1
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Akheralie Z, Scidmore TJ, Pearson BJ. aristaless-like homeobox-3 is wound induced and promotes a low-Wnt environment required for planarian head regeneration. Development 2023; 150:dev201777. [PMID: 37681295 PMCID: PMC10560571 DOI: 10.1242/dev.201777] [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: 03/13/2023] [Accepted: 08/30/2023] [Indexed: 09/09/2023]
Abstract
The planarian Schmidtea mediterranea is a well-established model of adult regeneration, which is dependent on a large population of adult stem cells called neoblasts. Upon amputation, planarians undergo transcriptional wounding programs and coordinated stem cell proliferation to give rise to missing tissues. Interestingly, the Wnt signaling pathway is key to guiding what tissues are regenerated, yet less known are the transcriptional regulators that ensure proper activation and timing of signaling pathway components. Here, we have identified an aristaless-like homeobox transcription factor, alx-3, that is enriched in a population of putative neural-fated progenitor cells at homeostasis, and is also upregulated in stem cells and muscle cells at anterior-facing wounds upon amputation. Knockdown of alx-3 results in failure of head regeneration and patterning defects in amputated tail fragments. alx-3 is required for the expression of several early wound-induced genes, including the Wnt inhibitor notum, which is required to establish anterior polarity during regeneration. Together, these findings reveal a role for alx-3 as an early wound-response transcriptional regulator in both muscle cells and stem cells that is required for anterior regeneration by promoting a low-Wnt environment.
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Affiliation(s)
- Zaleena Akheralie
- 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 M5S1A8, Canada
| | - Tanner J. Scidmore
- 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 M5S1A8, Canada
| | - 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 M5S1A8, Canada
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2
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Clark EG, Petersen CP. BMP suppresses WNT to integrate patterning of orthogonal body axes in adult planarians. PLoS Genet 2023; 19:e1010608. [PMID: 37729232 PMCID: PMC10545109 DOI: 10.1371/journal.pgen.1010608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 10/02/2023] [Accepted: 09/05/2023] [Indexed: 09/22/2023] Open
Abstract
Adult regeneration restores patterning of orthogonal body axes after damage in a post-embryonic context. Planarians regenerate using distinct body-wide signals primarily regulating each axis dimension: anteroposterior Wnts, dorsoventral BMP, and mediolateral Wnt5 and Slit determinants. How regeneration can coordinate perpendicular tissue axes without symmetry-breaking embryonic events is not fully understood. Here, we report that the planarian dorsoventral regulator bmp4 suppresses the posterior determinant wnt1 to provide patterning input to the anteroposterior axis. Double-FISH identified distinct anteroposterior domains within dorsal midline muscle that express either bmp4 or wnt1. Homeostatic inhibition bmp4 and smad1 expanded the wnt1 expression anteriorly, while elevation of BMP signaling through nog1;nog2 RNAi reduced the wnt1 expression domain and elevated bmp4 expression. Homeostatic BMP signal perturbation broadly affected anteroposterior identity as measured by expression of posterior Wnt pathway factors, and caused mislocalization of AP-regionalized pharynx progenitors, without strongly affecting expression domains of anterior regulators. Additionally, wnt1 inhibition elevated bmp4 expression in the tip of the tail. Therefore, dorsal BMP signals and posterior wnt1 mutually antagonize for patterning the tail. Furthermore, homeostatic bmp4 RNAi caused medial expansion of the lateral determinant wnt5 and reduced expression of the medial regulator slit. By contrast, nog1;nog2 RNAi restricted wnt5 expression. Double RNAi of bmp4 and wnt5 resulted in lateral ectopic eye phenotypes, suggesting bmp4 acts upstream of wnt5 to pattern the mediolateral axis. These results indicate bmp4 controls dorsoventral information and also, through suppression of Wnt signals, influences anteroposterior and mediolateral identity. Based on related functions across vertebrates and Cnidarians, Wnt and BMP cross-regulation could form an ancient mechanism for coordinating orthogonal axis patterning.
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Affiliation(s)
- Eleanor G. Clark
- Department of Molecular Biosciences, Northwestern University; Evanston Illinois, United States of America
| | - Christian P. Petersen
- Department of Molecular Biosciences, Northwestern University; Evanston Illinois, United States of America
- Robert Lurie Comprehensive Cancer Center, Northwestern University; Evanston, Illinois, United States of America
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3
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Clark EG, Petersen CP. BMP suppresses WNT to integrate patterning of orthogonal body axes in adult planarians. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523528. [PMID: 36711474 PMCID: PMC9882038 DOI: 10.1101/2023.01.10.523528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Adult regeneration restores patterning of orthogonal body axes after damage in a post-embryonic context. Planarians regenerate using distinct body-wide signals primarily regulating each axis dimension: anteroposterior Wnts, dorsoventral BMP, and mediolateral Wnt5 and Slit determinants. How regeneration can consistently form perpendicular tissue axes without symmetry-breaking embryonic events is unknown, and could either occur using fully independent, or alternatively, integrated signals defining each dimension. Here, we report that the planarian dorsoventral regulator bmp4 suppresses the posterior determinant wnt1 to pattern the anteroposterior axis. Double-FISH identified distinct anteroposterior domains within dorsal midline muscle that express either bmp4 or wnt1 . Homeostatic inhibition bmp4 and smad1 expanded the wnt1 expression anteriorly, while elevation of BMP signaling through nog1;nog2 RNAi reduced the wnt1 expression domain. BMP signal perturbation broadly affected anteroposterior identity as measured by expression of posterior Wnt pathway factors, without affecting head regionalization. Therefore, dorsal BMP signals broadly limit posterior identity. Furthermore, bmp4 RNAi caused medial expansion of the lateral determinant wnt5 and reduced expression of the medial regulator slit . Double RNAi of bmp4 and wnt5 resulted in lateral ectopic eye phenotypes, suggesting bmp4 acts upstream of wnt5 to pattern the mediolateral axis. Therefore, bmp4 acts at the top of a patterning hierarchy both to control dorsoventral information and also, through suppression of Wnt signals, to regulate anteroposterior and mediolateral identity. These results reveal that adult pattern formation involves integration of signals controlling individual orthogonal axes. Author Summary Systems that coordinate long-range communication across axes are likely critical for enabling tissue restoration in regenerative animals. While individual axis pathways have been identified, there is not yet an understanding of how signal integration allows repatterning across 3-dimensions. Here, we report an unanticipated linkage between anteroposterior, dorsoventral, and mediolateral systems in planarians through BMP signaling. We find that dorsally expressed BMP restricts posterior and lateral identity by suppressing distinct Wnt signals in adult planarians. These results demonstrate that orthogonal axis information is not fully independent and suggest a potentially ancient role of integrated axis patterning in generating stable 3-dimensional adult forms.
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Affiliation(s)
- Eleanor G. Clark
- Department of Molecular Biosciences, Northwestern University; Evanston IL 60208
| | - Christian P. Petersen
- Department of Molecular Biosciences, Northwestern University; Evanston IL 60208
- Robert Lurie Comprehensive Cancer Center, Northwestern University; Evanston IL 60208
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4
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Petersen CP. Wnt signaling in whole-body regeneration. Curr Top Dev Biol 2023; 153:347-380. [PMID: 36967200 DOI: 10.1016/bs.ctdb.2023.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Regeneration abilities are widespread among animals and select species can restore any body parts removed by wounds that sever the major body axes. This capability of whole-body regeneration as exemplified in flatworm planarians, Acoels, and Cnidarians involves initial responses to injury, the assessment of wound site polarization, determination of missing tissue and programming of blastema fate, and patterned outgrowth to restore axis content and proportionality. Wnt signaling drives many shared and conserved aspects of the biology of whole-body regeneration in the planarian species Schmidtea mediterranea and Dugesia japonica, in the Acoel Hofstenia miamia, and in Cnidarians Hydra and Nematostella. These overlapping mechanisms suggest whole-body regeneration might be an ancestral property across diverse animal taxa.
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Affiliation(s)
- Christian P Petersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States; Robert Lurie Comprehensive Cancer Center, Northwestern University, Evanston, IL, United States.
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5
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Scimone ML, Cloutier JK, Maybrun CL, Reddien PW. The planarian wound epidermis gene equinox is required for blastema formation in regeneration. Nat Commun 2022; 13:2726. [PMID: 35585061 PMCID: PMC9117669 DOI: 10.1038/s41467-022-30412-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 04/09/2022] [Indexed: 11/25/2022] Open
Abstract
Regeneration often involves the formation of a blastema, an outgrowth or regenerative bud formed at the plane of injury where missing tissues are produced. The mechanisms that trigger blastema formation are therefore fundamental for regeneration. Here, we identify a gene, which we named equinox, that is expressed within hours of injury in the planarian wound epidermis. equinox encodes a predicted secreted protein that is conserved in many animal phyla. Following equinox inhibition, amputated planarians fail to maintain wound-induced gene expression and to subsequently undergo blastema outgrowth. Associated with these defects is an inability to reestablish lost positional information needed for missing tissue specification. Our findings link the planarian wound epidermis, through equinox, to regeneration of positional information and blastema formation, indicating a broad regulatory role of the wound epidermis in diverse regenerative contexts.
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Affiliation(s)
- M Lucila Scimone
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | - Jennifer K Cloutier
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Harvard/MIT MD-PhD, Harvard Medical School, Boston, MA, 02115, USA
| | - Chloe L Maybrun
- Whitehead Institute for Biomedical Research, 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 for Biomedical Research, Cambridge, MA, 02142, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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6
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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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7
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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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8
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Reddien PW. Principles of regeneration revealed by the planarian eye. Curr Opin Cell Biol 2021; 73:19-25. [PMID: 34134046 PMCID: PMC11064094 DOI: 10.1016/j.ceb.2021.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023]
Abstract
One approach to elucidating the principles of regeneration is to investigate mechanisms that regenerate a target organ. Planarian eyes are discrete, visible structures that are dispensable for viability, making them powerful for studying the logic of regeneration. Fate specification in eye regeneration occurs in stem cells (neoblasts), generating eye progenitors. Eye progenitor production is not responsive to the presence or absence of the eye, with regeneration explained by constant progenitor production in the appropriate positional environment. Eye progenitors display coarse spatial specification. A combination of eye-extrinsic cues and self-organization with differentiated eye cells dictate where migratory eye progenitors target. Finally, guidepost-like cells influence regenerating axons to facilitate the restoration of eye circuitry. These findings from the eye as a case study present a model that explains how regeneration can occur.
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Affiliation(s)
- Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA; Department of Biology, MIT, Cambridge, MA, 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA, 02139, USA.
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9
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Le D, Sabry Z, Chandra A, Kristan WB, Collins EMS, Kristan WB. Planarian fragments behave as whole animals. Curr Biol 2021; 31:5111-5117.e4. [PMID: 34624209 DOI: 10.1016/j.cub.2021.09.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/08/2021] [Accepted: 09/22/2021] [Indexed: 12/11/2022]
Abstract
Behavioral responses of freshwater planarians have been studied for over a century.1 In recent decades, behavior has been used as a readout to study planarian development and regeneration,2-6 wound healing,7,8 molecular evolution,4,9,10 neurotoxicology,11-13 and learning and memory.14-17The planarian nervous system is among the simplest of the bilaterally symmetric animals,18 with an anterior brain attached to two ventral nerve cords interconnected by multiple commissures. We found that, in response to mechanical and near-UV stimulation, head stimulation produces turning, tail stimulation produces contraction, and trunk stimulation produces midbody elongation in the planarian Dugesia japonica. When cut into two or three pieces, the anterior end of each headless piece switched its behavior to turning instead of elongation; i.e., it responded as though it were the head. In addition, posterior ends of the head and midbody pieces sometimes produced contraction instead of elongation. Thus, each severed piece acts like an intact animal, with each midbody region having nearly complete behavioral capabilities. These observations show that each midbody region reads the global state of the organism and adapts its response to incoming signals from the remaining tissue. Selective lateral incisions showed that the changes in behavior are not due to nonselective pain responses and that the ventral nerve cords and cross-connectives are responsible for coordinating local behaviors. Our findings highlight a fast functional reorganization of the planarian nervous system that complements the slower repairs provided by regeneration. This reorganization provides needed behavioral responses for survival as regeneration proceeds.
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Affiliation(s)
- Dylan Le
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Ziad Sabry
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
| | - Aarav Chandra
- The Bishop's School, 7607 La Jolla Boulevard, La Jolla, CA 92037, USA
| | - William B Kristan
- Department of Biological Sciences, California State University San Marcos, 333 South Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Eva-Maria S Collins
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA; Department of Physics and Astronomy, 500 College Avenue, Swarthmore College, Swarthmore, PA 19081, USA; Department of Physics, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Boulevard, Philadelphia, PA, USA.
| | - William B Kristan
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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10
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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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11
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Sinigaglia C, Peron S, Eichelbrenner J, Chevalier S, Steger J, Barreau C, Houliston E, Leclère L. Pattern regulation in a regenerating jellyfish. eLife 2020; 9:e54868. [PMID: 32894220 PMCID: PMC7524552 DOI: 10.7554/elife.54868] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 09/05/2020] [Indexed: 12/13/2022] Open
Abstract
Jellyfish, with their tetraradial symmetry, offer a novel paradigm for addressing patterning mechanisms during regeneration. Here we show that an interplay between mechanical forces, cell migration and proliferation allows jellyfish fragments to regain shape and functionality rapidly, notably by efficient restoration of the central feeding organ (manubrium). Fragmentation first triggers actomyosin-powered remodeling that restores body umbrella shape, causing radial smooth muscle fibers to converge around 'hubs' which serve as positional landmarks. Stabilization of these hubs, and associated expression of Wnt6, depends on the configuration of the adjoining muscle fiber 'spokes'. Stabilized hubs presage the site of the manubrium blastema, whose growth is Wnt/β-catenin dependent and fueled by both cell proliferation and long-range cell recruitment. Manubrium morphogenesis is modulated by its connections with the gastrovascular canal system. We conclude that body patterning in regenerating jellyfish emerges mainly from local interactions, triggered and directed by the remodeling process.
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Affiliation(s)
- Chiara Sinigaglia
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Sophie Peron
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Jeanne Eichelbrenner
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Sandra Chevalier
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Julia Steger
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Carine Barreau
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Evelyn Houliston
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
| | - Lucas Leclère
- Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV)Villefranche-sur-merFrance
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12
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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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13
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Vu HTK, Mansour S, Kücken M, Blasse C, Basquin C, Azimzadeh J, Myers EW, Brusch L, Rink JC. Dynamic Polarization of the Multiciliated Planarian Epidermis between Body Plan Landmarks. Dev Cell 2020; 51:526-542.e6. [PMID: 31743666 DOI: 10.1016/j.devcel.2019.10.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 07/15/2019] [Accepted: 10/23/2019] [Indexed: 11/18/2022]
Abstract
Polarity is a universal design principle of biological systems that manifests at all organizational scales, yet its coordination across scales remains poorly understood. Here, we make use of the extreme anatomical plasticity of planarian flatworms to probe the interplay between global body plan polarity and local cell polarity. Our quantitative analysis of ciliary rootlet orientation in the epidermis reveals a dynamic polarity field with head and tail as independent determinants of anteroposterior (A/P) polarization and the body margin as determinant of mediolateral (M/L) polarization. Mathematical modeling rationalizes the global polarity field and its response to experimental manipulations as superposition of separate A/P and M/L fields, and we identify the core PCP and Ft/Ds pathways as their molecular mediators. Overall, our study establishes a framework for the alignment of cellular polarity vectors relative to planarian body plan landmarks and establishes the core PCP and Ft/Ds pathways as evolutionarily conserved 2D-polarization module.
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Affiliation(s)
- Hanh Thi-Kim Vu
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Sarah Mansour
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Michael Kücken
- Technische Universität Dresden, Zentrum für Informationsdienste und Hochleistungsrechnen (ZIH), Helmholtzstrasse 10, 01069 Dresden, Germany
| | - Corinna Blasse
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Cyril Basquin
- Institut Jacques Monod, Bâtiment Buffon, 15 rue Hélène Brion, 75205 Paris CEDEX 13, France
| | - Juliette Azimzadeh
- Institut Jacques Monod, Bâtiment Buffon, 15 rue Hélène Brion, 75205 Paris CEDEX 13, France
| | - Eugene Wimberly Myers
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; Center for Systems Biology Dresden, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Lutz Brusch
- Technische Universität Dresden, Zentrum für Informationsdienste und Hochleistungsrechnen (ZIH), Helmholtzstrasse 10, 01069 Dresden, Germany.
| | - Jochen Christian Rink
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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14
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Tewari AG, Stern SR, Oderberg IM, Reddien PW. Cellular and Molecular Responses Unique to Major Injury Are Dispensable for Planarian Regeneration. Cell Rep 2019; 25:2577-2590.e3. [PMID: 30485821 PMCID: PMC6475882 DOI: 10.1016/j.celrep.2018.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/11/2018] [Accepted: 10/31/2018] [Indexed: 11/18/2022] Open
Abstract
The fundamental requirements for regeneration are poorly understood. Planarians can robustly regenerate all tissues after injury, involving stem cells, positional information, and a set of cellular and molecular responses collectively called the "missing tissue" or "regenerative" response. follistatin, which encodes an extracellular Activin inhibitor, is required for the missing tissue response after head amputation and for subsequent regeneration. We found that follistatin is required for the missing tissue response regardless of the wound context, but causes regeneration failure only after head amputation. This head regeneration failure involves follistatin-mediated regulation of Wnt signaling at wounds and is not a consequence of a diminished missing tissue response. All tested contexts of regeneration, including head regeneration, could occur with a defective missing tissue response, but at a slower pace. Our findings suggest that major cellular and molecular programs induced specifically by large injuries function to accelerate regeneration but are dispensable for regeneration itself.
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Affiliation(s)
- Aneesha G Tewari
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sarah R Stern
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Isaac M Oderberg
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - 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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15
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Hsf1 Phosphorylation Generates Cell-to-Cell Variation in Hsp90 Levels and Promotes Phenotypic Plasticity. Cell Rep 2019; 22:3099-3106. [PMID: 29562166 PMCID: PMC5893160 DOI: 10.1016/j.celrep.2018.02.083] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/11/2017] [Accepted: 02/22/2018] [Indexed: 01/07/2023] Open
Abstract
Clonal populations of cells exhibit cell-to-cell variation in the transcription of individual genes. In addition to this noise in gene expression, heterogeneity in the proteome and the proteostasis network expands the phenotypic diversity of a population. Heat shock factor 1 (Hsf1) regulates chaperone gene expression, thereby coupling transcriptional noise to proteostasis. Here we show that cell-to-cell variation in Hsf1 activity is an important determinant of phenotypic plasticity. Budding yeast cells with high Hsf1 activity were enriched for the ability to acquire resistance to an antifungal drug, and this enrichment depended on Hsp90, a known phenotypic capacitor and canonical Hsf1 target. We show that Hsf1 phosphorylation promotes cell-to-cell variation, and this variation, rather than absolute Hsf1 activity, promotes antifungal resistance. We propose that Hsf1 phosphorylation enables differential tuning of the proteostasis network in individual cells, allowing populations to access a range of phenotypic states.
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16
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Ivankovic M, Haneckova R, Thommen A, Grohme MA, Vila-Farré M, Werner S, Rink JC. Model systems for regeneration: planarians. Development 2019; 146:146/17/dev167684. [PMID: 31511248 DOI: 10.1242/dev.167684] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Planarians are a group of flatworms. Some planarian species have remarkable regenerative abilities, which involve abundant pluripotent adult stem cells. This makes these worms a powerful model system for understanding the molecular and evolutionary underpinnings of regeneration. By providing a succinct overview of planarian taxonomy, anatomy, available tools and the molecular orchestration of regeneration, this Primer aims to showcase both the unique assets and the questions that can be addressed with this model system.
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Affiliation(s)
- Mario Ivankovic
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Radmila Haneckova
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
| | - Albert Thommen
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Markus A Grohme
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Miquel Vila-Farré
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
| | - Steffen Werner
- FOM Institute AMOLF, Department of Systems Biology, Science Park 104, 1098 XG, Amsterdam, The Netherlands
| | - Jochen C Rink
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany .,Department of Tissue Dynamics and Regeneration, Max Planck Institute for Biophysical Chemistry, am Fassberg 11, 37077 Göttingen, Germany
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17
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Ochoa SD, Dores MR, Allen JM, Tran T, Osman M, Vázquez Castellanos NP, Trejo J, Zayas RM. A modular laboratory course using planarians to study genes involved in tissue regeneration. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 47:547-559. [PMID: 31194289 PMCID: PMC6731126 DOI: 10.1002/bmb.21259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 04/10/2019] [Accepted: 05/15/2019] [Indexed: 05/02/2023]
Abstract
Undergraduate research experiences are excellent opportunities to engage students in science alongside experienced scientists, but at large institutions, it is challenging to accommodate all students. To address and engage a larger number of students, we developed a modular laboratory course based on the course-based undergraduate research experiences model. This new course was integrated with the scientific aims of a research laboratory studying the cellular and molecular mechanisms underlying tissue regeneration in planarians. In this course, students were asked to identify genes with roles in planarian biology. Students analyzed and cloned an assigned gene, determined its expression pattern in situ and examined its function in regeneration. Additionally, we developed critical thinking and scientific communication skills by incorporating activities focused on critical concepts. Students obtained high quality primary data and were successful in completing and mastering the course learning outcomes. They benefitted by developing basic research skills, learning to perform, trouble-shooting experiments, reading and critically analyzing primary literature, and using the information to defend and explain their experimental results. Through this course, students also increased their confidence and ability to perform independent scientific research. The course was designed to make it accessible to the community to implement and adapt as appropriate in diverse institutions. © 2019 International Union of Biochemistry and Molecular Biology, 47(5):547-559, 2019.
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Affiliation(s)
- Stacy D Ochoa
- Department of Biology, San Diego State University, San Diego, California
- Department of Pharmacology, University of California San Diego, La Jolla, California
| | - Michael R Dores
- Department of Pharmacology, University of California San Diego, La Jolla, California
- Department of Biology, Hofstra University, Hempstead, New York
| | - John M Allen
- Department of Biology, San Diego State University, San Diego, California
| | - Tuan Tran
- Department of Biology, San Diego State University, San Diego, California
| | - Maryan Osman
- Department of Biology, San Diego State University, San Diego, California
| | | | - JoAnn Trejo
- Department of Pharmacology, University of California San Diego, La Jolla, California
| | - Ricardo M Zayas
- Department of Biology, San Diego State University, San Diego, California
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18
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The Cellular and Molecular Basis for Planarian Regeneration. Cell 2019; 175:327-345. [PMID: 30290140 DOI: 10.1016/j.cell.2018.09.021] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/07/2018] [Accepted: 09/12/2018] [Indexed: 01/03/2023]
Abstract
Regeneration is one of the great mysteries of biology. Planarians are flatworms capable of dramatic feats of regeneration, which have been studied for over 2 centuries. Recent findings identify key cellular and molecular principles underlying these feats. A stem cell population (neoblasts) generates new cells and is comprised of pluripotent stem cells (cNeoblasts) and fate-specified cells (specialized neoblasts). Positional information is constitutively active and harbored primarily in muscle, where it acts to guide stem cell-mediated tissue turnover and regeneration. I describe here a model in which positional information and stem cells combine to enable regeneration.
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19
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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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20
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Planarian regeneration between 1960s and 1990s: From skilful baffled ancestors to bold integrative descendants. A personal account. Semin Cell Dev Biol 2019; 87:3-12. [DOI: 10.1016/j.semcdb.2018.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/13/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
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21
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Sureda-Gomez M, Adell T. Planarian organizers. Semin Cell Dev Biol 2019; 87:95-104. [DOI: 10.1016/j.semcdb.2018.05.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/09/2018] [Accepted: 05/18/2018] [Indexed: 12/27/2022]
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22
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Scimone ML, Wurtzel O, Malecek K, Fincher CT, Oderberg IM, Kravarik KM, Reddien PW. foxF-1 Controls Specification of Non-body Wall Muscle and Phagocytic Cells in Planarians. Curr Biol 2018; 28:3787-3801.e6. [PMID: 30471994 DOI: 10.1016/j.cub.2018.10.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/17/2018] [Accepted: 10/10/2018] [Indexed: 12/31/2022]
Abstract
Planarians are flatworms capable of regenerating any missing body part in a process requiring stem cells and positional information. Muscle is a major source of planarian positional information and consists of several types of fibers with distinct regulatory roles in regeneration. The transcriptional regulatory programs used to specify different muscle fibers are poorly characterized. Using single-cell RNA sequencing, we define the transcriptomes of planarian dorsal-ventral muscle (DVM), intestinal muscle (IM), and pharynx muscle. This analysis identifies foxF-1, which encodes a broadly conserved Fox-family transcription factor, as a master transcriptional regulator of all non-body wall muscle. The transcription factors encoded by nk4 and gata4/5/6-2 specify two different subsets of DVM, lateral and medial, respectively, whereas gata4/5/6-3 specifies IM. These muscle types all express planarian patterning genes. Both lateral and medial DVM are required for medial-lateral patterning in regeneration, whereas medial DVM and IM have a role in maintaining and regenerating intestine morphology. In addition to the role in muscle, foxF-1 is required for the specification of multiple cell types with transcriptome similarities, including high expression levels of cathepsin genes. These cells include pigment cells, glia, and several other cells with unknown function. cathepsin+ cells phagocytose E. coli, suggesting these are phagocytic cells. In conclusion, we describe a regulatory program for planarian muscle cell subsets and phagocytic cells, both driven by foxF-1. FoxF proteins specify different mesoderm-derived tissues in other organisms, suggesting that FoxF regulates formation of an ancient and broadly conserved subset of mesoderm derivatives in the Bilateria.
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Affiliation(s)
- M Lucila Scimone
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Omri Wurtzel
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Kathryn Malecek
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Christopher T Fincher
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Isaac M Oderberg
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Kellie M Kravarik
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Peter W Reddien
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.
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23
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Characterizing the role of SWI/SNF-related chromatin remodeling complexes in planarian regeneration and stem cell function. Stem Cell Res 2018; 32:91-103. [DOI: 10.1016/j.scr.2018.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/18/2018] [Accepted: 09/06/2018] [Indexed: 11/21/2022] Open
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24
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Sandoval-Guzmán T, Currie JD. The journey of cells through regeneration. Curr Opin Cell Biol 2018; 55:36-41. [PMID: 30031323 DOI: 10.1016/j.ceb.2018.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 05/10/2018] [Indexed: 10/28/2022]
Abstract
The process of building an organ, appendage, or organism requires the precise coordination of cells in space and time. Regeneration of those same tissues adds an additional element of complexity, emerging from the chaos of disease or injury to build a mass of progenitors from mature tissue. Translating insights from natural examples of tissue regeneration into engineered regenerative therapies requires a deep understanding of the journey of a cell directly following injury to its contribution to functional, scaled replacement tissue. Here we step through the chronological phases of regeneration and highlight emerging work that brings us closer to elucidating the unique intrinsic and extrinsic properties of cells during epimorphic regeneration.
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Affiliation(s)
- Tatiana Sandoval-Guzmán
- DFG-Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Fetscherstrasse 105, 01307 Dresden, Germany.
| | - Joshua D Currie
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario M5S 3G5, Canada.
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25
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Rojo-Laguna JI, Garcia-Cabot S, Saló E. Tissue transplantation in planarians: A useful tool for molecular analysis of pattern formation. Semin Cell Dev Biol 2018; 87:116-124. [PMID: 29787860 DOI: 10.1016/j.semcdb.2018.05.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/16/2018] [Accepted: 05/18/2018] [Indexed: 01/03/2023]
Abstract
Freshwater planarians are well known for their remarkable plasticity and regenerative capabilities. Most studies of planarian regeneration have specifically examined regeneration after transverse or longitudinal sectioning or during homeostasis in intact adults. However, tissue transplantation, first performed over a century ago, constitutes another important tool in the study of regeneration in planarians, and can be easily performed given this species' extraordinary healing capacity and its lack of a circulatory system. Studies conducted to date have demonstrated the viability of transplantations involving a variety of tissue types of different positional identities, affecting any of the 3 main body axes. Moreover, these grafting experiments have shown that tissues possess axial positional identities, which are retained following transplantation. The confrontation between different positional identities that occurs after any type of tissue transplantation is resolved by the formation of a blastema, consisting of undifferentiated tissue produced by adult pluripotent stem cells (neoblasts). This blastema intercalates the positional identities of the graft and host tissues. The recent discovery of pathways involved in planarian growth, patterning, and organogenesis, as well as corresponding molecular markers, makes tissue transplantation a vital new tool with which to explore pattern formation. Here, we discuss the different grafting approaches used in planarians, and the corresponding intercalary regenerative response, placing particular emphasis on the respective contributions of donor and host tissue. Moreover, we discuss the temporal induction of blastema formation, and present new molecular data on the generation of an ectopic anterior/posterior axis in response to dorsal/ventral confrontations between host and donor tissue.
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Affiliation(s)
- Jose Ignacio Rojo-Laguna
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
| | - Sergi Garcia-Cabot
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
| | - Emili Saló
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain.
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26
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Atabay KD, LoCascio SA, de Hoog T, Reddien PW. Self-organization and progenitor targeting generate stable patterns in planarian regeneration. Science 2018; 360:404-409. [PMID: 29545509 PMCID: PMC6135251 DOI: 10.1126/science.aap8179] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/26/2018] [Indexed: 12/26/2022]
Abstract
During animal regeneration, cells must organize into discrete and functional systems. We show that self-organization, along with patterning cues, govern progenitor behavior in planarian regeneration. Surgical paradigms allowed the manipulation of planarian eye regeneration in predictable locations and numbers, generating alternative stable neuroanatomical states for wild-type animals with multiple functional ectopic eyes. We used animals with multiple ectopic eyes and eye transplantation to demonstrate that broad progenitor specification, combined with self-organization, allows anatomy maintenance during regeneration. We propose a model for regenerative progenitors involving (i) migratory targeting cues, (ii) self-organization into existing or regenerating eyes, and (iii) a broad zone, associated with coarse progenitor specification, in which eyes can be targeted by progenitors. These three properties help explain how tissues can be organized during regeneration.
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Affiliation(s)
- Kutay Deniz Atabay
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Samuel A LoCascio
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Thom de Hoog
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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27
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Rink JC. Stem Cells, Patterning and Regeneration in Planarians: Self-Organization at the Organismal Scale. Methods Mol Biol 2018; 1774:57-172. [PMID: 29916155 DOI: 10.1007/978-1-4939-7802-1_2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The establishment of size and shape remains a fundamental challenge in biological research that planarian flatworms uniquely epitomize. Planarians can regenerate complete and perfectly proportioned animals from tiny and arbitrarily shaped tissue pieces; they continuously renew all organismal cell types from abundant pluripotent stem cells, yet maintain shape and anatomy in the face of constant turnover; they grow when feeding and literally degrow when starving, while scaling form and function over as much as a 40-fold range in body length or an 800-fold change in total cell numbers. This review provides a broad overview of the current understanding of the planarian stem cell system, the mechanisms that pattern the planarian body plan and how the interplay between patterning signals and cell fate choices orchestrates regeneration. What emerges is a conceptual framework for the maintenance and regeneration of the planarian body plan on basis of the interplay between pluripotent stem cells and self-organizing patterns and further, the general utility of planarians as model system for the mechanistic basis of size and shape.
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Affiliation(s)
- Jochen C Rink
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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Abnave P, Aboukhatwa E, Kosaka N, Thompson J, Hill MA, Aboobaker AA. Epithelial-mesenchymal transition transcription factors control pluripotent adult stem cell migration in vivo in planarians. Development 2017; 144:3440-3453. [PMID: 28893948 PMCID: PMC5665486 DOI: 10.1242/dev.154971] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/14/2017] [Indexed: 01/23/2023]
Abstract
Migration of stem cells underpins the physiology of metazoan animals. For tissues to be maintained, stem cells and their progeny must migrate and differentiate in the correct positions. This need is even more acute after tissue damage by wounding or pathogenic infection. Inappropriate migration also underpins metastasis. Despite this, few mechanistic studies address stem cell migration during repair or homeostasis in adult tissues. Here, we present a shielded X-ray irradiation assay that allows us to follow stem cell migration in planarians. We demonstrate the use of this system to study the molecular control of stem cell migration and show that snail-1, snail-2 and zeb-1 EMT transcription factor homologs are necessary for cell migration to wound sites and for the establishment of migratory cell morphology. We also observed that stem cells undergo homeostatic migration to anterior regions that lack local stem cells, in the absence of injury, maintaining tissue homeostasis. This requires the polarity determinant notum Our work establishes planarians as a suitable model for further in-depth study of the processes controlling stem cell migration in vivo.
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Affiliation(s)
- Prasad Abnave
- Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - Ellen Aboukhatwa
- Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - Nobuyoshi Kosaka
- Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
| | - James Thompson
- CRUK/MRC Oxford Institute for Radiation Oncology, ORCRB Roosevelt Drive, University of Oxford, Oxford OX3 7DQ, UK
| | - Mark A Hill
- CRUK/MRC Oxford Institute for Radiation Oncology, ORCRB Roosevelt Drive, University of Oxford, Oxford OX3 7DQ, UK
| | - A Aziz Aboobaker
- Department of Zoology, Tinbergen Building, South Parks Road, University of Oxford, Oxford OX1 3PS, UK
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