoblast class was present in all neoblast colonies, suggesting that pluripotency is not the exclusive property of any known class. We tested this possibility with single-cell transplantations, which indicate that at least some specialized neoblasts are likely clonogenic. On the basis of these findings, we propose a model for neoblast pluripotency in which neoblasts can undergo specialization during the cell cycle without loss of potency.
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Affiliation(s)
- Amelie A Raz
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Omri Wurtzel
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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25
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Cloutier JK, McMann CL, Oderberg IM, Reddien PW. activin-2 is required for regeneration of polarity on the planarian anterior-posterior axis. PLoS Genet 2021; 17:e1009466. [PMID: 33780442 PMCID: PMC8057570 DOI: 10.1371/journal.pgen.1009466] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/20/2021] [Accepted: 03/03/2021] [Indexed: 01/16/2023] Open
Abstract
Planarians are flatworms and can perform whole-body regeneration. This ability involves a mechanism to distinguish between anterior-facing wounds that require head regeneration and posterior-facing wounds that require tail regeneration. How this head-tail regeneration polarity decision is made is studied to identify principles underlying tissue-identity specification in regeneration. We report that inhibition of activin-2, which encodes an Activin-like signaling ligand, resulted in the regeneration of ectopic posterior-facing heads following amputation. During tissue turnover in uninjured planarians, positional information is constitutively expressed in muscle to maintain proper patterning. Positional information includes Wnts expressed in the posterior and Wnt antagonists expressed in the anterior. Upon amputation, several wound-induced genes promote re-establishment of positional information. The head-versus-tail regeneration decision involves preferential wound induction of the Wnt antagonist notum at anterior-facing over posterior-facing wounds. Asymmetric activation of notum represents the earliest known molecular distinction between head and tail regeneration, yet how it occurs is unknown. activin-2 RNAi animals displayed symmetric wound-induced activation of notum at anterior- and posterior-facing wounds, providing a molecular explanation for their ectopic posterior-head phenotype. activin-2 RNAi animals also displayed anterior-posterior (AP) axis splitting, with two heads appearing in anterior blastemas, and various combinations of heads and tails appearing in posterior blastemas. This was associated with ectopic nucleation of anterior poles, which are head-tip muscle cells that facilitate AP and medial-lateral (ML) pattern at posterior-facing wounds. These findings reveal a role for Activin signaling in determining the outcome of AP-axis-patterning events that are specific to regeneration. A central problem in animal regeneration is how animals determine what body part to regenerate. Planarians are flatworms that can regenerate any missing body region, and are studied to identify mechanisms underlying regeneration. At transverse amputation planes, a poorly understood mechanism specifies regeneration of either a head or a tail. This head-versus-tail regeneration decision-making process is referred to as regeneration polarity and has been studied for over a century to identify mechanisms that specify what to regenerate. The gene notum, which encodes a Wnt antagonist, is induced within hours after injury preferentially at anterior-facing wounds, where it specifies head regeneration. We report that Activin signaling is required for regeneration polarity, and the underlying asymmetric activation of notum at anterior- over posterior-facing wounds. We propose that Activin signaling is involved in regeneration-specific responses broadly in the animal kingdom.
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Affiliation(s)
- Jennifer K. Cloutier
- Whitehead Institute for Biomedical Research, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Howard Hughes Medical Institute, Chevy Chase, MD, United States of America
- Harvard/MIT MD-PhD, Harvard Medical School, Boston, MA, United States of America
| | - Conor L. McMann
- Whitehead Institute for Biomedical Research, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Howard Hughes Medical Institute, Chevy Chase, MD, United States of America
| | - Isaac M. Oderberg
- Whitehead Institute for Biomedical Research, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Howard Hughes Medical Institute, Chevy Chase, MD, United States of America
| | - Peter W. Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
- Howard Hughes Medical Institute, Chevy Chase, MD, United States of America
- * E-mail:
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26
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Kangale LJ, Raoult D, Fournier PE, Abnave P, Ghigo E. Planarians (Platyhelminthes)-An Emerging Model Organism for Investigating Innate Immune Mechanisms. Front Cell Infect Microbiol 2021; 11:619081. [PMID: 33732660 PMCID: PMC7958881 DOI: 10.3389/fcimb.2021.619081] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
An organism responds to the invading pathogens such as bacteria, viruses, protozoans, and fungi by engaging innate and adaptive immune system, which functions by activating various signal transduction pathways. As invertebrate organisms (such as sponges, worms, cnidarians, molluscs, crustaceans, insects, and echinoderms) are devoid of an adaptive immune system, and their defense mechanisms solely rely on innate immune system components. Investigating the immune response in such organisms helps to elucidate the immune mechanisms that vertebrates have inherited or evolved from invertebrates. Planarians are non-parasitic invertebrates from the phylum Platyhelminthes and are being investigated for several decades for understanding the whole-body regeneration process. However, recent findings have emerged planarians as a useful model for studying innate immunity as they are resistant to a broad spectrum of bacteria. This review intends to highlight the research findings on various antimicrobial resistance genes, signaling pathways involved in innate immune recognition, immune-related memory and immune cells in planarian flatworms.
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Affiliation(s)
- Luis Johnson Kangale
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.,Institut Hospitalo-Universitaire-Méditerranée-Infection, Marseille, France
| | - Didier Raoult
- Institut Hospitalo-Universitaire-Méditerranée-Infection, Marseille, France.,Aix-Marseille Univ, IRD, AP-HM, MEPHI, Marseille, France.,Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Pierre-Edouard Fournier
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.,Institut Hospitalo-Universitaire-Méditerranée-Infection, Marseille, France
| | | | - Eric Ghigo
- Institut Hospitalo-Universitaire-Méditerranée-Infection, Marseille, France.,TechnoJouvence, Marseille, France
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27
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Stelman CR, Smith BM, Chandra B, Roberts-Galbraith RH. CBP/p300 homologs CBP2 and CBP3 play distinct roles in planarian stem cell function. Dev Biol 2021; 473:130-143. [PMID: 33607113 DOI: 10.1016/j.ydbio.2021.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 11/19/2022]
Abstract
Chromatin modifications function as critical regulators of gene expression and cellular identity, especially in the regulation and maintenance of the pluripotent state. However, many studies of chromatin modification in stem cells-and pluripotent stem cells in particular-are performed in mammalian stem cell culture, an in vitro condition mimicking a very transient state during mammalian development. Thus, new models for studying pluripotent stem cells in vivo could be helpful for understanding the roles of chromatin modification, for confirming prior in vitro studies, and for exploring evolution of the pluripotent state. The freshwater flatworm, Schmidtea mediterranea, is an excellent model for studying adult pluripotent stem cells, particularly in the context of robust, whole-body regeneration. To identify chromatin modifying and remodeling enzymes critical for planarian regeneration and stem cell maintenance, we took a candidate approach and screened planarian homologs of 25 genes known to regulate chromatin biology in other organisms. Through our study, we identified six genes with novel functions in planarian homeostasis, regeneration, and behavior. Of the list of genes characterized, we identified five planarian homologs of the mammalian CREB-Binding Protein (CBP) and p300 family of histone acetyltransferases, representing an expansion of this family in planarians. We find that two planarian CBP family members are required for planarian survival, with knockdown of Smed-CBP2 and Smed-CBP3 causing distinct defects in stem cell maintenance or function. Loss of CBP2 causes a quick, dramatic loss of stem cells, while knockdown of CBP3 affects stem cells more narrowly, influencing differentiation of several cell types that include neuronal subtypes and cells of the eye. Further, we find that Smed-CBP1 is required for planarian fissioning behavior. We propose that the division of labor among a diversified CBP family in planarians presents an opportunity to dissect specific functions of a broadly important histone acetyltransferase family.
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Affiliation(s)
- Clara R Stelman
- Department of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Britessia M Smith
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Bidushi Chandra
- Department of Cellular Biology, University of Georgia, Athens, GA, USA
| | - Rachel H Roberts-Galbraith
- Department of Molecular and Cellular Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Cellular Biology, University of Georgia, Athens, GA, USA.
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28
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Analysis of Fox genes in Schmidtea mediterranea reveals new families and a conserved role of Smed-foxO in controlling cell death. Sci Rep 2021; 11:2947. [PMID: 33536473 PMCID: PMC7859237 DOI: 10.1038/s41598-020-80627-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/18/2020] [Indexed: 01/30/2023] Open
Abstract
The forkhead box (Fox) genes encode transcription factors that control several key aspects of development. Present in the ancestor of all eukaryotes, Fox genes underwent several duplications followed by loss and diversification events that gave rise to the current 25 families. However, few Fox members have been identified from the Lophotrochozoa clade, and specifically from planarians, which are a unique model for understanding development, due to the striking plasticity of the adult. The aim of this study was to identify and perform evolutionary and functional studies of the Fox genes of lophotrochozoan species and, specifically, of the planarian Schmidtea mediterranea. Generating a pipeline for identifying Forkhead domains and using phylogenetics allowed us the phylogenetic reconstruction of Fox genes. We corrected the annotation for misannotated genes and uncovered a new family, the QD, present in all metazoans. According to the new phylogeny, the 27 Fox genes found in Schmidtea mediterranea were classified into 12 families. In Platyhelminthes, family losses were accompanied by extensive gene diversification and the appearance of specific families, the A(P) and N(P). Among the newly identified planarian Fox genes, we found a single copy of foxO, which shows an evolutionary conserved role in controlling cell death.
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29
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Johnson CJ, Razy-Krajka F, Stolfi A. Expression of smooth muscle-like effectors and core cardiomyocyte regulators in the contractile papillae of Ciona. EvoDevo 2020; 11:15. [PMID: 32774829 PMCID: PMC7397655 DOI: 10.1186/s13227-020-00162-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/22/2020] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The evolution of vertebrate smooth muscles is obscured by lack of identifiable smooth muscle-like cells in tunicates, the invertebrates most closely related to vertebrates. A recent evolutionary model was proposed in which smooth muscles arose before the last bilaterian common ancestor, and were later diversified, secondarily lost or modified in the branches leading to extant animal taxa. However, there is currently no data from tunicates to support this scenario. METHODS AND RESULTS Here, we show that the axial columnar cells, a unique cell type in the adhesive larval papillae of the tunicate Ciona, are enriched for orthologs of vertebrate smooth/non-muscle-specific effectors of contractility, in addition to developing from progenitors that express conserved cardiomyocyte regulatory factors. We show that these cells contract during the retraction of the Ciona papillae during larval settlement and metamorphosis. CONCLUSIONS We propose that the axial columnar cells of Ciona are a myoepithelial cell type required for transducing external stimuli into mechanical forces that aid in the attachment of the motile larva to its final substrate. Furthermore, they share developmental and functional features with vertebrate myoepithelial cells, vascular smooth muscle cells, and cardiomyocytes. We discuss these findings in the context of the proposed models of vertebrate smooth muscle and cardiomyocyte evolution.
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30
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Scimone ML, Atabay KD, Fincher CT, Bonneau AR, Li DJ, Reddien PW. Muscle and neuronal guidepost-like cells facilitate planarian visual system regeneration. Science 2020; 368:368/6498/eaba3203. [PMID: 32586989 PMCID: PMC8128157 DOI: 10.1126/science.aba3203] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/06/2020] [Indexed: 12/12/2022]
Abstract
Neuronal circuits damaged or lost after injury can be regenerated in some adult organisms, but the mechanisms enabling this process are largely unknown. We used the planarian Schmidtea mediterranea to study visual system regeneration after injury. We identify a rare population of muscle cells tightly associated with photoreceptor axons at stereotyped positions in both uninjured and regenerating animals. Together with a neuronal population, these cells promote de novo assembly of the visual system in diverse injury and eye transplantation contexts. These muscle guidepost-like cells are specified independently of eyes, and their position is defined by an extrinsic array of positional information cues. These findings provide a mechanism, involving adult formation of guidepost-like cells typically observed in embryos, for axon pattern restoration in regeneration.
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Affiliation(s)
- M Lucila Scimone
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kutay D Atabay
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christopher T Fincher
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ashley R Bonneau
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Dayan J Li
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. .,Whitehead Institute, 455 Main Street, Cambridge, MA 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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31
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Arenas Gómez CM, Sabin KZ, Echeverri K. Wound healing across the animal kingdom: Crosstalk between the immune system and the extracellular matrix. Dev Dyn 2020; 249:834-846. [PMID: 32314465 PMCID: PMC7383677 DOI: 10.1002/dvdy.178] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/10/2020] [Accepted: 04/11/2020] [Indexed: 12/11/2022] Open
Abstract
Tissue regeneration is widespread in the animal kingdom. To date, key roles for different molecular and cellular programs in regeneration have been described, but the ultimate blueprint for this talent remains elusive. In animals capable of tissue regeneration, one of the most crucial stages is wound healing, whose main goal is to close the wound and prevent infection. In this stage, it is necessary to avoid scar formation to facilitate the activation of the immune system and remodeling of the extracellular matrix, key factors in promoting tissue regeneration. In this review, we will discuss the current state of knowledge regarding the role of the immune system and the interplay with the extracellular matrix to trigger a regenerative response.
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Affiliation(s)
- Claudia M. Arenas Gómez
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological LaboratoryWoods HoleMassachusettsUSA
| | - Keith Z. Sabin
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological LaboratoryWoods HoleMassachusettsUSA
| | - Karen Echeverri
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological LaboratoryWoods HoleMassachusettsUSA
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32
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Abstract
The lateral plate mesoderm (LPM) forms the progenitor cells that constitute the heart and cardiovascular system, blood, kidneys, smooth muscle lineage and limb skeleton in the developing vertebrate embryo. Despite this central role in development and evolution, the LPM remains challenging to study and to delineate, owing to its lineage complexity and lack of a concise genetic definition. Here, we outline the processes that govern LPM specification, organization, its cell fates and the inferred evolutionary trajectories of LPM-derived tissues. Finally, we discuss the development of seemingly disparate organ systems that share a common LPM origin. Summary: The lateral plate mesoderm is the origin of several major cell types and organ systems in the vertebrate body plan. How this mesoderm territory emerges and partitions into its downstream fates provides clues about vertebrate development and evolution.
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Affiliation(s)
- Karin D Prummel
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA.,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Susan Nieuwenhuize
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA.,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Christian Mosimann
- University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, 12801 E 17th Avenue, Aurora, CO 80045, USA .,Department of Molecular Life Sciences, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
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33
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Forsthoefel DJ, Cejda NI, Khan UW, Newmark PA. Cell-type diversity and regionalized gene expression in the planarian intestine. eLife 2020; 9:e52613. [PMID: 32240093 PMCID: PMC7117911 DOI: 10.7554/elife.52613] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/06/2020] [Indexed: 12/17/2022] Open
Abstract
Proper function and repair of the digestive system are vital to most animals. Deciphering the mechanisms involved in these processes requires an atlas of gene expression and cell types. Here, we applied laser-capture microdissection (LCM) and RNA-seq to characterize the intestinal transcriptome of Schmidtea mediterranea, a planarian flatworm that can regenerate all organs, including the gut. We identified hundreds of genes with intestinal expression undetected by previous approaches. Systematic analyses revealed extensive conservation of digestive physiology and cell types with other animals, including humans. Furthermore, spatial LCM enabled us to uncover previously unappreciated regionalization of gene expression in the planarian intestine along the medio-lateral axis, especially among intestinal goblet cells. Finally, we identified two intestine-enriched transcription factors that specifically regulate regeneration (hedgehog signaling effector gli-1) or maintenance (RREB2) of goblet cells. Altogether, this work provides resources for further investigation of mechanisms involved in gastrointestinal function, repair and regeneration.
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Affiliation(s)
- David J Forsthoefel
- Genes and Human Disease Research Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Nicholas I Cejda
- Genes and Human Disease Research Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
| | - Umair W Khan
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Phillip A Newmark
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
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34
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Racioppi C, Wiechecki KA, Christiaen L. Combinatorial chromatin dynamics foster accurate cardiopharyngeal fate choices. eLife 2019; 8:49921. [PMID: 31746740 PMCID: PMC6952182 DOI: 10.7554/elife.49921] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022] Open
Abstract
During embryogenesis, chromatin accessibility profiles control lineage-specific gene expression by modulating transcription, thus impacting multipotent progenitor states and subsequent fate choices. Subsets of cardiac and pharyngeal/head muscles share a common origin in the cardiopharyngeal mesoderm, but the chromatin landscapes that govern multipotent progenitors competence and early fate choices remain largely elusive. Here, we leveraged the simplicity of the chordate model Ciona to profile chromatin accessibility through stereotyped transitions from naive Mesp+ mesoderm to distinct fate-restricted heart and pharyngeal muscle precursors. An FGF-Foxf pathway acts in multipotent progenitors to establish cardiopharyngeal-specific patterns of accessibility, which govern later heart vs. pharyngeal muscle-specific expression profiles, demonstrating extensive spatiotemporal decoupling between early cardiopharyngeal enhancer accessibility and late cell-type-specific activity. We found that multiple cis-regulatory elements, with distinct chromatin accessibility profiles and motif compositions, are required to activate Ebf and Tbx1/10, two key determinants of cardiopharyngeal fate choices. We propose that these 'combined enhancers' foster spatially and temporally accurate fate choices, by increasing the repertoire of regulatory inputs that control gene expression, through either accessibility and/or activity.
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Affiliation(s)
- Claudia Racioppi
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Keira A Wiechecki
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
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35
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Tewari AG, Owen JH, Petersen CP, Wagner DE, Reddien PW. A small set of conserved genes, including sp5 and Hox, are activated by Wnt signaling in the posterior of planarians and acoels. PLoS Genet 2019; 15:e1008401. [PMID: 31626630 PMCID: PMC6821139 DOI: 10.1371/journal.pgen.1008401] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/30/2019] [Accepted: 09/05/2019] [Indexed: 11/19/2022] Open
Abstract
Wnt signaling regulates primary body axis formation across the Metazoa, with high Wnt signaling specifying posterior identity. Whether a common Wnt-driven transcriptional program accomplishes this broad role is poorly understood. We identified genes acutely affected after Wnt signaling inhibition in the posterior of two regenerative species, the planarian Schmidtea mediterranea and the acoel Hofstenia miamia, which are separated by >550 million years of evolution. Wnt signaling was found to maintain positional information in muscle and regional gene expression in multiple differentiated cell types. sp5, Hox genes, and Wnt pathway components are down-regulated rapidly after β-catenin RNAi in both species. Brachyury, a vertebrate Wnt target, also displays Wnt-dependent expression in Hofstenia. sp5 inhibits trunk gene expression in the tail of planarians and acoels, promoting separate tail-trunk body domains. A planarian posterior Hox gene, Post-2d, promotes normal tail regeneration. We propose that common regulation of a small gene set–Hox, sp5, and Brachyury–might underlie the widespread utilization of Wnt signaling in primary axis patterning across the Bilateria. How animals form and maintain their body axes is a fundamental topic in developmental biology. Wnt signaling is an important regulator of head-tail axis formation across animals, with high Wnt signaling specifying tail identity. In this study, we use two species that are separated by more than 550 million years of evolution, planarians and acoels, to find genes regulated by Wnt signaling in the tail broadly in the Bilateria. We identified a small conserved set of Wnt-regulated genes, including the transcription factor-encoding genes sp5 and Hox. This suggests that regulation of this gene set might be a key function of Wnt signaling in the tails of bilaterally symmetric animals. Inhibition of a planarian posterior Hox gene, Post-2d, by RNAi caused tail-regeneration defects. Inhibition of sp5 by RNAi revealed that it functions to restrict the expression of trunk genes in the tail of planarians and acoels. Since Wnt signaling activates both trunk and tail patterning gene expression in planarians, this suggests a mechanism by which Wnt signaling can establish separate trunk-tail body domains through regulation of sp5.
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Affiliation(s)
- Aneesha G. Tewari
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Jared H. Owen
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Christian P. Petersen
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Daniel E. Wagner
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Peter W. Reddien
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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36
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Li DJ, McMann CL, Reddien PW. Nuclear receptor NR4A is required for patterning at the ends of the planarian anterior-posterior axis. eLife 2019; 8:42015. [PMID: 31025936 PMCID: PMC6534381 DOI: 10.7554/elife.42015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 04/25/2019] [Indexed: 02/07/2023] Open
Abstract
Positional information is fundamental to animal regeneration and tissue turnover. In planarians, muscle cells express signaling molecules to promote positional identity. At the ends of the anterior-posterior (AP) axis, positional identity is determined by anterior and posterior poles, which are putative organizers. We identified a gene, nr4A, that is required for anterior- and posterior-pole localization to axis extremes. nr4A encodes a nuclear receptor expressed predominantly in planarian muscle, including strongly at AP-axis ends and the poles. nr4A RNAi causes patterning gene expression domains to retract from head and tail tips, and ectopic anterior and posterior anatomy (e.g., eyes) to iteratively appear more internally. Our study reveals a novel patterning phenotype, in which pattern-organizing cells (poles) shift from their normal locations (axis extremes), triggering abnormal tissue pattern that fails to reach equilibrium. We propose that nr4A promotes pattern at planarian AP axis ends through restriction of patterning gene expression domains. Many animals are able to regenerate tissue that has been lost through illness or injury. Flatworms called planarians have long been used to study tissue regeneration because of their remarkable ability to completely regenerate their whole body from small pieces of tissue. Furthermore, the stem cells of adult planarians continually produce new cells to replace dying cells in a process called tissue turnover. For regeneration and tissue turnover to be successful, it is important for the new cells to form in the right location in the body; for example, new eye cells need to form in the head. Genes known as position control genes are active in muscle at specific locations along the body of a flatworm to regulate both regeneration and tissue turnover. However, it was not clear how these genes coordinate with stem cells to produce new cells in the correct positions in the body. Li et al. examined the effects of a gene known as nr4A that is particularly active in muscle at the head and tail ends of planarians. Using a technique called RNA interference to decrease the activity of nr4A in planarians disrupted the patterns of tissues at each end of the flatworms. Over time, the activity of the position control genes also became restricted to locations progressively farther away from the head and tail. As a result, cells that were intended to replace tissues in the head or tail were deposited increasingly far away from these locations. For example, new eyes formed repeatedly in the planarians, with each set farther away from the head tip than the last. Li et al. propose that these disruptions of normal tissue patterning ensue because the cells that organize such patterns at the ends of the planarian (the poles) are themselves misplaced within the existing body pattern. The nr4A gene can be found in a wide range of animal species. Understanding how this gene affects tissue patterns in planarians could therefore also help researchers to discover how adult tissue patterns form and are maintained in animals more generally.
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Affiliation(s)
- Dayan J Li
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States.,Harvard/MIT MD-PhD Program, Harvard Medical School, Boston, United States
| | - Conor L McMann
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Howard Hughes Medical Institute, Chevy Chase, United States
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Cote LE, Simental E, Reddien PW. Muscle functions as a connective tissue and source of extracellular matrix in planarians. Nat Commun 2019; 10:1592. [PMID: 30962434 PMCID: PMC6453901 DOI: 10.1038/s41467-019-09539-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 03/15/2019] [Indexed: 12/24/2022] Open
Abstract
Regeneration and tissue turnover require new cell production and positional information. Planarians are flatworms capable of regenerating all body parts using a population of stem cells called neoblasts. The positional information required for tissue patterning is primarily harbored by muscle cells, which also control body contraction. Here we produce an in silico planarian matrisome and use recent whole-animal single-cell-transcriptome data to determine that muscle is a major source of extracellular matrix (ECM). No other ECM-secreting, fibroblast-like cell type was detected. Instead, muscle cells express core ECM components, including all 19 collagen-encoding genes. Inhibition of muscle-expressed hemicentin-1 (hmcn-1), which encodes a highly conserved ECM glycoprotein, results in ectopic peripheral localization of cells, including neoblasts, outside of the muscle layer. ECM secretion and hmcn-1-dependent maintenance of tissue separation indicate that muscle functions as a planarian connective tissue, raising the possibility of broad roles for connective tissue in adult positional information. How the cellular source of positional information compares across regenerative animals is unclear. Here, the authors find that planarian muscle, which harbours positional information, acts as a connective tissue by being a major site of matrisome gene expression and by maintaining tissue architecture.
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Affiliation(s)
- Lauren E Cote
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 455 Main St, Cambridge, MA, 02142, USA
| | - Eric Simental
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 455 Main St, Cambridge, MA, 02142, USA.,University of California San Francisco, 600 16th Street, San Francisco, CA, 94143, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 455 Main St, Cambridge, MA, 02142, USA.
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