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Satake H, Sasakura Y. The neuroendocrine system of Ciona intestinalis Type A, a deuterostome invertebrate and the closest relative of vertebrates. Mol Cell Endocrinol 2024; 582:112122. [PMID: 38109989 DOI: 10.1016/j.mce.2023.112122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023]
Abstract
Deuterostome invertebrates, including echinoderms, hemichordates, cephalochordates, and urochordates, exhibit common and species-specific morphological, developmental, physiological, and behavioral characteristics that are regulated by neuroendocrine and nervous systems. Over the past 15 years, omics, genetic, and/or physiological studies on deuterostome invertebrates have identified low-molecular-weight transmitters, neuropeptides and their cognate receptors, and have clarified their various biological functions. In particular, there has been increasing interest on the neuroendocrine and nervous systems of Ciona intestinalis Type A, which belongs to the subphylum Urochordata and occupies the critical phylogenetic position as the closest relative of vertebrates. During the developmental stage, gamma-aminobutylic acid, D-serine, and gonadotropin-releasing hormones regulate metamorphosis of Ciona. In adults, the neuropeptidergic mechanisms underlying ovarian follicle growth, oocyte maturation, and ovulation have been elucidated. This review article provides the most recent and fundamental knowledge of the neuroendocrine and nervous systems of Ciona, and their evolutionary aspects.
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Affiliation(s)
- Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan.
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
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2
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Krasovec G, Karaiskou A, Quéinnec É, Chambon JP. Comparative transcriptomic analysis reveals gene regulation mediated by caspase activity in a chordate organism. BMC Mol Cell Biol 2021; 22:51. [PMID: 34615460 PMCID: PMC8495957 DOI: 10.1186/s12860-021-00388-0] [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: 04/22/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Apoptosis is a caspase regulated cell death present in all metazoans defined by a conserved set of morphological features. A well-described function of apoptosis is the removal of excessive cells during development and homeostasis. Recent studies have shown an unexpected signalling property of apoptotic cells, affecting cell fate and/or behaviour of neighbouring cells. In contrast to the apoptotic function of cell elimination, this new role of apoptosis is not well understood but seems caspase-dependent. To deepen our understanding of apoptotic functions, it is necessary to work on a biological model with a predictable apoptosis pattern affecting cell fate and/or behaviour. The tunicate Ciona intestinalis has a bi-phasic life cycle with swimming larvae which undergo metamorphosis after settlement. Previously, we have shown that the tail regression step during metamorphosis, characterized by a predictable polarized apoptotic wave, ensures elimination of most tail cells and controls primordial germ cells survival and migration. RESULTS We performed differential transcriptomic analysis between control metamorphosing larvae and larvae treated with the pan-caspase inhibitor Z-VAD-fmk in order to explore the transcriptional control of apoptotic cells on neighbouring cells that survive and migrate. When caspase activity was impaired, genes known to be involved in metamorphosis were downregulated along with other implicated in cell migration and survival molecular pathways. CONCLUSION We propose these results as a confirmation that apoptotic cells can control surrounding cells fate and as a reference database to explore novel apoptotic functions in animals, including those related to migration and differentiation.
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Affiliation(s)
- Gabriel Krasovec
- Institut de Systématique, Evolution, Biodiversité (ISYEB), UMR 7205, Sorbonne Université, Muséum National d'histoire Naturelle, CNRS, EPHE, 7 Quai St-Bernard, F-75252, Paris Cedex 05, France. .,Center for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Anthi Karaiskou
- INSERM UMRS_938, Centre de recherche Saint-Antoine (CRSA), Sorbonne Université, Paris, France
| | - Éric Quéinnec
- Institut de Systématique, Evolution, Biodiversité (ISYEB), UMR 7205, Sorbonne Université, Muséum National d'histoire Naturelle, CNRS, EPHE, 7 Quai St-Bernard, F-75252, Paris Cedex 05, France
| | - Jean-Philippe Chambon
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000, Montpellier, France
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Blanchoud S, Rinkevich B, Wilson MJ. Whole-Body Regeneration in the Colonial Tunicate Botrylloides leachii. Results Probl Cell Differ 2018; 65:337-355. [PMID: 30083927 DOI: 10.1007/978-3-319-92486-1_16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The colonial marine invertebrate Botrylloides leachii belongs to the Tunicata subphylum, the closest invertebrate relatives to the vertebrate group and the only known class of chordates that can undergo whole-body regeneration (WBR). This dramatic developmental process allows a minute isolated fragment of B. leachii's vascular system, or a colony excised of all adults, to restore a functional animal in as little as 10 days. In addition to this exceptional regenerative capacity, B. leachii can reproduce both sexually, through a tadpole larval stage, and asexually, through palleal budding. Thus, three alternative developmental strategies lead to the establishment of filter-feeding adults. Consequently, B. leachii is particularly well suited for comparative studies on regeneration and should provide novel insights into regenerative processes in chordates.Here, after a short introduction on regeneration, we overview the biology of B. leachii as well as the current state of knowledge on WBR in this species and in related species of tunicates. Finally, we highlight the possible future directions that research might take in the study of WBR, including thoughts on technological approaches that appear most promising in this context. Overall, we provide a synthesis of the current knowledge on WBR in B. leachii to support research in this chordate species.
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Affiliation(s)
- Simon Blanchoud
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Buki Rinkevich
- Israel Oceanographic and Limnological Research, National Institute of Oceanography, Haifa, Israel
| | - Megan J Wilson
- Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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4
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Matsunobu S, Sasakura Y. Time course for tail regression during metamorphosis of the ascidian Ciona intestinalis. Dev Biol 2015; 405:71-81. [PMID: 26102482 DOI: 10.1016/j.ydbio.2015.06.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/27/2015] [Accepted: 06/15/2015] [Indexed: 12/24/2022]
Abstract
In most ascidians, the tadpole-like swimming larvae dramatically change their body-plans during metamorphosis and develop into sessile adults. The mechanisms of ascidian metamorphosis have been researched and debated for many years. Until now information on the detailed time course of the initiation and completion of each metamorphic event has not been described. One dramatic and important event in ascidian metamorphosis is tail regression, in which ascidian larvae lose their tails to adjust themselves to sessile life. In the present study, we measured the time associated with tail regression in the ascidian Ciona intestinalis. Larvae are thought to acquire competency for each metamorphic event in certain developmental periods. We show that the timing with which the competence for tail regression is acquired is determined by the time since hatching, and this timing is not affected by the timing of post-hatching events such as adhesion. Because larvae need to adhere to substrates with their papillae to induce tail regression, we measured the duration for which larvae need to remain adhered in order to initiate tail regression and the time needed for the tail to regress. Larvae acquire the ability to adhere to substrates before they acquire tail regression competence. We found that when larvae adhered before they acquired tail regression competence, they were able to remember the experience of adhesion until they acquired the ability to undergo tail regression. The time course of the events associated with tail regression provides a valuable reference, upon which the cellular and molecular mechanisms of ascidian metamorphosis can be elucidated.
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Affiliation(s)
- Shohei Matsunobu
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda 415-0025, Shizuoka, Japan.
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda 415-0025, Shizuoka, Japan
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5
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Karaiskou A, Swalla BJ, Sasakura Y, Chambon JP. Metamorphosis in solitary ascidians. Genesis 2014; 53:34-47. [PMID: 25250532 DOI: 10.1002/dvg.22824] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/15/2014] [Accepted: 09/19/2014] [Indexed: 12/19/2022]
Abstract
Embryonic and postembryonic development in ascidians have been studied for over a century, but it is only in the last 10 years that the complex molecular network involved in coordinating postlarval development and metamorphosis has started to emerge. In most ascidians, the transition from the larval to the sessile juvenile/adult stage, or metamorphosis, requires a combination of environmental and endogenous signals and is characterized by coordinated global morphogenetic changes that are initiated by the adhesion of the larvae. Cloney was the first to describe cellular events of ascidians' metamorphosis in 1978 and only recently elements of the molecular regulation of this crucial developmental step have been revealed. This review aims to present a thorough view of this crucial developmental step by combining recent molecular data to the already established cellular events.
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Affiliation(s)
- Anthi Karaiskou
- Sorbonne Universités, UPMC Univ Paris 06, UMR7622-Biologie du Développement, Paris, France
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6
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Ueda N, Degnan SM. Nitric oxide acts as a positive regulator to induce metamorphosis of the ascidian Herdmania momus. PLoS One 2013; 8:e72797. [PMID: 24019877 PMCID: PMC3760835 DOI: 10.1371/journal.pone.0072797] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/12/2013] [Indexed: 12/13/2022] Open
Abstract
Marine invertebrates commonly have a biphasic life cycle in which the metamorphic transition from a pelagic larva to a benthic post-larva is mediated by the nitric oxide signalling pathway. Nitric oxide (NO) is synthesised by nitric oxide synthase (NOS), which is a client protein of the molecular chaperon heat shock protein 90 (HSP90). It is notable, then, that both NO and HSP90 have been implicated in regulating metamorphosis in marine invertebrates as diverse as urochordates, echinoderms, molluscs, annelids, and crustaceans. Specifically, the suppression of NOS activity by the application of either NOS- or HSP90-inhibiting pharmacological agents has been shown consistently to induce the initiation of metamorphosis, leading to the hypothesis that a negative regulatory role of NO is widely conserved in biphasic life cycles. Further, the induction of metamorphosis by heat-shock has been demonstrated for multiple species. Here, we investigate the regulatory role of NO in induction of metamorphosis of the solitary tropical ascidian, Herdmania momus. By coupling pharmacological treatments with analysis of HmNOS and HmHSP90 gene expression, we present compelling evidence of a positive regulatory role for NO in metamorphosis of this species, in contrast to all existing ascidian data that supports the hypothesis of NO as a conserved negative regulator of metamorphosis. The exposure of competent H. momus larvae to a NOS inhibitor or an NO donor results in an up-regulation of NOS and HSP90 genes. Heat shock of competent larvae induces metamorphosis in a temperature dependent manner, up to a thermal tolerance that approaches 35°C. Both larval/post-larval survival and the appearance of abnormal morphologies in H. momus post-larvae reflect the magnitude of up-regulation of the HSP90 gene in response to heat-shock. The demonstrated role of NO as a positive metamorphic regulator in H. momus suggests the existence of inter-specific adaptations of NO regulation in ascidian metamorphosis.
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Affiliation(s)
- Nobuo Ueda
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Sandie M. Degnan
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
- * E-mail:
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7
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Parrinello N, Vizzini A, Salerno G, Sanfratello MA, Cammarata M, Arizza V, Vazzana M, Parrinello D. Inflamed adult pharynx tissues and swimming larva of Ciona intestinalis share CiTNFα-producing cells. Cell Tissue Res 2010; 341:299-311. [DOI: 10.1007/s00441-010-0993-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 05/06/2010] [Indexed: 12/14/2022]
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8
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Caicci F, Zaniolo G, Burighel P, Degasperi V, Gasparini F, Manni L. Differentiation of papillae and rostral sensory neurons in the larva of the ascidian Botryllus schlosseri (Tunicata). J Comp Neurol 2010; 518:547-66. [PMID: 20020541 DOI: 10.1002/cne.22222] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
During the metamorphosis of tunicate ascidians, the swimming larva uses its three anterior papillae to detect the substrate for settlement, reabsorbs its chordate-like tail, and becomes a sessile oozooid. In view of the crucial role played by the anterior structures and their nerve relations, we applied electron microscopy and immunocytochemistry to study the larva of the colonial ascidian Botryllus schlosseri, following differentiation of the anterior epidermis during late embryogenesis, the larval stage, and the onset of metamorphosis. Rudiments of the papillae appear in the early tail-bud stage as ectodermic protrusions, the apexes of which differentiate into central and peripheral bipolar neurons. Axons fasciculate into two nerves direct to the brain. Distally, the long, rod-like dendritic terminations extend during the larval stage, becoming exposed to sea water. After the larva selects and adheres to the substrate, these neurons retract and regress. Adjacent to the papillae, other scattered neurons insinuate dendrites into the tunic and form the net of rostral trunk epidermal neurons (RTENs) which fasciculate together with the papillary neurons. Our data indicate that the papillae are simple and coniform, the papillary neurons are mechanoreceptors, and the RTENs are chemoreceptors. The interpapillary epidermal area, by means of an apocrine secretion, provides sticky material for temporary adhesion of the larva to the substrate.
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Affiliation(s)
- Federico Caicci
- Dipartimento di Biologia, Università degli Studi di Padova, I-35121 Padova, Italy
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9
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Roper KE, Beamish H, Garson MJ, Skilleter GA, Degnan BM. Convergent antifouling activities of structurally distinct bioactive compounds synthesized within two sympatric Haliclona demosponges. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2009; 11:188-198. [PMID: 18690486 DOI: 10.1007/s10126-008-9132-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 05/26/2008] [Accepted: 07/15/2008] [Indexed: 05/26/2023]
Abstract
A wide range of sessile and sedentary marine invertebrates synthesize secondary metabolites that have potential as industrial antifoulants. These antifoulants tend to differ in structure, even between closely related species. Here, we determine if structurally divergent secondary metabolites produced within two sympatric haliclonid demosponges have similar effects on the larvae of a wide range of benthic competitors and potential fouling metazoans (ascidians, molluscs, bryozoans, polychaetes, and sponges). The sponges Haliclona sp. 628 and sp. 1031 synthesize the tetracyclic alkaloid, haliclonacyclamine A (HA), and the long chain alkyl amino alcohol, halaminol A (LA), respectively. Despite structural differences, HA and LA have identical effects on phylogenetically disparate ascidian larvae, inducing rapid larval settlement but preventing subsequent metamorphosis at precisely the same stage. HA and LA also have similar effects on sponge, polychaete, gastropod and bryozoan larvae, inhibiting both settlement and metamorphosis. Despite having identical roles in preventing fouling and colonisation, HA and LA differentially affect the physiology of cultured HeLa human cells, indicating they have different molecular targets. From these data, we infer that the secondary metabolites within marine sponges may emerge by varying evolutionary and biosynthetic trajectories that converge on specific ecological roles.
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Affiliation(s)
- K E Roper
- School of Integrative Biology, University of Queensland, Brisbane, 4072, Queensland, Australia
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10
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Nakayama-Ishimura A, Chambon JP, Horie T, Satoh N, Sasakura Y. Delineating metamorphic pathways in the ascidian Ciona intestinalis. Dev Biol 2009; 326:357-67. [DOI: 10.1016/j.ydbio.2008.11.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 09/10/2008] [Accepted: 11/18/2008] [Indexed: 10/21/2022]
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11
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Abstract
Little is known about the ancient chordates that gave rise to the first vertebrates, but the descendants of other invertebrate chordates extant at the time still flourish in the ocean. These invertebrates include the cephalochordates and tunicates, whose larvae share with vertebrate embryos a common body plan with a central notochord and a dorsal nerve cord. Tunicates are now thought to be the sister group of vertebrates. However, research based on several species of ascidians, a diverse and wide-spread class of tunicates, revealed that the molecular strategies underlying their development appear to diverge greatly from those found in vertebrates. Furthermore, the adult body plan of most tunicates, which arises following an extensive post-larval metamorphosis, shows little resemblance to the body plan of any other chordate. In this review, we compare the developmental strategies of ascidians and vertebrates and argue that the very divergence of these strategies reveals the surprising level of plasticity of the chordate developmental program and is a rich resource to identify core regulatory mechanisms that are evolutionarily conserved in chordates. Further, we propose that the comparative analysis of the architecture of ascidian and vertebrate gene regulatory networks may provide critical insight into the origin of the chordate body plan.
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12
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Fedders H, Leippe M. A reverse search for antimicrobial peptides in Ciona intestinalis: identification of a gene family expressed in hemocytes and evaluation of activity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:286-98. [PMID: 17658598 DOI: 10.1016/j.dci.2007.06.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 06/01/2007] [Accepted: 06/05/2007] [Indexed: 05/16/2023]
Abstract
In search of antimicrobial peptides in the tunicate Ciona intestinalis, we used the recently completed genome project and the substantial number of expressed sequence tag (EST) data available as a screening matrix. By this means, we identified a putative gene family that exhibits several structural features typical of antimicrobial peptides. We designed and synthesized a peptide corresponding to the core region of a member of this peptide family, which is predicted to adopt an amphipathic alpha-helical structure. The synthetic peptide exerted potent antimicrobial activity against a variety of bacteria and against the yeast Candida albicans but was not cytolytic for mammalian erythrocytes. Moreover, by employing a non-cell-permeable fluorescent dye it became evident that the peptide kills bacteria by permeabilizing their cytoplasmic membranes. Using the synthetic peptide as an antigen, we generated specific antibodies and localized the natural parent molecule to a compartment of a distinct hemocyte type, the univacuolar refractile granulocytes. As C. intestinalis apparently does not possess gene products that resemble well-known antimicrobial peptides of tunicates and of other animals, the aforementioned peptide family may represent a potent armamentarium of the hemocytes to combat microbial infection in sea squirts.
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Affiliation(s)
- Henning Fedders
- Department of Zoophysiology, Zoological Institute, University of Kiel, Olshausenstr. 40, 24098 Kiel, Germany
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13
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Rinkevich Y, Douek J, Haber O, Rinkevich B, Reshef R. Urochordate whole body regeneration inaugurates a diverse innate immune signaling profile. Dev Biol 2007; 312:131-46. [PMID: 17964563 DOI: 10.1016/j.ydbio.2007.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 08/28/2007] [Accepted: 09/06/2007] [Indexed: 10/22/2022]
Abstract
The phenomenon of whole body regeneration (WBR) from minute soma fragments is a rare event in chordates, confined to the subfamily of botryllid ascidians and is poorly understood on the cellular and molecular levels. We assembled a list of 1326 ESTs from subtracted mRNA, at early stages of Botrylloides leachi WBR, and classified them into functional categories. Sixty-seven (15%) ESTs with roles in innate immunity signaling were classified into a broad functional group, a result supported by domain search and RT-PCR reactions. Gene ontology analysis for human homologous to the immune gene category, identified 22 significant entries, of which "peptidase activity" and "protease inhibitor activity", stood out as functioning during WBR. Analyzing expressions of serine protease Bl-TrSP, a representative candidate gene from the "peptidase activity" subgroup, revealed low transcript levels in naïve vasculature with upregulated expression during WBR. This was confirmed by in situ hybridization that further elucidated staining restricted to a circulating population of macrophage cells. Furthermore, Bl-TrSP was localized in regeneration niches within vasculature, in regenerating buds, and in buds, during blastogenesis. Functional inhibition of serine protease activity disrupts early remodeling processes of the vasculature microenvironment and hinders WBR. Comparison of genome-wide transcription of WBR with five other developmental processes in ascidians (including metamorphosis, budding and blastogenesis), revealed a broad conservation of immune signaling expressions, suggesting a ubiquitous route of harnessing immune-related genes within a broader range of tunicate developmental context. This, in turn, may have enabled the high diversity of life history traits represented by urochordate ascidians.
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Affiliation(s)
- Yuval Rinkevich
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel.
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14
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Chambon JP, Nakayama A, Takamura K, McDougall A, Satoh N. ERK- and JNK-signalling regulate gene networks that stimulate metamorphosis and apoptosis in tail tissues of ascidian tadpoles. Development 2007; 134:1203-19. [PMID: 17332536 DOI: 10.1242/dev.002220] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In ascidian tadpoles, metamorphosis is triggered by a polarized wave of apoptosis, via mechanisms that are largely unknown. We demonstrate that the MAP kinases ERK and JNK are both required for the wave of apoptosis and metamorphosis. By employing a gene-profiling-based approach, we identified the network of genes controlled by either ERK or JNK activity that stimulate the onset of apoptosis. This approach identified a gene network involved in hormonal signalling, in innate immunity, in cell-cell communication and in the extracellular matrix. Through gene silencing, we show that Ci-sushi, a cell-cell communication protein controlled by JNK activity, is required for the wave of apoptosis that precedes tail regression. These observations lead us to propose a model of metamorphosis whereby JNK activity in the CNS induces apoptosis in several adjacent tissues that compose the tail by inducing the expression of genes such as Ci-sushi.
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Affiliation(s)
- Jean-Philippe Chambon
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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15
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Roberts B, Davidson B, MacMaster G, Lockhart V, Ma E, Wallace SS, Swalla BJ. A complement response may activate metamorphosis in the ascidian Boltenia villosa. Dev Genes Evol 2007; 217:449-58. [PMID: 17497166 DOI: 10.1007/s00427-007-0157-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2007] [Accepted: 04/09/2007] [Indexed: 12/11/2022]
Abstract
Ascidian metamorphosis transforms a free-swimming larval chordate ascidian into a sessile adult through a distinct series of metamorphic events. Initially, larvae must become competent to respond to settlement cues. Settlement is then marked by dramatic body plan remodeling and may be accompanied by attachment to the substrate. Subtractive hybridization has revealed that many innate immunity transcripts are upregulated during metamorphosis in the ascidian Boltenia villosa. Several of these genes have well-known roles in the mannose-binding lectin (MBL)-complement pathway of innate immunity, including MBL and MBL-activated serine protease (MASP). MBL recognizes and binds to bacterial pathogens, activates MASP, and triggers the complement cascade. In B. villosa, larvae upregulate BvMASP at the time of competency to initiate settlement. We show that several bacterial strains can induce settlement and that the timing of BvMASP expression in the papillae-associated tissue (PAT) cells is tightly correlated with larval competency. We further demonstrate that serine protease inhibitors used to block the complement response also block metamorphosis, allowing tail resorption, but preventing further morphological changes. Based on these experiments, we propose that the MBL-complement pathway may be important for competency, bacterial substrate detection and body plan remodeling during metamorphosis.
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Affiliation(s)
- Brock Roberts
- Biology Department and Center for Developmental Biology, 24 Kincaid Hall, University of Washington, P.O. Box 351800, Seattle, WA 98195-1800, USA
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16
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Comes S, Locascio A, Silvestre F, d'Ischia M, Russo GL, Tosti E, Branno M, Palumbo A. Regulatory roles of nitric oxide during larval development and metamorphosis in Ciona intestinalis. Dev Biol 2007; 306:772-84. [PMID: 17499701 DOI: 10.1016/j.ydbio.2007.04.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 04/11/2007] [Accepted: 04/16/2007] [Indexed: 01/30/2023]
Abstract
Metamorphosis in the ascidian Ciona intestinalis is a very complex process which converts a swimming tadpole to an adult. The process involves reorganisation of the body plan and a remarkable regression of the tail, which is controlled by caspase-dependent apoptosis. However, the endogenous signals triggering apoptosis and metamorphosis are little explored. Herein, we report evidence that nitric oxide (NO) regulates tail regression in a dose-dependent manner, acting on caspase-dependent apoptosis. An increase or decrease of NO levels resulted in a delay or acceleration of tail resorption, without affecting subsequent juvenile development. A similar hastening effect was induced by suppression of cGMP-dependent NO signalling. Inhibition of NO production resulted in an increase in caspase-3-like activity with respect to untreated larvae. Detection of endogenously activated caspase-3 and NO revealed the existence of a spatial correlation between the diminution of the NO signal and caspase-3 activation during the last phases of tail regression. Real-time PCR during development, from early larva to early juveniles, showed that during all stages examined, NO synthase (NOS) is always more expressed than arginase and it reaches the maximum value at late larva, the stage immediately preceding tail resorption. The spatial expression pattern of NOS is very dynamic, moving rapidly along the body in very few hours, from the anterior part of the trunk to central nervous system (CNS), tail and new forming juvenile digestive organs. NO detection revealed free diffusion from the production sites to other cellular districts. Overall, the results of this study provide a new important link between NO signalling and apoptosis during metamorphosis in C. intestinalis and hint at novel roles for the NO signalling system in other developmental and metamorphosis-related events preceding and following tail resorption.
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Affiliation(s)
- Stefania Comes
- Biochemistry and Molecular Biology Laboratory, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
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Sasakura Y. Germline transgenesis and insertional mutagenesis in the ascidianCiona intestinalis. Dev Dyn 2007; 236:1758-67. [PMID: 17342755 DOI: 10.1002/dvdy.21111] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Stable transgenesis is a splendid technique that is applicable to the creation of useful marker lines, enhancer/gene traps, and insertional mutagenesis. Recently, transposon-mediated transformation using a Tc1/mariner transposable element Minos has been reported in two ascidians: Ciona intestinalis and C. savignyi. The transposon derived from an insect, Drosophila hydei, has high activity for excision in Ciona embryos and transposition in their genome. As much as 37% of Minos-injected C. intestinalis transmitted transposon insertions to the subsequent generation. Minos-mediated germline transgenesis has also been achieved by means of electroporation method. Minos techniques have been applied to enhancer traps and insertional mutagenesis in Ciona. For those reasons, Minos offers the high potential for use as a powerful tool for future genetic studies. This review specifically addresses recent achievements of transformation techniques in Ciona, as exemplified using the Minos system.
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Affiliation(s)
- Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan.
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Jang WS, Kim CH, Kang MS, Chae HJ, Son SM, Seo SJ, Lee IH. cDNA cloning of halocidin and a new antimicrobial peptide derived from the N-terminus of Ci-META4. Peptides 2005; 26:2360-7. [PMID: 15946769 DOI: 10.1016/j.peptides.2005.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 05/03/2005] [Accepted: 05/03/2005] [Indexed: 11/26/2022]
Abstract
Halocidin is an antimicrobial peptide, which is isolated from hemocytes from the tunicate, Halocynthiaaurantium. In this study, we cloned the full-length cDNA of halocidin from pharyngeal tissue, using a combination of RT-PCR and 5'-RACE-PCR. The observed cDNA structure indicated that halocidin is synthesized as a 10.37 kDa prepropeptide. Based on the cDNA structure and the known amino acid sequence of the mature peptide, it was concluded that the precursor of halocidin contains a 21-residue signal peptide, followed by the 18 residues of the mature peptide, and a 56-residue anionic C-terminal extension, which is removed later on in the process. The signal sequence of halocidin exhibited a high degree of similarity with the corresponding portion of the Ci-META4 protein, which had been previously discovered in the coelomic cells of another tunicate, Cionaintestinalis, and is considered to play a role in metamorphosis. However, in several respects, the cDNA structure of Ci-META4 suggested that it might constitute a precursor for an antimicrobial peptide. Thus, we prepared a synthetic peptide, which was comprised of 19 N-terminal amino acid residues in the predicted mature region of Ci-META4, and tested it with regard to its antimicrobial activity. As a result, we confirmed that the synthetic peptide exhibited potent antimicrobial activity against Gram (+) and (-) bacteria, while evidencing no hemolytic activity toward human erythrocytes.
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Affiliation(s)
- Woong Sik Jang
- Department of Bio-Technology, Hoseo University, Asan City, Chungnam-Do 336-795, South Korea
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Sasakura Y, Nakashima K, Awazu S, Matsuoka T, Nakayama A, Azuma JI, Satoh N. Transposon-mediated insertional mutagenesis revealed the functions of animal cellulose synthase in the ascidian Ciona intestinalis. Proc Natl Acad Sci U S A 2005; 102:15134-9. [PMID: 16214891 PMCID: PMC1257696 DOI: 10.1073/pnas.0503640102] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Indexed: 11/18/2022] Open
Abstract
Tunicates are the only animals that perform cellulose biosynthesis. The tunicate gene for cellulose synthase, Ci-CesA, was likely acquired by horizontal transfer from bacteria and was a key innovation in the evolution of tunicates. Transposon-based mutagenesis in an ascidian, Ciona intestinalis, has generated a mutant, swimming juvenile (sj). Ci-CesA is the gene responsible for the sj mutant, in which a drastic reduction in cellulose was observed in the tunic. Furthermore, during metamorphosis, which in ascidians convert the vertebrate-like larva into a sessile filter feeder, sj showed abnormalities in the order of metamorphic events. In normal larvae, the metamorphic events in the trunk region are initiated after tail resorption. In contrast, sj mutant larvae initiated the metamorphic events in the trunk without tail resorption. Thus, sj larvae show a "swimming juvenile" phenotype, the juvenile-like trunk structure with a complete tail and the ability to swim. It is likely that ascidian cellulose synthase is required for the coordination of the metamorphic events in the trunk and tail in addition to cellulose biosynthesis.
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Affiliation(s)
- Yasunori Sasakura
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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Nakayama A, Satoh N, Sasakura Y. Tissue-Specific Profile of DNA Replication in the Swimming Larvae of Ciona intestinalis. Zoolog Sci 2005; 22:301-9. [PMID: 15795492 DOI: 10.2108/zsj.22.301] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The cell cycle is strictly regulated during development and its regulation is essential for organ formation and developmental timing. Here we observed the pattern of DNA replication in swimming larvae of an ascidian, Ciona intestinalis. Usually, Ciona swimming larvae obtain competence for metamorphosis at about 4-5 h after hatching, and these competent larvae initiate metamorphosis soon after they adhere to substrate with their papillae. In these larvae, three major tissues (epidermis, endoderm and mesenchyme) showed extensive DNA replication with distinct pattern and timing, suggesting tissue-specific cell cycle regulation. However, DNA replication did not continue in aged larvae which kept swimming for several days, suggesting that the cell cycle is arrested in these larvae at a certain time to prevent further growth of adult organ rudiments until the initiation of metamorphosis. Inhibition of the cell cycle by aphidicolin during the larval stage affects only the speed of metamorphosis, and not the formation of adult organ rudiments or the timing of the initiation of metamorphosis. However, after the completion of tail resorption, DNA replication is necessary for further metamorphic events. Our data showed that DNA synthesis in the larval trunk is not directly associated with the organization of adult organs, but it contributes to the speed of metamorphosis after settlement.
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Affiliation(s)
- Akie Nakayama
- Department of Zoology, Graduate School of Science, Kyoto University, Japan
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Woods RG, Roper KE, Gauthier M, Bebell LM, Sung K, Degnan BM, Lavin MF. Gene expression during early ascidian metamorphosis requires signalling by Hemps, an EGF-like protein. Development 2004; 131:2921-33. [PMID: 15169757 DOI: 10.1242/dev.01120] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hemps, a novel epidermal growth factor (EGF)-like protein, is expressed during larval development and early metamorphosis in the ascidian Herdmania curvata and plays a direct role in triggering metamorphosis. In order to identify downstream genes in the Hemps pathway we used a gene expression profiling approach, in which we compared post-larvae undergoing normal metamorphosis with larval metamorphosis blocked with an anti-Hemps antibody. Molecular profiling revealed that there are dynamic changes in gene expression within the first 30 minutes of normal metamorphosis with a significant portion of the genome (approximately 49%) being activated or repressed. A more detailed analysis of the expression of 15 of these differentially expressed genes through embryogenesis, larval development and metamorphosis revealed that while there is a diversity of temporal expression patterns, a number of genes are transiently expressed during larval development and metamorphosis. These and other differentially expressed genes were localised to a range of specific cell and tissue types in Herdmania larvae and post-larvae. The expression of approximately 24%of the genes that were differentially expressed during early metamorphosis was affected in larvae treated with the anti-Hemps antibody. Knockdown of Hemps activity affected the expression of a range of genes within 30 minutes of induction, suggesting that the Hemps pathway directly regulates early response genes at metamorphosis. In most cases, it appears that the Hemps pathway contributes to the modulation of gene expression, rather than initial gene activation or repression. A total of 151 genes that displayed the greatest alterations in expression in response to anti-Hemps antibody were sequenced. These genes were implicated in a range of developmental and physiological roles, including innate immunity, signal transduction and in the regulation of gene transcription. These results suggest that there is significant gene activity during the very early stages of H. curvata metamorphosis and that the Hemps pathway plays a key role in regulating the expression of many of these genes.
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Affiliation(s)
- Rick G Woods
- The Queensland Institute of Medical Research, PO Royal Brisbane Hospital, Herston, Brisbane 4029, Australia.
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Satou Y, Kawashima T, Kohara Y, Satoh N. Large scale EST analyses in Ciona intestinalis: its application as Northern blot analyses. Dev Genes Evol 2003; 213:314-8. [PMID: 12736826 DOI: 10.1007/s00427-003-0327-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2003] [Accepted: 03/25/2003] [Indexed: 11/28/2022]
Abstract
We have conducted large-scale EST analyses of transcripts expressed in the basal chordate Ciona intestinalis. The cDNA libraries examined were from fertilized eggs, cleaving embryos, gastrulae/neurulae, tailbud embryos, larvae and whole young adults, and the gonad (ovary and testis), endostyle, neural complex, heart, and blood cells of the adult. Because the libraries were not normalized or amplified, the occurrence of cDNA clones or EST counts in each library may reflect the quantity of transcripts of the corresponding genes. Thus, comparison of the EST counts of a certain gene at the six developmental stages may reflect the temporal expression pattern of the gene, while the comparison of EST counts in different tissues of the adult may reflect the spatial expression pattern of the gene. Here we present evidence that this is the case, and that the EST count can therefore be used like "Northern blot analysis" of Ciona genes.
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Affiliation(s)
- Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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