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Álvarez-Campos P, García-Castro H, Emili E, Pérez-Posada A, Del Olmo I, Peron S, Salamanca-Díaz DA, Mason V, Metzger B, Bely AE, Kenny NJ, Özpolat BD, Solana J. Annelid adult cell type diversity and their pluripotent cellular origins. Nat Commun 2024; 15:3194. [PMID: 38609365 PMCID: PMC11014941 DOI: 10.1038/s41467-024-47401-6] [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: 07/28/2023] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Many annelids can regenerate missing body parts or reproduce asexually, generating all cell types in adult stages. However, the putative adult stem cell populations involved in these processes, and the diversity of cell types generated by them, are still unknown. To address this, we recover 75,218 single cell transcriptomes of the highly regenerative and asexually-reproducing annelid Pristina leidyi. Our results uncover a rich cell type diversity including annelid specific types as well as novel types. Moreover, we characterise transcription factors and gene networks that are expressed specifically in these populations. Finally, we uncover a broadly abundant cluster of putative stem cells with a pluripotent signature. This population expresses well-known stem cell markers such as vasa, piwi and nanos homologues, but also shows heterogeneous expression of differentiated cell markers and their transcription factors. We find conserved expression of pluripotency regulators, including multiple chromatin remodelling and epigenetic factors, in piwi+ cells. Finally, lineage reconstruction analyses reveal computational differentiation trajectories from piwi+ cells to diverse adult types. Our data reveal the cell type diversity of adult annelids by single cell transcriptomics and suggest that a piwi+ cell population with a pluripotent stem cell signature is associated with adult cell type differentiation.
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Affiliation(s)
- Patricia Álvarez-Campos
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) & Departamento de Biología (Zoología), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain.
| | - Helena García-Castro
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Elena Emili
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Alberto Pérez-Posada
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Irene Del Olmo
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) & Departamento de Biología (Zoología), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Sophie Peron
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Living Systems Institute, University of Exeter, Exeter, UK
| | - David A Salamanca-Díaz
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Living Systems Institute, University of Exeter, Exeter, UK
| | - Vincent Mason
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Bria Metzger
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 05432, USA
- Department of Biology, Washington University in St. Louis. 1 Brookings Dr. Saint Louis, Saint Louis, MO, 63130, USA
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Nathan J Kenny
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, Aotearoa, New Zealand
| | - B Duygu Özpolat
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 05432, USA.
- Department of Biology, Washington University in St. Louis. 1 Brookings Dr. Saint Louis, Saint Louis, MO, 63130, USA.
| | - Jordi Solana
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK.
- Living Systems Institute, University of Exeter, Exeter, UK.
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Boilly B, Hondermarck H, Aguado MT. Nerves and availability of mesodermal cells are essential for the function of the segment addition zone (SAZ) during segment regeneration in polychaete annelids. Dev Genes Evol 2024:10.1007/s00427-024-00713-5. [PMID: 38336874 DOI: 10.1007/s00427-024-00713-5] [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: 11/10/2023] [Accepted: 01/12/2024] [Indexed: 02/12/2024]
Abstract
Most of annelids grow all over their asexual life through the continuous addition of segments from a special zone called "segment addition zone" (SAZ) adjacent to the posterior extremity called pygidium. Amputation of posterior segments leads to regeneration (posterior regeneration-PR) of the pygidium and a new SAZ, as well as new segments issued from this new SAZ. Amputation of anterior segments leads some species to regeneration (anterior regeneration-AR) of the prostomium and a SAZ which produces new segments postero-anteriorly as during PR. During the 1960s and 1970s decades, experimental methods on different species (Syllidae, Nereidae, Aricidae) showed that the function of SAZ depends on the presence and number of mesodermal regeneration cells. Selective destruction of mesodermal regeneration cells in AR had no effect on the regeneration of the prostomium, but as for PR, it inhibited segment regeneration. Thus, worms deprived of mesodermal regeneration cells are always able to regenerate the pygidium or the prostomium, but they are unable to regenerate segments, a result which indicates that the SAZ functions only if these regeneration cells are present during PR or AR. Additionally, during AR, nerve fibres regenerate from the cut nerve cord toward the newformed brain, a situation which deprives the SAZ of local regenerating nerve fibres and their secreted growth factors. In contrast, during PR, nerve fibres regenerate both during the entire regeneration phase and then in normal growth. This review summarizes the experimental evidence for mesoderm cell involvement in segment regeneration, and the differential impact of the digestive tube and the regenerated nerve cord during PR vs AR.
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Affiliation(s)
- Benoni Boilly
- Département de Biologie, Université de Lille, 59650, Villeneuve d'Ascq, France.
| | - Hubert Hondermarck
- Hunter Medical Research Institute, School of Biomedical Sciences & Pharmacy, College of Medicine and Wellbeing, University of Newcastle, Callaghan, New South Wales, 2308, Australia
| | - M Teresa Aguado
- Biodiversitätsmuseum, Georg August University, Untere Karspüle, 2, 37073, Göttingen, Germany.
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3
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Álvarez-Campos P, García-Castro H, Emili E, Pérez-Posada A, Salamanca-Díaz DA, Mason V, Metzger B, Bely AE, Kenny N, Özpolat BD, Solana J. Annelid adult cell type diversity and their pluripotent cellular origins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.25.537979. [PMID: 37163014 PMCID: PMC10168269 DOI: 10.1101/2023.04.25.537979] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Annelids are a broadly distributed, highly diverse, economically and environmentally important group of animals. Most species can regenerate missing body parts, and many are able to reproduce asexually. Therefore, many annelids can generate all adult cell types in adult stages. However, the putative adult stem cell populations involved in these processes, as well as the diversity of adult cell types generated by them, are still unknown. Here, we recover 75,218 single cell transcriptomes of Pristina leidyi, a highly regenerative and asexually-reproducing freshwater annelid. We characterise all major annelid adult cell types, and validate many of our observations by HCR in situ hybridisation. Our results uncover complex patterns of regionally expressed genes in the annelid gut, as well as neuronal, muscle and epidermal specific genes. We also characterise annelid-specific cell types such as the chaetal sacs and globin+ cells, and novel cell types of enigmatic affinity, including a vigilin+ cell type, a lumbrokinase+ cell type, and a diverse set of metabolic cells. Moreover, we characterise transcription factors and gene networks that are expressed specifically in these populations. Finally, we uncover a broadly abundant cluster of putative stem cells with a pluripotent signature. This population expresses well-known stem cell markers such as vasa, piwi and nanos homologues, but also shows heterogeneous expression of differentiated cell markers and their transcription factors. In these piwi+ cells, we also find conserved expression of pluripotency regulators, including multiple chromatin remodelling and epigenetic factors. Finally, lineage reconstruction analyses reveal the existence of differentiation trajectories from piwi+ cells to diverse adult types. Our data reveal the cell type diversity of adult annelids for the first time and serve as a resource for studying annelid cell types and their evolution. On the other hand, our characterisation of a piwi+ cell population with a pluripotent stem cell signature will serve as a platform for the study of annelid stem cells and their role in regeneration.
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Affiliation(s)
- Patricia Álvarez-Campos
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM) & Departamento de Biología (Zoología), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Helena García-Castro
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Elena Emili
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Alberto Pérez-Posada
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | | | - Vincent Mason
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Bria Metzger
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, USA, 05432
- Department of Biology, Washington University in St. Louis. 1 Brookings Dr. Saint Louis, MO, USA, 63130
| | | | - Nathan Kenny
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, Aotearoa New Zealand
| | - B Duygu Özpolat
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, USA, 05432
- Department of Biology, Washington University in St. Louis. 1 Brookings Dr. Saint Louis, MO, USA, 63130
| | - Jordi Solana
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
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4
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Rennolds CW, Bely AE. Integrative biology of injury in animals. Biol Rev Camb Philos Soc 2023; 98:34-62. [PMID: 36176189 PMCID: PMC10087827 DOI: 10.1111/brv.12894] [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: 08/25/2021] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 01/12/2023]
Abstract
Mechanical injury is a prevalent challenge in the lives of animals with myriad potential consequences for organisms, including reduced fitness and death. Research on animal injury has focused on many aspects, including the frequency and severity of wounding in wild populations, the short- and long-term consequences of injury at different biological scales, and the variation in the response to injury within or among individuals, species, ontogenies, and environmental contexts. However, relevant research is scattered across diverse biological subdisciplines, and the study of the effects of injury has lacked synthesis and coherence. Furthermore, the depth of knowledge across injury biology is highly uneven in terms of scope and taxonomic coverage: much injury research is biomedical in focus, using mammalian model systems and investigating cellular and molecular processes, while research at organismal and higher scales, research that is explicitly comparative, and research on invertebrate and non-mammalian vertebrate species is less common and often less well integrated into the core body of knowledge about injury. The current state of injury research presents an opportunity to unify conceptually work focusing on a range of relevant questions, to synthesize progress to date, and to identify fruitful avenues for future research. The central aim of this review is to synthesize research concerning the broad range of effects of mechanical injury in animals. We organize reviewed work by four broad and loosely defined levels of biological organization: molecular and cellular effects, physiological and organismal effects, behavioural effects, and ecological and evolutionary effects of injury. Throughout, we highlight the diversity of injury consequences within and among taxonomic groups while emphasizing the gaps in taxonomic coverage, causal understanding, and biological endpoints considered. We additionally discuss the importance of integrating knowledge within and across biological levels, including how initial, localized responses to injury can lead to long-term consequences at the scale of the individual animal and beyond. We also suggest important avenues for future injury biology research, including distinguishing better between related yet distinct injury phenomena, expanding the subjects of injury research to include a greater variety of species, and testing how intrinsic and extrinsic conditions affect the scope and sensitivity of injury responses. It is our hope that this review will not only strengthen understanding of animal injury but will contribute to building a foundation for a more cohesive field of 'injury biology'.
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Affiliation(s)
- Corey W Rennolds
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
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5
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Bely AE. Journey beyond the embryo: The beauty of Pristina and naidine annelids for studying regeneration and agametic reproduction. Curr Top Dev Biol 2022; 147:469-495. [PMID: 35337459 DOI: 10.1016/bs.ctdb.2021.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Regeneration, asexual agametic reproduction, and other forms of postembryonic development are ecologically important and widely variable across animals, yet our understanding of this important aspect of animal diversity remains limited. A significant limitation has been the dearth of adequate study systems for exploring the mechanisms and evolution of these processes. Here I describe key parts of our journey in developing naid annelids as a study system for investigating the evolution and development of regeneration and fission. Naids are small freshwater annelids that provide numerous advantages for studying postembryonic development: they are small and reproduce readily by fission, they include species with diverse regenerative abilities, and many species are easy to culture. Among the naids, Pristina leidyi is a particularly useful study species, being largely transparent and quite robust to a variety of experimental manipulations. Building on a sparse but long history of past research on these animals, we have developed this system by establishing methods and generating resources for working with them. Naids are yielding novel insights into the evolution of regeneration and fission, providing one of many examples of the value of developing new study species to enable the exploration of fundamental and understudied questions in biology. Establishing new study systems comes with challenges but is exciting and rewarding, and I provide perspectives from my own experiences with the hope of encouraging the further expansion of study systems in biology.
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Affiliation(s)
- Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD, United States.
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Glossiphoniid leeches as a touchstone for studies of development in clitellate annelids. Curr Top Dev Biol 2022; 147:433-468. [PMID: 35337458 DOI: 10.1016/bs.ctdb.2021.12.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
My goals in this chapter are to share my enthusiasm for studying the biology of leeches, to place this work in context by presenting my rationale for studying non-traditional biological models in general, and to sample just three of the questions that intrigue me in leech biology, namely segmentation, genome evolution and neuronal fate specification. I first became excited about the idea of using leeches as a subject of investigation as an undergraduate in 1970 and have been engaged in this work since I arrived at Berkeley as a postdoc in 1976, intending to study leech neurobiology. Both my research interests and the rationale for the work have expanded greatly since then. What follows is a fragmentary personal and historical account-the interested reader may find more comprehensive treatments elsewhere (Kuo et al., 2020; Shankland & Savage, 1997; Shain, 2009; Weisblat & Huang, 2001; Weisblat & Kuo, 2009, 2014; Weisblat & Winchell, 2020).
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Elchaninov A, Sukhikh G, Fatkhudinov T. Evolution of Regeneration in Animals: A Tangled Story. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.621686] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The evolution of regenerative capacity in multicellular animals represents one of the most complex and intriguing problems in biology. How could such a seemingly advantageous trait as self-repair become consistently attenuated by the evolution? This review article examines the concept of the origin and nature of regeneration, its connection with the processes of embryonic development and asexual reproduction, as well as with the mechanisms of tissue homeostasis. The article presents a variety of classical and modern hypotheses explaining different trends in the evolution of regenerative capacity which is not always beneficial for the individual and notably for the species. Mechanistically, these trends are driven by the evolution of signaling pathways and progressive restriction of differentiation plasticity with concomitant advances in adaptive immunity. Examples of phylogenetically enhanced regenerative capacity are considered as well, with appropriate evolutionary reasoning for the enhancement and discussion of its molecular mechanisms.
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Injury-Induced Innate Immune Response During Segment Regeneration of the Earthworm, Eisenia andrei. Int J Mol Sci 2021; 22:ijms22052363. [PMID: 33673408 PMCID: PMC7956685 DOI: 10.3390/ijms22052363] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 11/18/2022] Open
Abstract
Regeneration of body parts and their interaction with the immune response is a poorly understood aspect of earthworm biology. Consequently, we aimed to study the mechanisms of innate immunity during regeneration in Eisenia andrei earthworms. In the course of anterior and posterior regeneration, we documented the kinetical aspects of segment restoration by histochemistry. Cell proliferation peaked at two weeks and remitted by four weeks in regenerating earthworms. Apoptotic cells were present throughout the cell renewal period. Distinct immune cell (e.g., coelomocyte) subsets were accumulated in the newly-formed blastema in the close proximity of the apoptotic area. Regenerating earthworms have decreased pattern recognition receptors (PRRs) (e.g., TLR, except for scavenger receptor) and antimicrobial peptides (AMPs) (e.g., lysenin) mRNA patterns compared to intact earthworms. In contrast, at the protein level, mirroring regulation of lysenins became evident. Experimental coelomocyte depletion caused significantly impaired cell divisions and blastema formation during anterior and posterior regeneration. These obtained novel data allow us to gain insight into the intricate interactions of regeneration and invertebrate innate immunity.
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Zattara EE, Özpolat BD. Quantifying Cell Proliferation During Regeneration of Aquatic Worms. Methods Mol Biol 2021; 2219:163-180. [PMID: 33074540 DOI: 10.1007/978-1-0716-0974-3_10] [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: 03/27/2023]
Abstract
Many species of aquatic worms, including members of the phyla Nemertea, Annelida, Platyhelminthes, and Xenacoelomorpha, can regenerate large parts of their body after amputation. In most species, cell proliferation plays key roles in the reconstruction of lost tissues. For example, in annelids and flatworms, inhibition of cell proliferation by irradiation or chemicals prevents regeneration. Cell proliferation also plays crucial roles in growth, body patterning (e.g., segmentation) and asexual reproduction in many groups of aquatic worms. Cell proliferation dynamics in these organisms can be studied using immunohistochemical detection of proteins expressed during proliferation-associated processes or by incorporation and labeling of thymidine analogues during DNA replication. In this chapter, we present protocols for labeling and quantifying cell proliferation by (a) antibody-based detection of either phosphorylated histone H3 during mitosis or proliferating cell nuclear antigen (PCNA) during S-phase, and (b) incorporation of two thymidine analogues, 5'-bromo-2'-deoxyuridine (BrdU) and 5'-ethynyl-2'-deoxyuridine (EdU), detected by immunohistochemistry or inorganic "click" chemistry, respectively. Although these protocols have been developed for whole mounts of small (<2 cm) marine and freshwater worms, they can also be adapted for use in larger specimens or tissue sections.
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Affiliation(s)
- Eduardo E Zattara
- Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA), CONICET-Universidad Nacional del Comahue, Bariloche, Rio Negro, Argentina.
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Bae YS, Kim J, Yi J, Park SC, Lee HY, Cho SJ. Characterization of Perionyx excavatus Development and Its Head Regeneration. BIOLOGY 2020; 9:biology9090273. [PMID: 32899511 PMCID: PMC7564270 DOI: 10.3390/biology9090273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/23/2020] [Accepted: 09/03/2020] [Indexed: 12/15/2022]
Abstract
Regeneration is a biological process restoring lost or amputated body parts. The capability of regeneration varies among organisms and the regeneration of the central nervous system (CNS) is limited to specific animals, including the earthworm Perionyx excavatus. Thus, it is crucial to establish P. excavatus as a model system to investigate mechanisms of CNS regeneration. Here, we set up a culture system to sustain the life cycle of P. excavatus and characterize the development of P. excavatus, from embryo to juvenile, based on its morphology, myogenesis and neurogenesis. During development, embryos have EdU-positive proliferating cells throughout the whole body, whereas juveniles maintain proliferating cells exclusively in the head and tail regions, not in the trunk region. Interestingly, juveniles amputated at the trunk, which lacks proliferating cells, are able to regenerate the entire head. In this process, a group of cells, which are fully differentiated, reactivates cell proliferation. Our data suggest that P. excavatus is a model system to study CNS regeneration, which is dependent on the dedifferentiation of cells.
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Affiliation(s)
- Yun Seon Bae
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (Y.S.B.); (J.Y.)
| | - Jung Kim
- Department of Molecular and Cell Biology, University of California, Berkeley, 142 Life Sciences Addition #3200, Berkeley, CA 94720-3200, USA;
| | - Jeesoo Yi
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (Y.S.B.); (J.Y.)
| | - Soon Cheol Park
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea;
| | - Hae-Youn Lee
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (Y.S.B.); (J.Y.)
- Correspondence: (H.-Y.L.); (S.-J.C.); Tel.: +82-43-261-2294 (H.-Y.L. & S.-J.C.)
| | - Sung-Jin Cho
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Chungbuk 28644, Korea; (Y.S.B.); (J.Y.)
- Correspondence: (H.-Y.L.); (S.-J.C.); Tel.: +82-43-261-2294 (H.-Y.L. & S.-J.C.)
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Ribeiro RP, Ponz-Segrelles G, Bleidorn C, Aguado MT. Comparative transcriptomics in Syllidae (Annelida) indicates that posterior regeneration and regular growth are comparable, while anterior regeneration is a distinct process. BMC Genomics 2019; 20:855. [PMID: 31726983 PMCID: PMC6854643 DOI: 10.1186/s12864-019-6223-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 10/24/2019] [Indexed: 02/23/2023] Open
Abstract
Background Annelids exhibit remarkable postembryonic developmental abilities. Most annelids grow during their whole life by adding segments through the action of a segment addition zone (SAZ) located in front of the pygidium. In addition, they show an outstanding ability to regenerate their bodies. Experimental evidence and field observations show that many annelids are able to regenerate their posterior bodies, while anterior regeneration is often limited or absent. Syllidae, for instance, usually show high abilities of posterior regeneration, although anterior regeneration varies across species. Some syllids are able to partially restore the anterior end, while others regenerate all lost anterior body after bisection. Here, we used comparative transcriptomics to detect changes in the gene expression profiles during anterior regeneration, posterior regeneration and regular growth of two syllid species: Sphaerosyllis hystrix and Syllis gracilis; which exhibit limited and complete anterior regeneration, respectively. Results We detected a high number of genes with differential expression: 4771 genes in S. hystrix (limited anterior regeneration) and 1997 genes in S. gracilis (complete anterior regeneration). For both species, the comparative transcriptomic analysis showed that gene expression during posterior regeneration and regular growth was very similar, whereas anterior regeneration was characterized by up-regulation of several genes. Among the up-regulated genes, we identified putative homologs of regeneration-related genes associated to cellular proliferation, nervous system development, establishment of body axis, and stem-cellness; such as rup and JNK (in S. hystrix); and glutamine synthetase, elav, slit, Hox genes, β-catenin and PL10 (in S. gracilis). Conclusions Posterior regeneration and regular growth show no significant differences in gene expression in the herein investigated syllids. However, anterior regeneration is associated with a clear change in terms of gene expression in both species. Our comparative transcriptomic analysis was able to detect differential expression of some regeneration-related genes, suggesting that syllids share some features of the regenerative mechanisms already known for other annelids and invertebrates.
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Affiliation(s)
- Rannyele Passos Ribeiro
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain.
| | - Guillermo Ponz-Segrelles
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain
| | - Christoph Bleidorn
- Animal Evolution & Biodiversity, Georg-August-Universität Göttingen, 37073, Göttingen, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103, Leipzig, Germany
| | - Maria Teresa Aguado
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid, Spain. .,Animal Evolution & Biodiversity, Georg-August-Universität Göttingen, 37073, Göttingen, Germany. .,Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Madrid, 28049, España.
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12
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Iyer RG, Rogers DV, Levine M, Winchell CJ, Weisblat DA. Reproductive differences among species, and between individuals and cohorts, in the leech genus Helobdella (Lophotrochozoa; Annelida; Clitellata; Hirudinida; Glossiphoniidae), with implications for reproductive resource allocation in hermaphrodites. PLoS One 2019; 14:e0214581. [PMID: 30934006 PMCID: PMC6443171 DOI: 10.1371/journal.pone.0214581] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 03/16/2019] [Indexed: 01/26/2023] Open
Abstract
Leeches and oligochaetes comprise a monophyletic group of annelids, the Clitellata, whose reproduction is characterized by simultaneous hermaphroditism. While most clitellate species reproduce by cross-fertilization, self-fertilization has been described within the speciose genus Helobdella. Here we document the reproductive life histories and reproductive capacities for three other Helobdella species. Under laboratory conditions, both H. robusta and H. octatestisaca exhibit uniparental reproduction, apparently reflecting self-fertility, and suggesting that this trait is ancestral for the genus. However, the third species, H. austinensis, seems incapable of reproduction by self-fertilization, so we inferred its reproductive life history by analyzing reproduction in breeding cohorts. Comparing the reproductive parameters for H. robusta reproducing in isolation and in cohorts revealed that reproduction in cohorts is dramatically delayed with respect to that of isolated individuals, and that cohorts of leeches coordinate their cocoon deposition in a manner that is not predicted from the reproductive parameters of individuals reproducing in isolation. Finally, our comparisons of reproductive capacity for individuals versus cohorts for H. robusta, and between different sizes of cohorts for H. austinensis, reveal differences in resource allocation between male and female reproductive roles that are consistent with evolutionary theory.
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Affiliation(s)
- Roshni G. Iyer
- Dept. of Electrical Engineering & Computer Sciences, Univ. of California, Berkeley, CA, United States of America
| | - D. Valle Rogers
- Dept. of Molecular & Cell Biology, Univ. of California, Berkeley, CA, United States of America
| | - Michelle Levine
- Dept. of Molecular & Cell Biology, Univ. of California, Berkeley, CA, United States of America
| | - Christopher J. Winchell
- Dept. of Molecular & Cell Biology, Univ. of California, Berkeley, CA, United States of America
| | - David A. Weisblat
- Dept. of Molecular & Cell Biology, Univ. of California, Berkeley, CA, United States of America
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Sebestyén F, Barta Z, Tökölyi J. Reproductive mode, stem cells and regeneration in a freshwater cnidarian with postreproductive senescence. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13189] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Flóra Sebestyén
- MTA‐DE Behavioural Ecology Research Group, Department of Evolutionary Zoology University of Debrecen Debrecen Hungary
| | - Zoltán Barta
- MTA‐DE Behavioural Ecology Research Group, Department of Evolutionary Zoology University of Debrecen Debrecen Hungary
| | - Jácint Tökölyi
- MTA‐DE Behavioural Ecology Research Group, Department of Evolutionary Zoology University of Debrecen Debrecen Hungary
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Ricci L, Srivastava M. Wound-induced cell proliferation during animal regeneration. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e321. [PMID: 29719123 DOI: 10.1002/wdev.321] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 12/19/2022]
Abstract
Many animal species are capable of replacing missing tissues that are lost upon injury or amputation through the process of regeneration. Although the extent of regeneration is variable across animals, that is, some animals can regenerate any missing cell type whereas some can only regenerate certain organs or tissues, regulated cell proliferation underlies the formation of new tissues in most systems. Notably, many species display an increase in proliferation within hours or days upon wounding. While different cell types proliferate in response to wounding in various animal taxa, comparative molecular data are beginning to point to shared wound-induced mechanisms that regulate cell division during regeneration. Here, we synthesize current insights about early molecular pathways of regeneration from diverse model and emerging systems by considering these species in their evolutionary contexts. Despite the great diversity of mechanisms underlying injury-induced cell proliferation across animals, and sometimes even in the same species, similar pathways for proliferation have been implicated in distantly related species (e.g., small diffusible molecules, signaling from apoptotic cells, growth factor signaling, mTOR and Hippo signaling, and Wnt and Bmp pathways). Studies that explicitly interrogate molecular and cellular regenerative mechanisms in understudied animal phyla will reveal the extent to which early pathways in the process of regeneration are conserved or independently evolved. This article is categorized under: Comparative Development and Evolution > Body Plan Evolution Adult Stem Cells, Tissue Renewal, and Regeneration > Regeneration Comparative Development and Evolution > Model Systems.
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Affiliation(s)
- Lorenzo Ricci
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Mansi Srivastava
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
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Ribeiro RP, Bleidorn C, Aguado MT. Regeneration mechanisms in Syllidae (Annelida). REGENERATION (OXFORD, ENGLAND) 2018; 5:26-42. [PMID: 29721325 PMCID: PMC5911452 DOI: 10.1002/reg2.98] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/26/2018] [Accepted: 02/27/2018] [Indexed: 12/16/2022]
Abstract
Syllidae is one of the most species-rich groups within Annelida, with a wide variety of reproductive modes and different regenerative processes. Syllids have striking ability to regenerate their body anteriorly and posteriorly, which in many species is redeployed during sexual (schizogamy) and asexual (fission) reproduction. This review summarizes the available data on regeneration in syllids, covering descriptions of regenerative mechanisms in different species as well as regeneration in relation to reproductive modes. Our survey shows that posterior regeneration is widely distributed in syllids, whereas anterior regeneration is limited in most of the species, excepting those reproducing by fission. The latter reproductive mode is well known for a few species belonging to Autolytinae, Eusyllinae, and Syllinae. Patterns of fission areas have been studied in these animals. Deviations of the regular regeneration pattern or aberrant forms such as bifurcated animals or individuals with multiple heads have been reported for several species. Some of these aberrations show a deviation of the bilateral symmetry and antero-posterior axis, which, interestingly, can also be observed in the regular branching body pattern of some species of syllids.
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Affiliation(s)
- Rannyele P. Ribeiro
- Departamento de BiologíaFacultad de CienciasUniversidad Autónoma de MadridCantoblanco28049MadridSpain
| | - Christoph Bleidorn
- Animal Evolution and BiodiversityGeorg‐August‐Universität Göttingen37073 GöttingenGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig04103 LeipzigGermany
| | - M. Teresa Aguado
- Departamento de BiologíaFacultad de CienciasUniversidad Autónoma de MadridCantoblanco28049MadridSpain
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de Jong DM, Seaver EC. Investigation into the cellular origins of posterior regeneration in the annelid Capitella teleta. ACTA ACUST UNITED AC 2017; 5:61-77. [PMID: 29721327 PMCID: PMC5911572 DOI: 10.1002/reg2.94] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 12/11/2022]
Abstract
Many animals can regenerate, although there is great diversity in regenerative capabilities. A major question in regenerative biology is determining the cellular source of newly formed tissue. The polychaete annelid, Capitella teleta, can regenerate posterior segments following transverse amputation. However, the source, behavior and molecular characteristics of the cells that form new tissue during regeneration are largely unknown. Using an indirect cell tracking method involving 5′‐ethynyl‐2′‐deoxyuridine (EdU) incorporation, we show that cell migration occurs during C. teleta posterior regeneration. Expression of the multipotency/germ line marker CapI‐vasa led us to hypothesize that stem cells originate from a multipotent progenitor cell (MPC) cluster, migrate through the coelomic cavity, and contribute to regeneration of tissue. We show that the capacity for posterior regeneration and segment formation is greater with than without the MPC cluster. Finally, we propose a working model of posterior regeneration in C. teleta. This work is the first in C. teleta that addresses the potential source of cells contributing to posterior regeneration, and may provide clues as to why some animals are highly successful regenerators.
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Affiliation(s)
- Danielle M de Jong
- Whitney Laboratory for Marine Bioscience University of Florida St Augustine FL 32080 USA
| | - Elaine C Seaver
- Whitney Laboratory for Marine Bioscience University of Florida St Augustine FL 32080 USA
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Food availability drives plastic self-repair response in a basal metazoan- case study on the ctenophore Mnemiopsis leidyi A. Agassiz 1865. Sci Rep 2017; 7:16419. [PMID: 29180635 PMCID: PMC5703731 DOI: 10.1038/s41598-017-16346-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 11/10/2017] [Indexed: 12/02/2022] Open
Abstract
Many marine invertebrates including ctenophores are capable of extensive body regeneration when injured. However, as for the invasive ctenophore Mnemiopsis leidyi, there is a constant subportion of individuals not undergoing whole body regeneration but forming functionally stable half-animals instead. Yet, the driving factors of this phenomenon have not been addressed so far. This study sheds new light on how differences in food availability affect self-repair choice and regeneration success in cydippid larvae of M. leidyi. As expected, high food availability favored whole-body regeneration. However, under low food conditions half-animals became the preferential self-repair mode. Remarkably, both regenerating and half-animals showed very similar survival chances under respective food quantities. As a consequence of impaired food uptake after injury, degeneration of the digestive system would often occur indicating limited energy storage capacities. Taken together, this indicates that half-animals may represent an alternative energy-saving trajectory which implies self-repair plasticity as an adaptive trade-off between high regeneration costs and low energy storage capacities. We conclude that self-repair plasticity could lead to higher population fitness of ctenophores under adverse conditions such as in ships’ ballast water tanks which is postulated to be the major vector source for the species’ spreading around the globe.
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18
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Weidhase M, Beckers P, Bleidorn C, Aguado MT. On the role of the proventricle region in reproduction and regeneration in Typosyllis antoni (Annelida: Syllidae). BMC Evol Biol 2016; 16:196. [PMID: 27716025 PMCID: PMC5050598 DOI: 10.1186/s12862-016-0770-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 09/28/2016] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Syllids are a species rich annelid family possessing remarkable regenerative ability, which is not only the response after traumatic injury, but also a key step during the life cycle of several syllid taxa. In these animals the posterior part of the body becomes an epitoke and is later detached as a distinct unit named stolon. Such a sexual reproductive mode is named schizogamy or stolonization. The prostomium and the proventricle, a modified foregut structure, have been proposed to have a control function during this process, though the concrete mechanisms behind it have never been elucidated. RESULTS By using different experimental set-ups, histology and immunohistochemistry combined with subsequent cLSM analyzes, we investigate and document the regeneration and stolonization in specimens of Typosyllis antoni that were amputated at different levels throughout the antero-posterior body axis. The removal of the anterior end including the proventricle implies an incomplete anterior regeneration as well as severe deviations from the usual reproductive pattern, i.e. accelerated stolonization, masculinization and the occurrence of aberrant stolons. The detailed anatomy of aberrant stolons is described. A histological study of the proventricle revealed no signs of glandular or secretory structures. The ventricle and the caeca are composed of glandular tissue but they are not involved in the reproductive and regenerative processes. CONCLUSIONS As in other investigated syllids, the proventricle region has a significant role during stolonization and reproduction processes in Typosyllis antoni. When the proventricle region is absent, anterior and posterior regeneration are considerably deviated from the general patterns. However, proventricle ultrastructure does not show any glandular component, thereby questioning a direct involvement of this organ itself in the control of reproduction and regeneration. Our findings offer a comprehensive starting point for further studies of regeneration and reproductive control in syllids as well as annelids in general.
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Affiliation(s)
- Michael Weidhase
- Molecular Evolution & Animal Systematics, Institute of Biology, University of Leipzig, Talstraße 33, D-04103 Leipzig, Germany
| | - Patrick Beckers
- Zoology and Evolutionary Biology, Institute of Evolutionary Biology and Ecology, Rheinische Friedrich-Wilhelms-Universität Bonn, An der Immenburg 1, D-53121 Bonn, Germany
| | - Christoph Bleidorn
- Molecular Evolution & Animal Systematics, Institute of Biology, University of Leipzig, Talstraße 33, D-04103 Leipzig, Germany
- Museo Nacional de Ciencias Naturales, Spanish Research Council (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - M. Teresa Aguado
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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Özpolat BD, Sloane ES, Zattara EE, Bely AE. Plasticity and regeneration of gonads in the annelid Pristina leidyi. EvoDevo 2016; 7:22. [PMID: 27708756 PMCID: PMC5051023 DOI: 10.1186/s13227-016-0059-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/09/2016] [Indexed: 11/30/2022] Open
Abstract
Background Gonads are specialized gamete-producing structures that, despite their functional importance, are generated by diverse mechanisms across groups of animals and can be among the most plastic organs of the body. Annelids, the segmented worms, are a group in which gonads have been documented to be plastic and to be able to regenerate, but little is known about what factors influence gonad development or how these structures regenerate. In this study, we aimed to identify factors that influence the presence and size of gonads and to investigate gonad regeneration in the small asexually reproducing annelid, Pristina leidyi. Results We found that gonad presence and size in asexual adult P. leidyi are highly variable across individuals and identified several factors that influence these structures. An extrinsic factor, food availability, and two intrinsic factors, individual age and parental age, strongly influence the presence and size of gonads in P. leidyi. We also found that following head amputation in this species, gonads can develop by morphallactic regeneration in previously non-gonadal segments. We also identified a sexually mature individual from our laboratory culture that demonstrates that, although our laboratory strain reproduces only asexually, it retains the potential to become fully sexual. Conclusions Our findings demonstrate that gonads in P. leidyi display high phenotypic plasticity and flexibility with respect to their presence, their size, and the segments in which they can form. Considering our findings along with relevant data from other species, we find that, as a group, clitellate annelids can form gonads in at least four different contexts: post-starvation refeeding, fission, morphallactic regeneration, and epimorphic regeneration. This group is thus particularly useful for investigating the mechanisms involved in gonad formation and the evolution of post-embryonic phenotypic plasticity. Electronic supplementary material The online version of this article (doi:10.1186/s13227-016-0059-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- B Duygu Özpolat
- Department of Biology, University of Maryland, College Park, MD 20742 USA ; Institut Jacques Monod, Paris, France
| | - Emily S Sloane
- Department of Biology, University of Maryland, College Park, MD 20742 USA
| | - Eduardo E Zattara
- Department of Biology, University of Maryland, College Park, MD 20742 USA ; Department of Biology, Indiana University, Bloomington, IN USA
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD 20742 USA
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20
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Özpolat BD, Bely AE. Developmental and molecular biology of annelid regeneration: a comparative review of recent studies. Curr Opin Genet Dev 2016; 40:144-153. [PMID: 27505269 DOI: 10.1016/j.gde.2016.07.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 11/29/2022]
Abstract
Studies of annelid regeneration have greatly increased in frequency in recent years, providing new insights into the developmental basis and evolution of regeneration. In this review, we summarize recent findings related to regeneration in annelids, focusing on molecular and developmental studies of epimorphic (blastema-based) regeneration, morphallactic (tissue-remodeling based) regeneration, and development and regeneration of putative stem cells of the posterior growth zone and germline. Regeneration is being investigated in a broad range of annelids spanning the phylum, and comparing findings among species reveals both widely conserved features that may be ancestral for the phylum as well as features that are variable across the group.
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Affiliation(s)
- B Duygu Özpolat
- Department of Biology, University of Maryland, College Park, MD, USA.
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD, USA.
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21
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Kostyuchenko RP, Kozin VV, Kupriashova EE. Regeneration and asexual reproduction in annelids: Cells, genes, and evolution. BIOL BULL+ 2016. [DOI: 10.1134/s1062359016030067] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Zattara EE, Turlington KW, Bely AE. Long-term time-lapse live imaging reveals extensive cell migration during annelid regeneration. BMC DEVELOPMENTAL BIOLOGY 2016; 16:6. [PMID: 27006129 PMCID: PMC4804569 DOI: 10.1186/s12861-016-0104-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/10/2016] [Indexed: 01/09/2023]
Abstract
BACKGROUND Time-lapse imaging has proven highly valuable for studying development, yielding data of much finer resolution than traditional "still-shot" studies and allowing direct examination of tissue and cell dynamics. A major challenge for time-lapse imaging of animals is keeping specimens immobile yet healthy for extended periods of time. Although this is often feasible for embryos, the difficulty of immobilizing typically motile juvenile and adult stages remains a persistent obstacle to time-lapse imaging of post-embryonic development. RESULTS Here we describe a new method for long-duration time-lapse imaging of adults of the small freshwater annelid Pristina leidyi and use this method to investigate its regenerative processes. Specimens are immobilized with tetrodotoxin, resulting in irreversible paralysis yet apparently normal regeneration, and mounted in agarose surrounded by culture water or halocarbon oil, to prevent dehydration but allowing gas exchange. Using this method, worms can be imaged continuously and at high spatial-temporal resolution for up to 5 days, spanning the entire regeneration process. We performed a fine-scale analysis of regeneration growth rate and characterized cell migration dynamics during early regeneration. Our studies reveal the migration of several putative cell types, including one strongly resembling published descriptions of annelid neoblasts, a cell type suggested to be migratory based on "still-shot" studies and long hypothesized to be linked to regenerative success in annelids. CONCLUSIONS Combining neurotoxin-based paralysis, live mounting techniques and a starvation-tolerant study system has allowed us to obtain the most extensive high-resolution longitudinal recordings of full anterior and posterior regeneration in an invertebrate, and to detect and characterize several cell types undergoing extensive migration during this process. We expect the tetrodotoxin paralysis and time-lapse imaging methods presented here to be broadly useful in studying other animals and of particular value for studying post-embryonic development.
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Affiliation(s)
- Eduardo E. Zattara
- Department of Biology, University of Maryland, College Park, MD 20740 USA
| | - Kate W. Turlington
- Department of Biology, University of Maryland, College Park, MD 20740 USA
| | - Alexandra E. Bely
- Department of Biology, University of Maryland, College Park, MD 20740 USA
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23
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de Jong DM, Seaver EC. A Stable Thoracic Hox Code and Epimorphosis Characterize Posterior Regeneration in Capitella teleta. PLoS One 2016; 11:e0149724. [PMID: 26894631 PMCID: PMC4764619 DOI: 10.1371/journal.pone.0149724] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 02/04/2016] [Indexed: 12/21/2022] Open
Abstract
Regeneration, the ability to replace lost tissues and body parts following traumatic injury, occurs widely throughout the animal tree of life. Regeneration occurs either by remodeling of pre-existing tissues, through addition of new cells by cell division, or a combination of both. We describe a staging system for posterior regeneration in the annelid, Capitella teleta, and use the C. teleta Hox gene code as markers of regional identity for regenerating tissue along the anterior-posterior axis. Following amputation of different posterior regions of the animal, a blastema forms and by two days, proliferating cells are detected by EdU incorporation, demonstrating that epimorphosis occurs during posterior regeneration of C. teleta. Neurites rapidly extend into the blastema, and gradually become organized into discrete nerves before new ganglia appear approximately seven days after amputation. In situ hybridization shows that seven of the ten Hox genes examined are expressed in the blastema, suggesting roles in patterning the newly forming tissue, although neither spatial nor temporal co-linearity was detected. We hypothesized that following amputation, Hox gene expression in pre-existing segments would be re-organized to scale, and the remaining fragment would express the complete suite of Hox genes. Surprisingly, most Hox genes display stable expression patterns in the ganglia of pre-existing tissue following amputation at multiple axial positions, indicating general stability of segmental identity. However, the three Hox genes, CapI-lox4, CapI-lox2 and CapI-Post2, each shift its anterior expression boundary by one segment, and each shift includes a subset of cells in the ganglia. This expression shift depends upon the axial position of the amputation. In C. teleta, thoracic segments exhibit stable positional identity with limited morphallaxis, in contrast with the extensive body remodeling that occurs during regeneration of some other annelids, planarians and acoel flatworms.
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Affiliation(s)
- Danielle M. de Jong
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida, United States of America
| | - Elaine C. Seaver
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida, United States of America
- * E-mail:
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Özpolat BD, Bely AE. Gonad establishment during asexual reproduction in the annelid Pristina leidyi. Dev Biol 2015; 405:123-36. [PMID: 26134407 DOI: 10.1016/j.ydbio.2015.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 03/15/2015] [Accepted: 06/02/2015] [Indexed: 11/29/2022]
Abstract
Animals that can reproduce by both asexual agametic reproduction and sexual reproduction must transmit or re-establish their germ line post-embryonically. Although such a dual reproductive mode has evolved repeatedly among animals, how asexually produced individuals establish their germ line remains poorly understood in most groups. We investigated germ line development in the annelid Pristina leidyi, a species that typically reproduces asexually by paratomic fission, intercalating a new tail and head in the middle of the body followed by splitting. We found that in fissioning individuals, gonads occur in anterior segments in the anterior-most individual as well as in new heads forming within fission zones. Homologs of the germ line/multipotency genes piwi, vasa, and nanos are expressed in the gonads, as well as in proliferative tissues including the posterior growth zone, fission zone, and regeneration blastema. In fissioning animals, certain cells on the ventral nerve cord express a homolog of piwi, are abundant near fission zones, and sometimes make contact with gonads. Such cells are typically undetectable near the blastema and posterior growth zone. Time-lapse imaging provides direct evidence that cells on the ventral nerve cord migrate preferentially towards fission zones. Our findings indicate that gonads form routinely in fissioning individuals, that a population of piwi-positive cells on the ventral nerve cord is associated with fission and gonads, and that cells resembling these piwi-positive cells migrate along the ventral nerve cord. We suggest that the piwi-positive ventral cells are germ cells that transmit the germ line across asexually produced individuals via migration along the ventral nerve cord.
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Affiliation(s)
- B Duygu Özpolat
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
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Zattara EE, Bely AE. Fine taxonomic sampling of nervous systems within Naididae (Annelida: Clitellata) reveals evolutionary lability and revised homologies of annelid neural components. Front Zool 2015; 12:8. [PMID: 25960761 PMCID: PMC4424535 DOI: 10.1186/s12983-015-0100-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/27/2015] [Indexed: 11/17/2022] Open
Abstract
Introduction An important goal for understanding how animals have evolved is to reconstruct the ancestral features and evolution of the nervous system. Many inferences about nervous system evolution are weak because of sparse taxonomic sampling and deep phylogenetic distances among species compared. Increasing sampling within clades can strengthen inferences by revealing which features are conserved and which are variable within them. Among the Annelida, the segmented worms, the Clitellata are typically considered as having a largely conserved neural architecture, though this view is based on limited sampling. Results To gain better understanding of nervous system evolution within Clitellata, we used immunohistochemistry and confocal laser scanning microscopy to describe the nervous system architecture of 12 species of the basally branching family Naididae. Although we found considerable similarity in the nervous system architecture of naidids and that of other clitellate groups, our study identified a number of features that are variable within this family, including some that are variable even among relatively closely related species. Variable features include the position of the brain, the number of ciliary sense organs, the presence of septate ventral nerve cord ganglia, the distribution of serotonergic cells in the brain and ventral ganglia, and the number of peripheral segmental nerves. Conclusions Our analysis of patterns of serotonin immunoreactive perikarya in the central nervous system indicates that segmental units are not structurally homogeneous, and preliminary homology assessments suggest that whole sets of serotonin immunoreactive cells have been gained and lost across the Clitellata. We also found that the relative position of neuroectodermal and mesodermal segmental components is surprisingly evolutionarily labile; in turn, this revealed that scoring segmental nerves by their position relative to segmental ganglia rather than to segmental septa clarifies their homologies across Annelida. We conclude that fine taxonomic sampling in comparative studies aimed at elucidating the evolution of morphological diversity is fundamental for proper assessment of trait variability. Electronic supplementary material The online version of this article (doi:10.1186/s12983-015-0100-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eduardo E Zattara
- Department of Biology, University of Maryland, College Park, MD 20740 USA ; Current address: Department of Biology, Indiana University, 915 E. Third Street, Myers Hall 150, Bloomington, IN 47405-7107 USA
| | - Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD 20740 USA
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26
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Weidhase M, Helm C, Bleidorn C. Morphological investigations of posttraumatic regeneration in Timarete cf. punctata (Annelida: Cirratulidae). ZOOLOGICAL LETTERS 2015; 1:20. [PMID: 26605065 PMCID: PMC4657251 DOI: 10.1186/s40851-015-0023-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 06/23/2015] [Indexed: 05/10/2023]
Abstract
INTRODUCTION Annelids exhibit great regenerative abilities, which are mainly used after injury or during reproduction. These lophotrochozoans thus represent excellent models for regeneration research. However, detailed morphological studies concerning annelid musculature and nervous system redevelopment are limited to few taxa, and do not allow for broader comparisons and general conclusions regarding common patterns amongst annelids. RESULTS Using immunohistochemical staining combined with confocal laser scanning microscopy (cLSM), we investigated the redevelopment of body wall musculature and nervous system during anterior and posterior posttraumatic regeneration in Timarete cf. punctata. Both regeneration processes start with wound healing, blastema formation, and blastema patterning. In posterior regeneration, this leads to the development of a new pygidium and a segment addition zone (SAZ) anterior to this structure. New segments are subsequently added in a sequential fashion. Anterior regeneration in contrast shows the formation of a new prostomium and peristomium first, followed by the simultaneous redevelopment of three segments, and an additional three segments in sequential order. Anterior muscular regeneration shows an outgrowth of longitudinal musculature from the residual body wall musculature, while circular musculature develops independently within the blastema. During posterior regeneration, new musculature becomes visible when the new segments reached a certain age. Neuronal regeneration begins with neurite outgrowth from the old ventral nerve cord in both cases, which are later forming loop structures. In anterior regeneration, the brain redevelops at the anteriormost position of the loops. CONCLUSIONS Posterior regeneration recapitulates normal growth from a certain timepoint with serial segment development by a posterior segment addition zone. Anterior regeneration is more complex, showing similarities to larval development in matters of the order, in which prostomium, peristomium, and segments are generated. Furthermore, we demonstrate the usefulness of regeneration studies to investigate morphological structures and evolutionary processes.
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Affiliation(s)
- Michael Weidhase
- />Molecular Evolution & Animal Systematics, Institute of Biology, University of Leipzig, Talstraße 33, D-04103 Leipzig, Germany
| | - Conrad Helm
- />Sars International Centre for Marine Molecular Biology, Thormøhlensgt. 55, N-5008 Bergen, Norway
| | - Christoph Bleidorn
- />Molecular Evolution & Animal Systematics, Institute of Biology, University of Leipzig, Talstraße 33, D-04103 Leipzig, Germany
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Abstract
The ability to regenerate extensive portions of the body is widespread among the phylum Annelida and this group includes some of the most highly regenerative animals known. Knowledge of the cellular and molecular basis of regeneration in this group is thus important for understanding how regenerative processes have evolved both within the group and across animal phyla. Here, the cellular basis of annelid regeneration is reviewed, with a focus on the earliest steps of regeneration, namely wound-healing and formation of the blastema. Information from a wide range of annelids is compiled in order to identify common and variable elements. There is a large body of valuable older literature on the cellular basis of regeneration in annelids and an effort is made to review this literature in addition to more recent studies. Annelids typically seal the wound through muscular contraction and undergo some autolysis of tissue at the site of the wound. Bodily injury elicits extensive cell migration toward the wound, involving several different types of cells. Some migrating cells form a tissue-clot and phagocytize damaged tissues, whereas others are inferred to contribute to regenerated tissue, specifically mesodermal tissue. In one annelid subgroup, the clitellates, a group of mesodermal cells, sometimes referred to as neoblasts, is inferred to migrate over considerable distances, with cells moving to the wound from several segments away. Epidermis and gut epithelia severed upon amputation typically heal by fusing with like tissue, although not always. After amputation, cellular contacts with the extracellular matrix are disrupted and major changes in cell morphology and adhesion occur within tissues near the wound. Interactions of tissues at the wound appear key for initiating a blastema, with a particularly important role suggested for the ventral nerve cord, although species are variable in this regard; longer-distance effects mediated by the brain are also reported. The anterior-posterior polarity of the blastema can be mis-assigned, leading most commonly to double-headed worms, and the dorsal-ventral polarity of the blastema appears to be induced by the ventral nerve cord. The blastema is thought to arise from contributions of all three tissue layers, with each layer replacing itself in a tissue-specific manner. Blastemal cells originate mostly locally, although some long-distance migration of source-cells is suggested in clitellates. A number of important questions remain about the cellular basis of regeneration in annelids and addressing many of these would be greatly aided by developing approaches to identify and isolate specific cell types and techniques to image and trace cells in vivo.
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Affiliation(s)
- Alexandra E Bely
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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Weidhase M, Bleidorn C, Helm C. Structure and anterior regeneration of musculature and nervous system inCirratuluscf.cirratus(Cirratulidae, Annelida). J Morphol 2014; 275:1418-30. [DOI: 10.1002/jmor.20316] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 07/03/2014] [Accepted: 07/11/2014] [Indexed: 01/22/2023]
Affiliation(s)
- Michael Weidhase
- Molecular Evolution & Animal Systematics; Institute of Biology, University of Leipzig; Talstraße 33 D-04103 Leipzig Germany
| | - Christoph Bleidorn
- Molecular Evolution & Animal Systematics; Institute of Biology, University of Leipzig; Talstraße 33 D-04103 Leipzig Germany
| | - Conrad Helm
- Molecular Evolution & Animal Systematics; Institute of Biology, University of Leipzig; Talstraße 33 D-04103 Leipzig Germany
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