1
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Schnitzler CE, Chang ES, Waletich J, Quiroga-Artigas G, Wong WY, Nguyen AD, Barreira SN, Doonan LB, Gonzalez P, Koren S, Gahan JM, Sanders SM, Bradshaw B, DuBuc TQ, Febrimarsa, de Jong D, Nawrocki EP, Larson A, Klasfeld S, Gornik SG, Moreland RT, Wolfsberg TG, Phillippy AM, Mullikin JC, Simakov O, Cartwright P, Nicotra M, Frank U, Baxevanis AD. The genome of the colonial hydroid Hydractinia reveals that their stem cells use a toolkit of evolutionarily shared genes with all animals. Genome Res 2024; 34:498-513. [PMID: 38508693 PMCID: PMC11067881 DOI: 10.1101/gr.278382.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
Hydractinia is a colonial marine hydroid that shows remarkable biological properties, including the capacity to regenerate its entire body throughout its lifetime, a process made possible by its adult migratory stem cells, known as i-cells. Here, we provide an in-depth characterization of the genomic structure and gene content of two Hydractinia species, Hydractinia symbiolongicarpus and Hydractinia echinata, placing them in a comparative evolutionary framework with other cnidarian genomes. We also generated and annotated a single-cell transcriptomic atlas for adult male H. symbiolongicarpus and identified cell-type markers for all major cell types, including key i-cell markers. Orthology analyses based on the markers revealed that Hydractinia's i-cells are highly enriched in genes that are widely shared amongst animals, a striking finding given that Hydractinia has a higher proportion of phylum-specific genes than any of the other 41 animals in our orthology analysis. These results indicate that Hydractinia's stem cells and early progenitor cells may use a toolkit shared with all animals, making it a promising model organism for future exploration of stem cell biology and regenerative medicine. The genomic and transcriptomic resources for Hydractinia presented here will enable further studies of their regenerative capacity, colonial morphology, and ability to distinguish self from nonself.
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Affiliation(s)
- Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
- Department of Biology, University of Florida, Gainesville, Florida 32611, USA
| | - E Sally Chang
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Justin Waletich
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
- Department of Biology, University of Florida, Gainesville, Florida 32611, USA
| | - Gonzalo Quiroga-Artigas
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
- Department of Biology, University of Florida, Gainesville, Florida 32611, USA
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, Centre National de la Recherche Scientifique, 34293 Montpellier CEDEX 05, France
| | - Wai Yee Wong
- Department for Neurosciences and Developmental Biology, University of Vienna, 1030 Vienna, Austria
| | - Anh-Dao Nguyen
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Sofia N Barreira
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Liam B Doonan
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
| | - Paul Gonzalez
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Sergey Koren
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - James M Gahan
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Steven M Sanders
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Brian Bradshaw
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
| | - Timothy Q DuBuc
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
- Department of Biology, Swarthmore College, Swarthmore, Pennsylvania 19081, USA
| | - Febrimarsa
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
- Pharmaceutical Biology Laboratory, Faculty of Pharmacy, Universitas Muhammadiyah Surakarta, Jawa Tengah 57169, Indonesia
| | - Danielle de Jong
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
- Department of Biology, University of Florida, Gainesville, Florida 32611, USA
| | - Eric P Nawrocki
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Alexandra Larson
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, Florida 32080, USA
| | - Samantha Klasfeld
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Sebastian G Gornik
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
- Center for Organismal Studies, University of Heidelberg, 69117 Heidelberg, Germany
| | - R Travis Moreland
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Tyra G Wolfsberg
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Adam M Phillippy
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - James C Mullikin
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
- NIH Intramural Sequencing Center, Rockville, Maryland 20852, USA
| | - Oleg Simakov
- Department for Neurosciences and Developmental Biology, University of Vienna, 1030 Vienna, Austria
| | - Paulyn Cartwright
- Department of Evolution and Ecology, University of Kansas, Lawrence, Kansas 66045, USA
| | - Matthew Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
| | - Uri Frank
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway H91 W2TY, Ireland
| | - Andreas D Baxevanis
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;
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2
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Plessy C, Mansfield MJ, Bliznina A, Masunaga A, West C, Tan Y, Liu AW, Grašič J, Del Río Pisula MS, Sánchez-Serna G, Fabrega-Torrus M, Ferrández-Roldán A, Roncalli V, Navratilova P, Thompson EM, Onuma T, Nishida H, Cañestro C, Luscombe NM. Extreme genome scrambling in marine planktonic Oikopleura dioica cryptic species. Genome Res 2024; 34:426-440. [PMID: 38621828 PMCID: PMC11067885 DOI: 10.1101/gr.278295.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 02/28/2024] [Indexed: 04/17/2024]
Abstract
Genome structural variations within species are rare. How selective constraints preserve gene order and chromosome structure is a central question in evolutionary biology that remains unsolved. Our sequencing of several genomes of the appendicularian tunicate Oikopleura dioica around the globe reveals extreme genome scrambling caused by thousands of chromosomal rearrangements, although showing no obvious morphological differences between these animals. The breakpoint accumulation rate is an order of magnitude higher than in ascidian tunicates, nematodes, Drosophila, or mammals. Chromosome arms and sex-specific regions appear to be the primary unit of macrosynteny conservation. At the microsyntenic level, scrambling did not preserve operon structures, suggesting an absence of selective pressure to maintain them. The uncoupling of the genome scrambling with morphological conservation in O. dioica suggests the presence of previously unnoticed cryptic species and provides a new biological system that challenges our previous vision of speciation in which similar animals always share similar genome structures.
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Affiliation(s)
- Charles Plessy
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan;
| | - Michael J Mansfield
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Aleksandra Bliznina
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Aki Masunaga
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Charlotte West
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Yongkai Tan
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Andrew W Liu
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Jan Grašič
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - María Sara Del Río Pisula
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
| | - Gaspar Sánchez-Serna
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Spain
| | - Marc Fabrega-Torrus
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Spain
| | - Alfonso Ferrández-Roldán
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Spain
| | - Vittoria Roncalli
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Spain
| | - Pavla Navratilova
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany, 779 00 Olomouc, Czech Republic
- Sars International Centre, University of Bergen, Bergen N-5008, Norway
| | - Eric M Thompson
- Sars International Centre, University of Bergen, Bergen N-5008, Norway
- Department of Biological Sciences, University of Bergen, Bergen N-5020, Norway
| | - Takeshi Onuma
- Faculty of Science, Kagoshima University, Kagoshima 890-0065, Japan
- 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
| | - Cristian Cañestro
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), Barcelona 08028, Spain
- Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Barcelona 08028, Spain
| | - Nicholas M Luscombe
- Genomics and Regulatory Systems Unit, Okinawa Institute of Science and Technology Graduate University (OIST), Onna-son, Okinawa 904-0495, Japan
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3
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Pan Q, Mercker M, Klimovich A, Wittlieb J, Marciniak-Czochra A, Böttger A. Genetic interference with HvNotch provides new insights into the role of the Notch-signalling pathway for developmental pattern formation in Hydra. Sci Rep 2024; 14:8553. [PMID: 38609434 PMCID: PMC11014954 DOI: 10.1038/s41598-024-58837-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
The Notch-signalling pathway plays an important role in pattern formation in Hydra. Using pharmacological Notch inhibitors (DAPT and SAHM1), it has been demonstrated that HvNotch is required for head regeneration and tentacle patterning in Hydra. HvNotch is also involved in establishing the parent-bud boundary and instructing buds to develop feet and detach from the parent. To further investigate the functions of HvNotch, we successfully constructed NICD (HvNotch intracellular domain)-overexpressing and HvNotch-knockdown transgenic Hydra strains. NICD-overexpressing transgenic Hydra showed a pronounced inhibition on the expression of predicted HvNotch-target genes, suggesting a dominant negative effect of ectopic NICD. This resulted in a "Y-shaped" phenotype, which arises from the parent-bud boundary defect seen in polyps treated with DAPT. Additionally, "multiple heads", "two-headed" and "ectopic tentacles" phenotypes were observed. The HvNotch-knockdown transgenic Hydra with reduced expression of HvNotch exhibited similar, but not identical phenotypes, with the addition of a "two feet" phenotype. Furthermore, we observed regeneration defects in both, overexpression and knockdown strains. We integrated these findings into a mathematical model based on long-range gradients of signalling molecules underlying sharply defined positions of HvNotch-signalling cells at the Hydra tentacle and bud boundaries.
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Affiliation(s)
- Qin Pan
- Biocenter, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany.
| | - Moritz Mercker
- Institute of Applied Mathematics, Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Alexander Klimovich
- Zoological Institute, Christian-Albrechts-University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Jörg Wittlieb
- Zoological Institute, Christian-Albrechts-University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Anna Marciniak-Czochra
- Institute of Applied Mathematics, Heidelberg University, Im Neuenheimer Feld 205, 69120, Heidelberg, Germany
| | - Angelika Böttger
- Biocenter, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152, Planegg-Martinsried, Germany.
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4
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Schnitzler CE, Chang ES, Waletich J, Quiroga-Artigas G, Wong WY, Nguyen AD, Barreira SN, Doonan L, Gonzalez P, Koren S, Gahan JM, Sanders SM, Bradshaw B, DuBuc TQ, Febrimarsa, de Jong D, Nawrocki EP, Larson A, Klasfeld S, Gornik SG, Moreland RT, Wolfsberg TG, Phillippy AM, Mullikin JC, Simakov O, Cartwright P, Nicotra M, Frank U, Baxevanis AD. The genome of the colonial hydroid Hydractinia reveals their stem cells utilize a toolkit of evolutionarily shared genes with all animals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554815. [PMID: 37786714 PMCID: PMC10541594 DOI: 10.1101/2023.08.25.554815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Hydractinia is a colonial marine hydroid that exhibits remarkable biological properties, including the capacity to regenerate its entire body throughout its lifetime, a process made possible by its adult migratory stem cells, known as i-cells. Here, we provide an in-depth characterization of the genomic structure and gene content of two Hydractinia species, H. symbiolongicarpus and H. echinata, placing them in a comparative evolutionary framework with other cnidarian genomes. We also generated and annotated a single-cell transcriptomic atlas for adult male H. symbiolongicarpus and identified cell type markers for all major cell types, including key i-cell markers. Orthology analyses based on the markers revealed that Hydractinia's i-cells are highly enriched in genes that are widely shared amongst animals, a striking finding given that Hydractinia has a higher proportion of phylum-specific genes than any of the other 41 animals in our orthology analysis. These results indicate that Hydractinia's stem cells and early progenitor cells may use a toolkit shared with all animals, making it a promising model organism for future exploration of stem cell biology and regenerative medicine. The genomic and transcriptomic resources for Hydractinia presented here will enable further studies of their regenerative capacity, colonial morphology, and ability to distinguish self from non-self.
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Affiliation(s)
- Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - E Sally Chang
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA
| | - Justin Waletich
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Gonzalo Quiroga-Artigas
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, Centre National de la Recherche Scientifique, 34293 Montpellier CEDEX 05, France
| | - Wai Yee Wong
- Department of Molecular Evolution and Development, Faculty of Life Science, University of Vienna, A-1090 Vienna, Austria
| | - Anh-Dao Nguyen
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sofia N Barreira
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Liam Doonan
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
| | - Paul Gonzalez
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sergey Koren
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - James M Gahan
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Steven M Sanders
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brian Bradshaw
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
| | - Timothy Q DuBuc
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
- Swarthmore College, Swarthmore, PA 19081, USA
| | - Febrimarsa
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
| | - Danielle de Jong
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Eric P Nawrocki
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alexandra Larson
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA
| | - Samantha Klasfeld
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sebastian G Gornik
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
- Centre for Organismal Studies, University of Heidelberg, Germany
| | - R Travis Moreland
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tyra G Wolfsberg
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Adam M Phillippy
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - James C Mullikin
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
- NIH Intramural Sequencing Center, Rockville, MD 20852, USA
| | - Oleg Simakov
- Department of Molecular Evolution and Development, Faculty of Life Science, University of Vienna, A-1090 Vienna, Austria
| | - Paulyn Cartwright
- Department of Evolution and Ecology, University of Kansas, Lawrence, KS 66045, USA
| | - Matthew Nicotra
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Pittsburgh Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Uri Frank
- Centre for Chromosome Biology, College of Science and Engineering, University of Galway, Galway, Ireland
| | - Andreas D Baxevanis
- Division of Intramural Research, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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5
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Alacid E, Irwin NAT, Smilansky V, Milner DS, Kilias ES, Leonard G, Richards TA. A diversified and segregated mRNA spliced-leader system in the parasitic Perkinsozoa. Open Biol 2022; 12:220126. [PMID: 36000319 PMCID: PMC9399869 DOI: 10.1098/rsob.220126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Spliced-leader trans-splicing (SLTS) has been described in distantly related eukaryotes and acts to mark mRNAs with a short 5′ exon, giving different mRNAs identical 5′ sequence-signatures. The function of these systems is obscure. Perkinsozoa encompasses a diversity of parasitic protists that infect bivalves, toxic-tide dinoflagellates, fish and frog tadpoles. Here, we report considerable sequence variation in the SLTS-system across the Perkinsozoa and find that multiple variant SLTS-systems are encoded in parallel in the ecologically important Perkinsozoa parasite Parvilucifera sinerae. These results demonstrate that the transcriptome of P. sinerae is segregated based on the addition of different spliced-leader (SL) exons. This segregation marks different gene categories, suggesting that SL-segregation relates to functional differentiation of the transcriptome. By contrast, both sets of gene categories are present in the single SL-transcript type sampled from Maranthos, implying that the SL-segregation of the Parvilucifera transcriptome is a recent evolutionary innovation. Furthermore, we show that the SLTS-system marks a subsection of the transcriptome with increased mRNA abundance and includes genes that encode the spliceosome system necessary for SLTS-function. Collectively, these data provide a picture of how the SLTS-systems can vary within a major evolutionary group and identify how additional transcriptional-complexity can be achieved through SL-segregation.
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Affiliation(s)
- Elisabet Alacid
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| | - Nicholas A T Irwin
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK.,Merton College, University of Oxford, Oxford, Oxfordshire OX1 4JD, UK
| | - Vanessa Smilansky
- Living Systems Institute, University of Exeter, Exeter, Devon EX4 4QD, UK
| | - David S Milner
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| | - Estelle S Kilias
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| | - Guy Leonard
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
| | - Thomas A Richards
- Department of Zoology, University of Oxford, Oxford, Oxfordshire OX1 3SZ, UK
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6
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Kawakami R, Taguchi T, Vacarizas J, Ito M, Mezaki T, Tominaga A, Kubota S. Karyotypic analysis and isolation of four DNA markers of the scleractinian coral Favitespentagona (Esper, 1795) (Scleractinia, Anthozoa, Cnidaria). COMPARATIVE CYTOGENETICS 2022; 16:77-92. [PMID: 35437459 PMCID: PMC9005458 DOI: 10.3897/compcytogen.v16.i1.79953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/05/2022] [Indexed: 05/29/2023]
Abstract
We performed conventional and molecular cytogenetic studies on the Favitespentagona Esper, 1795, a scleractinian coral mostly found along the west coast of Japan. Karyotype analysis of F.pentagona by G-banding revealed a karyogram containing a homogenously staining region (HSR) on chromosome 10 in more than 50% of the examined metaphase spreads. This HSR consisted of sequences from 18S ribosomal RNA (rRNA) genes, as demonstrated by fluorescence in situ hybridization (FISH) and DNA sequencing. We highlighted the development of four chromosomal FISH markers from repetitive genes such as U2 small nuclear RNA linked to 5S rRNA sequence (U2 snRNA-5S), 18S rRNA, histone H3, and uncharacterized gene FP-9X. The chromosomal locations of the U2 snRNA-5S and 18S RNA were on the terminal end of long arm of chromosomes 2 and 10, respectively, while the histone H3 and the uncharacterized gene were located near the centromeres of chromosomes 1 and 9, respectively. These FISH markers will improve the karyotyping of F.pentagona from mitotic preparations which helps in widening our understanding of coral genetic structure and chromosome organization. In addition, these improvements in karyotyping will provide the basis in constructing of chromosome-level genome assembly for F.pentagona.
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Affiliation(s)
- Rei Kawakami
- Agriculture and Marine Science Program, Graduate School of Integrated Arts and Sciences, Kochi University, Kohasu, Oko-Cho, Nankoku, Kochi 783-8505, Japan
| | - Takahiro Taguchi
- Department of Nutrition, Faculty of Health Science, Kochi Gakuen University, 292-26 Asahitenjin-Cho, Kochi 780-0955, Japan
- Kuroshio Science Unit, Multidisciplinary Science Cluster, Kochi University, Kohasu, Oko-Cho, Nankoku, Kochi 783-8505, Japan
| | - Joshua Vacarizas
- Kuroshio Science Program, Graduate School of Integrated Arts and Sciences, Kochi University, Kohasu, Oko-Cho, Nankoku, Kochi 783-8505, Japan
| | - Masumi Ito
- Faculty of Agriculture and Marine Science, Kochi University, 200 Otsu, Monobe, Kochi 783-8502, Japan
- Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-Cho, Hakodate, Hokkaido, 041-8611, Japan
| | - Takuma Mezaki
- Kuroshio Biological Research Foundation, Otsuki, Hata County, Kochi 788-0333, Japan
| | - Akira Tominaga
- Kuroshio Science Program, Graduate School of Integrated Arts and Sciences, Kochi University, Kohasu, Oko-Cho, Nankoku, Kochi 783-8505, Japan
| | - Satoshi Kubota
- Kuroshio Science Unit, Multidisciplinary Science Cluster, Kochi University, Kohasu, Oko-Cho, Nankoku, Kochi 783-8505, Japan
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7
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Moneer J, Siebert S, Krebs S, Cazet J, Prexl A, Pan Q, Juliano C, Böttger A. Differential gene regulation in DAPT-treated Hydra reveals candidate direct Notch signalling targets. J Cell Sci 2021; 134:jcs258768. [PMID: 34346482 PMCID: PMC8353520 DOI: 10.1242/jcs.258768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/03/2021] [Indexed: 11/20/2022] Open
Abstract
In Hydra, Notch inhibition causes defects in head patterning and prevents differentiation of proliferating nematocyte progenitor cells into mature nematocytes. To understand the molecular mechanisms by which the Notch pathway regulates these processes, we performed RNA-seq and identified genes that are differentially regulated in response to 48 h of treating the animals with the Notch inhibitor DAPT. To identify candidate direct regulators of Notch signalling, we profiled gene expression changes that occur during subsequent restoration of Notch activity and performed promoter analyses to identify RBPJ transcription factor-binding sites in the regulatory regions of Notch-responsive genes. Interrogating the available single-cell sequencing data set revealed the gene expression patterns of Notch-regulated Hydra genes. Through these analyses, a comprehensive picture of the molecular pathways regulated by Notch signalling in head patterning and in interstitial cell differentiation in Hydra emerged. As prime candidates for direct Notch target genes, in addition to Hydra (Hy)Hes, we suggest Sp5 and HyAlx. They rapidly recovered their expression levels after DAPT removal and possess Notch-responsive RBPJ transcription factor-binding sites in their regulatory regions.
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Affiliation(s)
- Jasmin Moneer
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Stefan Krebs
- Ludwig-Maximilians-University Munich, Gene Center Munich, Feodor-Lynen-Str. 25 81377 Munich, Germany
| | - Jack Cazet
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Andrea Prexl
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Qin Pan
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
| | - Celina Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Angelika Böttger
- Ludwig Maximilians-University Munich, Germany, Biocenter, 82152 Planegg-Martinsried, Großhaderner Str. 2, Germany
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8
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Cytogenetic markers using single-sequence probes reveal chromosomal locations of tandemly repetitive genes in scleractinian coral Acropora pruinosa. Sci Rep 2021; 11:11326. [PMID: 34059722 PMCID: PMC8167085 DOI: 10.1038/s41598-021-90580-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/13/2021] [Indexed: 02/04/2023] Open
Abstract
The short and similar sized chromosomes of Acropora pose a challenge for karyotyping. Conventional methods, such as staining of heterochromatic regions, provide unclear banding patterns that hamper identification of such chromosomes. In this study, we used short single-sequence probes from tandemly repetitive 5S ribosomal RNA (rRNA) and core histone coding sequences to identify specific chromosomes of Acropora pruinosa. Both the probes produced intense signals in fluorescence in situ hybridization, which distinguished chromosome pairs. The locus of the 5S rDNA probe was on chromosome 5, whereas that of core histone probe was on chromosome 8. The sequence of the 5S rDNA probe was composed largely of U1 and U2 spliceosomal small nuclear RNA (snRNA) genes and their interspacers, flanked by short sequences of the 5S rDNA. This is the first report of a tandemly repetitive linkage of snRNA and 5S rDNA sequences in Cnidaria. Based on the constructed tentative karyogram and whole genome hybridization, the longest chromosome pair (chromosome 1) was heteromorphic. The probes also hybridized effectively with chromosomes of other Acropora species and population, revealing an additional core histone gene locus. We demonstrated the applicability of short-sequence probes as chromosomal markers with potential for use across populations and species of Acropora.
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9
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Islas-Flores T, Galán-Vásquez E, Villanueva MA. Screening a Spliced Leader-Based Symbiodinium microadriaticum cDNA Library Using the Yeast-Two Hybrid System Reveals a Hemerythrin-Like Protein as a Putative SmicRACK1 Ligand. Microorganisms 2021; 9:microorganisms9040791. [PMID: 33918967 PMCID: PMC8070245 DOI: 10.3390/microorganisms9040791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/13/2021] [Accepted: 03/16/2021] [Indexed: 11/16/2022] Open
Abstract
The dinoflagellate Symbiodiniaceae family plays a central role in the health of the coral reef ecosystem via the symbiosis that establishes with its inhabiting cnidarians and supports the host metabolism. In the last few decades, coral reefs have been threatened by pollution and rising temperatures which have led to coral loss. These events have raised interest in studying Symbiodiniaceae and their hosts; however, progress in understanding their metabolism, signal transduction pathways, and physiology in general, has been slow because dinoflagellates present peculiar characteristics. We took advantage of one of these peculiarities; namely, the post-transcriptional addition of a Dino Spliced Leader (Dino-SL) to the 5' end of the nuclear mRNAs, and used it to generate cDNA libraries from Symbiodinium microadriaticum. We compared sequences from two Yeast-Two Hybrid System cDNA Libraries, one based on the Dino-SL sequence, and the other based on the SMART technology (Switching Mechanism at 5' end of RNA Transcript) which exploits the template switching function of the reverse transcriptase. Upon comparison of the performance of both libraries, we obtained a significantly higher yield, number and length of sequences, number of transcripts, and better 5' representation from the Dino-SL based library than from the SMART library. In addition, we confirmed that the cDNAs from the Dino-SL library were adequately expressed in the yeast cells used for the Yeast-Two Hybrid System which resulted in successful screening for putative SmicRACK1 ligands, which yielded a putative hemerythrin-like protein.
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Affiliation(s)
- Tania Islas-Flores
- Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, UNAM, Prolongación Avenida Niños Héroes S/N, Puerto Morelos, Quintana Roo 77580, México
- Correspondence: (T.I.-F.); (M.A.V.); Tel.: +52-998-871-0009 (T.I.-F. & M.A.V.)
| | - Edgardo Galán-Vásquez
- Departamento de Ingeniería de Sistemas Computacionales y Automatización, Instituto de Investigación en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, UNAM, Circuito Escolar 3000, Ciudad Universitaria, Ciudad de México CP 04510, México;
| | - Marco A. Villanueva
- Unidad Académica de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, UNAM, Prolongación Avenida Niños Héroes S/N, Puerto Morelos, Quintana Roo 77580, México
- Correspondence: (T.I.-F.); (M.A.V.); Tel.: +52-998-871-0009 (T.I.-F. & M.A.V.)
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10
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Wenzel MA, Müller B, Pettitt J. SLIDR and SLOPPR: flexible identification of spliced leader trans-splicing and prediction of eukaryotic operons from RNA-Seq data. BMC Bioinformatics 2021; 22:140. [PMID: 33752599 PMCID: PMC7986045 DOI: 10.1186/s12859-021-04009-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/08/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Spliced leader (SL) trans-splicing replaces the 5' end of pre-mRNAs with the spliced leader, an exon derived from a specialised non-coding RNA originating from elsewhere in the genome. This process is essential for resolving polycistronic pre-mRNAs produced by eukaryotic operons into monocistronic transcripts. SL trans-splicing and operons may have independently evolved multiple times throughout Eukarya, yet our understanding of these phenomena is limited to only a few well-characterised organisms, most notably C. elegans and trypanosomes. The primary barrier to systematic discovery and characterisation of SL trans-splicing and operons is the lack of computational tools for exploiting the surge of transcriptomic and genomic resources for a wide range of eukaryotes. RESULTS Here we present two novel pipelines that automate the discovery of SLs and the prediction of operons in eukaryotic genomes from RNA-Seq data. SLIDR assembles putative SLs from 5' read tails present after read alignment to a reference genome or transcriptome, which are then verified by interrogating corresponding SL RNA genes for sequence motifs expected in bona fide SL RNA molecules. SLOPPR identifies RNA-Seq reads that contain a given 5' SL sequence, quantifies genome-wide SL trans-splicing events and predicts operons via distinct patterns of SL trans-splicing events across adjacent genes. We tested both pipelines with organisms known to carry out SL trans-splicing and organise their genes into operons, and demonstrate that (1) SLIDR correctly detects expected SLs and often discovers novel SL variants; (2) SLOPPR correctly identifies functionally specialised SLs, correctly predicts known operons and detects plausible novel operons. CONCLUSIONS SLIDR and SLOPPR are flexible tools that will accelerate research into the evolutionary dynamics of SL trans-splicing and operons throughout Eukarya and improve gene discovery and annotation for a wide range of eukaryotic genomes. Both pipelines are implemented in Bash and R and are built upon readily available software commonly installed on most bioinformatics servers. Biological insight can be gleaned even from sparse, low-coverage datasets, implying that an untapped wealth of information can be retrieved from existing RNA-Seq datasets as well as from novel full-isoform sequencing protocols as they become more widely available.
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Affiliation(s)
- Marius A Wenzel
- School of Biological Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK.
| | - Berndt Müller
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, UK
| | - Jonathan Pettitt
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, AB25 2ZD, UK
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11
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Calvelo J, Juan H, Musto H, Koziol U, Iriarte A. SLFinder, a pipeline for the novel identification of splice-leader sequences: a good enough solution for a complex problem. BMC Bioinformatics 2020; 21:293. [PMID: 32640978 PMCID: PMC7346339 DOI: 10.1186/s12859-020-03610-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 06/17/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Spliced Leader trans-splicing is an important mechanism for the maturation of mRNAs in several lineages of eukaryotes, including several groups of parasites of great medical and economic importance. Nevertheless, its study across the tree of life is severely hindered by the problem of identifying the SL sequences that are being trans-spliced. RESULTS In this paper we present SLFinder, a four-step pipeline meant to identify de novo candidate SL sequences making very few assumptions regarding the SL sequence properties. The pipeline takes transcriptomic de novo assemblies and a reference genome as input and allows the user intervention on several points to account for unexpected features of the dataset. The strategy and its implementation were tested on real RNAseq data from species with and without SL Trans-Splicing. CONCLUSIONS SLFinder is capable to identify SL candidates with good precision in a reasonable amount of time. It is especially suitable for species with unknown SL sequences, generating candidate sequences for further refining and experimental validation.
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Affiliation(s)
- Javier Calvelo
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Hernán Juan
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Héctor Musto
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Uriel Koziol
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
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12
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Siebert S, Farrell JA, Cazet JF, Abeykoon Y, Primack AS, Schnitzler CE, Juliano CE. Stem cell differentiation trajectories in Hydra resolved at single-cell resolution. Science 2019; 365:eaav9314. [PMID: 31346039 PMCID: PMC7104783 DOI: 10.1126/science.aav9314] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/11/2019] [Indexed: 12/31/2022]
Abstract
The adult Hydra polyp continually renews all of its cells using three separate stem cell populations, but the genetic pathways enabling this homeostatic tissue maintenance are not well understood. We sequenced 24,985 Hydra single-cell transcriptomes and identified the molecular signatures of a broad spectrum of cell states, from stem cells to terminally differentiated cells. We constructed differentiation trajectories for each cell lineage and identified gene modules and putative regulators expressed along these trajectories, thus creating a comprehensive molecular map of all developmental lineages in the adult animal. In addition, we built a gene expression map of the Hydra nervous system. Our work constitutes a resource for addressing questions regarding the evolution of metazoan developmental processes and nervous system function.
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Affiliation(s)
- Stefan Siebert
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA.
| | - Jeffrey A Farrell
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Jack F Cazet
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Yashodara Abeykoon
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Abby S Primack
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA
| | - Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience and Department of Biology, University of Florida, St. Augustine, FL, USA
| | - Celina E Juliano
- Department of Molecular and Cellular Biology, University of California, Davis, CA, USA.
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13
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Fugacium Spliced Leader Genes Identified from Stranded RNA-Seq Datasets. Microorganisms 2019; 7:microorganisms7060171. [PMID: 31212635 PMCID: PMC6616646 DOI: 10.3390/microorganisms7060171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 01/10/2023] Open
Abstract
Trans-splicing mechanisms have been documented in many lineages that are widely distributed phylogenetically, including dinoflagellates. The spliced leader (SL) sequence itself is conserved in dinoflagellates, although its gene sequences and arrangements have diversified within or across different species. In this study, we present 18 Fugacium kawagutii SL genes identified from stranded RNA-seq reads. These genes typically have a single SL but can contain several partial SLs with lengths ranging from 103 to 292 bp. Unexpectedly, we find the SL gene transcripts contain sequences upstream of the canonical SL, suggesting that generation of mature transcripts will require additional modifications following trans-splicing. We have also identified 13 SL-like genes whose expression levels and length are comparable to Dino-SL genes. Lastly, introns in these genes were identified and a new site for Sm-protein binding was proposed. Overall, this study provides a strategy for fast identification of SL genes and identifies new sequences of F. kawagutii SL genes to supplement our understanding of trans-splicing.
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14
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Barnes SN, Masonbrink RE, Maier TR, Seetharam A, Sindhu AS, Severin AJ, Baum TJ. Heterodera glycines utilizes promiscuous spliced leaders and demonstrates a unique preference for a species-specific spliced leader over C. elegans SL1. Sci Rep 2019; 9:1356. [PMID: 30718603 PMCID: PMC6362198 DOI: 10.1038/s41598-018-37857-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/13/2018] [Indexed: 12/30/2022] Open
Abstract
Spliced leader trans-splicing (SLTS) plays a part in the maturation of pre-mRNAs in select species across multiple phyla but is particularly prevalent in Nematoda. The role of spliced leaders (SL) within the cell is unclear and an accurate assessment of SL occurrence within an organism is possible only after extensive sequencing data are available, which is not currently the case for many nematode species. SL discovery is further complicated by an absence of SL sequences from high-throughput sequencing results due to incomplete sequencing of the 5'-ends of transcripts during RNA-seq library preparation, known as 5'-bias. Existing datasets and novel methodology were used to identify both conserved SLs and unique hypervariable SLs within Heterodera glycines, the soybean cyst nematode. In H. glycines, twenty-one distinct SL sequences were found on 2,532 unique H. glycines transcripts. The SL sequences identified on the H. glycines transcripts demonstrated a high level of promiscuity, meaning that some transcripts produced as many as nine different individual SL-transcript combinations. Most uniquely, transcriptome analysis revealed that H. glycines is the first nematode to demonstrate a higher SL trans-splicing rate using a species-specific SL over well-conserved Caenorhabditis elegans SL-like sequences.
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Affiliation(s)
- Stacey N Barnes
- Plant Pathology & Microbiology Department, Iowa State University, Ames, IA, 50011, USA
| | - Rick E Masonbrink
- Office of Biotechnology, Genome Informatics Facility, Iowa State University, Ames, IA, 50011, USA
| | - Thomas R Maier
- Plant Pathology & Microbiology Department, Iowa State University, Ames, IA, 50011, USA
| | - Arun Seetharam
- Office of Biotechnology, Genome Informatics Facility, Iowa State University, Ames, IA, 50011, USA
| | | | - Andrew J Severin
- Office of Biotechnology, Genome Informatics Facility, Iowa State University, Ames, IA, 50011, USA
| | - Thomas J Baum
- Plant Pathology & Microbiology Department, Iowa State University, Ames, IA, 50011, USA.
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15
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Gold DA, Katsuki T, Li Y, Yan X, Regulski M, Ibberson D, Holstein T, Steele RE, Jacobs DK, Greenspan RJ. The genome of the jellyfish Aurelia and the evolution of animal complexity. Nat Ecol Evol 2018; 3:96-104. [PMID: 30510179 DOI: 10.1038/s41559-018-0719-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/12/2018] [Indexed: 11/09/2022]
Abstract
We present the genome of the moon jellyfish Aurelia, a genome from a cnidarian with a medusa life stage. Our analyses suggest that gene gain and loss in Aurelia is comparable to what has been found in its morphologically simpler relatives-the anthozoan corals and sea anemones. RNA sequencing analysis does not support the hypothesis that taxonomically restricted (orphan) genes play an oversized role in the development of the medusa stage. Instead, genes broadly conserved across animals and eukaryotes play comparable roles throughout the life cycle. All life stages of Aurelia are significantly enriched in the expression of genes that are hypothesized to interact in protein networks found in bilaterian animals. Collectively, our results suggest that increased life cycle complexity in Aurelia does not correlate with an increased number of genes. This leads to two possible evolutionary scenarios: either medusozoans evolved their complex medusa life stage (with concomitant shifts into new ecological niches) primarily by re-working genetic pathways already present in the last common ancestor of cnidarians, or the earliest cnidarians had a medusa life stage, which was subsequently lost in the anthozoans. While we favour the earlier hypothesis, the latter is consistent with growing evidence that many of the earliest animals were more physically complex than previously hypothesized.
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Affiliation(s)
- David A Gold
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. .,Department of Earth and Planetary Sciences, University of California Davis, Davis, CA, USA.
| | - Takeo Katsuki
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA, USA.
| | - Yang Li
- Department of Computer Science, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Xifeng Yan
- Department of Computer Science, University of California Santa Barbara, Santa Barbara, CA, USA
| | | | - David Ibberson
- Deep Sequencing Core Facility, Cell Networks, Heidelberg University, Heidelberg, Germany
| | - Thomas Holstein
- Department of Molecular Evolution and Genomics, Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | - Robert E Steele
- Department of Biological Chemistry and Developmental Biology Center, University of California Irvine, Irvine, CA, USA
| | - David K Jacobs
- Department of Ecology and Evolution, University of California Los Angeles, Los Angeles, CA, USA
| | - Ralph J Greenspan
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA, USA. .,Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA. .,Department of Cognitive Science, University of California San Diego, La Jolla, CA, USA.
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16
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Matsuo M, Katahata A, Satoh S, Matsuzaki M, Nomura M, Ishida KI, Inagaki Y, Obokata J. Characterization of spliced leader trans-splicing in a photosynthetic rhizarian amoeba, Paulinella micropora, and its possible role in functional gene transfer. PLoS One 2018; 13:e0200961. [PMID: 30024971 PMCID: PMC6053224 DOI: 10.1371/journal.pone.0200961] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/04/2018] [Indexed: 02/04/2023] Open
Abstract
Paulinella micropora is a rhizarian thecate amoeba, belonging to a photosynthetic Paulinella species group that has a unique organelle termed chromatophore, whose cyanobacterial origin is distinct from that of plant and algal chloroplasts. Because acquisition of the chromatophore was quite a recent event compared with that of the chloroplast ancestor, the Paulinella species are thought to be model organisms for studying the early process of primary endosymbiosis. To obtain insight into how endosymbiotically transferred genes acquire expression competence in the host nucleus, here we analyzed the 5′ end sequences of the mRNAs of P. micropora MYN1 strain with the aid of a cap-trapper cDNA library. As a result, we found that mRNAs of 27 genes, including endosymbiotically transferred genes, possessed the common 5′ end sequence of 28–33 bases that were posttranscriptionally added by spliced leader (SL) trans-splicing. We also found two subtypes of SL RNA genes encoded by the P. micropora MYN1 genome. Differing from the other SL trans-splicing organisms that usually possess poly(A)-less SL RNAs, this amoeba has polyadenylated SL RNAs. In this study, we characterize the SL trans-splicing of this unique organism and discuss the putative merits of SL trans-splicing in functional gene transfer and genome evolution.
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Affiliation(s)
- Mitsuhiro Matsuo
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Atsushi Katahata
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Soichirou Satoh
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Motomichi Matsuzaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Mami Nomura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ken-ichiro Ishida
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yuji Inagaki
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan
| | - Junichi Obokata
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
- * E-mail:
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17
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On the Possibility of an Early Evolutionary Origin for the Spliced Leader Trans-Splicing. J Mol Evol 2017; 85:37-45. [DOI: 10.1007/s00239-017-9803-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/17/2017] [Indexed: 01/12/2023]
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18
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Taguchi T, Kubota S, Tagami E, Mezaki T, Sekida S, Okuda K, Tominaga A. Molecular Cytogenetic Analysis and Isolation of a 5S rRNA-Related Marker in the Scleractinian Coral Platygyra contorta Veron 1990 (Hexacorallia, Anthozoa, Cnidaria). CYTOLOGIA 2017. [DOI: 10.1508/cytologia.82.205] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Takahiro Taguchi
- Division of Human Health and Medical Science, Graduate School of Kuroshio Science, Kochi University
| | - Satoshi Kubota
- Division of Human Health and Medical Science, Graduate School of Kuroshio Science, Kochi University
| | - Erika Tagami
- Department of Molecular & Cellular Biology, Kochi Medical School
| | | | - Satoko Sekida
- Division of Marine Bioresources, Graduate School of Kuroshio Science, Kochi University
| | - Kazuo Okuda
- Division of Marine Bioresources, Graduate School of Kuroshio Science, Kochi University
| | - Akira Tominaga
- Division of Human Health and Medical Science, Graduate School of Kuroshio Science, Kochi University
- Department of Molecular & Cellular Biology, Kochi Medical School
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19
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Wenger Y, Buzgariu W, Galliot B. Loss of neurogenesis in Hydra leads to compensatory regulation of neurogenic and neurotransmission genes in epithelial cells. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150040. [PMID: 26598723 PMCID: PMC4685579 DOI: 10.1098/rstb.2015.0040] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hydra continuously differentiates a sophisticated nervous system made of mechanosensory cells (nematocytes) and sensory-motor and ganglionic neurons from interstitial stem cells. However, this dynamic adult neurogenesis is dispensable for morphogenesis. Indeed animals depleted of their interstitial stem cells and interstitial progenitors lose their active behaviours but maintain their developmental fitness, and regenerate and bud when force-fed. To characterize the impact of the loss of neurogenesis in Hydra, we first performed transcriptomic profiling at five positions along the body axis. We found neurogenic genes predominantly expressed along the central body column, which contains stem cells and progenitors, and neurotransmission genes predominantly expressed at the extremities, where the nervous system is dense. Next, we performed transcriptomics on animals depleted of their interstitial cells by hydroxyurea, colchicine or heat-shock treatment. By crossing these results with cell-type-specific transcriptomics, we identified epithelial genes up-regulated upon loss of neurogenesis: transcription factors (Dlx, Dlx1, DMBX1/Manacle, Ets1, Gli3, KLF11, LMX1A, ZNF436, Shox1), epitheliopeptides (Arminins, PW peptide), neurosignalling components (CAMK1D, DDCl2, Inx1), ligand-ion channel receptors (CHRNA1, NaC7), G-Protein Coupled Receptors and FMRFRL. Hence epitheliomuscular cells seemingly enhance their sensing ability when neurogenesis is compromised. This unsuspected plasticity might reflect the extended multifunctionality of epithelial-like cells in early eumetazoan evolution.
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Affiliation(s)
- Y Wenger
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (IGe3), Faculty of Sciences, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - W Buzgariu
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (IGe3), Faculty of Sciences, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
| | - B Galliot
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (IGe3), Faculty of Sciences, University of Geneva, 30 quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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20
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Co-evolution of SNF spliceosomal proteins with their RNA targets in trans-splicing nematodes. Genetica 2016; 144:487-96. [PMID: 27450547 DOI: 10.1007/s10709-016-9918-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/15/2016] [Indexed: 10/21/2022]
Abstract
Although the mechanism of pre-mRNA splicing has been well characterized, the evolution of spliceosomal proteins is poorly understood. The U1A/U2B″/SNF family (hereafter referred to as the SNF family) of RNA binding spliceosomal proteins participates in both the U1 and U2 small interacting nuclear ribonucleoproteins (snRNPs). The highly constrained nature of this system has inhibited an analysis of co-evolutionary trends between the proteins and their RNA binding targets. Here we report accelerated sequence evolution in the SNF protein family in Phylum Nematoda, which has allowed an analysis of protein:RNA co-evolution. In a comparison of SNF genes from ecdysozoan species, we found a correlation between trans-splicing species (nematodes) and increased phylogenetic branch lengths of the SNF protein family, with respect to their sister clade Arthropoda. In particular, we found that nematodes (~70-80 % of pre-mRNAs are trans-spliced) have experienced higher rates of SNF sequence evolution than arthropods (predominantly cis-spliced) at both the nucleotide and amino acid levels. Interestingly, this increased evolutionary rate correlates with the reliance on trans-splicing by nematodes, which would alter the role of the SNF family of spliceosomal proteins. We mapped amino acid substitutions to functionally important regions of the SNF protein, specifically to sites that are predicted to disrupt protein:RNA and protein:protein interactions. Finally, we investigated SNF's RNA targets: the U1 and U2 snRNAs. Both are more divergent in nematodes than arthropods, suggesting the RNAs have co-evolved with SNF in order to maintain the necessarily high affinity interaction that has been characterized in other species.
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21
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A functional difference between native and horizontally acquired genes in bdelloid rotifers. Gene 2016; 590:186-91. [PMID: 27312952 DOI: 10.1016/j.gene.2016.06.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 02/06/2023]
Abstract
The form of RNA processing known as SL trans-splicing involves the transfer of a short conserved sequence, the spliced leader (SL), from a noncoding SL RNA to the 5' ends of mRNA molecules. SL trans-splicing occurs in several animal taxa, including bdelloid rotifers (Rotifera, Bdelloidea). One striking feature of these aquatic microinvertebrates is the large proportion of foreign genes, i.e. those acquired by horizontal gene transfer from other organisms, in their genomes. However, whether such foreign genes behave similarly to native genes has not been tested in bdelloids or any other animal. We therefore used a combination of experimental and computational methods to examine whether transcripts of foreign genes in bdelloids were SL trans-spliced, like their native counterparts. We found that many foreign transcripts contain SLs, use similar splice acceptor sequences to native genes, and are able to undergo alternative trans-splicing. However, a significantly lower proportion of foreign mRNAs contains SL sequences than native transcripts. This demonstrates a novel functional difference between foreign and native genes in bdelloids and suggests that SL trans-splicing is not essential for the expression of foreign genes, but is acquired during their domestication.
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22
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Lei Q, Li C, Zuo Z, Huang C, Cheng H, Zhou R. Evolutionary Insights into RNA trans-Splicing in Vertebrates. Genome Biol Evol 2016; 8:562-77. [PMID: 26966239 PMCID: PMC4824033 DOI: 10.1093/gbe/evw025] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Pre-RNA splicing is an essential step in generating mature mRNA. RNA trans-splicing combines two separate pre-mRNA molecules to form a chimeric non-co-linear RNA, which may exert a function distinct from its original molecules. Trans-spliced RNAs may encode novel proteins or serve as noncoding or regulatory RNAs. These novel RNAs not only increase the complexity of the proteome but also provide new regulatory mechanisms for gene expression. An increasing amount of evidence indicates that trans-splicing occurs frequently in both physiological and pathological processes. In addition, mRNA reprogramming based on trans-splicing has been successfully applied in RNA-based therapies for human genetic diseases. Nevertheless, clarifying the extent and evolution of trans-splicing in vertebrates and developing detection methods for trans-splicing remain challenging. In this review, we summarize previous research, highlight recent advances in trans-splicing, and discuss possible splicing mechanisms and functions from an evolutionary viewpoint.
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Affiliation(s)
- Quan Lei
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Cong Li
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Zhixiang Zuo
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
| | - Chunhua Huang
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Hanhua Cheng
- Department of Cell Biology, College of Life Sciences, Wuhan University, P.R. China
| | - Rongjia Zhou
- Department of Genetics, College of Life Sciences, Wuhan University, P.R. China
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23
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Mourão MDM, Bitar M, Lobo FP, Peconick AP, Grynberg P, Prosdocimi F, Waisberg M, Cerqueira GC, Macedo AM, Machado CR, Yoshino T, Franco GR. A directed approach for the identification of transcripts harbouring the spliced leader sequence and the effect of trans-splicing knockdown in Schistosoma mansoni. Mem Inst Oswaldo Cruz 2014; 108:707-17. [PMID: 24037192 PMCID: PMC3970683 DOI: 10.1590/0074-0276108062013006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/13/2013] [Indexed: 11/22/2022] Open
Abstract
Schistosomiasis is a major neglected tropical disease caused by trematodes from the genus Schistosoma. Because schistosomes exhibit a complex life cycle and numerous mechanisms for regulating gene expression, it is believed that spliced leader (SL) trans-splicing could play an important role in the biology of these parasites. The purpose of this study was to investigate the function of trans-splicing in Schistosoma mansoni through analysis of genes that may be regulated by this mechanism and via silencing SL-containing transcripts through RNA interference. Here, we report our analysis of SL transcript-enriched cDNA libraries from different S. mansoni life stages. Our results show that the trans-splicing mechanism is apparently not associated with specific genes, subcellular localisations or life stages. In cross-species comparisons, even though the sets of genes that are subject to SL trans-splicing regulation appear to differ between organisms, several commonly shared orthologues were observed. Knockdown of trans-spliced transcripts in sporocysts resulted in a systemic reduction of the expression levels of all tested trans-spliced transcripts; however, the only phenotypic effect observed was diminished larval size. Further studies involving the findings from this work will provide new insights into the role of trans-splicing in the biology of S. mansoni and other organisms. All Expressed Sequence Tags generated in this study were submitted to dbEST as five different libraries. The accessions for each library and for the individual sequences are as follows: (i) adult worms of mixed sexes (LIBEST_027999: JZ139310 - JZ139779), (ii) female adult worms (LIBEST_028000: JZ139780 - JZ140379), (iii) male adult worms (LIBEST_028001: JZ140380 - JZ141002), (iv) eggs (LIBEST_028002: JZ141003 - JZ141497) and (v) schistosomula (LIBEST_028003: JZ141498 - JZ141974).
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Affiliation(s)
- Marina de Moraes Mourão
- Grupo de Genômica e Biologia Computacional, Centro de Pesquisas René Rachou, Fiocruz, Belo HorizonteMG, Brasil
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24
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Abstract
Tunicates have been extensively studied because of their crucial phylogenetic location (the closest living relatives of vertebrates) and particular developmental plan. Recent genome efforts have disclosed that tunicates are also remarkable in their genome organization and molecular evolutionary patterns. Here, we review these latter aspects, comparing the similarities and specificities of two model species of the group: Oikopleura dioica and Ciona intestinalis. These species exhibit great genome plasticity and Oikopleura in particular has undergone a process of extreme genome reduction and compaction that can be explained in part by gene loss, but is mostly due to other mechanisms such as shortening of intergenic distances and introns, and scarcity of mobile elements. In Ciona, genome reorganization was less severe being more similar to the other chordates in several aspects. Rates and patterns of molecular evolution are also peculiar in tunicates, being Ciona about 50% faster than vertebrates and Oikopleura three times faster. In fact, the latter species is considered as the fastest evolving metazoan recorded so far. Two processes of increase in evolutionary rates have taken place in tunicates. One of them is more extreme, and basically restricted to genes encoding regulatory proteins (transcription regulators, chromatin remodeling proteins, and metabolic regulators), and the other one is less pronounced but affects the whole genome. Very likely adaptive evolution has played a very significant role in the first, whereas the functional and/or evolutionary causes of the second are less clear and the evidence is not conclusive. The evidences supporting the incidence of increased mutation and less efficient negative selection are presented and discussed.
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Affiliation(s)
- Luisa Berná
- Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Montevideo, UruguayUnidad de Biología Molecular, Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Fernando Alvarez-Valin
- Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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25
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Bitar M, Boroni M, Macedo AM, Machado CR, Franco GR. The spliced leader trans-splicing mechanism in different organisms: molecular details and possible biological roles. Front Genet 2013; 4:199. [PMID: 24130571 PMCID: PMC3795323 DOI: 10.3389/fgene.2013.00199] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Accepted: 09/19/2013] [Indexed: 01/28/2023] Open
Abstract
The spliced leader (SL) is a gene that generates a functional ncRNA that is composed of two regions: an intronic region of unknown function (SLi) and an exonic region (SLe), which is transferred to the 5′ end of independent transcripts yielding mature mRNAs, in a process known as spliced leader trans-splicing (SLTS). The best described function for SLTS is to solve polycistronic transcripts into monocistronic units, specifically in Trypanosomatids. In other metazoans, it is speculated that the SLe addition could lead to increased mRNA stability, differential recruitment of the translational machinery, modification of the 5′ region or a combination of these effects. Although important aspects of this mechanism have been revealed, several features remain to be elucidated. We have analyzed 157 SLe sequences from 148 species from seven phyla and found a high degree of conservation among the sequences of species from the same phylum, although no considerable similarity seems to exist between sequences of species from different phyla. When analyzing case studies, we found evidence that a given SLe will always be related to a given set of transcripts in different species from the same phylum, and therefore, different SLe sequences from the same species would regulate different sets of transcripts. In addition, we have observed distinct transcript categories to be preferential targets for the SLe addition in different phyla. This work sheds light into crucial and controversial aspects of the SLTS mechanism. It represents a comprehensive study concerning various species and different characteristics of this important post-transcriptional regulatory mechanism.
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Affiliation(s)
- Mainá Bitar
- Laboratório de Genética Bioquímica, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Belo Horizonte, Brazil
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26
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Rossi A, Ross EJ, Jack A, Sánchez Alvarado A. Molecular cloning and characterization of SL3: a stem cell-specific SL RNA from the planarian Schmidtea mediterranea. Gene 2013; 533:156-67. [PMID: 24120894 DOI: 10.1016/j.gene.2013.09.101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 08/26/2013] [Accepted: 09/26/2013] [Indexed: 01/03/2023]
Abstract
Spliced leader (SL) trans-splicing is a biological phenomenon, common among many metazoan taxa, consisting in the transfer of a short leader sequence from a small SL RNA to the 5' end of a subset of pre-mRNAs. While knowledge of the biochemical mechanisms driving this process has accumulated over the years, the functional consequences of such post-transcriptional event at the organismal level remain unclear. In addition, the fact that functional analyses have been undertaken mainly in trypanosomes and nematodes leaves a somehow fragmented picture of the possible biological significance and evolution of SL trans-splicing in eukaryotes. Here, we analyzed the spatial expression of SL RNAs in the planarian flatworm Schmidtea mediterranea, with the goal of identifying novel developmental paradigms for the study of trans-splicing in metazoans. Besides the previously identified SL1 and SL2, S. mediterranea expresses a third SL RNA described here as SL3. While, SL1 and SL2 are collectively expressed in a broad range of planarian cell types, SL3 is highly enriched in a subset of the planarian stem cells engaged in regenerative responses. Our findings provide new opportunities to study how trans-splicing may regulate the phenotype of a cell.
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Affiliation(s)
- Alessandro Rossi
- Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO 64110, USA.
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27
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Wenger Y, Galliot B. RNAseq versus genome-predicted transcriptomes: a large population of novel transcripts identified in an Illumina-454 Hydra transcriptome. BMC Genomics 2013; 14:204. [PMID: 23530871 PMCID: PMC3764976 DOI: 10.1186/1471-2164-14-204] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 03/14/2013] [Indexed: 01/11/2023] Open
Abstract
Background Evolutionary studies benefit from deep sequencing technologies that generate
genomic and transcriptomic sequences from a variety of organisms. Genome
sequencing and RNAseq have complementary strengths. In this study, we
present the assembly of the most complete Hydra transcriptome to
date along with a comparative analysis of the specific features of RNAseq
and genome-predicted transcriptomes currently available in the freshwater
hydrozoan Hydra vulgaris. Results To produce an accurate and extensive Hydra transcriptome, we
combined Illumina and 454 Titanium reads, giving the primacy to Illumina
over 454 reads to correct homopolymer errors. This strategy yielded an
RNAseq transcriptome that contains 48’909 unique sequences including
splice variants, representing approximately 24’450 distinct genes.
Comparative analysis to the available genome-predicted transcriptomes
identified 10’597 novel Hydra transcripts that encode 529
evolutionarily-conserved proteins. The annotation of 170 human orthologs
points to critical functions in protein biosynthesis, FGF and TOR signaling,
vesicle transport, immunity, cell cycle regulation, cell death,
mitochondrial metabolism, transcription and chromatin regulation. However, a
majority of these novel transcripts encodes short ORFs, at least 767 of them
corresponding to pseudogenes. This RNAseq transcriptome also lacks
11’270 predicted transcripts that correspond either to silent genes or
to genes expressed below the detection level of this study. Conclusions We established a simple and powerful strategy to combine Illumina and 454
reads and we produced, with genome assistance, an extensive and accurate
Hydra transcriptome. The comparative analysis of the RNAseq
transcriptome with genome-predicted transcriptomes lead to the
identification of large populations of novel as well as missing transcripts
that might reflect Hydra-specific evolutionary events.
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Affiliation(s)
- Yvan Wenger
- Department of Genetics and Evolution, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Geneva, Switzerland
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28
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Uyar B, Chu JS, Vergara IA, Chua SY, Jones MR, Wong T, Baillie DL, Chen N. RNA-seq analysis of the C. briggsae transcriptome. Genome Res 2012; 22:1567-80. [PMID: 22772596 PMCID: PMC3409270 DOI: 10.1101/gr.134601.111] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 04/30/2012] [Indexed: 12/18/2022]
Abstract
Curation of a high-quality gene set is the critical first step in genome research, enabling subsequent analyses such as ortholog assignment, cis-regulatory element finding, and synteny detection. In this project, we have reannotated the genome of Caenorhabditis briggsae, the best studied sister species of the model organism Caenorhabditis elegans. First, we applied a homology-based gene predictor genBlastG to annotate the C. briggsae genome. We then validated and further improved the C. briggsae gene annotation through RNA-seq analysis of the C. briggsae transcriptome, which resulted in the first validated C. briggsae gene set (23,159 genes), among which 7347 genes (33.9% of all genes with introns) have all of their introns confirmed. Most genes (14,812, or 68.3%) have at least one intron validated, compared with only 3.9% in the most recent WormBase release (WS228). Of all introns in the revised gene set (103,083), 61,503 (60.1%) have been confirmed. Additionally, we have identified numerous trans-splicing leaders (SL1 and SL2 variants) in C. briggsae, leading to the first genome-wide annotation of operons in C. briggsae (1105 operons). The majority of the annotated operons (564, or 51.0%) are perfectly conserved in C. elegans, with an additional 345 operons (or 31.2%) somewhat divergent. Additionally, RNA-seq analysis revealed over 10 thousand small-size assembly errors in the current C. briggsae reference genome that can be readily corrected. The revised C. briggsae genome annotation represents a solid platform for comparative genomics analysis and evolutionary studies of Caenorhabditis species.
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Affiliation(s)
- Bora Uyar
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- CIHR/MSFHR Bioinformatics Training Program, Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1G1, Canada
| | - Jeffrey S.C. Chu
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Ismael A. Vergara
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Shu Yi Chua
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Martin R. Jones
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Tammy Wong
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - David L. Baillie
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Nansheng Chen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- CIHR/MSFHR Bioinformatics Training Program, Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, British Columbia V5Z 1G1, Canada
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29
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Sun W, Song X, Yan R, Xu L, Li X. Cloning and characterization of a selenium-independent glutathione peroxidase (HC29) from adult Haemonchus contortus. J Vet Sci 2012; 13:49-58. [PMID: 22437536 PMCID: PMC3317457 DOI: 10.4142/jvs.2012.13.1.49] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The complete coding sequence of Haemonchus (H.) contortus HC29 cDNA was generated by rapid amplification of cDNA ends in combination with PCR using primers targeting the 5'- and 3'-ends of the partial mRNA sequence. The cloned HC29 cDNA was shown to be 1,113 bp in size with an open reading frame of 507 bp, encoding a protein of 168 amino acid with a calculated molecular mass of 18.9 kDa. Amino acid sequence analysis revealed that the cloned HC29 cDNA contained the conserved catalytic triad and dimer interface of selenium-independent glutathione peroxidase (GPX). Alignment of the predicted amino acid sequences demonstrated that the protein shared 44.7~80.4% similarity with GPX homologues in the thioredoxin-like family. Phylogenetic analysis revealed close evolutionary proximity of the GPX sequence to the counterpart sequences. These results suggest that HC29 cDNA is a GPX, a member of the thioredoxin-like family. Alignment of the nucleic acid and amino acid sequences of HC29 with those of the reported selenium-independent GPX of H. contortus showed that HC29 contained different types of spliced leader sequences as well as dimer interface sites, although the active sites of both were identical. Enzymatic analysis of recombinant prokaryotic HC29 protein showed activity for the hydrolysis of H2O2. These findings indicate that HC29 is a selenium-independent GPX of H. contortus.
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Affiliation(s)
- Wei Sun
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China
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30
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Dash B, Phillips TD. Molecular characterization of a catalase from Hydra vulgaris. Gene 2012; 501:144-52. [PMID: 22521743 DOI: 10.1016/j.gene.2012.04.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 04/03/2012] [Accepted: 04/05/2012] [Indexed: 01/06/2023]
Abstract
Catalase, an antioxidant and hydroperoxidase enzyme protects the cellular environment from harmful effects of hydrogen peroxide by facilitating its degradation to oxygen and water. Molecular information on a cnidarian catalase and/or peroxidase is, however, limited. In this work an apparent full length cDNA sequence coding for a catalase (HvCatalase) was isolated from Hydra vulgaris using 3'- and 5'- (RLM) RACE approaches. The 1859 bp HvCatalase cDNA included an open reading frame of 1518 bp encoding a putative protein of 505 amino acids with a predicted molecular mass of 57.44 kDa. The deduced amino acid sequence of HvCatalase contained several highly conserved motifs including the heme-ligand signature sequence RLFSYGDTH and the active site signature FXRERIPERVVHAKGXGA. A comparative analysis showed the presence of conserved catalytic amino acids [His(71), Asn(145), and Tyr(354)] in HvCatalase as well. Homology modeling indicated the presence of the conserved features of mammalian catalase fold. Hydrae exposed to thermal, starvation, metal and oxidative stress responded by regulating its catalase mRNA transcription. These results indicated that the HvCatalase gene is involved in the cellular stress response and (anti)oxidative processes triggered by stressor and contaminant exposure.
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Affiliation(s)
- Bhagirathi Dash
- Faculty of Toxicology, Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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31
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Dana CE, Glauber KM, Chan TA, Bridge DM, Steele RE. Incorporation of a horizontally transferred gene into an operon during cnidarian evolution. PLoS One 2012; 7:e31643. [PMID: 22328943 PMCID: PMC3273482 DOI: 10.1371/journal.pone.0031643] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 01/10/2012] [Indexed: 12/19/2022] Open
Abstract
Genome sequencing has revealed examples of horizontally transferred genes, but we still know little about how such genes are incorporated into their host genomes. We have previously reported the identification of a gene (flp) that appears to have entered the Hydra genome through horizontal transfer. Here we provide additional evidence in support of our original hypothesis that the transfer was from a unicellular organism, and we show that the transfer occurred in an ancestor of two medusozoan cnidarian species. In addition we show that the gene is part of a bicistronic operon in the Hydra genome. These findings identify a new animal phylum in which trans-spliced leader addition has led to the formation of operons, and define the requirements for evolution of an operon in Hydra. The identification of operons in Hydra also provides a tool that can be exploited in the construction of transgenic Hydra strains.
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Affiliation(s)
- Catherine E. Dana
- Department of Biological Chemistry, University of California Irvine, Irvine, California, United States of America
- Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
| | - Kristine M. Glauber
- Department of Biological Chemistry, University of California Irvine, Irvine, California, United States of America
- Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
| | - Titus A. Chan
- Department of Biological Chemistry, University of California Irvine, Irvine, California, United States of America
- Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
| | - Diane M. Bridge
- Department of Biology, Elizabethtown College, Elizabethtown, Pennsylvania, United States of America
| | - Robert E. Steele
- Department of Biological Chemistry, University of California Irvine, Irvine, California, United States of America
- Developmental Biology Center, University of California Irvine, Irvine, California, United States of America
- * E-mail:
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32
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A heat shock protein and Wnt signaling crosstalk during axial patterning and stem cell proliferation. Dev Biol 2011; 362:271-81. [PMID: 22155526 DOI: 10.1016/j.ydbio.2011.11.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 11/16/2011] [Accepted: 11/22/2011] [Indexed: 01/22/2023]
Abstract
Both Wnt signaling and heat shock proteins play important roles in development and disease. As such, they have been widely, though separately, studied. Here we show a link between a heat shock protein and Wnt signaling in a member of the basal phylum, Cnidaria. A heat shock at late gastrulation in the clonal marine hydrozoan, Hydractinia, interferes with axis development, specifically inhibiting head development, while aboral structures remain unaffected. The heat treatment upregulated Hsc71, a constitutive Hsp70 related gene, followed by a transient upregulation, and long-term downregulation, of Wnt signaling components. Downregulating Hsc71 by RNAi in heat-shocked animals rescued these defects, resulting in normal head development. Transgenic animals, ectopically expressing Hsc71, had similar developmental abnormalities as heat-shocked animals in terms of both morphology and Wnt3 expression. We also found that Hsc71 is upregulated in response to ectopic Wnt activation, but only in the context of stem cell proliferation and not in head development. Hsc71's normal expression is consistent with a conserved role in mitosis and apoptosis inhibition. Our results demonstrate a hitherto unknown crosstalk between heat shock proteins and Wnt/β-catenin signaling. This link likely has important implications in understanding normal development, congenital defects and cancer biology.
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33
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MARZ MANJA, VANZO NATHALIE, STADLER PETERF. TEMPERATURE-DEPENDENT STRUCTURAL VARIABILITY OF RNAs: SPLICED LEADER RNAs AND THEIR EVOLUTIONARY HISTORY. J Bioinform Comput Biol 2011; 8:1-17. [DOI: 10.1142/s0219720010004525] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 08/16/2009] [Accepted: 09/14/2009] [Indexed: 11/18/2022]
Abstract
The structures attained by RNA molecules depend not only on their sequence but also on environmental parameters such as their temperature. So far, this effect has been largely neglected in bioinformatics studies. Here, we show that structural comparisons can be facilitated and more coherent structural models can be obtained when differences in environmental parameters are taken into account. We re-evaluate the secondary structures of the spliced leader (SL) RNAs from the seven eukaryotic phyla in which SL RNA trans-splicing has been described. Adjusting structure prediction to the natural growth temperatures and considering energetically similar secondary structures, we observe striking similarities among Euglenida, Kinetoplastida, Dinophyceae, Cnidaria, Rotifera, Nematoda, Platyhelminthes, and Tunicata that cannot be explained easily by the independent innovation of SL RNAs in each of these phyla. Supplementary Table is available at .
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Affiliation(s)
- MANJA MARZ
- Bioinformatics Group, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
| | - NATHALIE VANZO
- Centre de Biologie du Développement, UMR 5547 C. N. R. S. Université Paul Sabatier, F-31062 Toulouse Cedex, France
| | - PETER F. STADLER
- Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, University of Leipzig, Härtelstraße 16-18, D-04107 Leipzig, Germany
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, D-04103 Leipzig, Germany
- Fraunhofer Institut für Zelltherapie und Immunologie – IZI, Perlickstraße 1, D-04103 Leipzig, Germany
- Department of Theoretical Chemistry, University of Vienna, Währingerstraße 17, A-1090 Wien, Austria
- Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM 87501, USA
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34
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The falsifiability of the models for the origin of eukaryotes. Curr Genet 2011; 57:367-90. [DOI: 10.1007/s00294-011-0357-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 01/13/2023]
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Molecular cloning, expression and characterization of enolase from adult Haemonchus contortus. Res Vet Sci 2011; 92:259-65. [PMID: 21444098 DOI: 10.1016/j.rvsc.2011.03.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Revised: 03/03/2011] [Accepted: 03/10/2011] [Indexed: 11/23/2022]
Abstract
Enolase represents a multifunctional protein involved in basic energy metabolism. In the present research, the enolase gene of Haemonchus contortus (HcENO) was cloned and characterized. Specific primers for the rapid amplification of cDNA ends (RACE) were designed based on the expression sequence tag (EST, GenBank Accession No. BF422728) to amplify the 3'- and 5'-ends of HcENO. The full length of cDNA from this gene was obtained by overlapping the sequences of 3'- and 5'-extremities and amplification by reverse transcription PCR. The biochemical activities of the recombinant protein HcENO, which was expressed in prokaryotic cells and purified by affinity chromatography, were analyzed by assays of enzymatic activity, stability to pH. The results showed that the cloned full length cDNA comprised 1583 bp and encoded a peptide with 434 amino acid residues which showed sequence similarity to several known enolases. The biochemical assay showed that the protein encoded by the HcENO exhibited enzymatic activity, whilst the HcENO was stable between pH 6 and 8. The natural enolase of H. contortus detected by immunoblot assay was approximately 49 kDa in size, and the recombinant HcENO was recognized strongly by serum from experimentally infected goats.
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36
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Gasparini F, Shimeld SM. Analysis of a botryllid enriched-full-length cDNA library: insight into the evolution of spliced leader trans-splicing in tunicates. Dev Genes Evol 2011; 220:329-36. [PMID: 21331664 DOI: 10.1007/s00427-011-0351-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 01/24/2011] [Indexed: 01/22/2023]
Abstract
In some animals, mRNA may be modified after transcription by the addition of a 5' spliced leader sequence. This is known as spliced leader (SL) trans-splicing, and is of uncertain function and evolutionary origin. Here, we report the identification of SL trans-splicing in the colonial ascidian Botryllus schlosseri. Combining our own expressed sequence tag (EST) data with additional data from GenBank, we identify the dominant spliced leader sequence and show it to be similar to that of other ascidians and to that of Oikopleura dioica, a basally diverging tunicate. Gene Ontology analysis of B. schlosseri ESTs with and without a 5' spliced leader shows that genes encoding ribosomal proteins tend not to be trans-spliced, a character shared with the ascidian Ciona intestinalis. We also examine individual cases of genes that produce mRNAs that are SL trans-spliced in B. schlosseri but not in C. intestinalis. We conclude that SL trans-splicing evolved early in the tunicate lineage and shows stability over considerable evolutionary time. However, SL trans-splicing may be gained or lost in individual genes.
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Affiliation(s)
- Fabio Gasparini
- Dipartimento di Biologia, Università degli Studi di Padova, Italy.
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37
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Abstract
Trans-splicing is the joining together of portions of two separate pre-mRNA molecules. The two distinct categories of spliceosomal trans-splicing are genic trans-splicing, which joins exons of different pre-mRNA transcripts, and spliced leader (SL) trans-splicing, which involves an exon donated from a specialized SL RNA. Both depend primarily on the same signals and components as cis-splicing. Genic trans-splicing events producing protein-coding mRNAs have been described in a variety of organisms, including Caenorhabditis elegans and Drosophila. In mammalian cells, genic trans-splicing can be associated with cancers and translocations. SL trans-splicing has mainly been studied in nematodes and trypanosomes, but there are now numerous and diverse phyla (including primitive chordates) where this type of trans-splicing has been detected. Such diversity raises questions as to the evolutionary origin of the process. Another intriguing question concerns the function of trans-splicing, as operon resolution can only account for a small proportion of the total amount of SL trans-splicing.
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Affiliation(s)
- Erika L Lasda
- University of Colorado Denver, Department of Biochemistry and Molecular Genetics; University of Colorado Boulder, Department of Molecular, Cellular, and Developmental Biology
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38
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Lange C, Hemmrich G, Klostermeier UC, López-Quintero JA, Miller DJ, Rahn T, Weiss Y, Bosch TCG, Rosenstiel P. Defining the origins of the NOD-like receptor system at the base of animal evolution. Mol Biol Evol 2010; 28:1687-702. [PMID: 21183612 DOI: 10.1093/molbev/msq349] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Distinguishing self from nonself and the onset of defense effector mechanisms upon recognition of pathogens are essential for the survival of all life forms in the animal kingdom. The family of nucleotide -binding and oligomeriszation domain-like receptors (NLRs) was first identified in vertebrates and comprises a group of pivotal sensor protein of the innate immune system for microbial cell wall components or danger signals. Here, we provide first evidence that early diverging metazoans have large and complex NLR repertoires. The cnidarian NACHT/NB-ARC genes include novel combinations of domains, and the number of one specific type (NB-ARC and tetratricopeptide repeat containing) in Hydra is particularly large. We characterize the transcript structure and expression patterns of a selected HyNLR, HyNLR type 1 and describe putative interaction partners. In a heterologous expression system, we show induced proximity recruitment of an effector caspase (HyDD-Caspase) to the HyNLR type 1 protein upon oligomerization indicating a potential role of caspase activation downstream of NLR activation in Hydra. These results add substantially to our understanding of the ancestral innate immune repertoire as well as providing the first insights into putative cytoplasmic defense mechanisms at the base of animal evolution.
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Affiliation(s)
- Christina Lange
- Zoological Institute, Christian-Albrechts-University Kiel, Kiel, Germany
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40
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Cloning, expression and characterization of NAD+-dependent glyceraldehyde-3-phosphate dehydrogenase of adult Haemonchus contortus†. J Helminthol 2010; 85:421-9. [DOI: 10.1017/s0022149x10000763] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractGlyceraldehyde-3-phosphate dehydrogenase (GAPDH) regulates a wide range of biological processes, including pathogen evasion. In the present research, the GAPDH gene of Haemonchus contortus (HcGAPDH) was cloned and characterized. Specific primers for the rapid amplification of cDNA ends (RACE) were designed based on the expressed sequence tag (EST, AW670737) to amplify the 3′ and 5′ ends of HcGAPDH. The full length of cDNA from this gene was obtained by overlapping the sequences of 3′ and 5′ extremities and amplification by reverse transcription polymerase chain reaction (RT-PCR). The biochemical activities of the recombinant protein HcGAPDH, which was expressed in prokaryotic cells and purified by affinity chromatography, were analysed by assays of enzymatic activity, thermal stability and pH. The results showed that the cloned full-length cDNA comprised 1303 bp and encoded a peptide with 341 amino acid residues which showed sequence similarity to several known GAPDHs. The biochemical assay showed that the protein encoded by the HcGAPDH exhibited enzymatic activity with NAD+ as a cofactor. HcGAPDH was stable between pH 5 and 9 and maintained activity at high temperatures of up to 75°C. The natural GAPDH of Haemonchus contortus detected by immunoblot assay was approximately 38 kDa in size, and the recombinant HcGAPDH was recognized strongly by serum from naturally infected goats.
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Steele RE, David CN, Technau U. A genomic view of 500 million years of cnidarian evolution. Trends Genet 2010; 27:7-13. [PMID: 21047698 DOI: 10.1016/j.tig.2010.10.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 09/23/2010] [Accepted: 10/08/2010] [Indexed: 01/29/2023]
Abstract
Cnidarians (corals, anemones, jellyfish and hydras) are a diverse group of animals of interest to evolutionary biologists, ecologists and developmental biologists. With the publication of the genome sequences of Hydra and Nematostella, whose last common ancestor was the stem cnidarian, researchers are beginning to see the genomic underpinnings of cnidarian biology. Cnidarians are known for the remarkable plasticity of their morphology and life cycles. This plasticity is reflected in the Hydra and Nematostella genomes, which differ to an exceptional degree in size, base composition, transposable element content and gene conservation. It is now known what cnidarian genomes, given 500 million years, are capable of; as we discuss here, the next challenge is to understand how this genomic history has led to the striking diversity seen in this group.
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Affiliation(s)
- Robert E Steele
- Department of Biological Chemistry and the Developmental Biology Center, University of California, Irvine, CA 92697, USA.
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Duffy DJ, Plickert G, Kuenzel T, Tilmann W, Frank U. Wnt signaling promotes oral but suppresses aboral structures in Hydractinia metamorphosis and regeneration. Development 2010; 137:3057-66. [DOI: 10.1242/dev.046631] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We studied the role of Wnt signaling in axis formation during metamorphosis and regeneration in the cnidarian Hydractinia. Activation of Wnt downstream events during metamorphosis resulted in a complete oralization of the animals and repression of aboral structures (i.e. stolons). The expression of Wnt3, Tcf and Brachyury was upregulated and became ubiquitous. Rescue experiments using Tcf RNAi resulted in normal metamorphosis and quantitatively normal Wnt3 and Brachyury expression. Isolated, decapitated polyps regenerated only heads but no stolons. Activation of Wnt downstream targets in regenerating animals resulted in oralization of the polyps. Knocking down Tcf or Wnt3 by RNAi inhibited head regeneration and resulted in complex phenotypes that included ectopic aboral structures. Multiple heads then grew when the RNAi effect had dissipated. Our results provide functional evidence that Wnt promotes head formation but represses the formation of stolons, whereas downregulation of Wnt promotes stolons and represses head formation.
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Affiliation(s)
- David J. Duffy
- School of Natural Sciences and Martin Ryan Marine Science Institute, National University of Ireland, Galway, Galway, Ireland
| | - Günter Plickert
- Biozentrum Köln, University of Köln, Zülpicher Str. 47b, 50674 Köln, Germany
| | - Timo Kuenzel
- Biozentrum Köln, University of Köln, Zülpicher Str. 47b, 50674 Köln, Germany
| | - Wido Tilmann
- Biozentrum Köln, University of Köln, Zülpicher Str. 47b, 50674 Köln, Germany
| | - Uri Frank
- School of Natural Sciences and Martin Ryan Marine Science Institute, National University of Ireland, Galway, Galway, Ireland
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Harrison N, Kalbfleisch A, Connolly B, Pettitt J, Müller B. SL2-like spliced leader RNAs in the basal nematode Prionchulus punctatus: New insight into the evolution of nematode SL2 RNAs. RNA (NEW YORK, N.Y.) 2010; 16:1500-7. [PMID: 20566669 PMCID: PMC2905750 DOI: 10.1261/rna.2155010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Spliced-leader (SL) trans-splicing has been found in all molecularly characterized nematode species to date, and it is likely to be a nematode synapomorphy. Most information regarding SL trans-splicing has come from the study of nematodes from a single monophyletic group, the Rhabditida, all of which employ SL RNAs that are identical to, or variants of, the SL1 RNA first characterized in Caenorhabditis elegans. In contrast, the more distantly related Trichinella spiralis, belonging to the subclass Dorylaimia, utilizes a distinct set of SL RNAs that display considerable sequence diversity. To investigate whether this is true of other members of the Dorylaimia, we have characterized SL RNAs from Prionchulus punctatus. Surprisingly, this revealed the presence of a set of SLs that show clear sequence similarity to the SL2 family of spliced leaders, which have previously only been found within the rhabditine group (which includes C. elegans). Expression of one of the P. punctatus SL RNAs in C. elegans reveals that it can compete specifically with the endogenous C. elegans SL2 spliced leaders, being spliced to the pre-mRNAs derived from downstream genes in operons, but does not compete with the SL1 spliced leaders. This discovery raises the possibility that SL2-like spliced leaders were present in the last common ancestor of the nematode phylum.
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Affiliation(s)
- Neale Harrison
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, United Kingdom
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44
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Notch signalling defines critical boundary during budding in Hydra. Dev Biol 2010; 344:331-45. [DOI: 10.1016/j.ydbio.2010.05.517] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 05/04/2010] [Accepted: 05/28/2010] [Indexed: 11/19/2022]
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45
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Abstract
Spliced leader trans-splicing occurs in many primitive eukaryotes including nematodes. Most of our knowledge of trans-splicing in nematodes stems from the model organism Caenorhabditis elegans and relatives, and from work with Ascaris. Our investigation of spliced leader trans-splicing in distantly related Dorylaimia nematodes indicates that spliced-leader trans-splicing arose before the nematode phylum and suggests that the spliced leader RNA gene complements in extant nematodes have evolved from a common ancestor with a diverse set of spliced leader RNA genes.
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Abstract
Operons are clusters of genes that are co-regulated from a common promoter. Operons are typically associated with prokaryotes, although a small number of eukaryotes have been shown to possess them. Among metazoans, operons have been extensively characterized in the nematode Caenorhabditis elegans in which ∼15% of the total genes are organized into operons. The most recent genome assembly for the ascidian Ciona intestinalis placed ∼20% of the genes (2909 total) into 1310 operons. The majority of these operons are composed of two genes, while the largest are composed of six. Here is reported a computational analysis of the genes that comprise the Ciona operons. Gene ontology (GO) terms were identified for about two-thirds of the operon-encoded genes. Using the extensive collection of public EST libraries, estimates of temporal patterns of gene expression were generated for the operon-encoded genes. Lastly, conservation of operons was analyzed by determining how many operon-encoded genes were present in the ascidian Ciona savignyi and whether these genes were organized in orthologous operons. Over 68% of the operon-encoded genes could be assigned one or more GO terms and 697 of the 1310 operons contained genes in which all genes had at least one GO term. Of these 697 operons, GO terms were shared by all of the genes within 146 individual operons, suggesting that most operons encode genes with unrelated functions. An analysis of operon gene expression from nine different EST libraries indicated that for 587 operons, all of the genes that comprise an individual operon were expressed together in at least one EST library, suggesting that these genes may be co-regulated. About 50% (74/146) of the operons with shared GO terms also showed evidence of gene co-regulation. Comparisons with the C. savignyi genome identified orthologs for 1907 of 2909 operon genes. About 38% (504/1310) of the operons are conserved between the two Ciona species. These results suggest that like C. elegans, operons in Ciona are comprised of a variety of genes that are not necessarily related in function. The genes in only 50% of the operons appear to be co-regulated, suggesting that more complex gene regulatory mechanisms are likely operating.
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Affiliation(s)
- Robert W Zeller
- Center for Applied and Experimental Genomics, Department of Biology MC 4616, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4614, USA.
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Yeats B, Matsumoto J, Mortimer SI, Shoguchi E, Satoh N, Hastings KEM. SL RNA genes of the ascidian tunicates Ciona intestinalis and Ciona savignyi. Zoolog Sci 2010; 27:171-80. [PMID: 20141422 DOI: 10.2108/zsj.27.171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We characterized by bioinformatics the trans-spliced leader donor RNA (SL RNA) genes of two ascidians, Ciona intestinalis and Ciona savignyi. The Ciona intestinalis genome contains approximately 670 copies of the SL RNA gene, principally on a 264-bp tandemly repeated element. Fluorescent in-situ hybridization mapped most of the repeats to a single site on the short arm of chromosome 8. The Ciona intestinalis genome also contains approximately 100 copies of a >3.6-kb element that carries 1) an SL RNA-related sequence (possible a pseudogene) and 2) genes for the U6 snRNA and a histone-like protein. The Ciona savignyi genome contains two SL RNA gene classes having the same SL sequence as Ciona intestinalis but differing in the intron-like segments. These reside in similar but distinct repeat units of 575 bp ( approximately 410 copies) and 552 bp ( approximately 250 copies) that are arranged as separate tandem repeats. In neither Ciona species is the 5S RNA gene present within the SL RNA gene repeat unit. Although the number of SL RNA genes is similar, there is little sequence similarity between the intestinalis and savignyi repeat units, apart from the region encoding the SL RNA itself. This suggests that cis-regulatory elements involved in transcription and 3'-end processing are likely to be present within the transcribed region. The genomes of both Ciona species also include > 100 dispersed short elements containing the 16-nt SL sequence and up to 6 additional nucleotides of the SL RNA sequence.
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Affiliation(s)
- Brendan Yeats
- Montreal Neurological Institute and Department of Biology, McGill University, 3801 University Street, Montréal, Québec, Canada H3A 2B4
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Derelle R, Momose T, Manuel M, Da Silva C, Wincker P, Houliston E. Convergent origins and rapid evolution of spliced leader trans-splicing in metazoa: insights from the ctenophora and hydrozoa. RNA (NEW YORK, N.Y.) 2010; 16:696-707. [PMID: 20142326 PMCID: PMC2844618 DOI: 10.1261/rna.1975210] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 12/23/2009] [Indexed: 05/20/2023]
Abstract
Replacement of mRNA 5' UTR sequences by short sequences trans-spliced from specialized, noncoding, spliced leader (SL) RNAs is an enigmatic phenomenon, occurring in a set of distantly related animal groups including urochordates, nematodes, flatworms, and hydra, as well as in Euglenozoa and dinoflagellates. Whether SL trans-splicing has a common evolutionary origin and biological function among different organisms remains unclear. We have undertaken a systematic identification of SL exons in cDNA sequence data sets from non-bilaterian metazoan species and their closest unicellular relatives. SL exons were identified in ctenophores and in hydrozoan cnidarians, but not in other cnidarians, placozoans, or sponges, or in animal unicellular relatives. Mapping of SL absence/presence obtained from this and previous studies onto current phylogenetic trees favors an evolutionary scenario involving multiple origins for SLs during eumetazoan evolution rather than loss from a common ancestor. In both ctenophore and hydrozoan species, multiple SL sequences were identified, showing high sequence diversity. Detailed analysis of a large data set generated for the hydrozoan Clytia hemisphaerica revealed trans-splicing of given mRNAs by multiple alternative SLs. No evidence was found for a common identity of trans-spliced mRNAs between different hydrozoans. One feature found specifically to characterize SL-spliced mRNAs in hydrozoans, however, was a marked adenosine enrichment immediately 3' of the SL acceptor splice site. Our findings of high sequence divergence and apparently indiscriminate use of SLs in hydrozoans, along with recent findings in other taxa, indicate that SL genes have evolved rapidly in parallel in diverse animal groups, with constraint on SL exon sequence evolution being apparently rare.
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Affiliation(s)
- Romain Derelle
- Biologie du Développement (UMR 7138) Observatoire Océanologique, Université Pierre et Marie Curie (UPMC-Univ Paris 06) and Centre National de la Recherche Scientifique (CNRS), 06230 Villefranche-sur-mer, France
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49
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Matsumoto J, Dewar K, Wasserscheid J, Wiley GB, Macmil SL, Roe BA, Zeller RW, Satou Y, Hastings KEM. High-throughput sequence analysis of Ciona intestinalis SL trans-spliced mRNAs: alternative expression modes and gene function correlates. Genome Res 2010; 20:636-45. [PMID: 20212022 DOI: 10.1101/gr.100271.109] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Pre-mRNA 5' spliced-leader (SL) trans-splicing occurs in some metazoan groups but not in others. Genome-wide characterization of the trans-spliced mRNA subpopulation has not yet been reported for any metazoan. We carried out a high-throughput analysis of the SL trans-spliced mRNA population of the ascidian tunicate Ciona intestinalis by 454 Life Sciences (Roche) pyrosequencing of SL-PCR-amplified random-primed reverse transcripts of tailbud embryo RNA. We obtained approximately 250,000 high-quality reads corresponding to 8790 genes, approximately 58% of the Ciona total gene number. The great depth of this data revealed new aspects of trans-splicing, including the existence of a significant class of "infrequently trans-spliced" genes, accounting for approximately 28% of represented genes, that generate largely non-trans-spliced mRNAs, but also produce trans-spliced mRNAs, in part through alternative promoter use. Thus, the conventional qualitative dichotomy of trans-spliced versus non-trans-spliced genes should be supplanted by a more accurate quantitative view recognizing frequently and infrequently trans-spliced gene categories. Our data include reads representing approximately 80% of Ciona frequently trans-spliced genes. Our analysis also revealed significant use of closely spaced alternative trans-splice acceptor sites which further underscores the mechanistic similarity of cis- and trans-splicing and indicates that the prevalence of +/-3-nt alternative splicing events at tandem acceptor sites, NAGNAG, is driven by spliceosomal mechanisms, and not nonsense-mediated decay, or selection at the protein level. The breadth of gene representation data enabled us to find new correlations between trans-splicing status and gene function, namely the overrepresentation in the frequently trans-spliced gene class of genes associated with plasma/endomembrane system, Ca(2+) homeostasis, and actin cytoskeleton.
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Affiliation(s)
- Jun Matsumoto
- Department of Neurology & Neurosurgery, McGill University, Montreal Neurological Institute, Montréal, Québec H3A 2B4, Canada
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50
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Douris V, Telford MJ, Averof M. Evidence for multiple independent origins of trans-splicing in Metazoa. Mol Biol Evol 2009; 27:684-93. [PMID: 19942614 DOI: 10.1093/molbev/msp286] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In contrast to conventional splicing, which joins exons from a single primary transcript, trans-splicing links stretches of RNA from separate transcripts, derived from distinct regions of the genome. Spliced leader (SL) trans-splicing is particularly well known in trypanosomes, nematodes, and flatworms, where it provides messenger RNAs with a leader sequence and cap that allow them to be translated efficiently. One of the largest puzzles regarding SL trans-splicing is its evolutionary origin. Until now SL trans-splicing has been found in a small and disparate set of organisms (including trypanosomes, dinoflagellates, cnidarians, rotifers, nematodes, flatworms, and urochordates) but not in most other eukaryotic lineages, including well-studied groups such as fungi, plants, arthropods, and vertebrates. This patchy distribution could either suggest that trans-splicing was present in early eukaryotes/metazoans and subsequently lost in multiple lineages or that it evolved several times independently. Starting from the serendipitous discovery of SL trans-splicing in an arthropod, we undertook a comprehensive survey of this process in the animal kingdom. By surveying expressed sequence tag data from more than 70 metazoan species, we show that SL trans-splicing also occurs in at least two groups of arthropods (amphipod and copepod crustaceans), in ctenophores, and in hexactinellid sponges. However, we find no evidence for SL trans-splicing in other groups of arthropods and sponges or in 15 other phyla that we have surveyed. Although the presence of SL trans-splicing in hydrozoan cnidarians, hexactinellid sponges, and ctenophores might suggest that it was present at the base of the Metazoa, the patchy distribution that is evident at higher resolution suggests that SL trans-splicing has evolved repeatedly among metazoan lineages. In agreement with this scenario, we discuss evidence that SL precursor RNAs can readily evolve from ubiquitous small nuclear RNAs that are used for conventional splicing.
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Affiliation(s)
- Vassilis Douris
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology Hellas, Iraklio, Crete, Greece
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