1
|
Benita O, Nesher N, Shomrat T. Neurophysiological measurements of planarian brain activity: a unique model for neuroscience research. Biol Open 2024; 13:bio060480. [PMID: 38979914 DOI: 10.1242/bio.060480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/28/2024] [Indexed: 07/10/2024] Open
Abstract
Planarians are well-known model organisms for regeneration and developmental biology research due to their remarkable regenerative capacity. Here, we aim to advocate for the use of planaria as a valuable model for neurobiology, as well. Planarians have most of the major qualities of more developed organisms, including a primal brain. These traits combined with their exceptional regeneration capabilities, allow neurobiological experiments not possible in any other model organism, as we demonstrate by electrophysiological recording from planaria with two heads that controlling a shared body. To facilitate planarian neuroscience research, we developed an extracellular multi-unit recording procedure for the planarians fragile brain (Dugesia japonica). We created a semi-intact preparation restrained with fine dissection pins, enabling hours of reliable recording, via a suction electrode. Here, we demonstrate the feasibility and potential of planarian neurophysiological research by characterizing the neuronal activity during simple learning processes and responses to various stimuli. In addition, we examined the use of linalool as anesthetic agent to allows recordings from an intact, large worm and for fine electrophysiological approaches such as intracellular recording. The demonstrated ability for neurophysiological measurements, along with the inherent advantages of planarians, promotes this exceptional model organism for neuroscience research.
Collapse
Affiliation(s)
- Orel Benita
- Department of Neurobiology, Hebrew University, Jerusalem 9190401, Israel
| | - Nir Nesher
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret 4029700, Israel
| | - Tal Shomrat
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret 4029700, Israel
| |
Collapse
|
2
|
Herrera E, Chédotal A, Mason C. Development of the Binocular Circuit. Annu Rev Neurosci 2024; 47:303-322. [PMID: 38635868 DOI: 10.1146/annurev-neuro-111020-093230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Seeing in three dimensions is a major property of the visual system in mammals. The circuit underlying this property begins in the retina, from which retinal ganglion cells (RGCs) extend to the same or opposite side of the brain. RGC axons decussate to form the optic chiasm, then grow to targets in the thalamus and midbrain, where they synapse with neurons that project to the visual cortex. Here we review the cellular and molecular mechanisms of RGC axonal growth cone guidance across or away from the midline via receptors to cues in the midline environment. We present new views on the specification of ipsi- and contralateral RGC subpopulations and factors implementing their organization in the optic tract and termination in subregions of their targets. Lastly, we describe the functional and behavioral aspects of binocular vision, focusing on the mouse, and discuss recent discoveries in the evolution of the binocular circuit.
Collapse
Affiliation(s)
- Eloísa Herrera
- Instituto de Neurociencias (CSIC-UMH), Consejo Superior de Investigaciones Científicas and Universidad Miguel Hernández, Alicante, Spain;
| | - Alain Chédotal
- Université Claude Bernard Lyon 1, MeLiS, CNRS UMR5284, INSERM U1314, Lyon, France
- Institut de Pathologie, Groupe Hospitalier Est, Hospices Civils de Lyon, Lyon, France
- Institut de la Vision, INSERM, Sorbonne Université, Paris, France;
| | - Carol Mason
- Departments of Pathology and Cell Biology, Neuroscience, and Ophthalmology, Zuckerman Institute, Columbia University, New York, NY, USA;
| |
Collapse
|
3
|
Zhao WJ, Yang XQ, Shi CY, Zhang HC, Chen GW, Liu DZ. Neurotoxicity of Glyphosate to Planarian Dugesia japonica. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2023; 111:66. [PMID: 37904018 DOI: 10.1007/s00128-023-03826-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/13/2023] [Indexed: 11/01/2023]
Abstract
As one of the most widely used herbicides in agricultural industry, the residues of glyphosate (GLY) are frequent environmental pollutants. Freshwater planarian Dugesia japonica has been developed as a model for neurotoxicology. In this study, the effects of GLY on locomotion and feeding behavior, as well as neuroenzyme activities and mRNA expressions of D. japonica were determined. Additionally, histochemical localization was executed to explore the damage to the central nervous system (CNS) of planarians stressed by GLY. The results showed that the locomotor velocity, ingestion rate and the neuroenzyme activity were inhibited and the gene expressions were altered. Also, histo-architecture injury to CNS of planarians upon GLY exposure in a time-dependent manner was observed. Collectively, our results indicate that GLY can cause neurotoxicity to freshwater planarians representing as reduction in locomotor velocity and feeding rate by disturbing the neurotransmission systems and damaging the structure of CNS.
Collapse
Affiliation(s)
- Wen-Jing Zhao
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China
| | - Xiao-Qing Yang
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China
| | - Chang-Ying Shi
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China
| | - He-Cai Zhang
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China.
| | - Guang-Wen Chen
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China.
| | - De-Zeng Liu
- College of Life Sciences, Henan Normal University, No.46, Jianshe East Road, Xinxiang, 453007, China
| |
Collapse
|
4
|
Wang S, Sun Y, Liu X, Guo Y, Huang Y, Zhang S, Tian Q. Meis1 Controls the Differentiation of Eye Progenitor Cells and the Formation of Posterior Poles during Planarian Regeneration. Int J Mol Sci 2023; 24:ijms24043505. [PMID: 36834910 PMCID: PMC9961902 DOI: 10.3390/ijms24043505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/21/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
As a member of TALE family, Meis1 has been proven to regulate cell proliferation and differentiation during cell fate commitment; however, the mechanism is still not fully understood. The planarian, which has an abundance of stem cells (neoblasts) responsible for regenerating any organ after injury, is an ideal model for studying the mechanisms of tissue identity determination. Here, we characterized a planarian homolog of Meis1 from the planarian Dugesia japonica. Importantly, we found that knockdown of DjMeis1 inhibits the differentiation of neoblasts into eye progenitor cells and results in an eyeless phenotype with normal central nervous system. Furthermore, we observed that DjMeis1 is required for the activation of Wnt signaling pathway by promoting the Djwnt1 expression during posterior regeneration. The silencing of DjMeis1 suppresses the expression of Djwnt1 and results in the inability to reconstruct posterior poles. In general, our findings indicated that DjMeis1 acts as a trigger for the activation of eye and tail regeneration by regulating the differentiation of eye progenitor cells and the formation of posterior poles, respectively.
Collapse
Affiliation(s)
- Shaocong Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yujia Sun
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaomai Liu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yajun Guo
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yongding Huang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Shoutao Zhang
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou 450046, China
- Correspondence: (S.Z.); (Q.T.)
| | - Qingnan Tian
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (S.Z.); (Q.T.)
| |
Collapse
|
5
|
Guo Y, Sun Y, Ma M, Huang Y, Zhang S, Tian Q. Djsnon, a downstream gene of Djfoxk1, is required for the regeneration of the planarian central nervous system. Biochem Biophys Res Commun 2023; 643:8-15. [PMID: 36584589 DOI: 10.1016/j.bbrc.2022.12.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/23/2022] [Indexed: 12/25/2022]
Abstract
Regulators of adult neurogenesis are crucial targets for neuronal repair. Freshwater planarians are ideal model systems for studying neuronal regeneration as they can regenerate their entire central nervous system (CNS) using pluripotent adult stem cells. Here, we identified Djfoxk1 in planarian Dugesia japonica to be required for planarian CNS regeneration. Knockdown of Djfoxk1 inhibits the regeneration of the cephalic ganglia, resulting in the failure of eye regeneration. By RNAi screening of Djfoxk1 downstream genes, we identified Djsnon as another regulator of planarian neuronal regeneration. Inhibition of Djsnon with RNA interference (RNAi) results in similar phenotypes caused by Djfoxk1 RNAi without affecting cell proliferation and wound healing. Our findings show that Djsnon as a downstream gene of Djfoxk1 regulates the regeneration of the planarian CNS.
Collapse
Affiliation(s)
- Yajun Guo
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yujia Sun
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Mengwen Ma
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Yongding Huang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Shoutao Zhang
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China; Longhu Laboratory of Advanced Immunology, Zhengzhou, Henan, China.
| | - Qingnan Tian
- School of LifeSciences, Zhengzhou University, Zhengzhou, Henan, China.
| |
Collapse
|
6
|
Reho G, Lelièvre V, Cadiou H. Planarian nociception: Lessons from a scrunching flatworm. Front Mol Neurosci 2022; 15:935918. [PMID: 35959107 PMCID: PMC9362985 DOI: 10.3389/fnmol.2022.935918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/08/2022] [Indexed: 11/20/2022] Open
Abstract
In addition to being studied for their exceptional regeneration abilities, planarians (i.e., flatworms) have also been extensively used in the context of pharmacological experiments during the past century. Many researchers used planarians as a model system for the study of drug abuse because they display high similarities with the nervous system of vertebrates at cellular and molecular levels (e.g., neuronal morphology, neurotransmitter ligands, and receptor function). This research field recently led to the discovery of causal relationships between the expression of Transient Receptor Potential ion channels in planarians and their behavioral responses to noxious stimuli such as heat, cold or pharmacological analogs such as TRP agonists, among others. It has also been shown that some antinociceptive drugs modulate these behaviors. However, among the few authors that tried to implement a full behavior analysis, none reached a consensual use of the terms used to describe planarian gaits yet, nor did they establish a comprehensive description of a potential planarian nociceptive system. The aim of this review is therefore to aggregate the ancient and the most recent evidence for a true nociceptive behavior in planarians. It also highlights the convenience and relevance of this invertebrate model for nociceptive tests and suggests further lines of research. In regards to past pharmacological studies, this review finally discusses the opportunities given by the model to extensively screen for novel antinociceptive drugs.
Collapse
|
7
|
Gao T, Sun B, Xu Z, Chen Q, Yang M, Wan Q, Song L, Chen G, Jing C, Zeng EY, Yang G. Exposure to polystyrene microplastics reduces regeneration and growth in planarians. JOURNAL OF HAZARDOUS MATERIALS 2022; 432:128673. [PMID: 35303662 DOI: 10.1016/j.jhazmat.2022.128673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/23/2022] [Accepted: 03/09/2022] [Indexed: 05/10/2023]
Abstract
The potential adverse effects of microplastics (MPs) on ecosystems and human health have received much attention in recent years. However, only limited data are available on the mechanisms for the uptake, distribution, and effects of MPs in freshwater organisms, especially with respect to tissue repair, regeneration and impairment of stem cell functions. To address this knowledge gap, we conducted exposure experiments in which planarians (Dugesia japonica) were exposed to polystyrene (PS)-MPs mixed in liver homogenate and examined the tissue growth and regeneration, stem cell functions, and oxidative stress. The body and blastema areas decreased upon exposure to PS-MPs, indicating that the growth and regeneration of planarians were delayed. The proliferation and differentiation processes of stem cells were inhibited, and the proportion of mitotic stem cells decreased, which may be related to the activation of the TGFβ/SMAD4 and Notch signaling pathways. The enhancement of antioxidant enzyme activities and malondialdehyde on the first day of exposure to PS-MPs confirmed the oxidative stress response of planarians to PS-MPs. The present study demonstrated the likelihood of biotoxicity induced by PS-MPs. These results will provide clues for further investigations into the potential risks of PS-MPs to human stem cells.
Collapse
Affiliation(s)
- Tianyu Gao
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China; Department of Epidemiology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Bingbing Sun
- School of Environment, Jinan University, Guangzhou 510632, China; Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China; State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Zhenbiao Xu
- College of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Qiaoyun Chen
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Meng Yang
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Qinli Wan
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China
| | - Linxia Song
- College of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Guo Chen
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, MOE Key Laboratory of Tumor Molecular Biology, Jinan University, Guangzhou 510632, China
| | - Chunxia Jing
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou 510632, China; Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China
| | - Eddy Y Zeng
- School of Environment, Jinan University, Guangzhou 510632, China; Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
| | - Guang Yang
- Department of Pathogen Biology, School of Medicine, Jinan University, Guangzhou 510632, China; Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, China.
| |
Collapse
|
8
|
Inoue T, Agata K. Quantification of planarian behaviors. Dev Growth Differ 2021; 64:16-37. [PMID: 34866186 DOI: 10.1111/dgd.12765] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 10/06/2021] [Accepted: 10/23/2021] [Indexed: 11/30/2022]
Abstract
Research on individual behaviors can help to reveal the processes and mechanisms that mediate an animal's habits and interactions with the environment. Importantly, individual behaviors arise as outcomes of genetic programs, morphogenesis, physiological processes, and neural functions; thus, behavioral analyses can be used to detect disorders in these processes. Planarians belong to an early branching bilateral group of organisms that possess a simple central nervous system. Furthermore, planarians display various behavioral responses to the environment via their nervous system. Planarians also have remarkable regenerative abilities, including whole-brain regeneration. Therefore, the combination of planarians' phylogenetic position, behavioral properties, regenerative ability, and genetic accessibility provides a unique opportunity to understand the basic mechanisms underlying the anatomical properties of neural morphogenesis and the dynamic physiological processes and neural function. Here, we describe a step-by-step protocol for conducting simple behavioral analyses in planarians with the aim of helping to introduce researchers to the utility of performing behavioral analyses in planarians. Since the conditions of planarians impact experimental results and reproducibility, this protocol begins with a method for maintaining planarians. Next, we introduce the behavioral tests as well as the methods for quantifying them using minimal and cost-effective equipment and materials. Finally, we present a unique RNAi technique that enables conditional silencing of neural activity in the brain of planarians.
Collapse
Affiliation(s)
- Takeshi Inoue
- Division of Adaptation Physiology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Kiyokazu Agata
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
Almazan EMP, Ryan JF, Rouhana L. Regeneration of Planarian Auricles and Reestablishment of Chemotactic Ability. Front Cell Dev Biol 2021; 9:777951. [PMID: 34901022 PMCID: PMC8662385 DOI: 10.3389/fcell.2021.777951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 11/04/2021] [Indexed: 11/13/2022] Open
Abstract
Detection of chemical stimuli is crucial for living systems and also contributes to quality of life in humans. Since loss of olfaction becomes more prevalent with aging, longer life expectancies have fueled interest in understanding the molecular mechanisms behind the development and maintenance of chemical sensing. Planarian flatworms possess an unsurpassed ability for stem cell-driven regeneration that allows them to restore any damaged or removed part of their bodies. This includes anteriorly-positioned lateral flaps known as auricles, which have long been thought to play a central role in chemotaxis. The contribution of auricles to the detection of positive chemical stimuli was tested in this study using Girardia dorotocephala, a North American planarian species known for its morphologically prominent auricles. Behavioral experiments staged under laboratory conditions revealed that removal of auricles by amputation leads to a significant decrease in the ability of planarians to find food. However, full chemotactic capacity is observed as early as 2 days post-amputation, which is days prior from restoration of auricle morphology, but correlative with accumulation of ciliated cells in the position of auricle regeneration. Planarians subjected to x-ray irradiation prior to auricle amputation were unable to restore auricle morphology, but were still able to restore chemotactic capacity. These results indicate that although regeneration of auricle morphology requires stem cells, some restoration of chemotactic ability can still be achieved in the absence of normal auricle morphology, corroborating with the initial observation that chemotactic success is reestablished 2-days post-amputation in our assays. Transcriptome profiles of excised auricles were obtained to facilitate molecular characterization of these structures, as well as the identification of genes that contribute to chemotaxis and auricle development. A significant overlap was found between genes with preferential expression in auricles of G. dorotocephala and genes with reduced expression upon SoxB1 knockdown in Schmidtea mediterranea, suggesting that SoxB1 has a conserved role in regulating auricle development and function. Models that distinguish between possible contributions to chemotactic behavior obtained from cellular composition, as compared to anatomical morphology of the auricles, are discussed.
Collapse
Affiliation(s)
| | - Joseph F. Ryan
- Whitney Laboratory of Marine Biosciences, University of Florida, St. Augustine, FL, United States
- Department of Biology, University of Florida, Gainesville, FL, United States
| | - Labib Rouhana
- Department of Biological Sciences, Wright State University, Dayton, OH, United States
| |
Collapse
|
11
|
Huang M, Gao S, Gao L, Liu D, Liu X, Sun Z, Deng H, Zhao B, Liu B, Li A, Pang Q. β-Thymosin is an essential regulator of stem cell proliferation and neuron regeneration in planarian (Dugesia japonica). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 121:104097. [PMID: 33831480 DOI: 10.1016/j.dci.2021.104097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/30/2021] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
β-Thymosin is a multifunctional peptide ubiquitously expressed in vertebrates and invertebrates. Many studies have found β-thymosin is critical for wound healing, angiogenesis, cardiac repair, hair regrowth, and anti-fibrosis in vertebrates, and plays an important role in antimicrobial immunity in invertebrates. However, whether β-thymosin participates in the regeneration of organisms is still poorly understood. In this study, we identified a β-thymosin gene in Dugesia japonica which played an important role in stem cell proliferation and neuron regeneration during the tissue repair process in D. japonica. Sequencing analysis showed that β-thymosin contained two conserved β-thymosin domains and two actin-binding motifs, and had a high similarity with other β-thymosins of invertebrates. In situ or fluorescence in situ hybridization analysis revealed that Djβ-thymosin was co-localized with DjPiWi in the neoblast cells of intact adult planarians and the blastema of regenerating planarians, suggesting Djβ-thymosin has a potential function of regeneration. Disruption Djβ-thymosin by RNA interference results in a slightly curled up head of planarian and stem cell proliferation defects. Additionally, we found that, upon amputation, Djβ-thymosin RNAi-treated animals had impaired regeneration ability, including impaired blastema formation, delayed eyespot formation, decreased brain area, and disrupted central CNS formation, implying Djβ-thymosin is an essential regulator of stem cell proliferation and neuron regeneration.
Collapse
Affiliation(s)
- Mujie Huang
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Sijia Gao
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Lili Gao
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Dongwu Liu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Xi Liu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Zhe Sun
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Hongkuan Deng
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Bosheng Zhao
- Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China
| | - Baohua Liu
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Shenzhen University of Health Science Center, District Shenzhen, 518060, China
| | - Ao Li
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China.
| | - Qiuxiang Pang
- Anti-aging & Regenerative Medicine Research Institution, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China; Laboratory of Developmental and Evolutionary Biology, School of Life Sciences, Shandong University of Technology, Zibo, 255049, PR China.
| |
Collapse
|
12
|
Liu H, Song Q, Zhen H, Deng H, Zhao B, Cao Z. miR-8b is involved in brain and eye regeneration of Dugesia japonica in head regeneration. Biol Open 2021; 10:269275. [PMID: 34184734 PMCID: PMC8272931 DOI: 10.1242/bio.058538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/20/2021] [Indexed: 11/23/2022] Open
Abstract
MicroRNAs (miRNAs) are a class of evolutionarily conserved small non-coding RNAs that regulate gene expression at the translation level in cell growth, proliferation and differentiation. In addition, some types of miRNAs have been proven to be key modulators of both CNS development and plasticity, such as let-7, miR-9 and miR-124. In this research, we found miR-8b acts as an important regulator involved in brain and eyespot regeneration in Dugesia japonica. miR-8b was highly conserved among species and was abundantly expressed in central nervous system. Here, we detected the expression dynamics of miR-8b by qPCR during the head regeneration of D. japonica. Knockdown miR-8b by anti-MIRs method caused severe defects of eyes and CNS. Our study revealed the evolutionary conserved role of miR-8b in the planarian regeneration process, and further provided more research ideas and available information for planarian miRNAs. Summary: Most miRNAs in planarians are homologous to humans and other mammals, and may also play a similar regulatory role. Knockdown miR-8b planarian miR-8b induces brain and eyespot defects during head regeneration.
Collapse
Affiliation(s)
- Hongjin Liu
- School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Qian Song
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo 255049, China
| | - Hui Zhen
- Laboratory of Developmental and Evolutionary Biology, Shandong University of Technology, Zibo 255049, China
| | - Hongkuan Deng
- School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Bosheng Zhao
- School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| | - Zhonghong Cao
- School of Life Sciences, Shandong University of Technology, Zibo 255049, China
| |
Collapse
|
13
|
Discovery of a body-wide photosensory array that matures in an adult-like animal and mediates eye-brain-independent movement and arousal. Proc Natl Acad Sci U S A 2021; 118:2021426118. [PMID: 33941643 DOI: 10.1073/pnas.2021426118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The ability to respond to light has profoundly shaped life. Animals with eyes overwhelmingly rely on their visual circuits for mediating light-induced coordinated movements. Building on previously reported behaviors, we report the discovery of an organized, eye-independent (extraocular), body-wide photosensory framework that allows even a head-removed animal to move like an intact animal. Despite possessing sensitive cerebral eyes and a centralized brain that controls most behaviors, head-removed planarians show acute, coordinated ultraviolet-A (UV-A) aversive phototaxis. We find this eye-brain-independent phototaxis is mediated by two noncanonical rhabdomeric opsins, the first known function for this newly classified opsin-clade. We uncover a unique array of dual-opsin-expressing photoreceptor cells that line the periphery of animal body, are proximal to a body-wide nerve net, and mediate UV-A phototaxis by engaging multiple modes of locomotion. Unlike embryonically developing cerebral eyes that are functional when animals hatch, the body-wide photosensory array matures postembryonically in "adult-like animals." Notably, apart from head-removed phototaxis, the body-wide, extraocular sensory organization also impacts physiology of intact animals. Low-dose UV-A, but not visible light (ocular-stimulus), is able to arouse intact worms that have naturally cycled to an inactive/rest-like state. This wavelength selective, low-light arousal of resting animals is noncanonical-opsin dependent but eye independent. Our discovery of an autonomous, multifunctional, late-maturing, organized body-wide photosensory system establishes a paradigm in sensory biology and evolution of light sensing.
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
|
16
|
Miyamoto M, Hattori M, Hosoda K, Sawamoto M, Motoishi M, Hayashi T, Inoue T, Umesono Y. The pharyngeal nervous system orchestrates feeding behavior in planarians. SCIENCE ADVANCES 2020; 6:eaaz0882. [PMID: 32285000 PMCID: PMC7141820 DOI: 10.1126/sciadv.aaz0882] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 01/14/2020] [Indexed: 05/06/2023]
Abstract
Planarians exhibit traits of cephalization but are unique among bilaterians in that they ingest food by means of goal-directed movements of a trunk-positioned pharynx, following protrusion of the pharynx out of the body, raising the question of how planarians control such a complex set of body movements for achieving robust feeding. Here, we use the freshwater planarian Dugesia japonica to show that an isolated pharynx amputated from the planarian body self-directedly executes its entire sequence of feeding functions: food sensing, approach, decisions about ingestion, and intake. Gene-specific silencing experiments by RNA interference demonstrated that the pharyngeal nervous system (PhNS) is required not only for feeding functions of the pharynx itself but also for food-localization movements of individual animals, presumably via communication with the brain. These findings reveal an unexpected central role of the PhNS in the linkage between unique morphological phenotypes and feeding behavior in planarians.
Collapse
Affiliation(s)
- Mai Miyamoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Miki Hattori
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Kazutaka Hosoda
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Mika Sawamoto
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Minako Motoishi
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
| | - Tetsutaro Hayashi
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-minami, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Takeshi Inoue
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
- Corresponding author. (Y.U.); (T.I.)
| | - Yoshihiko Umesono
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
- Corresponding author. (Y.U.); (T.I.)
| |
Collapse
|
17
|
Abstract
One of the most important aspects of the scientific endeavour is the definition of specific concepts as precisely as possible. However, it is also important not to lose sight of two facts: (i) we divide the study of nature into manageable parts in order to better understand it owing to our limited cognitive capacities and (ii) definitions are inherently arbitrary and heavily influenced by cultural norms, language, the current political climate, and even personal preferences, among many other factors. As a consequence of these facts, clear-cut definitions, despite their evident importance, are oftentimes quite difficult to formulate. One of the most illustrative examples about the difficulty of articulating precise scientific definitions is trying to define the concept of a brain. Even though the current thinking about the brain is beginning to take into account a variety of organisms, a vertebrocentric bias still tends to dominate the scientific discourse about this concept. Here I will briefly explore the evolution of our 'thoughts about the brain', highlighting the difficulty of constructing a universally (or even a generally) accepted formal definition of it and using planarians as one of the earliest examples of organisms proposed to possess a 'traditional', vertebrate-style brain. I also suggest that the time is right to attempt to expand our view of what a brain is, going beyond exclusively structural and taxa-specific criteria. Thus, I propose a classification that could represent a starting point in an effort to expand our current definitions of the brain, hopefully to help initiate conversations leading to changes of perspective on how we think about this concept. This article is part of the theme issue 'Liquid brains, solid brains: How distributed cognitive architectures process information'.
Collapse
Affiliation(s)
- Oné R Pagán
- Department of Biology, West Chester University , West Chester, PA 19383 , USA
| |
Collapse
|
18
|
The planarian Vinculin is required for the regeneration of GABAergic neurons in Dugesia japonica. Exp Cell Res 2019; 383:111540. [PMID: 31369753 DOI: 10.1016/j.yexcr.2019.111540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/25/2019] [Accepted: 07/27/2019] [Indexed: 10/26/2022]
Abstract
Vinculin is a cytoskeletal protein associated with cell-cell and cell-matrix junctions, playing an important role in linkage of integrin adhesion molecules to the actin cytoskeleton. The planarian nervous system is a fascinating system for studying the organogenesis during regeneration. In this paper, a homolog gene of Vinculin, DjVinculin, was identified and characterized in Dugesia japonica. The DjVinculin sequence analysis revealed that it contains an opening reading frame encoding a putative protein of 975 amino acids with functionally domains that are highly conserved, including eight anti-parallel α-helical bundles organized into five distinct domains. Whole mount in situ hybridization showed that DjVinculin was predominantly expressed in the brain of intact and regenerating planarians. RNA interference of DjVinculin caused distinct defects in brain morphogenesis and influences the regeneration of planarian GABAergic neurons. The expression level of DjGAD protein was decreased in the DjVinculin-knockdown planarians. These findings suggest that DjVinculin is required for GABAergic neurons regeneration.
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Mori M, Narahashi M, Hayashi T, Ishida M, Kumagai N, Sato Y, Bagherzadeh R, Agata K, Inoue T. Calcium ions in the aquatic environment drive planarians to food. ZOOLOGICAL LETTERS 2019; 5:31. [PMID: 31720007 PMCID: PMC6836377 DOI: 10.1186/s40851-019-0147-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 10/21/2019] [Indexed: 05/08/2023]
Abstract
BACKGROUND Even subtle changes in environmental factors can exert behavioral effects on creatures, which may alter interspecific interactions and eventually affect the ecosystem. However, how changes in environmental factors impact complex behaviors regulated by neural processes is largely unknown. The freshwater planarian Dugesia japonica, a free-living flatworm, displays distinct behavioral traits mediated by sensitive perception of environmental cues. Planarians are thus useful organisms for examining interactions between environmental changes and specific behaviors of animals. RESULTS Here we found that feeding behavior was suppressed when the concentration of ions in the breeding water was low, while other behaviors were unaffected, resulting in differences in population size. Notably, the decline in feeding behavior was reversed in an ion-concentration-dependent manner soon after the planarians were moved to ion-containing water, which suggests that ions in environmental water rapidly promote feeding behavior in planarians. Moreover, the concentration of ions in the environmental water affected the feeding behavior by modulating the sensitivity of the response to foods. Finally, we found that calcium ions in the aquatic environment were required for the feeding behavior, and exposure to higher levels of calcium ions enhanced the feeding behavior, showing that there was a good correlation between the concentration of calcium ions and the responsiveness of planarians to foods. CONCLUSIONS Environmental calcium ions are indispensable for and potentiate the activity level of the feeding behavior of planarians. Our findings suggest that the ions in the aquatic environment profoundly impact the growth and survival of aquatic animals via modulating their neural activities and behaviors.
Collapse
Affiliation(s)
- Masato Mori
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
| | - Maria Narahashi
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
| | - Tetsutaro Hayashi
- Laboratory for Bioinformatics Research, RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan
| | - Miyuki Ishida
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
| | - Nobuyoshi Kumagai
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
| | - Yuki Sato
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
| | - Reza Bagherzadeh
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, Banihashem, Tehran, Iran
- Department of Developmental Biology, University of Science and Culture, Banihashem, Tehran, Iran
| | - Kiyokazu Agata
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
- National Institute for Basic Biology, National Institutes of Natural Science, 38 Nishigonaka, Myodaiji, Okazaki, Japan
| | - Takeshi Inoue
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, Japan
| |
Collapse
|
21
|
Akiyama Y, Agata K, Inoue T. Coordination between binocular field and spontaneous self-motion specifies the efficiency of planarians' photo-response orientation behavior. Commun Biol 2018; 1:148. [PMID: 30272024 PMCID: PMC6155068 DOI: 10.1038/s42003-018-0151-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/27/2018] [Indexed: 11/15/2022] Open
Abstract
Eyes show remarkable diversity in morphology among creatures. However, little is known about how morphological traits of eyes affect behaviors. Here, we investigate the mechanisms responsible for the establishment of efficient photo-response orientation behavior using the planarian Dugesia japonica as a model. Our behavioral assays reveal the functional angle of the visual field and show that the binocular field formed by paired eyes in D. japonica has an impact on the accurate recognition of the direction of a light source. Furthermore, we find that the binocular field in coordination with spontaneous wigwag self-motion of the head specifies the efficiency of photo-responsive evasive behavior in planarians. Our findings suggest that the linkage between the architecture of the sensory organs and spontaneous self-motion is a platform that serves for efficient and adaptive outcomes of planarian and potentially other animal behaviors. Yoshitaro Akiyama et al. report the use of innovative behavioral assays in planarian flatworms to investigate the mechanism by which they efficiently respond to light. They find that binocular vision and spontaneous self-motion are key factors for accurately detecting the direction of a light source.
Collapse
Affiliation(s)
- Yoshitaro Akiyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, 606-8502, Japan.,Department of Advanced Interdisciplinary Studies, Graduate School of Engineering, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, 606-8502, Japan.,Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan
| | - Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, 606-8502, Japan. .,Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan.
| |
Collapse
|
22
|
Yuan Z, Shao X, Miao Z, Zhao B, Zheng Z, Zhang J. Perfluorooctane sulfonate induced neurotoxicity responses associated with neural genes expression, neurotransmitter levels and acetylcholinesterase activity in planarians Dugesia japonica. CHEMOSPHERE 2018; 206:150-156. [PMID: 29738904 DOI: 10.1016/j.chemosphere.2018.05.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
As a persistent and widespread toxic organic pollutant in the environment, perfluorooctane sulfonate (PFOS) has the potential to cause great harm to wildlife. In our study, the effects of PFOS on neurodevelopment gene expression, neurotransmitter content, neuronal morphology, acetylcholinesterase (AChE) activity were examined, and the potential neurotoxicity mechanisms of PFOS were also investigated in planarians, Dugesia japonica. Using quantitative real-time PCR analysis, five neurodevelopmental related genes were measured, among which, DjotxA, DjotxB, DjFoxD, and DjFoxG were found to be down-regulated, while Djnlg was found to be up-regulated, following exposure to PFOS for 10 days compared with control groups. In addition, the neurotransmitters including dopamine, serotonin, and γ-aminobutyricacid as well as the acitivity of AChE were altered by PFOS exposure. Furthermore, PFOS exposure altered brain morphology as well as smaller cephalic ganglia which displayed reduced nerve fiber density decreased brain branches compared to controls. Our results demonstrate that neurotransmission was disturbed after exposure to PFOS and that exposure to this pollutant can cause neurotoxic defects. Results from this study provide valuable information regarding the neuro- and ecological toxicity of PFOS in aquatic animals and aquatic environments.
Collapse
Affiliation(s)
- Zuoqing Yuan
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China
| | - Xinxin Shao
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China
| | - Zili Miao
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China
| | - Bosheng Zhao
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China
| | - Ziyang Zheng
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China
| | - Jianyong Zhang
- School of Life Sciences, Shandong University of Technology, No. 266 Xincun West Road, Zibo 255000, China.
| |
Collapse
|
23
|
Umesono Y. Postembryonic Axis Formation in Planarians. DIVERSITY AND COMMONALITY IN ANIMALS 2018. [DOI: 10.1007/978-4-431-56609-0_33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
24
|
An Y, Kawaguchi A, Zhao C, Toyoda A, Sharifi-Zarchi A, Mousavi SA, Bagherzadeh R, Inoue T, Ogino H, Fujiyama A, Chitsaz H, Baharvand H, Agata K. Draft genome of Dugesia japonica provides insights into conserved regulatory elements of the brain restriction gene nou-darake in planarians. ZOOLOGICAL LETTERS 2018; 4:24. [PMID: 30181897 PMCID: PMC6114478 DOI: 10.1186/s40851-018-0102-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 07/03/2018] [Indexed: 05/03/2023]
Abstract
BACKGROUND Planarians are non-parasitic Platyhelminthes (flatworms) famous for their regeneration ability and for having a well-organized brain. Dugesia japonica is a typical planarian species that is widely distributed in the East Asia. Extensive cellular and molecular experimental methods have been developed to identify the functions of thousands of genes in this species, making this planarian a good experimental model for regeneration biology and neurobiology. However, no genome-level information is available for D. japonica, and few gene regulatory networks have been identified thus far. RESULTS To obtain whole-genome information on this species and to study its gene regulatory networks, we extracted genomic DNA from 200 planarians derived from a laboratory-bred asexual clonal strain, and sequenced 476 Gb of data by second-generation sequencing. Kmer frequency graphing and fosmid sequence analysis indicated a complex genome that would be difficult to assemble using second-generation sequencing short reads. To address this challenge, we developed a new assembly strategy and improved the de novo genome assembly, producing a 1.56 Gb genome sequence (DjGenome ver1.0, including 202,925 scaffolds and N50 length 27,741 bp) that covers 99.4% of all 19,543 genes in the assembled transcriptome, although the genome is fragmented as 80% of the genome consists of repeated sequences (genomic frequency ≥ 2). By genome comparison between two planarian genera, we identified conserved non-coding elements (CNEs), which are indicative of gene regulatory elements. Transgenic experiments using Xenopus laevis indicated that one of the CNEs in the Djndk gene may be a regulatory element, suggesting that the regulation of the ndk gene and the brain formation mechanism may be conserved between vertebrates and invertebrates. CONCLUSION This draft genome and CNE analysis will contribute to resolving gene regulatory networks in planarians. The genome database is available at: http://www.planarian.jp.
Collapse
Affiliation(s)
- Yang An
- Department of Biophysics, Kyoto University, Kyoto, Japan
- Present address: Immolife-biotech Co., Ltd., Nanjing, China
| | - Akane Kawaguchi
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
- Present address: Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Chen Zhao
- School of Pharmacy, Fudan University, Shanghai, China
- Present address: Immolife-biotech Co., Ltd., Nanjing, China
- Institute of Neurogenomics, Helmholtz Zentrum München, German Research Centre for Environmental Health, Neuherberg, Germany
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Japan
| | - Ali Sharifi-Zarchi
- Department of Computer Science, Colorado State University, Fort Collins, USA
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Computer Engineering, Sharif University of Technology, Tehran, Iran
| | - Seyed Ahmad Mousavi
- Department of Computer Science, Colorado State University, Fort Collins, USA
| | - Reza Bagherzadeh
- Department of Biophysics, Kyoto University, Kyoto, Japan
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Developmental Biology, University of Science and Culture, Tehran, Iran
- Present address: Department of Life Science, Gakushuin University, Tokyo, Japan
| | - Takeshi Inoue
- Department of Biophysics, Kyoto University, Kyoto, Japan
- Present address: Department of Life Science, Gakushuin University, Tokyo, Japan
| | - Hajime Ogino
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Japan
- Present address: Amphibian Research Center, Hiroshima University, Higashi-hiroshima, Japan
| | - Asao Fujiyama
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Japan
| | - Hamidreza Chitsaz
- Department of Computer Science, Colorado State University, Fort Collins, USA
| | - Hossein Baharvand
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
- Department of Developmental Biology, University of Science and Culture, Tehran, Iran
| | - Kiyokazu Agata
- Department of Biophysics, Kyoto University, Kyoto, Japan
- Present address: Department of Life Science, Gakushuin University, Tokyo, Japan
| |
Collapse
|
25
|
Birkholz TR, Beane WS. The planarian TRPA1 homolog mediates extraocular behavioral responses to near-ultraviolet light. J Exp Biol 2017; 220:2616-2625. [PMID: 28495872 PMCID: PMC5536891 DOI: 10.1242/jeb.152298] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 05/04/2017] [Indexed: 12/17/2022]
Abstract
Although light is most commonly thought of as a visual cue, many animals possess mechanisms to detect light outside of the eye for various functions, including predator avoidance, circadian rhythms, phototaxis and migration. Here we confirm that planarians (like Caenorhabditis elegans, leeches and Drosophila larvae) are capable of detecting and responding to light using extraocular photoreception. We found that, when either eyeless or decapitated worms were exposed to near-ultraviolet (near-UV) light, intense wild-type photophobic behaviors were still observed. Our data also revealed that behavioral responses to green wavelengths were mediated by ocular mechanisms, whereas near-UV responses were driven by extraocular mechanisms. As part of a candidate screen to uncover the genetic basis of extraocular photoreception in the planarian species Schmidtea mediterranea, we identified a potential role for a homolog of the transient receptor potential channel A1 (TRPA1) in mediating behavioral responses to extraocular light cues. RNA interference (RNAi) to Smed-TrpA resulted in worms that lacked extraocular photophobic responses to near-UV light, a mechanism previously only identified in Drosophila These data show that the planarian TRPA1 homolog is required for planarian extraocular-light avoidance and may represent a potential ancestral function of this gene. TRPA1 is an evolutionarily conserved detector of temperature and chemical irritants, including reactive oxygen species that are byproducts of UV-light exposure. Our results suggest that planarians possess extraocular photoreception and display an unconventional TRPA1-mediated photophobic response to near-UV light.
Collapse
Affiliation(s)
- Taylor R Birkholz
- Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI 49008, USA
| | - Wendy S Beane
- Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI 49008, USA
| |
Collapse
|
26
|
Adler CE, Sánchez Alvarado A. PHRED-1 is a divergent neurexin-1 homolog that organizes muscle fibers and patterns organs during regeneration. Dev Biol 2017; 427:165-175. [PMID: 28461239 PMCID: PMC5497596 DOI: 10.1016/j.ydbio.2017.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/05/2017] [Accepted: 04/20/2017] [Indexed: 12/18/2022]
Abstract
Regeneration of body parts requires the replacement of multiple cell types. To dissect this complex process, we utilized planarian flatworms that are capable of regenerating any tissue after amputation. An RNAi screen for genes involved in regeneration of the pharynx identified a novel gene, Pharynx regeneration defective-1 (PHRED-1) as essential for normal pharynx regeneration. PHRED-1 is a predicted transmembrane protein containing EGF, Laminin G, and WD40 domains, is expressed in muscle, and has predicted homologs restricted to other lophotrochozoan species. Knockdown of PHRED-1 causes abnormal regeneration of muscle fibers in both the pharynx and body wall muscle. In addition to defects in muscle regeneration, knockdown of PHRED-1 or the bHLH transcription factor MyoD also causes defects in muscle and intestinal regeneration. Together, our data demonstrate that muscle plays a key role in restoring the structural integrity of closely associated organs, and in planarians it may form a scaffold that facilitates normal intestinal branching.
Collapse
Affiliation(s)
- Carolyn E Adler
- Stowers Institute for Medical Research and Howard Hughes Medical Institute, 1000 E. 50th Street, Kansas City, MO 64110, USA; Department of Molecular Medicine, Cornell University, 930 Campus Road, VMC C3-167, Ithaca, NY 14853, USA.
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research and Howard Hughes Medical Institute, 1000 E. 50th Street, Kansas City, MO 64110, USA.
| |
Collapse
|
27
|
Ross KG, Currie KW, Pearson BJ, Zayas RM. Nervous system development and regeneration in freshwater planarians. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 6. [DOI: 10.1002/wdev.266] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/10/2017] [Accepted: 01/20/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Kelly G. Ross
- Department of Biology San Diego State University San Diego CA USA
| | - Ko W. Currie
- Program in Developmental and Stem Cell Biology The Hospital for Sick Children Toronto Canada
- Department of Molecular Genetics University of Toronto Toronto Canada
- Ontario Institute for Cancer Research Toronto Canada
| | - Bret J. Pearson
- Program in Developmental and Stem Cell Biology The Hospital for Sick Children Toronto Canada
- Department of Molecular Genetics University of Toronto Toronto Canada
- Ontario Institute for Cancer Research Toronto Canada
| | - Ricardo M. Zayas
- Department of Biology San Diego State University San Diego CA USA
| |
Collapse
|
28
|
Shimoyama S, Inoue T, Kashima M, Agata K. Multiple Neuropeptide-Coding Genes Involved in Planarian Pharynx Extension. Zoolog Sci 2016; 33:311-9. [PMID: 27268986 DOI: 10.2108/zs150170] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Planarian feeding behavior involves three steps: moving toward food, extending the pharynx from their planarian's ventral side after arriving at the food, and ingesting the food through the pharynx. Although pharynx extension is a remarkable behavior, it remains unknown what neuronal cell types are involved in its regulation. To identify neurons involved in regulating pharynx extension, we quantitatively analyzed pharynx extension and sought to identify these neurons by RNA interference (RNAi) and in situ hybridization. This assay, when performed using planarians with amputation of various body parts, clearly showed that the head portion is indispensable for inducing pharynx extension. We thus tested the effects of knockdown of brain neurons such as serotonergic, GABAergic, and dopaminergic neurons by RNAi, but did not observe any effects on pharynx extension behavior. However, animals with RNAi of the Prohormone Convertase 2 (PC2, a neuropeptide processing enzyme) gene did not perform the pharynx extension behavior, suggesting the possible involvement of neuropeptide(s in the regulation of pharynx extension. We screened 24 neuropeptide-coding genes, analyzed their functions by RNAi using the pharynx extension assay system, and identified at least five neuropeptide genes involved in pharynx extension. These was expressed in different cells or neurons, and some of them were expressed in the brain, suggesting complex regulation of planarian feeding behavior by the nervous system.
Collapse
Affiliation(s)
- Seira Shimoyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | - Makoto Kashima
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502, Japan
| | | |
Collapse
|
29
|
Ouyang K, Nayak S, Lee Y, Kim E, Wu M, Tallarida CS, Rawls SM. Behavioral effects of Splenda, Equal and sucrose: Clues from planarians on sweeteners. Neurosci Lett 2016; 636:213-217. [PMID: 27845240 DOI: 10.1016/j.neulet.2016.11.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 08/30/2016] [Accepted: 11/07/2016] [Indexed: 11/16/2022]
Abstract
Sweetened diets share commonalities with drugs of abuse, but studies comparing behavioral effects of different sweeteners are lacking. Common table sugar produces rewarding and withdrawal effects in planarians. We postulated that Splenda and Equal would produce similar responses and used a tetrad of behavioral assays to test this hypothesis. Acute exposure to a relatively high concentration (10%) of each sweetener produced stereotyped responses (C-shapes) and reduced motility, with Equal producing greater motor effects than sucrose or Splenda. In experiments testing for anxiogenic-like effects, planarians withdrawn from Splenda (1, 3%) or sucrose (1, 3%), but not Equal, and placed into a petri dish with dark and light compartments spent more time in the dark compared to water controls. In place conditioning experiments, both Splenda (0.01%) and sucrose (0.01%) produced an environmental preference shift. Maltodextrin (0.1%), a principal ingredient of Splenda and Equal, produced a significant preference shift. In contrast, sucralose, an indigestible polysaccharide contained in Splenda and Equal, was ineffective. Our data reveal that Splenda produces sucrose-like rewarding and withdrawal effects in planarians that may be dependent on maltodextrin and dextrose. The ineffectiveness of Equal may be due to the presence of aspartame, which is too water insoluble to test in our planarian assay, or to its bitter aftertaste that could mask any rewarding effects produce by maltodextrin or dextrose.
Collapse
Affiliation(s)
- Kevin Ouyang
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA
| | - Sunil Nayak
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA
| | - Young Lee
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA
| | - Erin Kim
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA
| | - Michael Wu
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA
| | - Christopher S Tallarida
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA; Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Scott M Rawls
- Center for Substance Abuse Research, Temple University School of Medicine, Philadelphia, PA, USA; Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
30
|
Deochand ME, Birkholz TR, Beane WS. Temporal regulation of planarian eye regeneration. ACTA ACUST UNITED AC 2016; 3:209-221. [PMID: 27800171 PMCID: PMC5084360 DOI: 10.1002/reg2.61] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 07/08/2016] [Accepted: 08/04/2016] [Indexed: 12/11/2022]
Abstract
While tissue regeneration is typically studied using standard injury models, in nature injuries vary greatly in the amount and location of tissues lost. Planarians have the unique ability to regenerate from many different injuries (including from tiny fragments with no brain), allowing us to study the effects of different injuries on regeneration timelines. We followed the timing of regeneration for one organ, the eye, after multiple injury types that involved tissue loss (single‐ and double‐eye ablation, and decapitation) in Schmidtea mediterranea. Our data reveal that the timing of regeneration remained constant despite changing injury parameters. Optic tissue regrowth, nerve re‐innervation, and functional recovery were similar between injury types (even when the animal was simultaneously regrowing its brain). Changes in metabolic rate (i.e., starving vs. fed regenerates) also had no effect on regeneration timelines. In addition, our data suggest there may exist a role for optic nerve degeneration following eye ablation. Our results suggest that the temporal regulation of planarian eye regeneration is tightly controlled and resistant to variations in injury type.
Collapse
Affiliation(s)
- Michelle E Deochand
- Department of Biological Sciences Western Michigan University Kalamazoo MI, USA
| | - Taylor R Birkholz
- Department of Biological Sciences Western Michigan University Kalamazoo MI, USA
| | - Wendy S Beane
- Department of Biological Sciences Western Michigan University Kalamazoo MI, USA
| |
Collapse
|
31
|
Wang IE, Lapan SW, Scimone ML, Clandinin TR, Reddien PW. Hedgehog signaling regulates gene expression in planarian glia. eLife 2016; 5:e16996. [PMID: 27612382 PMCID: PMC5055395 DOI: 10.7554/elife.16996] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/02/2016] [Indexed: 12/23/2022] Open
Abstract
Hedgehog signaling is critical for vertebrate central nervous system (CNS) development, but its role in CNS biology in other organisms is poorly characterized. In the planarian Schmidtea mediterranea, hedgehog (hh) is expressed in medial cephalic ganglia neurons, suggesting a possible role in CNS maintenance or regeneration. We performed RNA sequencing of planarian brain tissue following RNAi of hh and patched (ptc), which encodes the Hh receptor. Two misregulated genes, intermediate filament-1 (if-1) and calamari (cali), were expressed in a previously unidentified non-neural CNS cell type. These cells expressed orthologs of astrocyte-associated genes involved in neurotransmitter uptake and metabolism, and extended processes enveloping regions of high synapse concentration. We propose that these cells are planarian glia. Planarian glia were distributed broadly, but only expressed if-1 and cali in the neuropil near hh+ neurons. Planarian glia and their regulation by Hedgehog signaling present a novel tractable system for dissection of glia biology.
Collapse
Affiliation(s)
- Irving E Wang
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
- Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States
- Department of Neurobiology, Stanford University, Stanford, United States
| | - Sylvain W Lapan
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
- Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - M Lucila Scimone
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
- Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University, Stanford, United States
| | - Peter W Reddien
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, United States
- Whitehead Institute, Massachusetts Institute of Technology, Cambridge, United States
| |
Collapse
|
32
|
Ong TH, Romanova EV, Roberts-Galbraith RH, Yang N, Zimmerman TA, Collins JJ, Lee JE, Kelleher NL, Newmark PA, Sweedler JV. Mass Spectrometry Imaging and Identification of Peptides Associated with Cephalic Ganglia Regeneration in Schmidtea mediterranea. J Biol Chem 2016; 291:8109-20. [PMID: 26884331 PMCID: PMC4825013 DOI: 10.1074/jbc.m115.709196] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 12/21/2022] Open
Abstract
Tissue regeneration is a complex process that involves a mosaic of molecules that vary spatially and temporally. Insights into the chemical signaling underlying this process can be achieved with a multiplex and untargeted chemical imaging method such as mass spectrometry imaging (MSI), which can enablede novostudies of nervous system regeneration. A combination of MSI and multivariate statistics was used to differentiate peptide dynamics in the freshwater planarian flatwormSchmidtea mediterraneaat different time points during cephalic ganglia regeneration. A protocol was developed to makeS. mediterraneatissues amenable for MSI. MS ion images of planarian tissue sections allow changes in peptides and unknown compounds to be followed as a function of cephalic ganglia regeneration. In conjunction with fluorescence imaging, our results suggest that even though the cephalic ganglia structure is visible after 6 days of regeneration, the original chemical composition of these regenerated structures is regained only after 12 days. Differences were observed in many peptides, such as those derived from secreted peptide 4 and EYE53-1. Peptidomic analysis further identified multiple peptides from various known prohormones, histone proteins, and DNA- and RNA-binding proteins as being associated with the regeneration process. Mass spectrometry data also facilitated the identification of a new prohormone, which we have named secreted peptide prohormone 20 (SPP-20), and is up-regulated during regeneration in planarians.
Collapse
Affiliation(s)
- Ta-Hsuan Ong
- From the Department of Chemistry, and the Beckman Institute
| | | | - Rachel H Roberts-Galbraith
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ning Yang
- From the Department of Chemistry, and the Beckman Institute
| | | | - James J Collins
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | - Ji Eun Lee
- From the Department of Chemistry, and the Beckman Institute
| | - Neil L Kelleher
- the Departments of Chemistry and Molecular Biosciences, Proteomics Center of Excellence, Northwestern University, Evanston, Illinois 60611
| | - Phillip A Newmark
- the Department of Cell and Developmental Biology, Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, and
| | | |
Collapse
|
33
|
Adler CE, Sánchez Alvarado A. Types or States? Cellular Dynamics and Regenerative Potential. Trends Cell Biol 2015; 25:687-696. [PMID: 26437587 DOI: 10.1016/j.tcb.2015.07.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 07/13/2015] [Accepted: 07/29/2015] [Indexed: 01/31/2023]
Abstract
Many of our organs can maintain and repair themselves during homeostasis and injury, as a result of the action of tissue-specific, multipotent stem cells. However, recent evidence from mammalian systems suggests that injury stimulates dramatic plasticity, or transient changes in cell potential, in both stem cells and more differentiated cells. Planarian flatworms possess abundant stem cells, making them an exceptional model for understanding the cellular behavior underlying homeostasis and regeneration. Recent discoveries of cell lineages and regeneration-specific events provide an initial framework for unraveling the complex cellular contributions to regeneration. In this review, we discuss the concept of cellular plasticity in the context of planarian regeneration, and consider the possibility that pluripotency may be a transient, probabilistic state exhibited by stem cells.
Collapse
Affiliation(s)
- Carolyn E Adler
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA; Current address: Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, 1000 E. 50th Street, Kansas City, MO 64110, USA; Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815-6789, USA.
| |
Collapse
|
34
|
Reactive Oxygen Species in Planarian Regeneration: An Upstream Necessity for Correct Patterning and Brain Formation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:392476. [PMID: 26180588 PMCID: PMC4477255 DOI: 10.1155/2015/392476] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/30/2015] [Accepted: 05/04/2015] [Indexed: 12/12/2022]
Abstract
Recent research highlighted the impact of ROS as upstream regulators of tissue regeneration. We investigated their role and targeted processes during the regeneration of different body structures using the planarian Schmidtea mediterranea, an organism capable of regenerating its entire body, including its brain. The amputation of head and tail compartments induces a ROS burst at the wound site independently of the orientation. Inhibition of ROS production by diphenyleneiodonium (DPI) or apocynin (APO) causes regeneration defaults at both the anterior and posterior wound sites, resulting in reduced regeneration sites (blastemas) and improper tissue homeostasis. ROS signaling is necessary for early differentiation and inhibition of the ROS burst results in defects on the regeneration of the nervous system and on the patterning process. Stem cell proliferation was not affected, as indicated by histone H3-P immunostaining, fluorescence-activated cell sorting (FACS), in situ hybridization of smedwi-1, and transcript levels of proliferation-related genes. We showed for the first time that ROS modulate both anterior and posterior regeneration in a context where regeneration is not limited to certain body structures. Our results indicate that ROS are key players in neuroregeneration through interference with the differentiation and patterning processes.
Collapse
|
35
|
Ross KG, Omuro KC, Taylor MR, Munday RK, Hubert A, King RS, Zayas RM. Novel monoclonal antibodies to study tissue regeneration in planarians. BMC DEVELOPMENTAL BIOLOGY 2015; 15:2. [PMID: 25604901 PMCID: PMC4307677 DOI: 10.1186/s12861-014-0050-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 12/22/2014] [Indexed: 12/31/2022]
Abstract
Background Planarians are an attractive model organism for studying stem cell-based regeneration due to their ability to replace all of their tissues from a population of adult stem cells. The molecular toolkit for planarian studies currently includes the ability to study gene function using RNA interference (RNAi) and observe gene expression via in situ hybridizations. However, there are few antibodies available to visualize protein expression, which would greatly enhance analysis of RNAi experiments as well as allow further characterization of planarian cell populations using immunocytochemistry and other immunological techniques. Thus, additional, easy-to-use, and widely available monoclonal antibodies would be advantageous to study regeneration in planarians. Results We have created seven monoclonal antibodies by inoculating mice with formaldehyde-fixed cells isolated from dissociated 3-day regeneration blastemas. These monoclonal antibodies can be used to label muscle fibers, axonal projections in the central and peripheral nervous systems, two populations of intestinal cells, ciliated cells, a subset of neoblast progeny, and discrete cells within the central nervous system as well as the regeneration blastema. We have tested these antibodies using eight variations of a formaldehyde-based fixation protocol and determined reliable protocols for immunolabeling whole planarians with each antibody. We found that labeling efficiency for each antibody varies greatly depending on the addition or removal of tissue processing steps that are used for in situ hybridization or immunolabeling techniques. Our experiments show that a subset of the antibodies can be used alongside markers commonly used in planarian research, including anti-SYNAPSIN and anti-SMEDWI, or following whole-mount in situ hybridization experiments. Conclusions The monoclonal antibodies described in this paper will be a valuable resource for planarian research. These antibodies have the potential to be used to better understand planarian biology and to characterize phenotypes following RNAi experiments. In addition, we present alterations to fixation protocols and demonstrate how these changes can increase the labeling efficiencies of antibodies used to stain whole planarians. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0050-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kelly G Ross
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
| | - Kerilyn C Omuro
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
| | - Matthew R Taylor
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
| | - Roma K Munday
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
| | - Amy Hubert
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA. .,Present address: Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA.
| | - Ryan S King
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Ave., Urbana, IL, 61801, USA. .,Present address: Department of Biology, St. Norbert College, De Pere, WI, 54115, USA.
| | - Ricardo M Zayas
- Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
| |
Collapse
|
36
|
Thermosensory signaling by TRPM is processed by brain serotonergic neurons to produce planarian thermotaxis. J Neurosci 2015; 34:15701-14. [PMID: 25411498 DOI: 10.1523/jneurosci.5379-13.2014] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
For most organisms, sensitive recognition of even slight changes in environmental temperature is essential for adjusting their behavioral strategies to ensure homeostasis and survival. However, much remains to be understood about the molecular and cellular processes that regulate thermosensation and the corresponding behavioral responses. Planarians display clear thermotaxis, although they have a relatively simple brain. Here, we devised a quantitative thermotaxis assay and unraveled a neural pathway involved in planarian thermotaxis by combinatory behavioral assays and RNAi analysis. We found that thermosensory neurons that expressed a planarian Dugesia japonica homolog of the Transient Receptor Potential Melastatin family a (DjTRPMa) gene were required for the thermotaxis. Interestingly, although these thermosensory neurons are distributed throughout their body, planarians with a dysfunctional brain due to regeneration-dependent conditional gene knockdown (Readyknock) of the synaptotagmin gene completely lost their thermotactic behavior. These results suggest that brain function is required as a central processor for the thermosensory response. Therefore, we investigated the type(s) of brain neurons involved in processing the thermal signals by gene knockdown of limiting enzymes for neurotransmitter biosynthesis in the brain. We found that serotonergic neurons with dendrites that were elongated toward DjTRPMa-expressing thermosensory neurons might be required for the processing of signals from thermosensory neurons that results in thermotaxis. These results suggest that serotonergic neurons in the brain may interact with thermosensory neurons activated by TRPM ion channels to produce thermotaxis in planarians.
Collapse
|
37
|
Inoue T, Hoshino H, Yamashita T, Shimoyama S, Agata K. Planarian shows decision-making behavior in response to multiple stimuli by integrative brain function. ZOOLOGICAL LETTERS 2015; 1:7. [PMID: 26605052 PMCID: PMC4657317 DOI: 10.1186/s40851-014-0010-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/27/2014] [Indexed: 05/03/2023]
Abstract
INTRODUCTION Planarians belong to an evolutionarily early group of organisms that possess a central nervous system including a well-organized brain with a simple architecture but many types of neurons. Planarians display a number of behaviors, such as phototaxis and thermotaxis, in response to external stimuli, and it has been shown that various molecules and neural pathways in the brain are involved in controlling these behaviors. However, due to the lack of combinatorial assay methods, it remains obscure whether planarians possess higher brain functions, including integration in the brain, in which multiple signals coming from outside are coordinated and used in determining behavioral strategies. RESULTS In the present study, we designed chemotaxis and thigmotaxis/kinesis tracking assays to measure several planarian behaviors in addition to those measured by phototaxis and thermotaxis assays previously established by our group, and used these tests to analyze planarian chemotactic and thigmotactic/kinetic behaviors. We found that headless planarian body fragments and planarians that had specifically lost neural activity following regeneration-dependent conditional gene knockdown (Readyknock) of synaptotagmin in the brain lost both chemotactic and thigmotactic behaviors, suggesting that neural activity in the brain is required for the planarian's chemotactic and thigmotactic behaviors. Furthermore, we compared the strength of phototaxis, chemotaxis, thigmotaxis/kinesis, and thermotaxis by presenting simultaneous binary stimuli to planarians. We found that planarians showed a clear order of predominance of these behaviors. For example, when planarians were simultaneously exposed to 400 lux of light and a chemoattractant, they showed chemoattractive behavior irrespective of the direction of the light source, although exposure to light of this intensity alone induces evasive behavior away from the light source. In contrast, when the light intensity was increased to 800 or 1600 lux and the same dose of chemoattractant was presented, planarian behaviors were gradually shifted to negative phototaxis rather than chemoattraction. These results suggest that planarians may be capable of selecting behavioral strategies via the integration of discrete brain functions when exposed to multiple stimuli. CONCLUSIONS The planarian brain processes external signals received through the respective sensory neurons, thereby resulting in the production of appropriate behaviors. In addition, planarians can adjust behavioral features in response to stimulus conditions by integrating multiple external signals in the brain.
Collapse
Affiliation(s)
- Takeshi Inoue
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Hajime Hoshino
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Taiga Yamashita
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Seira Shimoyama
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| | - Kiyokazu Agata
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto 606-8502 Japan
| |
Collapse
|
38
|
Planarian Phototactic Assay Reveals Differential Behavioral Responses Based on Wavelength. PLoS One 2014; 9:e114708. [PMID: 25493551 PMCID: PMC4262426 DOI: 10.1371/journal.pone.0114708] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/12/2014] [Indexed: 11/23/2022] Open
Abstract
Planarians are free-living aquatic flatworms that possess a well-documented photophobic response to light. With a true central nervous system and simple cerebral eyes (ocelli), planarians are an emerging model for regenerative eye research. However, comparatively little is known about the physiology of their photoreception or how their behavior is affected by various wavelengths. Most phototactic studies have examined planarian behavior using white light. Here, we describe a novel planarian behavioral assay to test responses to small ranges of visible wavelengths (red, blue, green), as well as ultraviolet (UV) and infrared (IR) which have not previously been examined. Our data show that planarians display behavioral responses across a range of wavelengths. These responses occur in a hierarchy, with the shortest wavelengths (UV) causing the most intense photophobic responses while longer wavelengths produce no effect (red) or an apparent attraction (IR). In addition, our data reveals that planarian photophobia is comprised of both a general photophobic response (that drives planarians to escape the light source regardless of wavelength) and wavelength-specific responses that encompass specific behavioral reactions to individual wavelengths. Our results serve to improve the understanding of planarian phototaxis and suggest that behavioral studies performed with white light mask a complex behavioral interaction with the environment.
Collapse
|
39
|
Abstract
More than 90% of individuals who use cocaine also report concurrent ethanol use, but only a few studies, all conducted with vertebrates, have investigated pharmacodynamic interactions between ethanol and cocaine. Planaria, a type of flatworm often considered to have the simplest 'brain,' is an invertebrate species especially amenable to the quantification of drug-induced behavioral responses and identification of conserved responses. Here, we investigated stereotypical and environmental place conditioning (EPC) effects of ethanol administered alone and in combination with cocaine. Planarians displayed concentration-related increases in C-shaped movements following exposure to ethanol (0.01-1%) (maximal effect: 9.9±1.1 C-shapes/5 min at 0.5%) or cocaine (0.1-5 mM) (maximal effect: 42.8±4.1 C-shapes/5 min at 5 mM). For combined administration, cocaine (0.1-5 mM) was tested with submaximal ethanol concentrations (0.01, 0.1%); the observed effect for the combination was enhanced compared to its predicted effect, indicating synergism for the interaction. The synergy with ethanol was specific for cocaine, as related experiments revealed that combinations of ethanol and nicotine did not result in synergy. For EPC experiments, ethanol (0.0001-1%) concentration-dependently increased EPC, with significant environmental shifts detected at 0.01 and 1%. Cocaine (0.001-1 μM) produced an inverted U-shaped concentration-effect curve, with a significant environmental shift observed at 0.01 μM. For combined exposure, variable cocaine concentrations (0.001-1 μM) were administered with a statistically ineffective concentration of ethanol (0.0001%). For each concentration of cocaine, the environmental shift was enhanced by ethanol, with significance detected at 1 μM. Cocaethylene, a metabolite of cocaine and ethanol, also produced C-shapes and EPC. Lidocaine (0.001-10 μM), an anesthetic and analog of cocaine, did not produce EPC or C-shaped movements. Evidence from planarians that ethanol produces place-conditioning effects and motor dysfunction, and interacts synergistically with cocaine, suggests that aspects of ethanol neuropharmacology are conserved across species.
Collapse
|
40
|
Murugan NJ, Persinger MA. Comparisons of responses by planarian to micromolar to attomolar dosages of morphine or naloxone and/or weak pulsed magnetic fields: revealing receptor subtype affinities and non-specific effects. Int J Radiat Biol 2014; 90:833-40. [PMID: 24720710 DOI: 10.3109/09553002.2014.911421] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The behavioral responses of planaria to the exposures of a range of concentrations of morphine (μM to attoM) or the μ-opiate antagonist naloxone or to either of these compounds and a burst-firing magnetic field (5 μT) were studied. MATERIAL AND METHODS The locomotor velocity (LMV) of planaria was measured after individual worms were exposed to increasing concentrations from attomolar to micromolar of morphine or naloxone, physiologically patterned magnetic fields or a combination of the two. RESULTS Compared to spring water controls, the 2-hour exposure to the patterned magnetic field before measurement reduced activity by about 50% which was comparable to the non-specific effects of morphine and naloxone across all dosages except 1 attomolar that did not differ from spring water. The specific dosage of 100 nM produced additional marked reduction in activity for planaria exposed to either morphine or naloxone while only 1 pM of morphine produced this effect. CONCLUSION The results support the presence of at least two receptor subtypes that mediate the diminished activity effects elicited by morphine specifically and suggests that exposure to the specifically patterned magnetic field produces a behavioral suppression whose magnitude is similar to the 'dose independent' effects from this opiate.
Collapse
Affiliation(s)
- Nirosha J Murugan
- Department of Biomolecular Sciences and Behavioural Neuroscience Program, Laurentian University , Sudbury, Ontario , Canada
| | | |
Collapse
|
41
|
Adler CE, Seidel CW, McKinney SA, Sánchez Alvarado A. Selective amputation of the pharynx identifies a FoxA-dependent regeneration program in planaria. eLife 2014; 3:e02238. [PMID: 24737865 PMCID: PMC3985184 DOI: 10.7554/elife.02238] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/07/2014] [Indexed: 01/08/2023] Open
Abstract
Planarian flatworms regenerate every organ after amputation. Adult pluripotent stem cells drive this ability, but how injury activates and directs stem cells into the appropriate lineages is unclear. Here we describe a single-organ regeneration assay in which ejection of the planarian pharynx is selectively induced by brief exposure of animals to sodium azide. To identify genes required for pharynx regeneration, we performed an RNAi screen of 356 genes upregulated after amputation, using successful feeding as a proxy for regeneration. We found that knockdown of 20 genes caused a wide range of regeneration phenotypes and that RNAi of the forkhead transcription factor FoxA, which is expressed in a subpopulation of stem cells, specifically inhibited regrowth of the pharynx. Selective amputation of the pharynx therefore permits the identification of genes required for organ-specific regeneration and suggests an ancient function for FoxA-dependent transcriptional programs in driving regeneration. DOI: http://dx.doi.org/10.7554/eLife.02238.001.
Collapse
Affiliation(s)
- Carolyn E Adler
- Stowers Institute for Medical Research, Kansas City, United States
| | - Chris W Seidel
- Stowers Institute for Medical Research, Kansas City, United States
| | - Sean A McKinney
- Stowers Institute for Medical Research, Kansas City, United States
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, United States
- Howard Hughes Medical Institute, Stowers Institute for Medical Research, Kansas City, United States
| |
Collapse
|
42
|
Galantamine reverses scopolamine-induced behavioral alterations in Dugesia tigrina. INVERTEBRATE NEUROSCIENCE 2014; 14:91-101. [PMID: 24402079 DOI: 10.1007/s10158-013-0167-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 12/25/2013] [Indexed: 10/25/2022]
Abstract
In planaria (Dugesia tigrina), scopolamine, a nonselective muscarinic receptor antagonist, induced distinct behaviors of attenuated motility and C-like hyperactivity. Planarian locomotor velocity (pLMV) displayed a dose-dependent negative correlation with scopolamine concentrations from 0.001 to 1.0 mM, and a further increase in scopolamine concentration to 2.25 mM did not further decrease pLMV. Planarian hyperactivity counts was dose-dependently increased following pretreatment with scopolamine concentrations from 0.001 to 0.5 mM and then decreased for scopolamine concentrations ≥ 1 mM. Planarian learning and memory investigated using classical Pavlovian conditioning experiments demonstrated that scopolamine (1 mM) negatively influenced associative learning indicated by a significant decrease in % positive behaviors from 86 % (control) to 14 % (1 mM scopolamine) and similarly altered memory retention, which is indicated by a decrease in % positive behaviors from 69 % (control) to 27 % (1 mM scopolamine). Galantamine demonstrated a complex behavior in planarian motility experiments since co-application of low concentrations of galantamine (0.001 and 0.01 mM) protected planaria against 1 mM scopolamine-induced motility impairments; however, pLMV was significantly decreased when planaria were tested in the presence of 0.1 mM galantamine alone. Effects of co-treatment of scopolamine and galantamine on memory retention in planaria via classical Pavlovian conditioning experiments showed that galantamine (0.01 mM) partially reversed scopolamine (1 mM)-induced memory deficits in planaria as the % positive behaviors increased from 27 to 63 %. The results demonstrate, for the first time in planaria, scopolamine's effects in causing learning and memory impairments and galantamine's ability in reversing scopolamine-induced memory impairments.
Collapse
|
43
|
Pagán OR, Deats S, Baker D, Montgomery E, Wilk G, Tenaglia M, Semon J. Planarians require an intact brain to behaviorally react to cocaine, but not to react to nicotine. Neuroscience 2013; 246:265-70. [PMID: 23684614 DOI: 10.1016/j.neuroscience.2013.05.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/30/2013] [Accepted: 05/01/2013] [Indexed: 11/28/2022]
Abstract
Planarians possess a rudimentary brain with many features in common with vertebrate brains. They also display a remarkable capacity for tissue regeneration including the complete regeneration of the nervous system. Using the induction of planarian seizure-like movements (pSLMs) as a behavioral endpoint, we demonstrate that an intact nervous system is necessary for this organism to react to cocaine exposure, but not necessary to react to nicotine administration. Decapitated planarians (Girardia tigrina) display pSLMs indistinguishable from intact worms when exposed to nicotine, but cocaine-induced pSLMs are reduced by about 95% upon decapitation. Decapitated worms recover their normal sensitivity to cocaine within 5 days after head amputation. In worms where half of the brain was removed or partially dissected, the expression of cocaine-induced pSLMs was reduced by approximately 75%. Similar amputations at the level of the tail did not show a significant decrease to cocaine exposure. To the best of our knowledge, our work is the first report that explores how regenerating planarians react to the exposure of cocaine.
Collapse
Affiliation(s)
- O R Pagán
- Department of Biology, West Chester University, West Chester, PA, USA.
| | | | | | | | | | | | | |
Collapse
|
44
|
Elliott SA, Sánchez Alvarado A. The history and enduring contributions of planarians to the study of animal regeneration. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2013; 2:301-26. [PMID: 23799578 PMCID: PMC3694279 DOI: 10.1002/wdev.82] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Having an almost unlimited capacity to regenerate tissues lost to age and injury, planarians have long fascinated naturalists. In the Western hemisphere alone, their documented history spans more than 200 years. Planarians were described in the early 19th century as being 'immortal under the edge of the knife', and initial investigation of these remarkable animals was significantly influenced by studies of regeneration in other organisms and from the flourishing field of experimental embryology in the late 19th and early 20th centuries. This review strives to place the study of planarian regeneration into a broader historical context by focusing on the significance and evolution of knowledge in this field. It also synthesizes our current molecular understanding of the mechanisms of planarian regeneration uncovered since this animal's relatively recent entrance into the molecular-genetic age.
Collapse
Affiliation(s)
- Sarah A Elliott
- Howard Hughes Medical Institute and Stowers Institute for Medical Research, Kansas City, MO, USA.
| | | |
Collapse
|
45
|
Perez Y, Rieger V, Martin E, Müller CHG, Harzsch S. Neurogenesis in an early protostome relative: progenitor cells in the ventral nerve center of chaetognath hatchlings are arranged in a highly organized geometrical pattern. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 320:179-93. [PMID: 23483730 DOI: 10.1002/jez.b.22493] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/29/2012] [Accepted: 01/23/2013] [Indexed: 01/08/2023]
Abstract
Emerging evidence suggests that Chaetognatha represent an evolutionary lineage that is the sister group to all other Protostomia thus promoting these animals as a pivotal model for our understanding of bilaterian evolutionary history. We have analyzed the proliferation of neuronal progenitor cells in the developing ventral nerve center (VNC) of Spadella cephaloptera hatchlings. To that end, for the first time in Chaetognatha, we performed in vivo incorporation experiments with the S-phase specific mitosis marker bromodeoxyuridine (BrdU). Our experiments provide evidence for a high level of mitotic activity in the VNC for ca. 3 days after hatching. Neurogenesis is carried by presumptive neuronal progenitor cells that cycle rapidly and most likely divide asymmetrically. These progenitors are arranged in a distinct grid-like geometrical pattern including about 35 transverse rows. Considering Chaetognaths to be an early offshoot of the protostome lineage we conclude that the presence of neuronal progenitor cells with asymmetric division seems to be a feature that is rooted deeply in the Metazoa. In the light of previous evidence indicating the presence of serially iterated peptidergic neurons with individual identities in the chaetognath VNC, we discuss if these neuronal progenitor cells give rise to distinct lineages. Furthermore, we evaluate the serially iterated arrangement of the progenitor cells in the light of evolution of segmentation.
Collapse
Affiliation(s)
- Yvan Perez
- Institut Méditerranéen de Biodiversité et d'Ecologie Evolution Genome Environment, IMBE-UMR CNRS 7263/IRD 237 Aix-Marseille Université/Centre St Charles, Marseille cedex 3, France
| | | | | | | | | |
Collapse
|
46
|
Zhang C, Tallarida CS, Raffa RB, Rawls SM. Sucrose produces withdrawal and dopamine-sensitive reinforcing effects in planarians. Physiol Behav 2013; 112-113:8-13. [PMID: 23415661 DOI: 10.1016/j.physbeh.2013.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 11/13/2012] [Accepted: 02/08/2013] [Indexed: 11/15/2022]
Abstract
Sucrose produces physical dependence and reinforcing effects in rats. We hypothesized that similar effects could be demonstrated in planarians, the earliest animal with a centralized nervous system. We used two assays, one that quantifies withdrawal responses during drug absence as a reduction in motility and another that quantifies reinforcing effects using a conditioned place preference (CPP) design. In withdrawal experiments, planarians exposed to sucrose (1%) for 60 min and then tested in water for 5 min displayed reduced motility compared to water controls. Acute or continuous sucrose (1%) exposure did not affect motility. CPP experiments used a biased design to capitalize upon planarians' natural preference for the dark (pretest, sucrose conditioning in the light, posttest). Planarians conditioned with sucrose (1%) displayed a greater preference shift than sucrose-naïve planarians. Glucose (0.1, 1%), but not the non-digestible disaccharide lactulose (0.1, 1%), also produced a greater preference shift than water-exposed planarians. Development of sucrose-induced CPP was inhibited when sucrose (1%) conditioning was conducted in combination with dopamine receptor antagonists SCH 23390 (1 μM) or sulpiride (1 μM). These results suggest that the rewarding and reinforcing effects of sugar are highly conserved across species and that planarians offer an invertebrate model to provide insight into the pharmacological effects of sucrose and related sweeteners.
Collapse
Affiliation(s)
- Charlie Zhang
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | | | | | | |
Collapse
|
47
|
Nishimura O, Hirao Y, Tarui H, Agata K. Comparative transcriptome analysis between planarian Dugesia japonica and other platyhelminth species. BMC Genomics 2012; 13:289. [PMID: 22747887 PMCID: PMC3507646 DOI: 10.1186/1471-2164-13-289] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 06/04/2012] [Indexed: 11/10/2022] Open
Abstract
Background Planarians are considered to be among the extant animals close to one of the earliest groups of organisms that acquired a central nervous system (CNS) during evolution. Planarians have a bilobed brain with nine lateral branches from which a variety of external signals are projected into different portions of the main lobes. Various interneurons process different signals to regulate behavior and learning/memory. Furthermore, planarians have robust regenerative ability and are attracting attention as a new model organism for the study of regeneration. Here we conducted large-scale EST analysis of the head region of the planarian Dugesia japonica to construct a database of the head-region transcriptome, and then performed comparative analyses among related species. Results A total of 54,752 high-quality EST reads were obtained from a head library of the planarian Dugesia japonica, and 13,167 unigene sequences were produced by de novo assembly. A new method devised here revealed that proteins related to metabolism and defense mechanisms have high flexibility of amino-acid substitutions within the planarian family. Eight-two CNS-development genes were found in the planarian (cf. C. elegans 3; chicken 129). Comparative analysis revealed that 91% of the planarian CNS-development genes could be mapped onto the schistosome genome, but one-third of these shared genes were not expressed in the schistosome. Conclusions We constructed a database that is a useful resource for comparative planarian transcriptome studies. Analysis comparing homologous genes between two planarian species showed that the potential of genes is important for accumulation of amino-acid substitutions. The presence of many CNS-development genes in our database supports the notion that the planarian has a fundamental brain with regard to evolution and development at not only the morphological/functional, but also the genomic, level. In addition, our results indicate that the planarian CNS-development genes already existed before the divergence of planarians and schistosomes from their common ancestor.
Collapse
Affiliation(s)
- Osamu Nishimura
- Department of Biophysics and Global COE Program, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan
| | | | | | | |
Collapse
|
48
|
Dong Z, Yuwen Y, Wang Q, Chen G, Liu D. Eight genes expression patterns during visual system regeneration in Dugesia japonica. Gene Expr Patterns 2012; 12:1-6. [DOI: 10.1016/j.gep.2011.08.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 06/28/2011] [Accepted: 08/01/2011] [Indexed: 11/29/2022]
|
49
|
Mulligan BP, Gang N, Parker GH, Persinger MA. Magnetic Field Intensity/Melatonin-Molarity Interactions: Experimental Support with Planarian (Dugesia sp.) Activity for a Resonance-Like Process. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojbiphy.2012.24017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
50
|
Nakanishi N, Renfer E, Technau U, Rentzsch F. Nervous systems of the sea anemone Nematostella vectensis are generated by ectoderm and endoderm and shaped by distinct mechanisms. Development 2011; 139:347-57. [PMID: 22159579 DOI: 10.1242/dev.071902] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As a sister group to Bilateria, Cnidaria is important for understanding early nervous system evolution. Here we examine neural development in the anthozoan cnidarian Nematostella vectensis in order to better understand whether similar developmental mechanisms are utilized to establish the strikingly different overall organization of bilaterian and cnidarian nervous systems. We generated a neuron-specific transgenic NvElav1 reporter line of N. vectensis and used it in combination with immunohistochemistry against neuropeptides, in situ hybridization and confocal microscopy to analyze nervous system formation in this cnidarian model organism in detail. We show that the development of neurons commences in the ectoderm during gastrulation and involves interkinetic nuclear migration. Transplantation experiments reveal that sensory and ganglion cells are autonomously generated by the ectoderm. In contrast to bilaterians, neurons are also generated throughout the endoderm during planula stages. Morpholino-mediated gene knockdown shows that the development of a subset of ectodermal neurons requires NvElav1, the ortholog to bilaterian neural elav1 genes. The orientation of ectodermal neurites changes during planula development from longitudinal (in early-born neurons) to transverse (in late-born neurons), whereas endodermal neurites can grow in both orientations at any stage. Our findings imply that elav1-dependent ectodermal neurogenesis evolved prior to the divergence of Cnidaria and Bilateria. Moreover, they suggest that, in contrast to bilaterians, almost the entire ectoderm and endoderm of the body column of Nematostella planulae have neurogenic potential and that the establishment of connectivity in its seemingly simple nervous system involves multiple neurite guidance systems.
Collapse
Affiliation(s)
- Nagayasu Nakanishi
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormoehlensgt 55, 5008 Bergen, Norway
| | | | | | | |
Collapse
|