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Lagman D, Leon A, Cieminska N, Deng W, Chatzigeorgiou M, Henriet S, Chourrout D. Pax3/7 gene function in Oikopleura dioica supports a neuroepithelial-like origin for its house-making Fol territory. Dev Biol 2024:S0012-1606(24)00217-3. [PMID: 39181419 DOI: 10.1016/j.ydbio.2024.08.012] [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: 09/08/2023] [Revised: 08/15/2024] [Accepted: 08/19/2024] [Indexed: 08/27/2024]
Abstract
Larvacean tunicates feature a spectacular innovation not seen in other animals - the trunk oikoplastic epithelium (OE). This epithelium produces a house, a large and complex extracellular structure used for filtering and concentrating food particles. Previously we identified several homeobox transcription factor genes expressed during early OE patterning. Among these are two Pax3/7 copies that we named pax37A and pax37B. The vertebrate homologs, PAX3 and PAX7 are involved in developmental processes related to neural crest and muscles. In the ascidian tunicate Ciona intestinalis, Pax3/7 plays a role in the development of cells deriving from the neural plate border, including trunk epidermal sensory neurons and tail nerve cord neurons, as well as in the neural tube closure. Here we have investigated the roles of Oikopleura dioica pax37A and pax37B in the development of the OE, by using CRISPR-Cas9 mutant lines and analyzing scRNA-seq data from wild-type animals. We found that pax37B but not pax37A is essential for the differentiation of cell fields that produce the food concentrating filter of the house: the anterior Fol, giant Fol and Nasse cells. Trajectory analysis supported a neuroepithelial-like or a preplacodal ectoderm transcriptional signature in these cells. We propose that the highly specialized secretory epithelial cells of the Fol region either maintained or evolved neuroepithelial features. This is supported by a fragmented gene regulatory network involved in their development that also operates in ascidian epidermal neurons.
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Affiliation(s)
- David Lagman
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway; Department for Medical Cell Biology, Uppsala University, Uppsala, SE-75123, Sweden.
| | - Anthony Leon
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway
| | - Nadia Cieminska
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway
| | - Wei Deng
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway
| | | | - Simon Henriet
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway
| | - Daniel Chourrout
- Michael Sars Centre, University of Bergen, Bergen, NO-5020, Norway.
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2
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Lanoizelet M, Elkhoury Youhanna C, Roure A, Darras S. Molecular control of cellulosic fin morphogenesis in ascidians. BMC Biol 2024; 22:74. [PMID: 38561802 PMCID: PMC10986139 DOI: 10.1186/s12915-024-01872-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND The tunicates form a group of filter-feeding marine animals closely related to vertebrates. They share with them a number of features such as a notochord and a dorsal neural tube in the tadpole larvae of ascidians, one of the three groups that make tunicates. However, a number of typical chordate characters have been lost in different branches of tunicates, a diverse and fast-evolving phylum. Consequently, the tunic, a sort of exoskeleton made of extracellular material including cellulose secreted by the epidermis, is the unifying character defining the tunicate phylum. In the larva of ascidians, the tunic differentiates in the tail into a median fin (with dorsal and ventral extended blades) and a caudal fin. RESULTS Here we have performed experiments in the ascidian Phallusia mammillata to address the molecular control of tunic 3D morphogenesis. We have demonstrated that the tail epidermis medio-lateral patterning essential for peripheral nervous system specification also controls tunic elongation into fins. More specifically, when tail epidermis midline identity was abolished by BMP signaling inhibition, or CRISPR/Cas9 inactivation of the transcription factor coding genes Msx or Klf1/2/4/17, median fin did not form. We postulated that this genetic program should regulate effectors of tunic secretion. We thus analyzed the expression and regulation in different ascidian species of two genes acquired by horizontal gene transfer (HGT) from bacteria, CesA coding for a cellulose synthase and Gh6 coding for a cellulase. We have uncovered an unexpected dynamic history of these genes in tunicates and high levels of variability in gene expression and regulation among ascidians. Although, in Phallusia, Gh6 has a regionalized expression in the epidermis compatible with an involvement in fin elongation, our functional studies indicate a minor function during caudal fin formation only. CONCLUSIONS Our study constitutes an important step in the study of the integration of HGT-acquired genes into developmental networks and a cellulose-based morphogenesis of extracellular material in animals.
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Affiliation(s)
- Maxence Lanoizelet
- Sorbonne Université, CNRS, Biologie Intégrative Des Organismes Marins (BIOM), Banyuls/Mer, 66650, France.
- Present address: Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Louvain, Belgium.
| | - Christel Elkhoury Youhanna
- Sorbonne Université, CNRS, Biologie Intégrative Des Organismes Marins (BIOM), Banyuls/Mer, 66650, France
- Present address: Centre de Biologie Structurale, Univ Montpellier, CNRS UMR 5048, INSERM U1054, Montpellier, 34090, France
| | - Agnès Roure
- Sorbonne Université, CNRS, Biologie Intégrative Des Organismes Marins (BIOM), Banyuls/Mer, 66650, France
| | - Sébastien Darras
- Sorbonne Université, CNRS, Biologie Intégrative Des Organismes Marins (BIOM), Banyuls/Mer, 66650, France.
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Zemann B, Le MLV, Sherlock RE, Baum D, Katija K, Stach T. Evolutionary traces of miniaturization in a giant-Comparative anatomy of brain and brain nerves in Bathochordaeus stygius (Tunicata, Appendicularia). J Morphol 2023; 284:e21598. [PMID: 37313762 DOI: 10.1002/jmor.21598] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/04/2023] [Accepted: 05/07/2023] [Indexed: 06/15/2023]
Abstract
Appendicularia comprises 70 marine, invertebrate, chordate species. Appendicularians play important ecological and evolutionary roles, yet their morphological disparity remains understudied. Most appendicularians are small, develop rapidly, and with a stereotyped cell lineage, leading to the hypothesis that Appendicularia derived progenetically from an ascidian-like ancestor. Here, we describe the detailed anatomy of the central nervous system of Bathochordaeus stygius, a giant appendicularian from the mesopelagic. We show that the brain consists of a forebrain with on average smaller and more uniform cells and a hindbrain, in which cell shapes and sizes vary to a greater extent. Cell count for the brain was 102. We demonstrate the presence of three paired brain nerves. Brain nerve 1 traces into the epidermis of the upper lip region and consists of several fibers with some supportive bulb cells in its course. Brain nerve 2 innervates oral sensory organs and brain nerve 3 innervates the ciliary ring of the gill slits and lateral epidermis. Brain nerve 3 is asymmetric, with the right nerve consisting of two neurites originating posterior to the left one that contains three neurites. Similarities and differences to the anatomy of the brain of the model species Oikopleura dioica are discussed. We interpret the small number of cells in the brain of B. stygius as an evolutionary trace of miniaturization and conclude that giant appendicularians evolved from a small, progenetic ancestor that secondarily increased in size within Appendicularia.
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Affiliation(s)
| | - Mai-Lee Van Le
- Humboldt-Universität zu Berlin, Vergleichende Elektronenmikroskopie, Berlin, Germany
| | - Rob E Sherlock
- Monterey Bay Aquarium Research Institute, Moss Landing, California, USA
| | | | - Kakani Katija
- Monterey Bay Aquarium Research Institute, Moss Landing, California, USA
| | - Thomas Stach
- Humboldt-Universität zu Berlin, Vergleichende Elektronenmikroskopie, Berlin, Germany
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4
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Konishi M, Kishi K, Morita R, Yamada A, Onuma TA, Nishida H. Formation of the brain by stem cell divisions of large neuroblasts in Oikopleura dioica, a simple chordate. Dev Genes Evol 2023:10.1007/s00427-023-00704-y. [PMID: 37231211 DOI: 10.1007/s00427-023-00704-y] [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: 01/13/2023] [Accepted: 05/04/2023] [Indexed: 05/27/2023]
Abstract
Stem cell division contributes to the generation of various cell types during animal development, especially a diverse pool of neural cells in the nervous system. One example is reiterated unequal stem cell divisions, in which a large stem cell undergoes a series of oriented unequal divisions to produce a chain of small daughter cells that differentiate. We show that reiterated unequal stem cell divisions are involved in the formation of the brain in simple chordate appendicularians (larvaceans). Two large neuroblasts in the anterior and middle of the brain-forming region of hatched larvae were observed. They produced at least 30 neural cells out of 96 total brain cells before completion of brain formation at 10 hours after fertilization by reiterated unequal stem cell divisions. The daughter cells of the anterior neuroblast were postmitotic, and the number was at least 19. The neuroblast produced small daughter neural cells posteriorly every 20 min. The neural cells first moved toward the dorsal side, turned in the anterior direction, aligned in a single line according to their birth order, and showed collective movement to accumulate in the anterior part of the brain. The anterior neuroblast originated from the right-anterior blastomeres of the eight-cell embryos and the right a222 blastomere of the 64-cell embryo. The posterior neuroblast also showed reiterated unequal stem cell divisions, and generated at least 11 neural cells. Sequential unequal stem cell divisions without stem cell growth have been observed in protostomes, such as insects and annelids. The results provide the first examples of this kind of stem cell division during brain formation in non-vertebrate deuterostomes.
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Affiliation(s)
- Misako Konishi
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan
| | - Kanae Kishi
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan
| | - Ryo Morita
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan
| | - Atsuko Yamada
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan
| | - Takeshi A Onuma
- Faculty of Science, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan.
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Yamagishi M, Huang T, Hozumi A, Onuma TA, Sasakura Y, Ogasawara M. Differentiation of endostyle cells by Nkx2-1 and FoxE in the ascidian Ciona intestinalis type A: insights into shared gene regulation in glandular- and thyroid-equivalent elements of the chordate endostyle. Cell Tissue Res 2022; 390:189-205. [PMID: 36048302 DOI: 10.1007/s00441-022-03679-w] [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: 11/09/2021] [Accepted: 08/23/2022] [Indexed: 11/26/2022]
Abstract
Due to similarities in iodine concentrations and peroxidase activities, the thyroid in vertebrates is considered to originate from the endostyle of invertebrate chordates even though it is a glandular (mucus-producing) organ for aquatic suspension feeding. Among chordates with an endostyle, urochordates are useful evolutionary research models for the study of vertebrate traits. The ascidian Ciona intestinalis forms an endostyle with specific components of glandular- and thyroid-related elements, and molecular markers have been identified for these components. Since we previously examined a simple endostyle in the larvacean Oikopleura dioica, the expression of the thyroid-related transcription factor genes, Ciona Nkx2-1 and FoxE, was perturbed by TALEN-mediated gene knockout in the present study to elucidate the shared and/or divergent features of a complex ascidian endostyle. The knockout of Ciona Nkx2-1 and FoxE exerted different effects on the morphology of the developing endostyle. The knockout of Nkx2-1 eliminated the expression of both glandular and thyroidal differentiation marker genes, e.g., vWFL1, vWFL2, CiEnds1, TPO, and Duox, while that of FoxE eliminated the expression of the differentiation marker genes, TPO and CiEnds1. The supporting element-related expression of Pax2/5/8a, Pax2/5/8b, FoxQ1, and β-tubulin persisted in the hypoplastic endostyles of Nkx2-1- and FoxE-knockout juveniles. Although the gene regulation of ascidian-specific CiEnds1 remains unclear, these results provide insights into the evolution of the vertebrate thyroid as well as the urochordate endostyle.
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Affiliation(s)
- Masayuki Yamagishi
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Taoruo Huang
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Akiko Hozumi
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima-shi, Kagoshima, 890-0065, Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Michio Ogasawara
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
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6
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Onuma TA, Nishida H. Developmental biology of the larvacean Oikopleura dioica: Genome resources, functional screening, and imaging. Dev Growth Differ 2021; 64:67-82. [PMID: 34964127 DOI: 10.1111/dgd.12769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/13/2021] [Accepted: 12/13/2021] [Indexed: 12/01/2022]
Abstract
The larvacean Oikopleura dioica is a cosmopolitan planktonic chordate and is closely related to vertebrates. It is characterized by a tadpole-shaped morphology with notochord flanked by muscle in the tail and brain on the dorsal side, a short life cycle of five days, a compact genome of approximately 56 Mb, a simple and transparent body with a small number of cells (~4000 in functional juveniles), invariant embryonic cell lineages, and fast development that ensures complete morphogenesis and organ formation 10 h after fertilization. With these features, this marine chordate is a promising and advantageous animal model in which genetic manipulation is feasible. In this review, we introduce relevant resources and modern techniques that have been developed: (1) Genome and transcriptomes. Oikopleura dioica has the smallest genome among non-parasitic metazoans. Its genome databases have been generated using three geographically distant O. dioica populations, and several intra-species sequence differences are becoming evident; (2) Functional genetic knockdown techniques. Comprehensive screening of genes is feasible using ovarian microinjection and double-strand DNA-induced gene knockdown; and (3) Live imaging of embryos and larvae. Application of these techniques has uncovered novel aspects of development, including meiotic cell arrest, left-right patterning, epidermal cell patterning, and mouth formation involving the connection of ectoderm and endoderm sheets. Oikopleura dioca has become very useful for developmental and evolutionary studies in chordates.
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Affiliation(s)
- Takeshi A Onuma
- Graduate School of Science and Engineering, Faculty of Science, Kagoshima University, Kagoshima, Japan.,Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
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7
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Nishida H, Matsuo M, Konishi S, Ohno N, Manni L, Onuma TA. Germline development during embryogenesis of the larvacean, Oikopleura dioica. Dev Biol 2021; 481:188-200. [PMID: 34755656 DOI: 10.1016/j.ydbio.2021.10.009] [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: 07/21/2021] [Revised: 10/08/2021] [Accepted: 10/24/2021] [Indexed: 11/18/2022]
Abstract
Germ cells develop into eggs and sperms and represent a lineage that survives through multiple generations. Germ cell specification during embryogenesis proceeds through one of two basic modes: either the cell-autonomous mode or the inductive mode. In the cell-autonomous mode, specification of germ cell fate involves asymmetric partitioning of the specialized maternal cytoplasm, known as the germplasm. Oikopleura dioica is a larvacean (class Appendicularia) and a chordate. It is regarded as a promising animal model for studying chordate development because of its short life cycle (5 days) and small genome size (∼60 Mb). We show that their embryos possess germplasm, as observed in ascidians (class Ascidiacea). The vegetal cytoplasm shifted towards the future posterior pole before the first cleavage occurred. A bilateral pair of primordial germ cells (PGC, B11 cells) was formed at the posterior pole at the 32-cell stage through two rounds of unequal cleavage. These B11 cells did not undergo further division before hatching of the tadpole-shaped larvae. The centrosome-attracting body (CAB) is a subcellular structure that contains the germplasm and plays crucial roles in germ cell development in ascidians. The presence of CAB with germplasm was observed in the germline lineage cells of larvaceans via electron microscopy and using extracted embryos. The CAB appeared at the 8-cell stage and persisted until the middle stage of embryogenesis. The antigen for the phosphorylated histone 3 antibody was localized to the CAB and persisted in the PGC until hatching after the CAB disappeared. Maternal snail mRNA, which encodes a transcription factor, was co-localized with the antigen for the H3S28p antibody. Furthermore, we found a novel PGC-specific subcellular structure that we call the germ body (GB). This study thus highlights the conserved and non-conserved features of germline development between ascidians and larvaceans. The rapid development and short life cycle (five days) of O. dioica would open the way to genetically analyze germ cell development in the future.
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Affiliation(s)
- Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
| | - Masaki Matsuo
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Shohei Konishi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Nobuhiko Ohno
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, 444-8787, Japan; Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, via U. Bassi 58/B, I-35121, Padova, Italy
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
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8
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The pericardium of Oikopleura dioica (Tunicata, Appendicularia) contains two distinct cell types and is rotated by 90 degrees to the left. ZOOMORPHOLOGY 2021. [DOI: 10.1007/s00435-021-00538-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractThe planktonic Oikopleura dioica belongs to Tunicata, the probable sister taxon to Craniota, and might show plesiomorphic characters, conserved from the common lineage of Tunicata and Craniota. In O. dioica a pericardium in a position similar to other chordates but also to the heart and pericardium of craniates is found. Surprisingly, little is known about the ultrastructure of the pericardium in O. dioica. Here, we show based on electron microscopy that the pericardium is completely lined by a single layer of 16 epithelial cells: 6 epithelial myocardial cells on the left side of the pericardium and 10 peritoneal cells constituting the right side. One of the peritoneal cells, situated at the ventral border between peritoneal cells and myocardial cells has an extension that anchors the pericardium to the basal lamina beneath the latero-ventral epidermis. The primary body cavity of O. dioica appears quite uniformly clear in electron microscopic aspect but several sheets, resembling the basal lamina of the pericardium cross the larger spaces of the body cavity and connect to the pericardial basal lamina. This is the first detailed description of two distinct cell types in the epithelial lining of the pericardium of O. dioica. In comparison with other chordates, we conclude that two cell types can be reconstructed for the last common ancestor of Chordata at least. The position of the pericardium at the intersection of trunk and tail in combination with the basal-lamina like sheets spanning the hemocoel is probably of importance for the function of the circulation of the hemocoelic fluid. Similar to the tail, the axis of the pericardium is shifted through 90 degrees to the left as compared to the main body axis of the trunk and we infer that this shift is an apomorphic character of Appendicularia.
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Onuma TA, Nakanishi R, Sasakura Y, Ogasawara M. Nkx2-1 and FoxE regionalize glandular (mucus-producing) and thyroid-equivalent traits in the endostyle of the chordate Oikopleura dioica. Dev Biol 2021; 477:219-231. [PMID: 34107272 DOI: 10.1016/j.ydbio.2021.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 11/19/2022]
Abstract
The endostyle is a ventral pharyngeal organ used for internal filter feeding of basal chordates and is considered homologous to the follicular thyroid of vertebrates. It contains mucus-producing (glandular) and thyroid-equivalent regions organized along the dorsoventral (DV) axis. Although thyroid-related genes (Nkx2-1, FoxE, and thyroid peroxidase (TPO)) are known to be expressed in the endostyle, their roles in establishing regionalization within the organ have not been demonstrated. We report that Nkx2-1 and FoxE are essential for establishing DV axial identity in the endostyle of Oikopleura dioica. Genome and expression analyses showed von Willebrand factor-like (vWFL) and TPO/dual oxidase (Duox)/Nkx2-1/FoxE as orthologs of glandular and thyroid-related genes, respectively. Knockdown experiments showed that Nkx2-1 is necessary for the expression of glandular and thyroid-related genes, whereas FoxE is necessary only for thyroid-related genes. Moreover, Nkx2-1 expression is necessary for FoxE expression in larvae during organogenesis. The results demonstrate the essential roles of Nkx2-1 and FoxE in establishing regionalization in the endostyle, including (1) the Nkx2-1-dependent glandular region, and (2) the Nkx2-1/FoxE-dependent thyroid-equivalent region. DV axial regionalization may be responsible for organizing glandular and thyroid-equivalent traits of the pharynx along the DV axis.
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Affiliation(s)
- Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan.
| | - Rina Nakanishi
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Michio Ogasawara
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
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Razghandi K, Janßen N, Le MLV, Stach T. The filter-house of the larvacean Oikopleura dioica. A complex extracellular architecture: From fiber production to rudimentary state to inflated house. J Morphol 2021; 282:1259-1273. [PMID: 34041785 DOI: 10.1002/jmor.21382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/20/2021] [Accepted: 05/09/2021] [Indexed: 11/06/2022]
Abstract
While cellulose is the most abundant macromolecule in the biosphere, most animals are unable to produce cellulose with the exception of tunicates. Some tunicates have evolved the ability to secrete a complex house containing cellulosic fibers, yet little is known about the early stages of the house building process. Here, we investigate the rudimentary house of Oikopleura dioica for the first time using complementary light and electron microscopic techniques. In addition, we digitally modeled the arrangement of chambers, nets, and filters of the functional, expanded house in three dimensions based on life-video-imaging. Combining 3D-reconstructions based on serial histological semithin-sections, confocal laser scanning microscopy, transmission electron microscopy, scanning electron microscopy (SEM), and focused ion beam (FIB)-SEM, we were able to elucidate the arrangement of structural components, including cellulosic fibers, of the rudimentary house with a focus on the food concentration filter. We developed a model for the arrangement of folded structures in the house rudiment and show it is a precisely preformed structure with identifiable components intricately correlated with specific cells. Moreover, we demonstrate that structural details of the apical surfaces of Nasse cells provide the exact locations and shapes to produce the fibers of the house and interact among each other, with Giant Fol cells, and with the fibers to arrange them in the precise positions necessary for expansion of the house rudiment into the functional state. The presented data and hypotheses advance our knowledge about the interrelation of structure and function on different biological levels and prompt investigations into this astonishing biological object.
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Affiliation(s)
- Khashayar Razghandi
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.,Cluster of Excellence "Matters of Activity. Image Space Material", Humboldt Universität zu Berlin, Berlin, Germany
| | - Nils Janßen
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces, Potsdam, Germany
| | - Mai-Lee Van Le
- Institut für Biologie, AG Vergleichende Zoologie, Humboldt Universität zu Berlin, Berlin, Germany
| | - Thomas Stach
- Institut für Biologie, AG Vergleichende Elektronenmikroskopie, Humboldt Universität zu Berlin, Berlin, Germany
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11
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Nishida H, Ohno N, Caicci F, Manni L. 3D reconstruction of structures of hatched larva and young juvenile of the larvacean Oikopleura dioica using SBF-SEM. Sci Rep 2021; 11:4833. [PMID: 33649401 PMCID: PMC7921577 DOI: 10.1038/s41598-021-83706-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
The larvacean Oikopleura dioica is a planktonic chordate and an emerging model organism with a short life cycle of 5 days that belongs toTunicata (Urochordata), the sister clade of vertebrates. It is characterized by the rapid development of a tadpole-shaped body. Organ formation in the trunk proceeds within 7 h after the hatching of the tailbud larvae at 3 h after fertilization (hpf) and is completed at 10 hpf, giving rise to fully functional juveniles as miniature adult form. Serial block face scanning electron microscopy was used to acquire ~ 2000 serial transverse section images of a 3 hpf larva and a 10 hpf juvenile to characterize the structures and cellular composition of the trunk and organs using 3D images and movies. Germ cells were found to fuse and establish a central syncytial cell in the gonad as early as 10 hpf. Larval development gave rise to functional organs after several rounds of cell division through trunk morphogenesis. The feature would make O. dioica ideal for analyzing cellular behaviors during morphogenetic processes using live imaging. The detailed descriptions of the larvae and juveniles provided in this study can be utilized as the start and end points of organ morphogenesis in this rapidly developing organism.
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Affiliation(s)
- Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka, 560-0043, Japan.
| | - Nobuhiko Ohno
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, 444-8787, Japan.,Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Federico Caicci
- Dipartimento di Biologia, Università degli Studi di Padova, Via U. Bassi 58/B, 35131, Padova, Italy
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Via U. Bassi 58/B, 35131, Padova, Italy
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12
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Morita R, Onuma TA, Manni L, Ohno N, Nishida H. Mouth opening is mediated by separation of dorsal and ventral daughter cells of the lip precursor cells in the larvacean, Oikopleura dioica. Dev Genes Evol 2020; 230:315-327. [PMID: 32803391 DOI: 10.1007/s00427-020-00667-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 07/29/2020] [Indexed: 12/15/2022]
Abstract
Mouth formation involves the processes of mouth opening, formation of the oral cavity, and the development of associated sensory organs. In deuterostomes, the surface ectoderm and the anterior part of the archenteron are reconfigured and reconnected to make a mouth opening. This study of the larval development of the larvacean, Oikopleura dioica, investigates the cellular organization of the oral region, the developmental processes of the mouth, and the formation of associated sensory cells. O. dioica is a simple chordate whose larvae are transparent and have a small number of constituent cells. It completes organ morphogenesis in 7 h, between hatching 3 h after fertilization and the juvenile stage at 10 h, when it attains adult form and starts to feed. It has two types of mechanosensory cell embedded in the oral epithelium, which is a single layer of cells. There are twenty coronal sensory cells in the circumoral nerve ring and two dorsal sensory organ cells. Two bilateral lip precursor cells (LPCs), facing the anterior surface, divide dorsoventrally and make a wedge-shaped cleft between the two daughter cells named the dorsal lip cell (DLC) and the ventral lip cell (VLC). Eventually, the DLC and VLC become detached and separated into dorsal and ventral lips, triggering mouth opening. This is an intriguing example of cell division itself contributing to morphogenesis. The boundary between the ectoderm and endoderm is present between the lip cells and coronal sensory cells. All oral sensory cells, including dorsal sensory organ cells, were of endodermal origin and were not derived from the ectodermal placode. These observations on mouth formation provide a cellular basis for further studies at a molecular level, in this simple chordate.
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Affiliation(s)
- Ryo Morita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, via U. Bassi 58/B, I-35121, Padova, Italy
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
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13
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Wang K, Tomura R, Chen W, Kiyooka M, Ishizaki H, Aizu T, Minakuchi Y, Seki M, Suzuki Y, Omotezako T, Suyama R, Masunaga A, Plessy C, Luscombe NM, Dantec C, Lemaire P, Itoh T, Toyoda A, Nishida H, Onuma TA. A genome database for a Japanese population of the larvacean Oikopleura dioica. Dev Growth Differ 2020; 62:450-461. [PMID: 32677034 DOI: 10.1111/dgd.12689] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 01/01/2023]
Abstract
The larvacean Oikopleura dioica is a planktonic chordate and is a tunicate that belongs to the closest relatives to vertebrates. Its simple and transparent body, invariant embryonic cell lineages, and short life cycle of 5 days make it a promising model organism for the study of developmental biology. The genome browser OikoBase was established in 2013 using Norwegian O. dioica. However, genome information for other populations is not available, even though many researchers have studied local populations. In the present study, we sequenced using Illumina and PacBio RSII technologies the genome of O. dioica from a southwestern Japanese population that was cultured in our laboratory for 3 years. The genome of Japanese O. dioica was assembled into 576 scaffold sequences with a total length and N50 length of 56.6 and 1.5 Mb, respectively. A total of 18,743 gene models (transcript models) were predicted in the genome assembly, named OSKA2016. In addition, 19,277 non-redundant transcripts were assembled using RNA-seq data. The OSKA2016 has global sequence similarity of only 86.5% when compared with the OikoBase, highlighting the sequence difference between the two far distant O. dioica populations on the globe. The genome assembly, transcript assembly, and transcript models were incorporated into ANISEED (https://www.aniseed.cnrs.fr/) for genome browsing and BLAST searches. Mapping of reads obtained from male- or female-specific genome libraries yielded male-specific scaffolds in the OSKA2016 and revealed that over 2.6 Mb of sequence were included in the male-specific Y-region. The genome and transcriptome resources from two distinct populations will be useful datasets for developmental biology, evolutionary biology, and molecular ecology using this model organism.
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Affiliation(s)
- Kai Wang
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Ryo Tomura
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Wei Chen
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Miho Kiyooka
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Hinako Ishizaki
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Tomoyuki Aizu
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Yohei Minakuchi
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Masahide Seki
- Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Yutaka Suzuki
- Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Tatsuya Omotezako
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Ritsuko Suyama
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Aki Masunaga
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Charles Plessy
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Nicholas M Luscombe
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Christelle Dantec
- Centre de Recherches de Biochimie Macromoleculaire (CRBM), UMR5237, CNRS-Universite de Montpellier, Montpellier, France
| | - Patrick Lemaire
- Centre de Recherches de Biochimie Macromoleculaire (CRBM), UMR5237, CNRS-Universite de Montpellier, Montpellier, France
| | - Takehiko Itoh
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
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14
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Katija K, Troni G, Daniels J, Lance K, Sherlock RE, Sherman AD, Robison BH. Revealing enigmatic mucus structures in the deep sea using DeepPIV. Nature 2020; 583:78-82. [DOI: 10.1038/s41586-020-2345-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 03/19/2020] [Indexed: 11/09/2022]
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15
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A chordate species lacking Nodal utilizes calcium oscillation and Bmp for left-right patterning. Proc Natl Acad Sci U S A 2020; 117:4188-4198. [PMID: 32029598 DOI: 10.1073/pnas.1916858117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Larvaceans are chordates with a tadpole-like morphology. In contrast to most chordates of which early embryonic morphology is bilaterally symmetric and the left-right (L-R) axis is specified by the Nodal pathway later on, invariant L-R asymmetry emerges in four-cell embryos of larvaceans. The asymmetric cell arrangements exist through development of the tailbud. The tail thus twists 90° in a counterclockwise direction relative to the trunk, and the tail nerve cord localizes on the left side. Here, we demonstrate that larvacean embryos have nonconventional L-R asymmetries: 1) L- and R-cells of the two-cell embryo had remarkably asymmetric cell fates; 2) Ca2+ oscillation occurred through embryogenesis; 3) Nodal, an evolutionarily conserved left-determining gene, was absent in the genome; and 4) bone morphogenetic protein gene (Bmp) homolog Bmp.a showed right-sided expression in the tailbud and larvae. We also showed that Ca2+ oscillation is required for Bmp.a expression, and that BMP signaling suppresses ectopic expression of neural genes. These results indicate that there is a chordate species lacking Nodal that utilizes Ca2+ oscillation and Bmp.a for embryonic L-R patterning. The right-side Bmp.a expression may have arisen via cooption of conventional BMP signaling in order to restrict neural gene expression on the left side.
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16
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Ferrández-Roldán A, Martí-Solans J, Cañestro C, Albalat R. Oikopleura dioica: An Emergent Chordate Model to Study the Impact of Gene Loss on the Evolution of the Mechanisms of Development. Results Probl Cell Differ 2019; 68:63-105. [PMID: 31598853 DOI: 10.1007/978-3-030-23459-1_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The urochordate Oikopleura dioica is emerging as a nonclassical animal model in the field of evolutionary developmental biology (a.k.a. evo-devo) especially attractive for investigating the impact of gene loss on the evolution of mechanisms of development. This is because this organism fulfills the requirements of an animal model (i.e., has a simple and accessible morphology, a short generation time and life span, and affordable culture in the laboratory and amenable experimental manipulation), but also because O. dioica occupies a key phylogenetic position to understand the diversification and origin of our own phylum, the chordates. During its evolution, O. dioica genome has suffered a drastic process of compaction, becoming the smallest known chordate genome, a process that has been accompanied by exacerbating amount of gene losses. Interestingly, however, despite the extensive gene losses, including entire regulatory pathways essential for the embryonic development of other chordates, O. dioica retains the typical chordate body plan. This unexpected situation led to the formulation of the so-called inverse paradox of evo-devo, that is, when a genetic diversity is able to maintain a phenotypic unity. This chapter reviews the biological features of O. dioica as a model animal, along with the current data on the evolution of its genes and genome. We pay special attention to the numerous examples of gene losses that have taken place during the evolution of this unique animal model, which is helping us to understand to which the limits of evo-devo can be pushed off.
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Affiliation(s)
- Alfonso Ferrández-Roldán
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Josep Martí-Solans
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Cristian Cañestro
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Ricard Albalat
- Facultat de Biologia, Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Catalonia, Spain.
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17
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Mikhaleva Y, Skinnes R, Sumic S, Thompson EM, Chourrout D. Development of the house secreting epithelium, a major innovation of tunicate larvaceans, involves multiple homeodomain transcription factors. Dev Biol 2018; 443:117-126. [DOI: 10.1016/j.ydbio.2018.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/27/2018] [Accepted: 09/05/2018] [Indexed: 01/24/2023]
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