1
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Semi-occlusive dressing therapy versus surgical treatment in fingertip amputation injuries: a clinical study. Eur J Trauma Emerg Surg 2022; 49:1441-1447. [DOI: 10.1007/s00068-022-02193-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/27/2022] [Indexed: 12/14/2022]
Abstract
Abstract
Objectives
Treatment of fingertip amputations is subject of controversial debates. Recently, semi-occlusive dressings have increased in popularity in these injuries.
Aims
To compare clinical outcomes of conservative semi-occlusive dressing therapy versus surgical treatment of fingertip amputations.
Methods
Eighty-four patients with fingertip amputations were re-examined clinically after a mean follow-up of 28.1 months (range 9.6–46.2). Sixty-six patients (79%) were treated with semi-occlusive dressings (group 1) and 18 (21%) underwent surgery (group 2). Range of motion, grip strength, and two-point discrimination were measured at the final follow-up. Furthermore, VAS score, Quick-DASH score, subjective aesthetic outcome and loss of working days were obtained.
Results
Group 1 demonstrated healing in all 66 patients (100%) while in Group 2 5 out of 18 patients (28%) failed to achieve healing after a mean of 17 days (range 2–38) due to graft necrosis. Group 1 showed significantly lower VAS scores and significantly lower loss of two-point discrimination compared to Group 2. Work absence was significantly shorter in Group 1 versus Group 2. Trophic changes in finger (46%) and nail (30%) were significantly lower in Group 1 compared to Group 2 (44% and 70%, respectively). Disturbance during daily business activities (14%) and cold sensitivity (23%) were significantly lower in Group 1 compared to Group 2 (86% and 77%, respectively).
Conclusions
Semi-occlusive dressing therapy for fingertip amputations demonstrated excellent healing rates. Compared to surgical treatment, it resulted in significantly better clinical outcomes, lower complication rates and significantly higher reported satisfaction rates. Therefore, semi-occlusive dressing for fingertip injuries is a very successful procedure and shall be preferred over surgical treatment in most cases.
Level of evidence
III therapeutic.
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2
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Plasticity of body axis polarity in Hydra regeneration under constraints. Sci Rep 2022; 12:13368. [PMID: 35922470 PMCID: PMC9349251 DOI: 10.1038/s41598-022-17411-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
One of the major events in animal morphogenesis is the emergence of a polar body axis. Here, we combine classic grafting techniques with live imaging to explore the plasticity of polarity determination during whole body regeneration in Hydra. Composite tissues are made by fusing two rings, excised from separate animals, in different configurations that vary in the polarity and original positions of the rings along the body axes of the parent animals. Under frustrating initial configurations, body axis polarity that is otherwise stably inherited from the parent animal, can become labile and even be reversed. Importantly, the site of head regeneration exhibits a strong bias toward the edges of the tissue, even when this involves polarity reversal. In particular, we observe head formation at an originally aboral tissue edge, which is not compatible with models of Hydra regeneration based only on preexisting morphogen gradients or an injury response. The site of the new head invariably contains an aster-like defect in the organization of the supra-cellular ectodermal actin fibers. While a defect is neither required nor sufficient for head formation, we show that the defect at the new head site can arise via different routes, either appearing directly following excision as the tissue seals at its edge or through de novo defect formation at the fusion site. Altogether, our results show that the emergence of a polar body axis depends on the original polarity and position of the excised tissues as well as structural factors, suggesting that axis determination is an integrated process that arises from the dynamic interplay of multiple biochemical and mechanical processes.
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3
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Rosa MT, Loreto ELS. Revisiting the regeneration of Stenostomum leucops (Catenulida, Platyhelminthes). INVERTEBR REPROD DEV 2022. [DOI: 10.1080/07924259.2021.1994475] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marcos T. Rosa
- Programa de Pós-Graduação em Biodiversidade Animal, Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Elgion L. S. Loreto
- Department of Biochemistry and Molecular Biology, Universidade Federal de Santa Maria, Santa Maria, Brazil
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4
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Sasidharan V, Sánchez Alvarado A. The Diverse Manifestations of Regeneration and Why We Need to Study Them. Cold Spring Harb Perspect Biol 2021; 14:a040931. [PMID: 34750171 PMCID: PMC9438785 DOI: 10.1101/cshperspect.a040931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
For hundreds of years, the question of why some organisms can regenerate missing body parts while others cannot has remained poorly understood. This has been due in great part to the inability to genetically, molecularly, and cellularly dissect this problem for most of the history of the field. It has only been in the past 20-30 years that important mechanistic advances have been made in methodologies that introduce loss and gain of gene function in animals that can regenerate. However, we still have a very incomplete understanding of how broadly regenerative abilities may be dispersed across species and whether or not such properties share a common evolutionary origin, which may have emerged independently or both. Understanding regeneration, therefore, will require rigorously practiced fundamental, curiosity-driven, discovery research. Expanding the number of research organisms used to study regeneration allows us to uncover aspects of this problem we may not yet know exist and simultaneously increases our chances of solving this long-standing problem of biology.
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5
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Mitsi K, Arroyo AS, Ruiz-Trillo I. A global metabarcoding analysis expands molecular diversity of Platyhelminthes and reveals novel early-branching clades. Biol Lett 2019; 15:20190182. [PMID: 31506037 PMCID: PMC6769146 DOI: 10.1098/rsbl.2019.0182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 08/14/2019] [Indexed: 01/29/2023] Open
Abstract
Understanding biological diversity is crucial for ecological and evolutionary studies. Even though a great part of animal diversity has already been documented, both morphological surveys and metabarcoding analyses have previously shown that some animal groups, such as Platyhelminthes, may harbour hidden diversity. To better understand the molecular diversity of Platyhelminthes, one of the most diverse and biomedically important animal phyla, we here combined data from six marine and two freshwater metabarcoding expeditions that cover a broad variety of aquatic habitats and analysed the data by phylogenetic placement. Our results show that a great part of the hidden diversity is located in early-branching clades such as Catenulida and Macrostomorpha, as well as in late-diverging clades such as Proseriata and Rhabdocoela. We also report the first freshwater record of Gnosonesimida, a group previously thought to be exclusively marine. Finally, we identified two putative novel freshwater Platyhelminthes clades that branch between well-defined orders of the phylum. Thus, our analyses of several environmental datasets confirm that a large part of the diversity of Platyhelminthes remains undiscovered, point to groups with more potential novel species and identify freshwater environments as potential reservoirs for novel species of flatworms.
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Affiliation(s)
- Konstantina Mitsi
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Catalonia, Spain
| | - Alicia S. Arroyo
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Catalonia, Spain
| | - Iñaki Ruiz-Trillo
- Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, Barcelona 08003, Catalonia, Spain
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Catalonia, Spain
- ICREA, Pg. Lluís Companys 23, Barcelona 08010, Catalonia, Spain
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6
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Pietak A, Bischof J, LaPalme J, Morokuma J, Levin M. Neural control of body-plan axis in regenerating planaria. PLoS Comput Biol 2019; 15:e1006904. [PMID: 30990801 PMCID: PMC6485777 DOI: 10.1371/journal.pcbi.1006904] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 04/26/2019] [Accepted: 02/26/2019] [Indexed: 01/01/2023] Open
Abstract
Control of axial polarity during regeneration is a crucial open question. We developed a quantitative model of regenerating planaria, which elucidates self-assembly mechanisms of morphogen gradients required for robust body-plan control. The computational model has been developed to predict the fraction of heteromorphoses expected in a population of regenerating planaria fragments subjected to different treatments, and for fragments originating from different regions along the anterior-posterior and medio-lateral axis. This allows for a direct comparison between computational and experimental regeneration outcomes. Vector transport of morphogens was identified as a fundamental requirement to account for virtually scale-free self-assembly of the morphogen gradients observed in planarian homeostasis and regeneration. The model correctly describes altered body-plans following many known experimental manipulations, and accurately predicts outcomes of novel cutting scenarios, which we tested. We show that the vector transport field coincides with the alignment of nerve axons distributed throughout the planarian tissue, and demonstrate that the head-tail axis is controlled by the net polarity of neurons in a regenerating fragment. This model provides a comprehensive framework for mechanistically understanding fundamental aspects of body-plan regulation, and sheds new light on the role of the nervous system in directing growth and form.
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Affiliation(s)
- Alexis Pietak
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
| | - Johanna Bischof
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Joshua LaPalme
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Junji Morokuma
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, Massachusetts, United States of America
- Department of Biology, Tufts University, Medford, Massachusetts, United States of America
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7
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de Oliveira MS, Lopes KAR, Leite PMSCM, Morais FV, de Campos Velho NMR. Physiological evaluation of the behavior and epidermis of freshwater planarians ( Girardia tigrina and Girardia sp.) exposed to stressors. Biol Open 2018; 7:bio029595. [PMID: 29871871 PMCID: PMC6031348 DOI: 10.1242/bio.029595] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 04/24/2018] [Indexed: 12/15/2022] Open
Abstract
Planarians are metazoan freshwater flatworms which are free-living organisms. Their body has pluripotent stem cell promoters of tissue regeneration capacity. The water temperature and the potential of hydrogen (pH) of lentic ecosystems are important factors involved in the distribution and abundance of these animals. Although the pH factor is directly related to the physiology and behavior of planarians, their adaptive and regenerating capacities still remain unknown. The Critical Thermal Maximum (CTM) is a very widespread method used in the evaluation of thermal tolerance. In this study, Girardia tigrina (Girard, 1850) and Girardia sp., a species found in Brazil, which is under study as a new species, had their epidermis assessed by scanning electron microscopy (SEM) to analyze their physiological structures before and after exposure to different stressors. SEM was used as a method to evaluate the planarians' epidermis as a result of the increasing temperature (CTM) and pH alterations, the latter with the use of a new methodology defined as Critical Hydrogen ion concentration Maximum (CHM). In increasing temperatures from 20°C to 37°C, both Girardia tigrina and Girardia sp. proved to be adaptable to thermal stress. Girardia sp. was shown to be more resistant to higher temperatures. However, Girardia tigrina was more resistant to extreme pH conditions (4.0 to 10.0). SEM analysis showed morphological differences among planarian species, such as the arrangement of the structures and cell types of the dorsal epidermis. Moreover, planarians demonstrated the ability to change the surrounding pH of their external environment in order to maintain the function of their physiological mechanisms, suggesting that these animals have a complex survival system, possibly related to protonephridia, flame cells and excretory pores.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Matheus Salgado de Oliveira
- Planarian Laboratory, Nature Research Center, Faculty of Education and Arts, University of Vale do Paraíba, São José dos Campos, São Paulo 12244-000, Brazil
| | - Karla Andressa Ruiz Lopes
- Planarian Laboratory, Nature Research Center, Faculty of Education and Arts, University of Vale do Paraíba, São José dos Campos, São Paulo 12244-000, Brazil
| | | | - Flavia Villaça Morais
- Laboratory of Cellular and Molecular Biology of Fungi, Research and Development Institute, University of Vale do Paraíba, São José dos Campos, São Paulo 12244-000, Brazil
| | - Nádia Maria Rodrigues de Campos Velho
- Planarian Laboratory, Nature Research Center, Faculty of Education and Arts, University of Vale do Paraíba, São José dos Campos, São Paulo 12244-000, Brazil
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8
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Braun E, Keren K. HydraRegeneration: Closing the Loop with Mechanical Processes in Morphogenesis. Bioessays 2018; 40:e1700204. [DOI: 10.1002/bies.201700204] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 04/29/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Erez Braun
- Department of Physics & Network Biology Research LaboratoriesTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Kinneret Keren
- Department of Physics & Network Biology Research LaboratoriesTechnion – Israel Institute of TechnologyHaifaIsrael
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9
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Guo L, Accorsi A, He S, Guerrero-Hernández C, Sivagnanam S, McKinney S, Gibson M, Sánchez Alvarado A. An adaptable chromosome preparation methodology for use in invertebrate research organisms. BMC Biol 2018; 16:25. [PMID: 29482548 PMCID: PMC5828064 DOI: 10.1186/s12915-018-0497-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/07/2018] [Indexed: 12/16/2022] Open
Abstract
Background The ability to efficiently visualize and manipulate chromosomes is fundamental to understanding the genome architecture of organisms. Conventional chromosome preparation protocols developed for mammalian cells and those relying on species-specific conditions are not suitable for many invertebrates. Hence, a simple and inexpensive chromosome preparation protocol, adaptable to multiple invertebrate species, is needed. Results We optimized a chromosome preparation protocol and applied it to several planarian species (phylum Platyhelminthes), the freshwater apple snail Pomacea canaliculata (phylum Mollusca), and the starlet sea anemone Nematostella vectensis (phylum Cnidaria). We demonstrated that both mitotically active adult tissues and embryos can be used as sources of metaphase chromosomes, expanding the potential use of this technique to invertebrates lacking cell lines and/or with limited access to the complete life cycle. Simple hypotonic treatment with deionized water was sufficient for karyotyping; growing cells in culture was not necessary. The obtained karyotypes allowed the identification of differences in ploidy and chromosome architecture among otherwise morphologically indistinguishable organisms, as in the case of a mixed population of planarians collected in the wild. Furthermore, we showed that in all tested organisms representing three different phyla this protocol could be effectively coupled with downstream applications, such as chromosome fluorescent in situ hybridization. Conclusions Our simple and inexpensive chromosome preparation protocol can be readily adapted to new invertebrate research organisms to accelerate the discovery of novel genomic patterns across the branches of the tree of life.
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Affiliation(s)
- Longhua Guo
- University of California, Los Angeles, CA, USA
| | - Alice Accorsi
- Stowers Institute for Medical Research, Kansas City, MO, USA.,Howard Hughes Medical Institute, Kansas City, MO, USA
| | - Shuonan He
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | | | - Sean McKinney
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Matthew Gibson
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO, USA. .,Howard Hughes Medical Institute, Kansas City, MO, USA.
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10
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Martín-Durán JM, Ryan JF, Vellutini BC, Pang K, Hejnol A. Increased taxon sampling reveals thousands of hidden orthologs in flatworms. Genome Res 2017; 27:1263-1272. [PMID: 28400424 PMCID: PMC5495077 DOI: 10.1101/gr.216226.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/10/2017] [Indexed: 11/25/2022]
Abstract
Gains and losses shape the gene complement of animal lineages and are a fundamental aspect of genomic evolution. Acquiring a comprehensive view of the evolution of gene repertoires is limited by the intrinsic limitations of common sequence similarity searches and available databases. Thus, a subset of the gene complement of an organism consists of hidden orthologs, i.e., those with no apparent homology to sequenced animal lineages—mistakenly considered new genes—but actually representing rapidly evolving orthologs or undetected paralogs. Here, we describe Leapfrog, a simple automated BLAST pipeline that leverages increased taxon sampling to overcome long evolutionary distances and identify putative hidden orthologs in large transcriptomic databases by transitive homology. As a case study, we used 35 transcriptomes of 29 flatworm lineages to recover 3427 putative hidden orthologs, some unidentified by OrthoFinder and HaMStR, two common orthogroup inference algorithms. Unexpectedly, we do not observe a correlation between the number of putative hidden orthologs in a lineage and its “average” evolutionary rate. Hidden orthologs do not show unusual sequence composition biases that might account for systematic errors in sequence similarity searches. Instead, gene duplication with divergence of one paralog and weak positive selection appear to underlie hidden orthology in Platyhelminthes. By using Leapfrog, we identify key centrosome-related genes and homeodomain classes previously reported as absent in free-living flatworms, e.g., planarians. Altogether, our findings demonstrate that hidden orthologs comprise a significant proportion of the gene repertoire in flatworms, qualifying the impact of gene losses and gains in gene complement evolution.
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Affiliation(s)
- José M Martín-Durán
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen 5006, Norway
| | - Joseph F Ryan
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen 5006, Norway.,Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
| | - Bruno C Vellutini
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen 5006, Norway
| | - Kevin Pang
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen 5006, Norway
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen 5006, Norway
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11
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Shieh SJ, Cheng TC. Regeneration and repair of human digits and limbs: fact and fiction. ACTA ACUST UNITED AC 2015; 2:149-68. [PMID: 27499873 PMCID: PMC4857729 DOI: 10.1002/reg2.41] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Revised: 08/08/2015] [Accepted: 08/10/2015] [Indexed: 12/15/2022]
Abstract
A variety of digit and limb repair and reconstruction methods have been used in different clinical settings, but regeneration remains an item on every plastic surgeon's "wish list." Although surgical salvage techniques are continually being improved, unreplantable digits and limbs are still abundant. We comprehensively review the structural and functional salvage methods in clinical practice, from the peeling injuries of small distal fingertips to multisegmented amputated limbs, and the developmental and tissue engineering approaches for regenerating human digits and limbs in the laboratory. Although surgical techniques have forged ahead, there are still situations in which digits and limbs are unreplantable. Advances in the field are delineated, and the regeneration processes of salamander limbs, lizard tails, and mouse digits and each component of tissue engineering approaches for digit- and limb-building are discussed. Although the current technology is promising, there are many challenges in human digit and limb regeneration. We hope this review inspires research on the critical gap between clinical and basic science, and leads to more sophisticated digit and limb loss rescue and regeneration innovations.
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Affiliation(s)
- Shyh-Jou Shieh
- Division of Plastic and Reconstructive Surgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine National Cheng Kung University Tainan Taiwan; International Research Center for Wound Repair and Regeneration (iWRR) National Cheng Kung University Tainan Taiwan
| | - Tsun-Chih Cheng
- Division of Plastic and Reconstructive Surgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine National Cheng Kung University Tainan Taiwan
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12
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Tosenberger A, Bessonov N, Levin M, Reinberg N, Volpert V, Morozova N. A conceptual model of morphogenesis and regeneration. Acta Biotheor 2015; 63:283-94. [PMID: 25822060 DOI: 10.1007/s10441-015-9249-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/18/2015] [Indexed: 12/11/2022]
Abstract
This paper is devoted to computer modelling of the development and regeneration of multicellular biological structures. Some species (e.g. planaria and salamanders) are able to regenerate parts of their body after amputation damage, but the global rules governing cooperative cell behaviour during morphogenesis are not known. Here, we consider a simplified model organism, which consists of tissues formed around special cells that can be interpreted as stem cells. We assume that stem cells communicate with each other by a set of signals, and that the values of these signals depend on the distance between cells. Thus the signal distribution characterizes location of stem cells. If the signal distribution is changed, then the difference between the initial and the current signal distribution affects the behaviour of stem cells-e.g. as a result of an amputation of a part of tissue the signal distribution changes which stimulates stem cells to migrate to new locations, appropriate for regeneration of the proper pattern. Moreover, as stem cells divide and form tissues around them, they control the form and the size of regenerating tissues. This two-level organization of the model organism, with global regulation of stem cells and local regulation of tissues, allows its reproducible development and regeneration.
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Affiliation(s)
- A Tosenberger
- Institut des Hautes Études Scientifiques, 91440, Bures-sur-Yvette, France,
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13
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Geng J, Gates PB, Kumar A, Guenther S, Garza-Garcia A, Kuenne C, Zhang P, Looso M, Brockes JP. Identification of the orphan gene Prod 1 in basal and other salamander families. EvoDevo 2015; 6:9. [PMID: 25874078 PMCID: PMC4396064 DOI: 10.1186/s13227-015-0006-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/24/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The urodele amphibians (salamanders) are the only adult tetrapods able to regenerate the limb. It is unclear if this is an ancestral property that is retained in salamanders but lost in other tetrapods or if it evolved in salamanders. The three-finger protein Prod 1 is implicated in the mechanism of newt limb regeneration, and no orthologs have been found in other vertebrates, thus providing evidence for the second viewpoint. It has also been suggested that this protein could play a role in salamander-specific aspects of limb development. There are ten families of extant salamanders, and Prod 1 has only been identified in two of them to date. It is important to determine if it is present in other families and, particularly, the basal group of two families which diverged approximately 200 MYA. FINDINGS We have used polymerase chain reaction (PCR) to identify Prod 1 in a Chinese hynobiid species Batrachuperus longdongensis. We obtained an intestinal transcriptome of the plethodontid Aneides lugubris and, from this, identified a primer which allowed PCR of two Prod 1 genes from this species. All known Prod 1 sequences from nine species in four families have been aligned, and a phylogenetic tree has been derived. CONCLUSIONS Prod 1 is found in basal salamanders of the family Hynobiidae, and in at least three other families, so it may be present in all extant salamanders. It remains a plausible candidate to have been involved in the origins of limb regeneration, as well as the apomorphic aspects of limb development.
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Affiliation(s)
- Jie Geng
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006 China
| | - Phillip B Gates
- Institute of Structural and Molecular Biology, Division of Biosciences, UCL, Gower Street, London, WC1E 6BT UK
| | - Anoop Kumar
- Institute of Structural and Molecular Biology, Division of Biosciences, UCL, Gower Street, London, WC1E 6BT UK
| | - Stefan Guenther
- Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Acely Garza-Garcia
- National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA UK
| | - Carsten Kuenne
- Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Peng Zhang
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510006 China
| | - Mario Looso
- Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Jeremy P Brockes
- Institute of Structural and Molecular Biology, Division of Biosciences, UCL, Gower Street, London, WC1E 6BT UK
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14
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Laumer CE, Hejnol A, Giribet G. Nuclear genomic signals of the 'microturbellarian' roots of platyhelminth evolutionary innovation. eLife 2015; 4:e05503. [PMID: 25764302 PMCID: PMC4398949 DOI: 10.7554/elife.05503] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/06/2015] [Indexed: 12/25/2022] Open
Abstract
Flatworms number among the most diverse invertebrate phyla and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. In this study, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked 'microturbellarian' groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates.
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Affiliation(s)
- Christopher E Laumer
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
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15
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Almuedo-Castillo M, Crespo X, Seebeck F, Bartscherer K, Salò E, Adell T. JNK controls the onset of mitosis in planarian stem cells and triggers apoptotic cell death required for regeneration and remodeling. PLoS Genet 2014; 10:e1004400. [PMID: 24922054 PMCID: PMC4055413 DOI: 10.1371/journal.pgen.1004400] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 04/09/2014] [Indexed: 01/18/2023] Open
Abstract
Regeneration of lost tissues depends on the precise interpretation of molecular signals that control and coordinate the onset of proliferation, cellular differentiation and cell death. However, the nature of those molecular signals and the mechanisms that integrate the cellular responses remain largely unknown. The planarian flatworm is a unique model in which regeneration and tissue renewal can be comprehensively studied in vivo. The presence of a population of adult pluripotent stem cells combined with the ability to decode signaling after wounding enable planarians to regenerate a complete, correctly proportioned animal within a few days after any kind of amputation, and to adapt their size to nutritional changes without compromising functionality. Here, we demonstrate that the stress-activated c-jun-NH2-kinase (JNK) links wound-induced apoptosis to the stem cell response during planarian regeneration. We show that JNK modulates the expression of wound-related genes, triggers apoptosis and attenuates the onset of mitosis in stem cells specifically after tissue loss. Furthermore, in pre-existing body regions, JNK activity is required to establish a positive balance between cell death and stem cell proliferation to enable tissue renewal, remodeling and the maintenance of proportionality. During homeostatic degrowth, JNK RNAi blocks apoptosis, resulting in impaired organ remodeling and rescaling. Our findings indicate that JNK-dependent apoptotic cell death is crucial to coordinate tissue renewal and remodeling required to regenerate and to maintain a correctly proportioned animal. Hence, JNK might act as a hub, translating wound signals into apoptotic cell death, controlled stem cell proliferation and differentiation, all of which are required to coordinate regeneration and tissue renewal.
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Affiliation(s)
- María Almuedo-Castillo
- Department of Genetics and Institute of Biomedicine, University of Barcelona, Barcelona, Catalonia, Spain
| | - Xenia Crespo
- Department of Genetics and Institute of Biomedicine, University of Barcelona, Barcelona, Catalonia, Spain
| | - Florian Seebeck
- Max Planck Research Group Stem Cells and Regeneration, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Faculty of Medicine, University of Münster, Münster, Germany
| | - Kerstin Bartscherer
- Max Planck Research Group Stem Cells and Regeneration, Max Planck Institute for Molecular Biomedicine, Münster, Germany
- Faculty of Medicine, University of Münster, Münster, Germany
| | - Emili Salò
- Department of Genetics and Institute of Biomedicine, University of Barcelona, Barcelona, Catalonia, Spain
| | - Teresa Adell
- Department of Genetics and Institute of Biomedicine, University of Barcelona, Barcelona, Catalonia, Spain
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