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Treen N, Konishi S, Nishida H, Onuma TA, Sasakura Y. Zic-r.b controls cell numbers in Ciona embryos by activating CDKN1B. Dev Biol 2023; 498:26-34. [PMID: 36965841 DOI: 10.1016/j.ydbio.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 01/25/2023] [Accepted: 03/20/2023] [Indexed: 03/27/2023]
Abstract
The control of cell numbers and the establishment of cell types are two processes that are essential in early embryonic development. We have a reasonable understanding of how these processes occur individually, but we have considerably less sophisticated understanding of how these processes are linked. Tunicates have fixed cell lineages with predictable cell cycles, making them well suited to investigate these processes. In the ascidian Ciona, we show that the transcription factor Zic-r.b, known to be involved in establishing several cell types in early development also activates the expression of the cell cycle inhibitor CDKN1B. Zic-r.b is a major missing component of the cell division clock establishing specific cell numbers. We also show that a larvacean homolog of Zic-r.b is expressed one cell cycle earlier than its Ciona counterpart. The early expression in larvaceans may explain why they have half as many notochord cells as ascidians and may illustrate a general mechanism to evolve changes in morphology.
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Affiliation(s)
- Nicholas Treen
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda, Shizuoka, 415-0025, Japan.
| | - Shohei Konishi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Hiroki Nishida
- 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
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1, Shimoda, Shizuoka, 415-0025, Japan
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2
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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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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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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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5
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Martí-Solans J, Godoy-Marín H, Diaz-Gracia M, Onuma TA, Nishida H, Albalat R, Cañestro C. Massive Gene Loss and Function Shuffling in Appendicularians Stretch the Boundaries of Chordate Wnt Family Evolution. Front Cell Dev Biol 2021; 9:700827. [PMID: 34179025 PMCID: PMC8220140 DOI: 10.3389/fcell.2021.700827] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/19/2021] [Indexed: 01/17/2023] Open
Abstract
Gene loss is a pervasive source of genetic variation that influences species evolvability, biodiversity and the innovation of evolutionary adaptations. To better understand the evolutionary patterns and impact of gene loss, here we investigate as a case study the evolution of the wingless (Wnt) family in the appendicularian tunicate Oikopleura dioica, an emergent EvoDevo model characterized by its proneness to lose genes among chordates. Genome survey and phylogenetic analyses reveal that only four of the thirteen Wnt subfamilies have survived in O. dioica—Wnt5, Wnt10, Wnt11, and Wnt16,—representing the minimal Wnt repertoire described in chordates. While the loss of Wnt4 and Wnt8 likely occurred in the last common ancestor of tunicates, representing therefore a synapomorphy of this subphylum, the rest of losses occurred during the evolution of appendicularians. This work provides the first complete Wnt developmental expression atlas in a tunicate and the first insights into the evolution of Wnt developmental functions in appendicularians. Our work highlights three main evolutionary patterns of gene loss: (1) conservation of ancestral Wnt expression domains not affected by gene losses; (2) function shuffling among Wnt paralogs accompanied by gene losses; and (3) extinction of Wnt expression in certain embryonic directly correlated with gene losses. Overall our work reveals that in contrast to “conservative” pattern of evolution of cephalochordates and vertebrates, O. dioica shows an even more radical “liberal” evolutionary pattern than that described ascidian tunicates, stretching the boundaries of the malleability of Wnt family evolution in chordates.
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Affiliation(s)
- Josep Martí-Solans
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Hector Godoy-Marín
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Miriam Diaz-Gracia
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Osaka, Japan
| | - Ricard Albalat
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
| | - Cristian Cañestro
- Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain
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6
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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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7
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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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Matsuo M, Onuma TA, Omotezako T, Nishida H. Protein phosphatase 2A is essential to maintain meiotic arrest, and to prevent Ca 2+ burst at spawning and eventual parthenogenesis in the larvacean Oikopleura dioica. Dev Biol 2019; 460:155-163. [PMID: 31857067 DOI: 10.1016/j.ydbio.2019.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 11/13/2019] [Accepted: 12/09/2019] [Indexed: 12/22/2022]
Abstract
Unfertilized eggs of most animals are arrested at a certain point in the meiotic cell cycles. Reinitiation of meiosis and the start of embryogenesis are triggered by fertilization. This arrest is essential for preventing parthenogenetic activation and for promoting proper initiation of development by fertilization. In the larvacean Oikopleura dioica, which is a simple model organism for studies of chordate development, the unfertilized egg is arrested at metaphase of meiosis I. We show here that protein phosphatase 2A (PP2A) is essential for maintenance of meiotic arrest after spawning of oocytes. Knockdown (KD) of the maternal PP2A catalytic subunit, which was found in functional screening of maternal factors, caused unfertilized eggs to spontaneously release polar bodies after spawning, and then start pseudo-cleavages without fertilization, namely, parthenogenesis. Parthenogenetic embryos failed to undergo proper mitosis and cytokinesis because of lack of a centrosome, which is to be brought into the egg by a sperm. Activation of the KD oocytes was triggered by possible rise of ambient and intracellular pH upon their release from the gonad into seawater at spawning. Live recording of intracellular calcium level of the KD oocytes indicated that the pH rise caused an aberrant Ca2+ burst, which mimicked the Ca2+ burst that occurs at fertilization. Then, the aberrant Ca2+ burst triggered meiosis resumption through Calcium/calmodulin-dependent protein kinase (CaMK II). Therefore, PP2A is essential for maintenance of meiotic arrest and prevention of parthenogenesis by suppressing the aberrant Ca2+ burst at spawning.
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Affiliation(s)
- Masaki Matsuo
- 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
| | - Tatsuya Omotezako
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
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9
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Torres-Águila NP, Martí-Solans J, Ferrández-Roldán A, Almazán A, Roncalli V, D'Aniello S, Romano G, Palumbo A, Albalat R, Cañestro C. Diatom bloom-derived biotoxins cause aberrant development and gene expression in the appendicularian chordate Oikopleura dioica. Commun Biol 2018; 1:121. [PMID: 30272001 PMCID: PMC6123688 DOI: 10.1038/s42003-018-0127-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/31/2018] [Indexed: 12/18/2022] Open
Abstract
Investigating environmental hazards than could affect appendicularians is of prime ecological interest because they are among the most abundant components of the mesozooplankton. This work shows that embryo development of the appendicularian Oikopleura dioica is compromised by diatom bloom-derived biotoxins, even at concentrations in the same range as those measured after blooms. Developmental gene expression analysis of biotoxin-treated embryos uncovers an aberrant golf ball-like phenotype affecting morphogenesis, midline convergence, and tail elongation. Biotoxins induce a rapid upregulation of defensome genes, and considerable delay and silencing of zygotic transcription of developmental genes. Upon a possible future intensification of blooms associated with ocean warming and acidification, our work puts an alert on the potential impact that an increase of biotoxins may have on marine food webs, and points to defensome genes as molecular biosensors that marine ecologists could use to monitor the genetic stress of natural populations exposed to microalgal blooms.
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Affiliation(s)
- Nuria P Torres-Águila
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Josep Martí-Solans
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Alfonso Ferrández-Roldán
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Alba Almazán
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Vittoria Roncalli
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Salvatore D'Aniello
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 80121, Napoli, Italy
| | - Giovanna Romano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Anna Palumbo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 80121, Napoli, Italy
| | - Ricard Albalat
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
| | - Cristian Cañestro
- Departament de Genètica, Microbiologia i Estadística and Institut de Recerca de la Biodiversitat (IRBio), Facultat de Biologia, Universitat de Barcelona. Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
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