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Caccavale F, Annona G, Subirana L, Escriva H, Bertrand S, D'Aniello S. Crosstalk between nitric oxide and retinoic acid pathways is essential for amphioxus pharynx development. eLife 2021; 10:e58295. [PMID: 34431784 PMCID: PMC8387019 DOI: 10.7554/elife.58295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/31/2021] [Indexed: 11/13/2022] Open
Abstract
During animal ontogenesis, body axis patterning is finely regulated by complex interactions among several signaling pathways. Nitric oxide (NO) and retinoic acid (RA) are potent morphogens that play a pivotal role in vertebrate development. Their involvement in axial patterning of the head and pharynx shows conserved features in the chordate phylum. Indeed, in the cephalochordate amphioxus, NO and RA are crucial for the correct development of pharyngeal structures. Here, we demonstrate the functional cooperation between NO and RA that occurs during amphioxus embryogenesis. During neurulation, NO modulates RA production through the transcriptional regulation of Aldh1a.2 that irreversibly converts retinaldehyde into RA. On the other hand, RA directly or indirectly regulates the transcription of Nos genes. This reciprocal regulation of NO and RA pathways is essential for the normal pharyngeal development in amphioxus and it could be conserved in vertebrates.
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Affiliation(s)
- Filomena Caccavale
- Department of Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn NapoliNapoliItaly
| | - Giovanni Annona
- Department of Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn NapoliNapoliItaly
| | - Lucie Subirana
- Sorbonne Université CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire OcéanologiqueBanyuls-sur-MerFrance
| | - Hector Escriva
- Sorbonne Université CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire OcéanologiqueBanyuls-sur-MerFrance
| | - Stephanie Bertrand
- Sorbonne Université CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire OcéanologiqueBanyuls-sur-MerFrance
| | - Salvatore D'Aniello
- Department of Biology and Evolution of Marine Organisms (BEOM), Stazione Zoologica Anton Dohrn NapoliNapoliItaly
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2
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Lin CY, Lu MYJ, Yue JX, Li KL, Le Pétillon Y, Yong LW, Chen YH, Tsai FY, Lyu YF, Chen CY, Hwang SPL, Su YH, Yu JK. Molecular asymmetry in the cephalochordate embryo revealed by single-blastomere transcriptome profiling. PLoS Genet 2021; 16:e1009294. [PMID: 33382716 PMCID: PMC7806126 DOI: 10.1371/journal.pgen.1009294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/13/2021] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Studies in various animals have shown that asymmetrically localized maternal transcripts play important roles in axial patterning and cell fate specification in early embryos. However, comprehensive analyses of the maternal transcriptomes with spatial information are scarce and limited to a handful of model organisms. In cephalochordates (amphioxus), an early branching chordate group, maternal transcripts of germline determinants form a compact granule that is inherited by a single blastomere during cleavage stages. Further blastomere separation experiments suggest that other transcripts associated with the granule are likely responsible for organizing the posterior structure in amphioxus; however, the identities of these determinants remain unknown. In this study, we used high-throughput RNA sequencing of separated blastomeres to examine asymmetrically localized transcripts in two-cell and eight-cell stage embryos of the amphioxus Branchiostoma floridae. We identified 111 and 391 differentially enriched transcripts at the 2-cell stage and the 8-cell stage, respectively, and used in situ hybridization to validate the spatial distribution patterns for a subset of these transcripts. The identified transcripts could be categorized into two major groups: (1) vegetal tier/germ granule-enriched and (2) animal tier/anterior-enriched transcripts. Using zebrafish as a surrogate model system, we showed that overexpression of one animal tier/anterior-localized amphioxus transcript, zfp665, causes a dorsalization/anteriorization phenotype in zebrafish embryos by downregulating the expression of the ventral gene, eve1, suggesting a potential function of zfp665 in early axial patterning. Our results provide a global transcriptomic blueprint for early-stage amphioxus embryos. This dataset represents a rich platform to guide future characterization of molecular players in early amphioxus development and to elucidate conservation and divergence of developmental programs during chordate evolution.
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Affiliation(s)
- Che-Yi Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Mei-Yeh Jade Lu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jia-Xing Yue
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Kun-Lung Li
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yann Le Pétillon
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Luok Wen Yong
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Hua Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Fu-Yu Tsai
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Feng Lyu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Yi Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Sheng-Ping L. Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Hsien Su
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (Y-HS); (J-KY)
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Yilan, Taiwan
- * E-mail: (Y-HS); (J-KY)
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3
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Coppola U, Caccavale F, Scelzo M, Holland ND, Ristoratore F, D’Aniello S. Ran GTPase, an eukaryotic gene novelty, is involved in amphioxus mitosis. PLoS One 2018; 13:e0196930. [PMID: 30300344 PMCID: PMC6177115 DOI: 10.1371/journal.pone.0196930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 04/23/2018] [Indexed: 01/19/2023] Open
Abstract
Ran (ras-related nuclear protein) is a small GTPase belonging to the RAS superfamily that is specialized in nuclear trafficking. Through different accessory proteins, Ran plays key roles in several processes including nuclear import-export, mitotic progression and spindle assembly. Consequently, Ran dysfunction has been linked to several human pathologies. This work illustrates the high degree of amino acid conservation of Ran orthologues across evolution, reflected in its conserved role in nuclear trafficking. Moreover, we studied the evolutionary scenario of the pre-metazoan genetic linkage between Ran and Stx, and we hypothesized that chromosomal proximity of these two genes across metazoans could be related to a regulatory logic or a functional linkage. We studied, for the first time, Ran expression during amphioxus development and reported its presence in the neural vesicle, mouth, gill slits and gut corresponding to body regions involved in active cell division.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Filomena Caccavale
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Marta Scelzo
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
- Laboratory of Developmental Biology of Villefranche sur Mer, UMR7009 CNRS/UPMC Observatoire Océanologique, Villefranche sur Mer, France
| | - Nicholas D. Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, United States of America
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
| | - Salvatore D’Aniello
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Villa Comunale, Napoli, Italy
- * E-mail:
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Shi C, Huang J, Chen S, Li G, Wang Y. Generation of two transgenic amphioxus lines using the Tol2 transposon system. J Genet Genomics 2018; 45:513-516. [PMID: 30268359 DOI: 10.1016/j.jgg.2018.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 05/06/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Chenggang Shi
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China
| | - Jing Huang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Shixi Chen
- College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China; State-Province Joint Engineering Laboratory of Marine Bioproducts and Technology, Xiamen University, Xiamen 361102, China
| | - Guang Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.
| | - Yiquan Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen 361102, China.
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Zhang Z, Shi Y, Yang S, Xing D. Subdiffraction-limited second harmonic photoacoustic microscopy based on nonlinear thermal diffusion. Opt Lett 2018; 43:2336-2339. [PMID: 29762586 DOI: 10.1364/ol.43.002336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/21/2018] [Indexed: 05/26/2023]
Abstract
We have developed a second harmonic photoacoustic microscopy (SH-PAM) for subdiffraction-limited imaging based on nonlinear thermal diffusion. When a sine-modulated Gaussian temperature field is introduced by a laser beam, the temperature dependence of the thermal diffusivity induces a nonlinear photoacoustic (PA) effect and thus results in the production of second harmonic PA signals. We demonstrate through both simulation and experiment that the second harmonic PA images can be reconstructed with a lateral resolution exceeding that of conventional optical resolution PA microscopy. The feasibility of SH-PAM was verified on phantom samples. Amphioxus zygotes and germinated pollens have been studied by SH-PAM to demonstrate its biomedical imaging capability. This method expands the scope of conventional PA imaging and opens up new possibilities for super-resolution imaging, prefiguring great potential for biological imaging and material inspection.
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Soukup V, Kozmik Z. The Bmp signaling pathway regulates development of left-right asymmetry in amphioxus. Dev Biol 2018; 434:164-174. [PMID: 29224891 DOI: 10.1016/j.ydbio.2017.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 12/05/2017] [Accepted: 12/05/2017] [Indexed: 01/31/2023]
Abstract
Establishment of asymmetry along the left-right (LR) body axis in vertebrates requires interplay between Nodal and Bmp signaling pathways. In the basal chordate amphioxus, the left-sided activity of the Nodal signaling has been attributed to the asymmetric morphogenesis of paraxial structures and pharyngeal organs, however the role of Bmp signaling in LR asymmetry establishment has not been addressed to date. Here, we show that Bmp signaling is necessary for the development of LR asymmetric morphogenesis of amphioxus larvae through regulation of Nodal signaling. Loss of Bmp signaling results in loss of the left-sided expression of Nodal, Gdf1/3, Lefty and Pitx and in gain of ectopic expression of Cerberus on the left side. As a consequence, the larvae display loss of the offset arrangement of axial structures, loss of the left-sided pharyngeal organs including the mouth, and ectopic development of the right-sided organs on the left side. Bmp inhibition thus phenocopies inhibition of Nodal signaling and results in the right isomerism. We conclude that Bmp and Nodal pathways act in concert to specify the left side and that Bmp signaling plays a fundamental role during LR development in amphioxus.
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Affiliation(s)
- Vladimir Soukup
- Institute of Molecular Genetics, The Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic.
| | - Zbynek Kozmik
- Institute of Molecular Genetics, The Czech Academy of Sciences, Videnska 1083, 14220 Prague, Czech Republic
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Albuixech-Crespo B, López-Blanch L, Burguera D, Maeso I, Sánchez-Arrones L, Moreno-Bravo JA, Somorjai I, Pascual-Anaya J, Puelles E, Bovolenta P, Garcia-Fernàndez J, Puelles L, Irimia M, Ferran JL. Molecular regionalization of the developing amphioxus neural tube challenges major partitions of the vertebrate brain. PLoS Biol 2017; 15:e2001573. [PMID: 28422959 PMCID: PMC5396861 DOI: 10.1371/journal.pbio.2001573] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/22/2017] [Indexed: 11/25/2022] Open
Abstract
All vertebrate brains develop following a common Bauplan defined by anteroposterior (AP) and dorsoventral (DV) subdivisions, characterized by largely conserved differential expression of gene markers. However, it is still unclear how this Bauplan originated during evolution. We studied the relative expression of 48 genes with key roles in vertebrate neural patterning in a representative amphioxus embryonic stage. Unlike nonchordates, amphioxus develops its central nervous system (CNS) from a neural plate that is homologous to that of vertebrates, allowing direct topological comparisons. The resulting genoarchitectonic model revealed that the amphioxus incipient neural tube is unexpectedly complex, consisting of several AP and DV molecular partitions. Strikingly, comparison with vertebrates indicates that the vertebrate thalamus, pretectum, and midbrain domains jointly correspond to a single amphioxus region, which we termed Di-Mesencephalic primordium (DiMes). This suggests that these domains have a common developmental and evolutionary origin, as supported by functional experiments manipulating secondary organizers in zebrafish and mice.
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Affiliation(s)
- Beatriz Albuixech-Crespo
- Department of Genetics, School of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain
| | - Laura López-Blanch
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Demian Burguera
- Department of Genetics, School of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Ignacio Maeso
- Centro Andaluz de Biología del Desarrollo (CSIC/UPO/JA), Sevilla, Spain
| | - Luisa Sánchez-Arrones
- Centro de Biología Molecular Severo Ochoa CSIC-UAM and CIBERER, ISCIII, Madrid, Spain
| | | | - Ildiko Somorjai
- The Scottish Oceans Institute, University of St Andrews, St Andrews, Fife, Scotland, United Kingdom
- Biomedical Sciences Research Complex, University of St Andrews, Fife, Scotland, United Kingdom
| | | | - Eduardo Puelles
- Instituto de Neurociencias, UMH-CSIC, Campus de San Juan, Sant Joan d'Alacant, Alicante, Spain
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa CSIC-UAM and CIBERER, ISCIII, Madrid, Spain
| | - Jordi Garcia-Fernàndez
- Department of Genetics, School of Biology, and Institut de Biomedicina (IBUB), University of Barcelona, Barcelona, Spain
| | - Luis Puelles
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia (IMIB), Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Manuel Irimia
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - José Luis Ferran
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, Murcia, Spain
- Institute of Biomedical Research of Murcia (IMIB), Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
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8
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Lowe JWE. Normal development and experimental embryology: Edmund Beecher Wilson and Amphioxus. Stud Hist Philos Biol Biomed Sci 2016; 57:44-59. [PMID: 27054569 DOI: 10.1016/j.shpsc.2016.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/26/2016] [Accepted: 03/21/2016] [Indexed: 06/05/2023]
Abstract
This paper concerns the concept of normal development, and how it is enacted in experimental procedures. To that end, I use an historical case study to assess the three ways in which normal development is and has been produced, used, and interpreted in the practice of experimental biology. I argue that each of these approaches involves different processes of abstraction, which manage biological variation differently. I then document the way in which Edmund Beecher Wilson, a key contributor to late-nineteenth century experimental embryology, approached the study of normal development and show that his work does not fit any of the three established categories in the taxonomy. On the basis of this new case study, I present a new interpretation of normal development as a methodological norm which operates as a technical condition in various experimental systems. I close by suggesting the questions, and ways of investigating developmental biology, that are opened up by this perspective.
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Affiliation(s)
- James W E Lowe
- Department of Sociology, Philosophy and Anthropology, and Egenis, The Centre for the Study of Life Sciences, University of Exeter, UK.
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Bertrand S, Aldea D, Oulion S, Subirana L, de Lera AR, Somorjai I, Escriva H. Evolution of the Role of RA and FGF Signals in the Control of Somitogenesis in Chordates. PLoS One 2015; 10:e0136587. [PMID: 26371756 PMCID: PMC4570818 DOI: 10.1371/journal.pone.0136587] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 08/05/2015] [Indexed: 11/18/2022] Open
Abstract
During vertebrate development, the paraxial mesoderm becomes segmented, forming somites that will give rise to dermis, axial skeleton and skeletal muscles. Although recently challenged, the "clock and wavefront" model for somitogenesis explains how interactions between several cell-cell communication pathways, including the FGF, RA, Wnt and Notch signals, control the formation of these bilateral symmetric blocks. In the cephalochordate amphioxus, which belongs to the chordate phylum together with tunicates and vertebrates, the dorsal paraxial mesendoderm also periodically forms somites, although this process is asymmetric and extends along the whole body. It has been previously shown that the formation of the most anterior somites in amphioxus is dependent upon FGF signalling. However, the signals controlling somitogenesis during posterior elongation in amphioxus are still unknown. Here we show that, contrary to vertebrates, RA and FGF signals act independently during posterior elongation and that they are not mandatory for posterior somites to form. Moreover, we show that RA is not able to buffer the left/right asymmetry machinery that is controlled through the asymmetric expression of Nodal pathway actors. Our results give new insights into the evolution of the somitogenesis process in chordates. They suggest that RA and FGF pathways have acquired specific functions in the control of somitogenesis in vertebrates. We propose that the "clock and wavefront" system was selected specifically in vertebrates in parallel to the development of more complex somite-derived structures but that it was not required for somitogenesis in the ancestor of chordates.
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Affiliation(s)
- Stéphanie Bertrand
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
- * E-mail: (SB); (HE)
| | - Daniel Aldea
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
| | - Silvan Oulion
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
| | - Lucie Subirana
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
| | - Angel R. de Lera
- Departamento de Química Orgánica, Facultade de Química, CINBIO, Universidade de Vigo, and Instituto de Investigación Biomédica de Vigo (IBIV), Vigo, Spain
| | - Ildiko Somorjai
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
| | - Hector Escriva
- UPMC Univ Paris 06, UMR 7232, BIOM, Observatoire Océanologique de Banyuls sur Mer, F-66650, Banyuls/Mer, France
- * E-mail: (SB); (HE)
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Holland ND, Holland LZ, Heimberg A. Hybrids between the Florida amphioxus (Branchiostoma floridae) and the Bahamas lancelet (Asymmetron lucayanum): developmental morphology and chromosome counts. Biol Bull 2015; 228:13-24. [PMID: 25745097 DOI: 10.1086/bblv228n1p13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The cephalochordate genera Branchiostoma and Asymmetron diverged during the Mesozoic Era. In spite of the long separation of the parental clades, eggs of the Florida amphioxus, B. floridae, when fertilized with sperm of the Bahamas lancelet, A. lucayanum (and vice versa), develop through embryonic and larval stages. The larvae reach the chordate phylotypic stage (i.e., the pharyngula), characterized by a dorsal nerve cord, notochord, perforate pharynx, and segmented trunk musculature. After about 2 weeks of larval development, the hybrids die, as do the A. lucayanum purebreds, although all were eating the same algal diet that sustains B. floridae purebreds through adulthood in the laboratory; it is thus unclear whether death of the hybrids results from incompatible parental genomes or an inadequate diet. The diploid chromosome count in A. lucayanum and B. floridae purebreds is, respectively, 34 and 38, whereas it is 36 in hybrids in either direction. The hybrid larvae exhibit several morphological characters intermediate between those of the parents, including the size of the preoral ciliated pit and the angles of deflection of the gill slits and anus from the ventral midline. Based on the time since the two parent clades diverged (120 or 160 million years, respectively, by nuclear and mitochondrial gene analysis), the cross between Branchiostoma and Asymmetron is the most extreme example of hybridization that has ever been unequivocally demonstrated among multicellular animals.
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Affiliation(s)
- Nicholas D Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0202; and
| | - Linda Z Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California 92093-0202; and
| | - Alysha Heimberg
- EMBL Australia, Medicine, Nursing and Health Sciences, Clayton Campus, Monash University, Melbourne 3800, Australia
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Li WY, Wang YQ. [Establishment of full-sib families of Branchiostoma japonicum and the relationship between early development patterns and larvae survival rates]. Dongwuxue Yanjiu 2013; 34:446-452. [PMID: 24115654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
One general requirement of individual laboratory animals is that they have known genetic backgrounds. However, ensuring such genetic similarity is difficult, and can be facilitated by breeding a full strain for experimentation. To this end, the authors bred 34 full-sib families of amphioxus larvae/embryos. Due to the high mortality of the embryos and larvae, only seven full-sib families of juvenile amphioxus Branchiostoma japonicum were obtained. Among them, the highest and lowest survival ratios were 32.4% and 1.67%, respectively, whereas the shortest metamorphosis and longest larva duration were 24 d and 42 d, respectively. These results demonstrate the feasibility of establishing full-sib families of amphioxus, and provide fundamental data needed for the future breeding of amphioxus strains.
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Affiliation(s)
- Wei-Ye Li
- School of Life Sciences, Xiamen University, Xiamen 361005, China.
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