1
|
Pan X, Fang C, Shen C, Li X, Xie L, Li L, Huang S, Yan X, Zhu X. Directional ciliary beats across epithelia require Ccdc57-mediated coupling between axonemal orientation and basal body polarity. Nat Commun 2024; 15:10249. [PMID: 39592607 PMCID: PMC11599927 DOI: 10.1038/s41467-024-54766-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/19/2024] [Indexed: 11/28/2024] Open
Abstract
Motile cilia unify their axonemal orientations (AOs), or beat directions, across epithelia to drive liquid flows. This planar polarity results from cytoskeleton-driven swiveling of basal foot (BF), a basal body (BB) appendage coincident with the AO, in response to regulatory cues. How and when the BF-AO relationship is established, however, are unaddressed. Here, we show that the BF-AO coupling occurs during rotational polarizations of BBs and requires Ccdc57. Ccdc57 localizes on BBs as a rotationally-asymmetric punctum, which polarizes away from the BF in BBs having achieved the rotational polarity to probably fix the BF-AO relationship. Consistently, Ccdc57-deficient ependymal multicilia lack the BF-AO coupling and display directional beats at only single cell level. Ccdc57 -/- tracheal multicilia also fail to fully align their BFs. Furthermore, Ccdc57 -/- mice manifest severe hydrocephalus, due to impaired cerebrospinal fluid flow, and high mortality. These findings unravel mechanisms governing the planar polarity of epithelial motile cilia.
Collapse
Affiliation(s)
- Xinwen Pan
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Chuyu Fang
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chuan Shen
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xixia Li
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Lele Xie
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Luan Li
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shan Huang
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiumin Yan
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Institute of Early Life Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Xueliang Zhu
- Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
| |
Collapse
|
2
|
Sakurai H, Shiba K, Takamura K, Inaba K. Immunohistochemical Characterization of Spermatogenesis in the Ascidian Ciona robusta. Cells 2024; 13:1863. [PMID: 39594612 PMCID: PMC11592721 DOI: 10.3390/cells13221863] [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] [Received: 10/18/2024] [Revised: 11/04/2024] [Accepted: 11/07/2024] [Indexed: 11/28/2024] Open
Abstract
Animals show diverse processes of gametogenesis in the evolutionary pathway. Here, we characterized the spermatogenic cells in the testis of the marine invertebrate Ciona robusta. Ciona sperm differentiate in a non-cystic type of testis, comprising many follicles with various sizes and stages of spermatogenic cells. In the space among follicles, we observed free cells that were recognized by antibody against Müllerian inhibiting substance, a marker for vertebrate Sertoli cells. We further categorized the spermatogenic cells into four round stages (RI to RIV) and three elongated stages (EI to EIII) by morphological and immunohistochemical criteria. An antibody against a vertebrate Vasa homolog recognized a few large spermatogonium-like cells (RI) near the basal wall of a follicle. Consistent with the period of meiosis, a synaptonemal complex protein SYCP3 was recognized from early spermatocytes (RII) to early spermatids (E1). Acetylated tubulins were detected in spermatids before flagellar elongation at the RIV stage and became distributed along the flagella. Electron microscopy showed that the free cells outside the testicular follicle possessed a characteristic of vertebrate Sertoli cells. These results would provide a basis for basic and comparative studies on the mechanism of spermatogenesis.
Collapse
Affiliation(s)
- Haruka Sakurai
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda 415-0025, Shizuoka, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda 415-0025, Shizuoka, Japan
| | - Katsumi Takamura
- Faculty of Life Science and Biotechnology, Fukuyama University, Fukuyama 729-0292, Hiroshima, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda 415-0025, Shizuoka, Japan
| |
Collapse
|
3
|
Todorov LG, Oonuma K, Kusakabe TG, Levine MS, Lemaire LA. Neural crest lineage in the protovertebrate model Ciona. Nature 2024; 635:912-916. [PMID: 39443803 DOI: 10.1038/s41586-024-08111-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 09/25/2024] [Indexed: 10/25/2024]
Abstract
Neural crest cells are multipotent progenitors that produce defining features of vertebrates such as the 'new head'1. Here we use the tunicate, Ciona, to explore the evolutionary origins of neural crest since this invertebrate chordate is among the closest living relatives of vertebrates2-4. Previous studies identified two potential neural crest cell types in Ciona, sensory pigment cells and bipolar tail neurons5,6. Recent findings suggest that bipolar tail neurons are homologous to cranial sensory ganglia rather than derivatives of neural crest7,8. Here we show that the pigment cell lineage also produces neural progenitor cells that form regions of the juvenile nervous system following metamorphosis. Neural progenitors are also a major derivative of neural crest in vertebrates, suggesting that the last common ancestor of tunicates and vertebrates contained a multipotent progenitor population at the neural plate border. It would therefore appear that a key property of neural crest, multipotentiality, preceded the emergence of vertebrates.
Collapse
Affiliation(s)
- Lauren G Todorov
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Kouhei Oonuma
- Department of Biology, Faculty of Science and Engineering and Institute for Integrative Neurobiology, Konan University, Kobe, Japan
- Frontier Research Institute, Chubu University, Kasugai, Japan
| | - Takehiro G Kusakabe
- Department of Biology, Faculty of Science and Engineering and Institute for Integrative Neurobiology, Konan University, Kobe, Japan.
| | - Michael S Levine
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
| | - Laurence A Lemaire
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
- Department of Biology, Saint Louis University, St. Louis, MO, USA.
| |
Collapse
|
4
|
Anselmi C, Fuller GK, Stolfi A, Groves AK, Manni L. Sensory cells in tunicates: insights into mechanoreceptor evolution. Front Cell Dev Biol 2024; 12:1359207. [PMID: 38550380 PMCID: PMC10973136 DOI: 10.3389/fcell.2024.1359207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Tunicates, the sister group of vertebrates, offer a unique perspective for evolutionary developmental studies (Evo-Devo) due to their simple anatomical organization. Moreover, the separation of tunicates from vertebrates predated the vertebrate-specific genome duplications. As adults, they include both sessile and pelagic species, with very limited mobility requirements related mainly to water filtration. In sessile species, larvae exhibit simple swimming behaviors that are required for the selection of a suitable substrate on which to metamorphose. Despite their apparent simplicity, tunicates display a variety of mechanoreceptor structures involving both primary and secondary sensory cells (i.e., coronal sensory cells). This review encapsulates two decades of research on tunicate mechanoreception focusing on the coronal organ's sensory cells as prime candidates for understanding the evolution of vertebrate hair cells of the inner ear and the lateral line organ. The review spans anatomical, cellular and molecular levels emphasizing both similarity and differences between tunicate and vertebrate mechanoreception strategies. The evolutionary significance of mechanoreception is discussed within the broader context of Evo-Devo studies, shedding light on the intricate pathways that have shaped the sensory system in chordates.
Collapse
Affiliation(s)
- Chiara Anselmi
- Hopkins Marine Station, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Pacific Grove, CA, United States
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
| | - Gwynna K. Fuller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| |
Collapse
|
5
|
Fritzsch B, Glover JC. Gene networks and the evolution of olfactory organs, eyes, hair cells and motoneurons: a view encompassing lancelets, tunicates and vertebrates. Front Cell Dev Biol 2024; 12:1340157. [PMID: 38533086 PMCID: PMC10963430 DOI: 10.3389/fcell.2024.1340157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/26/2024] [Indexed: 03/28/2024] Open
Abstract
Key developmental pathways and gene networks underlie the formation of sensory cell types and structures involved in chemosensation, vision and mechanosensation, and of the efferents these sensory inputs can activate. We describe similarities and differences in these pathways and gene networks in selected species of the three main chordate groups, lancelets, tunicates, and vertebrates, leading to divergent development of olfactory receptors, eyes, hair cells and motoneurons. The lack of appropriately posited expression of certain transcription factors in lancelets and tunicates prevents them from developing vertebrate-like olfactory receptors and eyes, although they generate alternative structures for chemosensation and vision. Lancelets and tunicates lack mechanosensory cells associated with the sensation of acoustic stimuli, but have gravisensitive organs and ciliated epidermal sensory cells that may (and in some cases clearly do) provide mechanosensation and thus the capacity to respond to movement relative to surrounding water. Although functionally analogous to the vertebrate vestibular apparatus and lateral line, homology is questionable due to differences in the expression of the key transcription factors Neurog and Atoh1/7, on which development of vertebrate hair cells depends. The vertebrate hair cell-bearing inner ear and lateral line thus likely represent major evolutionary advances specific to vertebrates. Motoneurons develop in vertebrates under the control of the ventral signaling molecule hedgehog/sonic hedgehog (Hh,Shh), against an opposing inhibitory effect mediated by dorsal signaling molecules. Many elements of Shh-signaling and downstream genes involved in specifying and differentiating motoneurons are also exhibited by lancelets and tunicates, but the repertoire of MNs in vertebrates is broader, indicating greater diversity in motoneuron differentiation programs.
Collapse
Affiliation(s)
- Bernd Fritzsch
- Department of Biological Sciences, University of Nebraska Medical Center, Omaha, NE, United States
| | - Joel C. Glover
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
- Laboratory of Neural Development and Optical Recording (NDEVOR), Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
6
|
Holland ND, Mansfield JH. In Amphioxus Embryos, Some Neural Tube Cells Resemble Differentiating Coronet Cells of Fishes and Tunicates. THE BIOLOGICAL BULLETIN 2023; 244:1-8. [PMID: 37167617 DOI: 10.1086/724581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
AbstractFor neurula embryos of amphioxus (chordate subphylum Cephalochordata), the anterior region of the neural tube was studied with transmission electron microscopy. This survey demonstrated previously unreported cells, each characterized by a cilium bearing on its shaft a protruding lateral bubble packed with vesicles. Such cilia resemble those known from immature coronet cells in other chordates-namely, fishes in the Vertebrata and ascidians and appendicularians in the Tunicata. This wide occurrence of coronet-like cells raises questions about their possible homologies within the phylum Chordata. When considered at the level of the whole cell, such homology is not well supported. For example, the fish cells are generally thought to be glia, while the tunicate cells are considered to be neurons; moreover, cytoplasmic smooth endoplasmic reticulum, which is predominant in the former, is undetectable in the latter. In contrast, a more convincing case for homology can be made by limiting comparisons to the cell apices with their modified cilia. In addition to the fine-structural similarities between fishes and tunicates already mentioned, nonvisual opsins have been found associated with the vesicles in the modified cilia of both groups. Such opsins are thought to link photoreception to endocrine output controlling behavior. Further work would be needed to test the idea that the amphioxus diencephalic cells with lateral bubble cilia might similarly be opsin rich and could provide insights into the evolutionary history of the coronet cells within the phylum Chordata.
Collapse
|
7
|
Sakamoto A, Hozumi A, Shiraishi A, Satake H, Horie T, Sasakura Y. The
TRP
channel
PKD2
is involved in sensing the mechanical stimulus of adhesion for initiating metamorphosis in the chordate
Ciona. Dev Growth Differ 2022; 64:395-408. [DOI: 10.1111/dgd.12801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/07/2022] [Accepted: 07/10/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Aya Sakamoto
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Akiko Hozumi
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Akira Shiraishi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences Kyoto Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences Kyoto Japan
| | - Takeo Horie
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| |
Collapse
|
8
|
Shibata D, Morita M, Sato Y, Shiba K, Kitanobo S, Yokoya R, Inaba K. Axonemal Growth and Alignment During Paraspermatogenesis in the Marine Gastropod Strombus luhuanus. Front Cell Dev Biol 2022; 10:905748. [PMID: 35832793 PMCID: PMC9271582 DOI: 10.3389/fcell.2022.905748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/03/2022] [Indexed: 11/13/2022] Open
Abstract
Parasperm are non-fertilizing sperm that are produced simultaneously with fertile eusperm. They occur in several animal species and show considerable morphological diversity. We investigated the dynamics of axonemes during paraspermatogenesis in the marine snail S. luhuanus. Mature parasperm were characterized by two lateral undulating membranes for motility and many globular vesicles. Axonemes were first observed as brush-like structures that extruded from the anterior region. Multiple axonemes longer than the brush then started to extend inside the cytoplasm towards the posterior region. The mass of the axonemes separated into two lateral rows and formed an undulating membrane that drives bidirectional swimming in the mature parasperm. The central pair of axonemes was aligned in the undulating membrane, resulting in cooperative bend propagation. During paraspermatogenesis, centrioles were largely diminished and localized to the anterior region. CEP290, a major component of the transition zone, showed a broad distribution in the anterior area. Axonemes in the posterior region showed a 9 + 0 structure with both outer and inner arm dyneins. These observations provide a structural basis for understanding the physiological functions of parasperm in marine reproductive strategies.
Collapse
Affiliation(s)
- Daisuke Shibata
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Masaya Morita
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan
| | - Yu Sato
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Seiya Kitanobo
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Ryo Yokoya
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
- *Correspondence: Kazuo Inaba,
| |
Collapse
|
9
|
Fritzsch B, Martin PR. Vision and retina evolution: how to develop a retina. IBRO Neurosci Rep 2022; 12:240-248. [PMID: 35449767 PMCID: PMC9018162 DOI: 10.1016/j.ibneur.2022.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/30/2022] [Indexed: 12/29/2022] Open
Abstract
Early in vertebrate evolution, a single homeobox (Hox) cluster in basal chordates was quadrupled to generate the Hox gene clusters present in extant vertebrates. Here we ask how this expanded gene pool may have influenced the evolution of the visual system. We suggest that a single neurosensory cell type split into ciliated sensory cells (photoreceptors, which transduce light) and retinal ganglion cells (RGC, which project to the brain). In vertebrates, development of photoreceptors is regulated by the basic helix-loop-helix (bHLH) transcription factor Neurod1 whereas RGC development depends on Atoh7 and related bHLH genes. Lancelet (a basal chordate) does not express Neurod or Atoh7 and possesses a few neurosensory cells with cilia that reach out of the opening of the neural tube. Sea-squirts (Ascidians) do not express Neurod and express a different bHLH gene, Atoh8, that is likely expressed in the anterior vesicle. Recent data indicate the neurosensory cells in lancelets may correspond to three distinct eye fields in ascidians, which in turn may be the basis of the vertebrate retina, pineal and parapineal. In this review we contrast the genetic control of visual structure development in these chordates with that of basal vertebrates such as lampreys and hagfish, and jawed vertebrates. We propose an evolutionary sequence linking whole-genome duplications, initially to a split between photoreceptor and projection neurons (RGC) and subsequently between pineal and lateral eye structures.
Collapse
|
10
|
Oonuma K, Kusakabe TG. The complete cell lineage and MAPK- and Otx-dependent specification of the dopaminergic cells in the Ciona brain. Development 2021; 148:269114. [PMID: 34121117 DOI: 10.1242/dev.198754] [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: 11/17/2020] [Accepted: 05/17/2021] [Indexed: 11/20/2022]
Abstract
The Ciona larva has served as a unique model for understanding the development of dopaminergic cells at single-cell resolution owing to the exceptionally small number of neurons in its brain and its fixed cell lineage during embryogenesis. A recent study suggested that the transcription factors Fer2 and Meis directly regulate the dopamine synthesis genes in Ciona, but the dopaminergic cell lineage and the gene regulatory networks that control the development of dopaminergic cells have not been fully elucidated. Here, we reveal that the dopaminergic cells in Ciona are derived from a bilateral pair of cells called a9.37 cells at the center of the neural plate. The a9.37 cells divide along the anterior-posterior axis, and all of the descendants of the posterior daughter cells differentiate into the dopaminergic cells. We show that the MAPK pathway and the transcription factor Otx are required for the expression of Fer2 in the dopaminergic cell lineage. Our findings establish the cellular and molecular framework for fully understanding the commitment to dopaminergic cells in the simple chordate brain.
Collapse
Affiliation(s)
- Kouhei Oonuma
- Institute for Integrative Neurobiology and Department of Biology, Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
| | - Takehiro G Kusakabe
- Institute for Integrative Neurobiology and Department of Biology, Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
| |
Collapse
|
11
|
Shih Y, Wang K, Kumano G, Nishida H. Expression and Functional Analyses of Ectodermal Transcription Factors FoxJ-r, SoxF, and SP8/9 in Early Embryos of the Ascidian Halocynthia roretzi. Zoolog Sci 2021; 38:26-35. [PMID: 33639715 DOI: 10.2108/zs200128] [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: 08/11/2020] [Accepted: 09/06/2020] [Indexed: 11/17/2022]
Abstract
The spatiotemporal expression of zygotic genes is regulated by transcription factors, which mediate cell fate decision and morphogenesis. Investigation of the expression patterns and their transcriptional regulatory relationships is crucial to understand embryonic development. Staged RNA-seq of the ascidian Halocynthia roretzi has previously shown that nine genes encoding transcription factors are transiently expressed at the blastula stage, which is the stage at which cell fates are specified and differentiation starts. Six of these transcription factors have already been found to play important roles during early development. However, the functions of the other transcription factors (FoxJ-r, SoxF, and SP8/9) remain unknown. The study of the spatial and temporal expression patterns showed that all three genes were expressed in the animal hemisphere as early as the 16-cell stage. This is likely due to transcription factor genes that are expressed in the vegetal hemisphere, which have been extensively and comprehensively analyzed in previous studies of ascidians. Functional analyses using FoxJ-r morphants showed that they resulted in the disruption of laterality and the absence of epidermal mono-cilia, suggesting FoxJ-r functions in cilia formation and, consequently, in the generation of left-right asymmetry, as observed in vertebrates. SoxF knockdown resulted in incomplete epiboly by the ectoderm during gastrulation, while SP8/9 knockdown showed no phenotype until the tailbud stage in the present study, although it was expressed during blastula stages. Our results indicate that transcription factor genes expressed at the cleavage stages play roles in diverse functions, and are not limited to cell fate specification.
Collapse
Affiliation(s)
- Yu Shih
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan,
| | - Kai Wang
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Gaku Kumano
- Research Center for Marine Biology, Graduate School of Life Sciences, Tohoku University, Aomori 039-3501, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| |
Collapse
|
12
|
Wakai MK, Nakamura MJ, Sawai S, Hotta K, Oka K. Two-Round Ca 2+ transient in papillae by mechanical stimulation induces metamorphosis in the ascidian Ciona intestinalis type A. Proc Biol Sci 2021; 288:20203207. [PMID: 33593191 DOI: 10.1098/rspb.2020.3207] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Marine invertebrate larvae are known to begin metamorphosis in response to environmentally derived cues. However, little is known about the relationships between the perception of such cues and internal signalling for metamorphosis. To elucidate the mechanism underlying the initiation of metamorphosis in the ascidian, Ciona intestinalis type A (Ciona robusta), we artificially induced ascidian metamorphosis and investigated Ca2+ dynamics from pre- to post-metamorphosis. Ca2+ transients were observed and consisted of two temporally distinct phases with different durations before tail regression which is the early event of metamorphosis. In the first phase, Phase I, the Ca2+ transient in the papillae (adhesive organ of the anterior trunk) was coupled with the Ca2+ transient in dorsally localized cells and endoderm cells just after mechanical stimulation. The Ca2+ transients in Phase I were also observed when applying only short stimulation. In the second phase, Phase II, the Ca2+ transient in papillae was observed again and lasted for approximately 5-11 min just after the Ca2+ transient in Phase I continued for a few minutes. The impaired papillae by Foxg-knockdown failed to induce the second Ca2+ transient in Phase II and tail regression. In Phase II, a wave-like Ca2+ propagation was also observed across the entire epidermis. Our results indicate that the papillae sense a mechanical cue and two-round Ca2+ transients in papillae transmits the internal metamorphic signals to different tissues, which subsequently induces tail regression. Our study will help elucidate the internal mechanism of metamorphosis in marine invertebrate larvae in response to environmental cues.
Collapse
Affiliation(s)
- Maiki K Wakai
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Mitsuru J Nakamura
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
| | - Satoshi Sawai
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
| | - Kohji Hotta
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Kotaro Oka
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan.,Waseda Research Institute for Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan
| |
Collapse
|
13
|
Konno A, Inaba K. Region-Specific Loss of Two-Headed Ciliary Dyneins in Ascidian Endostyle. Zoolog Sci 2020; 37:512-518. [DOI: 10.2108/zs200095] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/09/2020] [Indexed: 11/17/2022]
Affiliation(s)
- Alu Konno
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415-0025, Japan
| |
Collapse
|
14
|
The ventral peptidergic system of the adult ascidian Ciona robusta (Ciona intestinalis Type A) insights from a transgenic animal model. Sci Rep 2020; 10:1892. [PMID: 32024913 PMCID: PMC7002689 DOI: 10.1038/s41598-020-58884-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/14/2020] [Indexed: 12/12/2022] Open
Abstract
Ascidians are the sister group of vertebrates and occupy a critical position in explorations of the evolution of the endocrine and nervous systems of chordates. Here, we describe the complete ventral peptidergic system in adult transgenic Ciona robusta (Ciona intestinalis Type A) which expresses the Kaede reporter gene driven by the prohormone convertase 2 (PC2) gene promoter. Numerous PC2 promoter-driven fluorescent (Kaede-positive) non-neural cells were distributed in the blood sinus located at the anterior end of the pharynx, suggesting the acquisition of a peptidergic circulatory system in Ciona. Kaede-positive ciliated columnar cells, rounded cells, and tall ciliated cells were observed in the alimentary organs, including the endostyle, pharynx, esophagus, stomach, and intestine, suggesting that digestive functions are regulated by multiple peptidergic systems. In the heart, Kaede-positive neurons were located in the ring-shaped plexus at both ends of the myocardium. Nerve fiber-like tracts ran along the raphe and appeared to be connected with the plexuses. Such unique structures suggest a role for the peptidergic system in cardiac function. Collectively, the present anatomic analysis revealed the major framework of the ventral peptidergic system of adult Ciona, which could facilitate investigations of peptidergic regulation of the pharynx, endostyle, alimentary tissues, and heart.
Collapse
|
15
|
Gomes IDL, Gazo I, Nabi D, Besnardeau L, Hebras C, McDougall A, Dumollard R. Bisphenols disrupt differentiation of the pigmented cells during larval brain formation in the ascidian. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 216:105314. [PMID: 31561137 DOI: 10.1016/j.aquatox.2019.105314] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/12/2019] [Accepted: 09/18/2019] [Indexed: 06/10/2023]
Abstract
The endocrine disruptor Bisphenol A (BPA), a widely employed molecule in plastics, has been shown to affect several biological processes in vertebrates, mostly via binding to nuclear receptors. Neurodevelopmental effects of BPA have been documented in vertebrates and linked to neurodevelopmental disorders, probably because some nuclear receptors are present in the vertebrate brain. Similarly, endocrine disruptors have been shown to affect neurodevelopment in marine invertebrates such as ascidians, mollusks or echinoderms, but whether invertebrate nuclear receptors are involved in the mode-of-action is largely unknown. In this study, we assessed the effect of BPA on larval brain development of the ascidian Phallusia mammillata. We found that BPA is toxic to P. mammillata embryos in a dose-dependent manner (EC50: 11.8μM; LC50: 21μM). Furthermore, micromolar doses of BPA impaired differentiation of the ascidian pigmented cells, by inhibiting otolith movement within the sensory vesicle. We further show that this phenotype is specific to other two bisphenols (BPE and BPF) over a bisphenyl (2,2 DPP). Because in vertebrates the estrogen-related receptor gamma (ERRγ) can bind bisphenols with high affinity but not bisphenyls, we tested whether the ascidian ERR participates in the neurodevelopmental phenotype induced by BPA. Interestingly, P. mammillata ERR is expressed in the larval brain, adjacent to the differentiating otolith. Furthermore, antagonists of vertebrate ERRs also inhibited the otolith movement but not pigmentation. Together our observations suggest that BPA may affect ascidian otolith differentiation by altering Pm-ERR activity whereas otolith pigmentation defects might be due to the known inhibitory effect of bisphenols on tyrosinase enzymatic activity.
Collapse
Affiliation(s)
- Isa D L Gomes
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France.
| | - Ievgeniia Gazo
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France; University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, Research Institute of Fish Culture and Hydrobiology, Laboratory of Molecular, Cellular and Quantitative Genetics, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Dalileh Nabi
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France
| | - Lydia Besnardeau
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France
| | - Céline Hebras
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France
| | - Alex McDougall
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France
| | - Rémi Dumollard
- Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV) UMR7009, Sorbonne Universités, Université Pierre-et-Marie-Curie, CNRS, Institut de la Mer de Villefranche (IMEV), Villefranche-sur-mer, France.
| |
Collapse
|
16
|
Ryan K, Meinertzhagen IA. Neuronal identity: the neuron types of a simple chordate sibling, the tadpole larva of Ciona intestinalis. Curr Opin Neurobiol 2019; 56:47-60. [PMID: 30530111 PMCID: PMC6551260 DOI: 10.1016/j.conb.2018.10.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022]
Abstract
Neurons of the sparsely populated nervous system of the tadpole larva in the tunicate Ciona intestinalis, a chordate sibling, are known from sporadic previous studies but especially two recent reports that document the connectome of both the central and peripheral nervous systems at EM level. About 330 CNS cells comprise mostly ciliated ependymal cells, with ∼180 neurons that constitute about 50 morphologically distinguishable types. The neurons reveal various chordate characters amid many features that are idiosyncratic. Most neurons are ciliated and lack dendrites, some even lack an axon. Synapses mostly form en passant between axons, and resemble those in basal invertebrates; some are dyads and all have heterogenous synaptic vesicle populations. Each neuron has on average 49 synapses with other cells; these constitute a synaptic network of unpredicted complexity.
Collapse
Affiliation(s)
- Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
| |
Collapse
|
17
|
Nomura M, Atsuji K, Hirose K, Shiba K, Yanase R, Nakayama T, Ishida KI, Inaba K. Microtubule stabilizer reveals requirement of Ca 2+-dependent conformational changes of microtubules for rapid coiling of haptonema in haptophyte algae. Biol Open 2019; 8:bio.036590. [PMID: 30700402 PMCID: PMC6398456 DOI: 10.1242/bio.036590] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
A haptonema is an elongated microtubule-based motile organelle uniquely present in haptophytes. The most notable and rapid movement of a haptonema is ‘coiling’, which occurs within a few milliseconds following mechanical stimulation in an unknown motor-independent mechanism. Here, we analyzed the coiling process in detail by high-speed filming and showed that haptonema coiling was initiated by left-handed twisting of the haptonema, followed by writhing to form a helix from the distal tip. On recovery from a mechanical stimulus, the helix slowly uncoiled from the proximal region. Electron microscopy showed that the seven microtubules in a haptonema were arranged mostly in parallel but that one of the microtubules often wound around the others in the extended state. A microtubule stabilizer, paclitaxel, inhibited coiling and induced right-handed twisting of the haptonema in the absence of Ca2+, suggesting changes in the mechanical properties of microtubules. Addition of Ca2+ resulted in the conversion of haptonematal twist into the planar bends near the proximal region. These results indicate that switching microtubule conformation, possibly with the aid of Ca2+-binding microtubule-associated proteins is responsible for rapid haptonematal coiling. Summary: Microscopy observations and pharmacological experiments revealed that the rapid coiling of a non-motor microtubule-based motile organelle, the haptonema, is explained by conformational changes of microtubules, including twisting and writhing.
Collapse
Affiliation(s)
- Mami Nomura
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Kohei Atsuji
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Keiko Hirose
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Ryuji Yanase
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| | - Takeshi Nakayama
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
| | - Ken-Ichiro Ishida
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
| |
Collapse
|
18
|
Ryan K, Lu Z, Meinertzhagen IA. The peripheral nervous system of the ascidian tadpole larva: Types of neurons and their synaptic networks. J Comp Neurol 2017; 526:583-608. [PMID: 29124768 DOI: 10.1002/cne.24353] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 01/01/2023]
Abstract
Physical and chemical cues from the environment are used to direct animal behavior through a complex network of connections originating in exteroceptors. In chordates, mechanosensory and chemosensory neurons of the peripheral nervous system (PNS) must signal to the motor circuits of the central nervous system (CNS) through a series of pathways that integrate and regulate the output to motor neurons (MN); ultimately these drive contraction of the tail and limb muscles. We used serial-section electron microscopy to reconstruct PNS neurons and their hitherto unknown synaptic networks in the tadpole larva of a sibling chordate, the ascidian, Ciona intestinalis. The larva has groups of neurons in its apical papillae, epidermal neurons in the rostral and apical trunk, caudal neurons in the dorsal and ventral epidermis, and a single tail tip neuron. The connectome reveals that the PNS input arises from scattered groups of these epidermal neurons, 54 in total, and has three main centers of integration in the CNS: in the anterior brain vesicle (which additionally receives input from photoreceptors of the ocellus), the motor ganglion (which contains five pairs of MN), and the tail, all of which in turn are themselves interconnected through important functional relay neurons. Some neurons have long collaterals that form autapses. Our study reveals interconnections with other sensory systems, and the exact inputs to the motor system required to regulate contractions in the tail that underlie larval swimming, or to the CNS to regulate substrate preference prior to the induction of larval settlement and metamorphosis.
Collapse
Affiliation(s)
- Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Zhiyuan Lu
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
19
|
The central nervous system of ascidian larvae. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:538-61. [DOI: 10.1002/wdev.239] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/05/2016] [Accepted: 04/09/2016] [Indexed: 11/07/2022]
|
20
|
Wang X, Liu B, Liu F, Huan P. A calaxin Gene in the Pacific Oyster Crassostrea gigas and Its Potential Roles in Cilia. Zoolog Sci 2015; 32:419-26. [DOI: 10.2108/zs150009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Xiaofei Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academyof Sciences, Qingdao, China
| | - Baozhong Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academyof Sciences, Qingdao, China
| | | | - Pin Huan
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academyof Sciences, Qingdao, China
| |
Collapse
|
21
|
The pre-vertebrate origins of neurogenic placodes. Nature 2015; 524:462-5. [PMID: 26258298 DOI: 10.1038/nature14657] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 06/09/2015] [Indexed: 11/09/2022]
Abstract
The sudden appearance of the neural crest and neurogenic placodes in early branching vertebrates has puzzled biologists for over a century. These embryonic tissues contribute to the development of the cranium and associated sensory organs, which were crucial for the evolution of the vertebrate "new head". A previous study suggests that rudimentary neural crest cells existed in ancestral chordates. However, the evolutionary origins of neurogenic placodes have remained obscure owing to a paucity of embryonic data from tunicates, the closest living relatives to those early vertebrates. Here we show that the tunicate Ciona intestinalis exhibits a proto-placodal ectoderm (PPE) that requires inhibition of bone morphogenetic protein (BMP) and expresses the key regulatory determinant Six1/2 and its co-factor Eya, a developmental process conserved across vertebrates. The Ciona PPE is shown to produce ciliated neurons that express genes for gonadotropin-releasing hormone (GnRH), a G-protein-coupled receptor for relaxin-3 (RXFP3) and a functional cyclic nucleotide-gated channel (CNGA), which suggests dual chemosensory and neurosecretory activities. These observations provide evidence that Ciona has a neurogenic proto-placode, which forms neurons that appear to be related to those derived from the olfactory placode and hypothalamic neurons of vertebrates. We discuss the possibility that the PPE-derived GnRH neurons of Ciona resemble an ancestral cell type, a progenitor to the complex neuronal circuit that integrates sensory information and neuroendocrine functions in vertebrates.
Collapse
|
22
|
Konno A, Shiba K, Cai C, Inaba K. Branchial cilia and sperm flagella recruit distinct axonemal components. PLoS One 2015; 10:e0126005. [PMID: 25962172 PMCID: PMC4427456 DOI: 10.1371/journal.pone.0126005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 03/21/2015] [Indexed: 01/28/2023] Open
Abstract
Eukaryotic cilia and flagella have highly conserved 9 + 2 structures. They are functionally diverged to play cell-type-specific roles even in a multicellular organism. Although their structural components are therefore believed to be common, few studies have investigated the molecular diversity of the protein components of the cilia and flagella in a single organism. Here we carried out a proteomic analysis and compared protein components between branchial cilia and sperm flagella in a marine invertebrate chordate, Ciona intestinalis. Distinct feature of protein recruitment in branchial cilia and sperm flagella has been clarified; (1) Isoforms of α- and β-tubulins as well as those of actins are distinctly used in branchial cilia or sperm flagella. (2) Structural components, such as dynein docking complex, tektins and an outer dense fiber protein, are used differently by the cilia and flagella. (3) Sperm flagella are specialized for the cAMP- and Ca2+-dependent regulation of outer arm dynein and for energy metabolism by glycolytic enzymes. Our present study clearly demonstrates that flagellar or ciliary proteins are properly recruited according to their function and stability, despite their apparent structural resemblance and conservation.
Collapse
Affiliation(s)
- Alu Konno
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415–0025, Japan
| | - Kogiku Shiba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415–0025, Japan
| | - Chunhua Cai
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415–0025, Japan
| | - Kazuo Inaba
- Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415–0025, Japan
- * E-mail:
| |
Collapse
|
23
|
Yokoyama TD, Hotta K, Oka K. Comprehensive morphological analysis of individual peripheral neuron dendritic arbors in ascidian larvae using the photoconvertible protein kaede. Dev Dyn 2014; 243:1362-73. [DOI: 10.1002/dvdy.24169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Takatoshi D. Yokoyama
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
| |
Collapse
|
24
|
Jin Y, Yaguchi S, Shiba K, Yamada L, Yaguchi J, Shibata D, Sawada H, Inaba K. Glutathione transferase theta in apical ciliary tuft regulates mechanical reception and swimming behavior of Sea Urchin Embryos. Cytoskeleton (Hoboken) 2013; 70:453-70. [PMID: 23907936 PMCID: PMC3812683 DOI: 10.1002/cm.21127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 07/13/2013] [Accepted: 07/23/2013] [Indexed: 12/15/2022]
Abstract
An apical tuft, which is observed in a wide range of embryos/larvae of marine invertebrates, is composed of a group of cilia that are longer and less motile than the abundant lateral cilia covering the rest of the embryonic surface. Although the apical tuft has been thought to function as a sensory organ, its molecular composition and roles are poorly understood. Here, we identified a glutathione transferase theta (GSTT) as an abundant and specific component of the apical tuft in sea urchin embryos. The expression of GSTT mRNA increases and becomes limited to the animal plate of the mesenchyme blastula, gastrula, and prism larva. Electron microscopy and tandem mass spectrometry demonstrated that the apical tuft contains almost every axonemal component for ciliary motility. Low concentrations of an inhibitor of glutathione transferase bromosulphophthalein (BSP) induce bending of apical tuft, suggesting that GSTT regulates motility of apical tuft cilia. Embryos treated with BSP swim with normal velocity and trajectories but show less efficiency of changing direction when they collide with an object. These results suggest that GSTT in the apical tuft plays an important role in the mechanical reception for the motility regulation of lateral motile cilia in sea urchin embryos.
Collapse
Affiliation(s)
- Yinhua Jin
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, 415-0025, Japan
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Thompson H, Shaw MK, Dawe HR, Shimeld SM. The formation and positioning of cilia in Ciona intestinalis embryos in relation to the generation and evolution of chordate left-right asymmetry. Dev Biol 2012; 364:214-23. [PMID: 22342242 DOI: 10.1016/j.ydbio.2012.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/30/2012] [Accepted: 02/02/2012] [Indexed: 01/08/2023]
Abstract
In the early mouse embryo monocilia on the ventral node rotate to generate a leftward flow of fluid. This nodal flow is essential for the left-sided expression of nodal and pitx2, and for subsequent asymmetric organ patterning. Equivalent left fluid flow has been identified in other vertebrates, including Xenopus and zebrafish, indicating it is an ancient vertebrate mechanism. Asymmetric nodal and Pitx expression have also been identified in several invertebrates, including the vertebrates' nearest relatives, the urochordates. However whether cilia regulate this asymmetric gene expression remains unknown, and previous studies in urochordates have not identified any cilia prior to the larval stage, when asymmetry is already long established. Here we use Scanning and Transmission Electron Microscopy and immunofluorescence to investigate cilia in the urochordate Ciona intestinalis. We show that single cilia are transiently present on each ectoderm cell of the late neurula/early tailbud stage embryo, a time point just before onset of asymmetric nodal expression. Mapping the position of each cilium on these cells shows they are posteriorly positioned, something also described for mouse node cilia. The C. intestinalis cilia have a 9+0 ring ultrastructure, however we find no evidence of structures associated with motility such as dynein arms, radial spokes or nexin. Furthermore the 9+0 ring structure becomes disorganised immediately after the cilia have exited the cell, indicative of cilia which are not capable of motility. Our results indicate that although cilia are present prior to molecular asymmetries, they are not motile and hence cannot be operating in the same way as the flow-generating cilia of the vertebrate node. We conclude that the cilia may have a role in the development of C. intestinalis left-right asymmetry but that this would have to be in a sensory capacity, perhaps as mechanosensors as hypothesised in two-cilia physical models of vertebrate cilia-driven asymmetry.
Collapse
|
26
|
Konno A, Setou M, Ikegami K. Ciliary and flagellar structure and function--their regulations by posttranslational modifications of axonemal tubulin. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 294:133-70. [PMID: 22364873 DOI: 10.1016/b978-0-12-394305-7.00003-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Eukaryotic cilia and flagella are evolutionarily conserved microtubule-based organelles protruding from the cell surface. They perform dynein-driven beating which contributes to cell locomotion or flow generation. They also play important roles in sensing as cellular antennae, which allows cells to respond to various external stimuli. The main components of cilia and flagella, α- and β-tubulins, are known to undergo various posttranslational modifications (PTMs), including phosphorylation, palmitoylation, tyrosination/detyrosination, Δ2 modification, acetylation, glutamylation, and glycylation. Recent identification of tubulin-modifying enzymes, especially tubulin tyrosine ligase-like proteins which perform tubulin glutamylation and glycylation, has demonstrated the importance of tubulin modifications for the assembly and functions of cilia and flagella. In this chapter, we review recent work on PTMs of ciliary and flagellar tubulins in conjunction with discussing the basic knowledge.
Collapse
Affiliation(s)
- Alu Konno
- Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | | | | |
Collapse
|
27
|
Prulière G, Cosson J, Chevalier S, Sardet C, Chenevert J. Atypical protein kinase C controls sea urchin ciliogenesis. Mol Biol Cell 2011; 22:2042-53. [PMID: 21508313 PMCID: PMC3113769 DOI: 10.1091/mbc.e10-10-0844] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The distribution and function of aPKC are examined during sea urchin ciliogenesis. The kinase concentrates in a ring at the transition zone between the basal body and the elongating axoneme. Inhibition of aPKC results in mislocalization of the kinase and defective ciliogenesis. Thus aPKC controls the growth of motile cilia in invertebrate embryos. The atypical protein kinase C (aPKC) is part of the conserved aPKC/PAR6/PAR3 protein complex, which regulates many cell polarity events, including the formation of a primary cilium at the apical surface of epithelial cells. Cilia are highly organized, conserved, microtubule-based structures involved in motility, sensory processes, signaling, and cell polarity. We examined the distribution and function of aPKC in the sea urchin embryo, which forms a swimming blastula covered with motile cilia. We found that in the early embryo aPKC is uniformly cortical and becomes excluded from the vegetal pole during unequal cleavages at the 8- to 64-cell stages. During the blastula and gastrula stages the kinase localizes at the base of cilia, forming a ring at the transition zone between the basal body and the elongating axoneme. A dose-dependent and reversible inhibition of aPKC results in mislocalization of the kinase, defective ciliogenesis, and lack of swimming. Thus, as in the primary cilium of differentiated mammalian cells, aPKC controls the growth of motile cilia in invertebrate embryos. We suggest that aPKC might function to phosphorylate kinesin and so activate the transport of intraflagellar vesicles.
Collapse
Affiliation(s)
- Gérard Prulière
- Observatoire Océanologique, Biologie du Développement, Université Pierre et Marie Curie and CNRS, Villefranche-sur-Mer, France.
| | | | | | | | | |
Collapse
|
28
|
Ohta N, Horie T, Satoh N, Sasakura Y. Transposon-mediated enhancer detection reveals the location, morphology and development of the cupular organs, which are putative hydrodynamic sensors, in the ascidian Ciona intestinalis. Zoolog Sci 2011; 27:842-50. [PMID: 21039122 DOI: 10.2108/zsj.27.842] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The adult of the ascidian Ciona intestinalis has cupular organs, i.e., putative hydrodynamic sensors, at the atrial epithelium. The cupular organ consists of support cells and sensory neurons, and it extends a gelatinous matrix, known as a cupula, toward the atrial cavity. These characteristics are shared with sensory hair cells in the vertebrate inner ear and lateral line neuromasts in fish and amphibians, which suggests an evolutionary link between the cupular organ and these vertebrate hydrodynamic sensors. In the present study, we have isolated and investigated two transposon-mediated enhancer detection lines that showed GFP expression in support cells of the cupular organs. Using the enhancer detection lines and neuron marker transgenic lines, we describe the position, morphology, and development of the cupular organs. Cupular organs were found at the atrial epithelium, but not in the branchial epithelium. We found that cupular organs are also present along the dorsal fold and the gonoducts. The cells lining the pre-atrial opening in juveniles are presumably precursor cells of the cupular organ. To our knowledge, the present study is the first precise description of the ascidian cupular organ, providing evidence that may help to resolve discrepancies among previous studies on the organ.
Collapse
Affiliation(s)
- Naoyuki Ohta
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | | | | | | |
Collapse
|
29
|
Ependymal cells of chordate larvae are stem-like cells that form the adult nervous system. Nature 2011; 469:525-8. [PMID: 21196932 DOI: 10.1038/nature09631] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 10/27/2010] [Indexed: 12/27/2022]
Abstract
In ascidian tunicates, the metamorphic transition from larva to adult is accompanied by dynamic changes in the body plan. For instance, the central nervous system (CNS) is subjected to extensive rearrangement because its regulating larval organs are lost and new adult organs are created. To understand how the adult CNS is reconstructed, we traced the fate of larval CNS cells during ascidian metamorphosis by using transgenic animals and imaging technologies with photoconvertible fluorescent proteins. Here we show that most parts of the ascidian larval CNS, except for the tail nerve cord, are maintained during metamorphosis and recruited to form the adult CNS. We also show that most of the larval neurons disappear and only a subset of cholinergic motor neurons and glutamatergic neurons are retained. Finally, we demonstrate that ependymal cells of the larval CNS contribute to the construction of the adult CNS and that some differentiate into neurons in the adult CNS. An unexpected role of ependymal cells highlighted by this study is that they serve as neural stem-like cells to reconstruct the adult nervous network during chordate metamorphosis. Consequently, the plasticity of non-neuronal ependymal cells and neuronal cells in chordates should be re-examined by future studies.
Collapse
|
30
|
Network structure of projections extending from peripheral neurons in the tunic of ascidian larva. Dev Dyn 2010; 239:2278-87. [DOI: 10.1002/dvdy.22361] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|