1
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Lagunas-Rangel FA. Giardia telomeres and telomerase. Parasitol Res 2024; 123:179. [PMID: 38584235 PMCID: PMC10999387 DOI: 10.1007/s00436-024-08200-6] [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: 12/23/2023] [Accepted: 04/02/2024] [Indexed: 04/09/2024]
Abstract
Giardia duodenalis, the protozoan responsible for giardiasis, is a significant contributor to millions of diarrheal diseases worldwide. Despite the availability of treatments for this parasitic infection, therapeutic failures are alarmingly frequent. Thus, there is a clear need to identify new therapeutic targets. Giardia telomeres were previously identified, but our understanding of these structures and the critical role played by Giardia telomerase in maintaining genomic stability and its influence on cellular processes remains limited. In this regard, it is known that all Giardia chromosomes are capped by small telomeres, organized and protected by specific proteins that regulate their functions. To counteract natural telomere shortening and maintain high proliferation, Giardia exhibits constant telomerase activity and employs additional mechanisms, such as the formation of G-quadruplex structures and the involvement of transposable elements linked to telomeric repeats. Thus, this study aims to address the existing knowledge gap by compiling the available information (until 2023) about Giardia telomeres and telomerase, focusing on highlighting the distinctive features within this parasite. Furthermore, the potential feasibility of targeting Giardia telomeres and/or telomerase as an innovative therapeutic strategy is discussed.
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Affiliation(s)
- Francisco Alejandro Lagunas-Rangel
- Department of Surgical Sciences, Uppsala University, Husargatan 3, BMC Box 593, 751 24, Uppsala, Sweden.
- Department of Genetics and Molecular Biology, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Gustavo A. Madero, 07360, Mexico City, Mexico.
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2
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Lyčka M, Bubeník M, Závodník M, Peska V, Fajkus P, Demko M, Fajkus J, Fojtová M. TeloBase: a community-curated database of telomere sequences across the tree of life. Nucleic Acids Res 2024; 52:D311-D321. [PMID: 37602392 PMCID: PMC10767889 DOI: 10.1093/nar/gkad672] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 07/27/2023] [Accepted: 08/14/2023] [Indexed: 08/22/2023] Open
Abstract
Discoveries over the recent decade have demonstrated the unexpected diversity of telomere DNA motifs in nature. However, currently available resources, 'Telomerase database' and 'Plant rDNA database', contain just fragments of all relevant literature published over decades of telomere research as they have a different primary focus and limited updates. To fill this gap, we gathered data about telomere DNA sequences from a thorough literature screen as well as by analysing publicly available NGS data, and we created TeloBase (http://cfb.ceitec.muni.cz/telobase/) as a comprehensive database of information about telomere motif diversity. TeloBase is supplemented by internal taxonomy utilizing popular on-line taxonomic resources that enables in-house data filtration and graphical visualisation of telomere DNA evolutionary dynamics in the form of heat tree plots. TeloBase avoids overreliance on administrators for future data updates by having a simple form and community-curation system for application and approval, respectively, of new telomere sequences by users, which should ensure timeliness of the database and topicality. To demonstrate TeloBase utility, we examined telomere motif diversity in species from the fungal genus Aspergillus, and discovered (TTTATTAGGG)n sequence as a putative telomere motif in the plant family Chrysobalanaceae. This was bioinformatically confirmed by analysing template regions of identified telomerase RNAs.
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Affiliation(s)
- Martin Lyčka
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, BrnoCZ-62500, Czech Republic
| | - Michal Bubeník
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, BrnoCZ-62500, Czech Republic
| | - Michal Závodník
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, BrnoCZ-62500, Czech Republic
| | - Vratislav Peska
- Department of Cell Biology and Radiobiology, Institute of Biophysics, Academy of Sciences of the Czech Republic, BrnoCZ-61200, Czech Republic
| | - Petr Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- Department of Cell Biology and Radiobiology, Institute of Biophysics, Academy of Sciences of the Czech Republic, BrnoCZ-61200, Czech Republic
| | - Martin Demko
- Core Facility Bioinformatics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- Faculty of Informatics, Masaryk University, BrnoCZ-62500, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, BrnoCZ-62500, Czech Republic
- Department of Cell Biology and Radiobiology, Institute of Biophysics, Academy of Sciences of the Czech Republic, BrnoCZ-61200, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, BrnoCZ-62500, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, BrnoCZ-62500, Czech Republic
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3
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Lim J, Kim W, Kim J, Lee J. Telomeric repeat evolution in the phylum Nematoda revealed by high-quality genome assemblies and subtelomere structures. Genome Res 2023; 33:gr.278124.123. [PMID: 37918961 PMCID: PMC10760449 DOI: 10.1101/gr.278124.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 10/16/2023] [Indexed: 11/04/2023]
Abstract
Telomeres are composed of tandem arrays of telomeric-repeat motifs (TRMs) and telomere-binding proteins (TBPs), which are responsible for ensuring end-protection and end-replication of chromosomes. TRMs are highly conserved owing to the sequence specificity of TBPs, although significant alterations in TRM have been observed in several taxa, except Nematoda. We used public whole-genome sequencing data sets to analyze putative TRMs of 100 nematode species and determined that three distinct branches included specific novel TRMs, suggesting that evolutionary alterations in TRMs occurred in Nematoda. We focused on one of the three branches, the Panagrolaimidae family, and performed a de novo assembly of four high-quality draft genomes of the canonical (TTAGGC) and novel TRM (TTAGAC) isolates; the latter genomes revealed densely clustered arrays of the novel TRM. We then comprehensively analyzed the subtelomeric regions of the genomes to infer how the novel TRM evolved. We identified DNA damage-repair signatures in subtelomeric sequences that were representative of consequences of telomere maintenance mechanisms by alternative lengthening of telomeres. We propose a hypothetical scenario in which TTAGAC-containing units are clustered in subtelomeric regions and pre-existing TBPs capable of binding both canonical and novel TRMs aided the evolution of the novel TRM in the Panagrolaimidae family.
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Affiliation(s)
- Jiseon Lim
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul 08826, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, South Korea
| | - Wonjoo Kim
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul 08826, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, South Korea
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul 08826, South Korea;
- Research Institute of Basic Sciences, Seoul National University, Seoul 08826, South Korea
- Department of Convergent Bioscience and Informatics, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, South Korea
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Gwanak-gu, Seoul 08826, South Korea
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, South Korea
- Research Institute of Basic Sciences, Seoul National University, Seoul 08826, South Korea
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Serrano-León IM, Prieto P, Aguilar M. Telomere and subtelomere high polymorphism might contribute to the specificity of homologous recognition and pairing during meiosis in barley in the context of breeding. BMC Genomics 2023; 24:642. [PMID: 37884878 PMCID: PMC10601145 DOI: 10.1186/s12864-023-09738-y] [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: 07/26/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Barley (Hordeum vulgare) is one of the most popular cereal crops globally. Although it is a diploid species, (2n = 2x = 14) the study of its genome organization is necessary in the framework of plant breeding since barley is often used in crosses with other cereals like wheat to provide them with advantageous characters. We already have an extensive knowledge on different stages of the meiosis, the cell division to generate the gametes in species with sexual reproduction, such as the formation of the synaptonemal complex, recombination, and chromosome segregation. But meiosis really starts with the identification of homologous chromosomes and pairing initiation, and it is still unclear how chromosomes exactly choose a partner to appropriately pair for additional recombination and segregation. In this work we present an exhaustive molecular analysis of both telomeres and subtelomeres of barley chromosome arms 2H-L, 3H-L and 5H-L. As expected, the analysis of multiple features, including transposable elements, repeats, GC content, predicted CpG islands, recombination hotspots, G4 quadruplexes, genes and targeted sequence motifs for key DNA-binding proteins, revealed a high degree of variability both in telomeres and subtelomeres. The molecular basis for the specificity of homologous recognition and pairing occurring in the early chromosomal interactions at the start of meiosis in barley may be provided by these polymorphisms. A more relevant role of telomeres and most distal part of subtelomeres is suggested.
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Affiliation(s)
- I M Serrano-León
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Avenida Menéndez Pidal S/N., Campus Alameda del Obispo, 14004, Córdoba, Spain
| | - P Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Avenida Menéndez Pidal S/N., Campus Alameda del Obispo, 14004, Córdoba, Spain.
| | - M Aguilar
- Área de Fisiología Vegetal, Universidad de Córdoba, Campus de Rabanales, Edif. C4, 3ª Planta, Córdoba, Spain
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Valeeva LR, Abdulkina LR, Agabekian IA, Shakirov EV. Telomere biology and ribosome biogenesis: structural and functional interconnections. Biochem Cell Biol 2023; 101:394-409. [PMID: 36989538 DOI: 10.1139/bcb-2022-0383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
Telomeres are nucleoprotein structures that play a pivotal role in the protection and maintenance of eukaryotic chromosomes. Telomeres and the enzyme telomerase, which replenishes telomeric DNA lost during replication, are important factors necessary to ensure continued cell proliferation. Cell proliferation is also dependent on proper and efficient protein synthesis, which is carried out by ribosomes. Mutations in genes involved in either ribosome biogenesis or telomere biology result in cellular abnormalities and can cause human genetic diseases, defined as ribosomopathies and telomeropathies, respectively. Interestingly, recent discoveries indicate that many of the ribosome assembly and rRNA maturation factors have additional noncanonical functions in telomere biology. Similarly, several key proteins and enzymes involved in telomere biology, including telomerase, have unexpected roles in rRNA transcription and maturation. These observations point to an intriguing cross-talk mechanism potentially explaining the multiple pleiotropic symptoms of mutations in many causal genes identified in various telomeropathy and ribosomopathy diseases. In this review, we provide a brief summary of eukaryotic telomere and rDNA loci structures, highlight several universal features of rRNA and telomerase biogenesis, evaluate intriguing interconnections between telomere biology and ribosome assembly, and conclude with an assessment of overlapping features of human diseases of telomeropathies and ribosomopathies.
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Affiliation(s)
- Liia R Valeeva
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
- Department of Biological Sciences, College of Science, Marshall University, Huntington, WV 25701, USA
| | - Liliia R Abdulkina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
| | - Inna A Agabekian
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan 420008, Republic of Tatarstan, Russia
| | - Eugene V Shakirov
- Department of Biological Sciences, College of Science, Marshall University, Huntington, WV 25701, USA
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA
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Závodník M, Fajkus P, Franek M, Kopecký D, Garcia S, Dodsworth S, Orejuela A, Kilar A, Ptáček J, Mátl M, Hýsková A, Fajkus J, Peška V. Telomerase RNA gene paralogs in plants - the usual pathway to unusual telomeres. THE NEW PHYTOLOGIST 2023; 239:2353-2366. [PMID: 37391893 DOI: 10.1111/nph.19110] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 06/06/2023] [Indexed: 07/02/2023]
Abstract
Telomerase, telomeric DNA and associated proteins together represent a complex, finely tuned and functionally conserved mechanism that ensures genome integrity by protecting and maintaining chromosome ends. Changes in its components can threaten an organism's viability. Nevertheless, molecular innovation in telomere maintenance has occurred multiple times during eukaryote evolution, giving rise to species/taxa with unusual telomeric DNA sequences, telomerase components or telomerase-independent telomere maintenance. The central component of telomere maintenance machinery is telomerase RNA (TR) as it templates telomere DNA synthesis, its mutation can change telomere DNA and disrupt its recognition by telomere proteins, thereby leading to collapse of their end-protective and telomerase recruitment functions. Using a combination of bioinformatic and experimental approaches, we examine a plausible scenario of evolutionary changes in TR underlying telomere transitions. We identified plants harbouring multiple TR paralogs whose template regions could support the synthesis of diverse telomeres. In our hypothesis, formation of unusual telomeres is associated with the occurrence of TR paralogs that can accumulate mutations, and through their functional redundancy, allow for the adaptive evolution of the other telomere components. Experimental analyses of telomeres in the examined plants demonstrate evolutionary telomere transitions corresponding to TR paralogs with diverse template regions.
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Affiliation(s)
- Michal Závodník
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, CZ-61137, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC Masaryk University, Brno, CZ-62500, Czech Republic
| | - Petr Fajkus
- Mendel Centre for Plant Genomics and Proteomics, CEITEC Masaryk University, Brno, CZ-62500, Czech Republic
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, CZ-61265, Czech Republic
| | - Michal Franek
- Mendel Centre for Plant Genomics and Proteomics, CEITEC Masaryk University, Brno, CZ-62500, Czech Republic
| | - David Kopecký
- Centre of Plant Structural and Functional Genomics, Institute of Experimental Botany of the Czech Academy of Sciences, Olomouc, CZ-779 00, Czech Republic
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC), Passeig del Migdia S/N, Barcelona, 08038, Catalonia, Spain
| | - Steven Dodsworth
- School of Biological Sciences, University of Portsmouth, King Henry Building, King Henry I St., Portsmouth, PO1 2DY, UK
| | - Andrés Orejuela
- Grupo de Investigación en Recursos Naturales Amazónicos - GRAM, Facultad de Ingenierías y Ciencias Básicas and Herbario Etnobotánico del Piedemonte Andino Amazónico (HEAA), Instituto Tecnológico del Putumayo - ITP, Mocoa, Putumayo, Colombia
| | - Agata Kilar
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, CZ-61137, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC Masaryk University, Brno, CZ-62500, Czech Republic
| | - Jiří Ptáček
- Potato Research Institute Havlíčkův Brod Ltd, Havlíčkův Brod, CZ-58001, Czech Republic
| | - Martin Mátl
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, CZ-61265, Czech Republic
| | - Anna Hýsková
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, CZ-61137, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, CZ-61137, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC Masaryk University, Brno, CZ-62500, Czech Republic
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, CZ-61265, Czech Republic
| | - Vratislav Peška
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, CZ-61265, Czech Republic
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Bhowmick BK, Sarkar S, Roychowdhury D, Patil SD, Lekhak MM, Ohri D, Rama Rao S, Yadav SR, Verma RC, Dhar MK, Raina SN, Jha S. Allium cytogenetics: a critical review on the Indian taxa. COMPARATIVE CYTOGENETICS 2023; 17:129-156. [PMID: 37304149 PMCID: PMC10252142 DOI: 10.3897/compcytogen.17.98903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/28/2023] [Indexed: 06/13/2023]
Abstract
The genus Allium Linnaeus, 1753 (tribe Allieae) contains about 800 species worldwide of which almost 38 species are reported in India, including the globally important crops (onion, garlic, leek, shallot) and many wild species. A satisfactory chromosomal catalogue of Allium species is missing which has been considered in the review for the species occurring in India. The most prominent base number is x=8, with few records of x=7, 10, 11. The genome size has sufficient clues for divergence, ranging from 7.8 pg/1C to 30.0 pg/1C in diploid and 15.16 pg/1C to 41.78 pg/1C in polyploid species. Although the karyotypes are seemingly dominated by metacentrics, substantial variation in nucleolus organizing regions (NORs) is noteworthy. The chromosomal rearrangement between A.cepa Linnaeus, 1753 and its allied species has paved way to appreciate genomic evolution within Allium. The presence of a unique telomere sequence and its conservation in Allium sets this genus apart from all other Amaryllids and supports monophyletic origin. Any cytogenetic investigation regarding NOR variability, telomere sequence and genome size in the Indian species becomes the most promising field to decipher chromosome evolution against the background of species diversity and evolution, especially in the Indian subcontinent.
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Affiliation(s)
- Biplab Kumar Bhowmick
- Department of Botany, Scottish Church College, 1&3, Urquhart Square, Kolkata- 700006, West Bengal, IndiaDepartment of Botany, Scottish Church CollegeKolkataIndia
| | - Sayantika Sarkar
- Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata- 700019, West Bengal, IndiaUniversity of CalcuttaKolkataIndia
| | - Dipasree Roychowdhury
- Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata- 700019, West Bengal, IndiaUniversity of CalcuttaKolkataIndia
| | - Sayali D. Patil
- Angiosperm Taxonomy Laboratory, Department of Botany, Shivaji University, Kolhapur, Maharashtra- 416004, IndiaShivaji UniversityKolhapurIndia
| | - Manoj M. Lekhak
- Angiosperm Taxonomy Laboratory, Department of Botany, Shivaji University, Kolhapur, Maharashtra- 416004, IndiaShivaji UniversityKolhapurIndia
| | - Deepak Ohri
- Amity Institute of Biotechnology, Research Cell, Amity University Uttar Pradesh, Lucknow Campus, Lucknow- 226028, Uttar Pradesh, IndiaAmity University Uttar PradeshLucknowIndia
| | - Satyawada Rama Rao
- Department of Biotechnology and Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya- 793022, IndiaNorth-Eastern Hill UniversityShillongIndia
| | - S. R. Yadav
- Angiosperm Taxonomy Laboratory, Department of Botany, Shivaji University, Kolhapur, Maharashtra- 416004, IndiaShivaji UniversityKolhapurIndia
| | - R. C. Verma
- School of Studies in Botany, Vikram University, Ujjain, Madhya Pradesh 456010, IndiaVikram UniversityUjjainIndia
| | - Manoj K. Dhar
- Genome Research Laboratory, School of Biotechnology, University of Jammu, Jammu, Jammu and Kashmir- 180006, IndiaUniversity of JammuJammuIndia
| | - S. N. Raina
- Amity Institute of Biotechnology, Amity University, Sector 125, Noida, Uttar Pradesh- 201313, IndiaAmity UniversityNoidaIndia
| | - Sumita Jha
- Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata- 700019, West Bengal, IndiaUniversity of CalcuttaKolkataIndia
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Sun Q, Wang H, Tao S, Xi X. Large-Scale Detection of Telomeric Motif Sequences in Genomic Data Using TelFinder. Microbiol Spectr 2023; 11:e0392822. [PMID: 36847562 PMCID: PMC10100673 DOI: 10.1128/spectrum.03928-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/04/2023] [Indexed: 03/01/2023] Open
Abstract
Telomeres are regions of tandem repeated sequences at the ends of linear chromosomes that protect against DNA damage and chromosome fusion. Telomeres are associated with senescence and cancers and have attracted the attention of an increasing number of researchers. However, few telomeric motif sequences are known. Given the mounting interest in telomeres, an efficient computational tool for the de novo detection of the telomeric motif sequence of new species is needed since experimental-based methods are costly in terms of time and effort. Here, we report the development of TelFinder, an easy-to-use and freely available tool for the de novo detection of telomeric motif sequences from genomic data. The vast quantity of readily available genomic data makes it possible to apply this tool to any species of interest, which will undoubtedly inspire studies requiring telomeric repeat information and improve the utilization of these genomic data sets. We have tested TelFinder on telomeric sequences available in the Telomerase Database, and the detection accuracy reaches 90%. In addition, variation analyses in telomere sequences can be performed by TelFinder for the first time. The telomere variation preference of different chromosomes and even at the ends of the chromosome can provide clues regarding the underlying mechanisms of telomeres. Overall, these results shed new light on the divergent evolution of telomeres. IMPORTANCE Telomeres are reported to be highly correlated with the cell cycle and aging. As a result, research on telomere composition and evolution has become more and more urgent. However, using experimental methods to detect telomeric motif sequences is slow and costly. To combat this challenge, we developed TelFinder, a computational tool for the de novo detection of the telomere composition only using genomic data. In this study, we showed that a lot of complicated telomeric motifs could be identified by TelFinder only using genomic data. In addition, TelFinder can be used to check variation analyses in telomere sequences, which could lead to a deeper understanding of telomere sequences.
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Affiliation(s)
- Qing Sun
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
| | - Hao Wang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
| | - Shiheng Tao
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, China
- State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi, China
| | - Xuguang Xi
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, LBPA, Gif-sur-Yvette, France
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9
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A Y, Shi S, Sun S, Jing Y, Li Z, Zhang X, Li X, Wu F. Telomerase activity, relative telomere length, and longevity in alfalfa ( Medicago sativa L.). PeerJ 2022. [DOI: 10.7717/peerj.14102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background
Medicago sativa L. ‘Qingshui’ is a valuable rhizomatous forage germplasm resource. We previously crossed Qingshui with the high-yielding Medicago sativa L. ‘WL168’ and obtained novel rhizomatous hybrid strains (RSA-01, RSA-02, and RSA-03). Telomere dynamics are more accurate predictors of survival and mortality than chronological age. Based on telomere analyses, we aimed to identify alfalfa varieties with increased stamina and longevity for the establishment of artificial grazing grasslands.
Methods
In this study, we performed longitudinal analysis of telomerase activity and relative telomere length in five alfalfa varieties (Qingshui, WL168, RSA-01, RSA-02, and RSA-03) at the age of 1 year and 5 years to examine the relationship among telomerase activity, rate of change in relative telomere length, and longevity. We further aimed to evaluate the longevity of the examined varieties. Telomerase activity and relative telomere length were measured using enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively.
Results
We observed significant differences in telomerase activity between plants aged 1 year and those aged 5 years in all varieties except WL168, and the rate of change in telomerase activity does not differ reliably with age. As telomerase activity and relative telomere length are complex phenomena, further studies examining the molecular mechanisms of telomere-related proteins are needed. Relative telomere lengths of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 in plants aged 5 years were higher than those aged 1 year by 11.41, 11.24, 9.21, 10.23, and 11.41, respectively. Relative telomere length of alfalfa tended to increase with age. Accordingly, alfalfa varieties can be classified according to rate of change in relative telomere length as long-lived (Qingshui, WL168, and RSA-03), medium-lived (RSA-02) and short-lived (RSA-01). The differences in relative telomere length distances of Qingshui, WL168, RSA-01, RSA-02, and RSA-03 between plants aged 1 and 5 years were 10.40, 13.02, 12.22, 11.22, and 13.25, respectively. The largest difference in relative telomere length was found between Qingshui and RSA-02 at 2.20. Our findings demonstrated that relative telomere length in alfalfa is influenced by genetic variation and age, with age exerting a greater effect.
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Affiliation(s)
- Yun A
- Gansu Agricultural University, Lanzhou, China
| | - Shangli Shi
- Gansu Agricultural University, Lanzhou, China
| | | | | | - Zili Li
- Gansu Agricultural University, Lanzhou, China
| | | | - Xiaolong Li
- Gansu Agricultural University, Lanzhou, China
| | - Fang Wu
- Gansu Agricultural University, Lanzhou, China
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10
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Telomeres and Their Neighbors. Genes (Basel) 2022; 13:genes13091663. [PMID: 36140830 PMCID: PMC9498494 DOI: 10.3390/genes13091663] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
Telomeres are essential structures formed from satellite DNA repeats at the ends of chromosomes in most eukaryotes. Satellite DNA repeat sequences are useful markers for karyotyping, but have a more enigmatic role in the eukaryotic cell. Much work has been done to investigate the structure and arrangement of repetitive DNA elements in classical models with implications for species evolution. Still more is needed until there is a complete picture of the biological function of DNA satellite sequences, particularly when considering non-model organisms. Celebrating Gregor Mendel’s anniversary by going to the roots, this review is designed to inspire and aid new research into telomeres and satellites with a particular focus on non-model organisms and accessible experimental and in silico methods that do not require specialized equipment or expensive materials. We describe how to identify telomere (and satellite) repeats giving many examples of published (and some unpublished) data from these techniques to illustrate the principles behind the experiments. We also present advice on how to perform and analyse such experiments, including details of common pitfalls. Our examples are a selection of recent developments and underexplored areas of research from the past. As a nod to Mendel’s early work, we use many examples from plants and insects, especially as much recent work has expanded beyond the human and yeast models traditional in telomere research. We give a general introduction to the accepted knowledge of telomere and satellite systems and include references to specialized reviews for the interested reader.
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11
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Zhou Y, Wang Y, Xiong X, Appel AG, Zhang C, Wang X. Profiles of telomeric repeats in Insecta reveal diverse forms of telomeric motifs in Hymenopterans. Life Sci Alliance 2022; 5:5/7/e202101163. [PMID: 35365574 PMCID: PMC8977481 DOI: 10.26508/lsa.202101163] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 03/04/2022] [Accepted: 03/04/2022] [Indexed: 12/23/2022] Open
Abstract
Telomeres consist of highly conserved simple tandem telomeric repeat motif (TRM): (TTAGG)n in arthropods, (TTAGGG)n in vertebrates, and (TTTAGGG)n in most plants. TRM can be detected from chromosome-level assembly, which typically requires long-read sequencing data. To take advantage of short-read data, we developed an ultra-fast Telomeric Repeats Identification Pipeline and evaluated its performance on 91 species. With proven accuracy, we applied Telomeric Repeats Identification Pipeline in 129 insect species, using 7 Tbp of short-read sequences. We confirmed (TTAGG)n as the TRM in 19 orders, suggesting it is the ancestral form in insects. Systematic profiling in Hymenopterans revealed a diverse range of TRMs, including the canonical 5-bp TTAGG (bees, ants, and basal sawflies), three independent losses of tandem repeat form TRM (Ichneumonoids, hunting wasps, and gall-forming wasps), and most interestingly, a common 8-bp (TTATTGGG)n in Chalcid wasps with two 9-bp variants in the miniature wasp (TTACTTGGG) and fig wasps (TTATTGGGG). Our results identified extraordinary evolutionary fluidity of Hymenopteran TRMs, and rapid evolution of TRM and repeat abundance at all evolutionary scales, providing novel insights into telomere evolution.
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Affiliation(s)
- Yihang Zhou
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China.,Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.,Auburn University Center for Advanced Science, Innovation, and Commerce, Alabama Agricultural Experiment Station, Auburn, AL, USA
| | - Yi Wang
- Ministry of Education Key Laboratory of Contemporary Anthropology, Department of Anthropology and Human Genetics, School of Life Sciences, Fudan University, Shanghai, China.,Human Phenome Institute, Fudan University, Shanghai, China
| | - Xiao Xiong
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China.,Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.,Auburn University Center for Advanced Science, Innovation, and Commerce, Alabama Agricultural Experiment Station, Auburn, AL, USA
| | - Arthur G Appel
- Auburn University Center for Advanced Science, Innovation, and Commerce, Alabama Agricultural Experiment Station, Auburn, AL, USA.,Department of Entomology and Plant Pathology, Auburn University, AL, USA
| | - Chao Zhang
- Fundamental Research Center, Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xu Wang
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.,Auburn University Center for Advanced Science, Innovation, and Commerce, Alabama Agricultural Experiment Station, Auburn, AL, USA.,Department of Entomology and Plant Pathology, Auburn University, AL, USA.,HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
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Gao D, Nascimento EFMB, Leal-Bertioli SCM, Abernathy B, Jackson SA, Araujo ACG, Bertioli DJ. TAR30, a homolog of the canonical plant TTTAGGG telomeric repeat, is enriched in the proximal chromosome regions of peanut (Arachis hypogaea L.). Chromosome Res 2022; 30:77-90. [DOI: 10.1007/s10577-022-09684-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 11/03/2022]
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Maravilla AJ, Rosato M, Álvarez I, Nieto Feliner G, Rosselló JA. Interstitial Arabidopsis-Type Telomeric Repeats in Asteraceae. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10122794. [PMID: 34961265 PMCID: PMC8705333 DOI: 10.3390/plants10122794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 05/13/2023]
Abstract
Tandem repeats of telomeric-like motifs at intra-chromosomal regions, known as interstitial telomeric repeats (ITR), have drawn attention as potential markers of structural changes, which might convey information about evolutionary relationships if preserved through time. Building on our previous work that reported outstanding ITR polymorphisms in the genus Anacyclus, we undertook a survey across 132 Asteraceae species, focusing on the six most speciose subfamilies and considering all the ITR data published to date. The goal was to assess whether the presence, site number, and chromosomal location of ITRs convey any phylogenetic signal. We conducted fluorescent in situ hybridization (FISH) using an Arabidopsis-type telomeric sequence as a probe on karyotypes obtained from mitotic chromosomes. FISH signals of ITR sites were detected in species of subfamilies Asteroideae, Carduoideae, Cichorioideae, Gymnarhenoideae, and Mutisioideae, but not in Barnadesioideae. Although six small subfamilies have not yet been sampled, altogether, our results suggest that the dynamics of ITR formation in Asteraceae cannot accurately trace the complex karyological evolution that occurred since the early diversification of this family. Thus, ITRs do not convey a reliable signal at deep or shallow phylogenetic levels and cannot help to delimitate taxonomic categories, a conclusion that might also hold for other important families such as Fabaceae.
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Affiliation(s)
- Alexis J. Maravilla
- Jardín Botánico, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, c/Quart 80, E-46008 Valencia, Spain; (A.J.M.); (M.R.)
| | - Marcela Rosato
- Jardín Botánico, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, c/Quart 80, E-46008 Valencia, Spain; (A.J.M.); (M.R.)
| | - Inés Álvarez
- Real Jardín Botánico (RJB), Consejo Superior de Investigaciones Científicas (CSIC), Plaza de Murillo 2, E-28014 Madrid, Spain; (I.Á.); (G.N.F.)
| | - Gonzalo Nieto Feliner
- Real Jardín Botánico (RJB), Consejo Superior de Investigaciones Científicas (CSIC), Plaza de Murillo 2, E-28014 Madrid, Spain; (I.Á.); (G.N.F.)
| | - Josep A. Rosselló
- Jardín Botánico, Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universitat de València, c/Quart 80, E-46008 Valencia, Spain; (A.J.M.); (M.R.)
- Correspondence: ; Tel.: +34-963-156-800
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14
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Maravilla AJ, Rosato M, Rosselló JA. Interstitial Telomeric-like Repeats (ITR) in Seed Plants as Assessed by Molecular Cytogenetic Techniques: A Review. PLANTS (BASEL, SWITZERLAND) 2021; 10:2541. [PMID: 34834904 PMCID: PMC8621592 DOI: 10.3390/plants10112541] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 05/12/2023]
Abstract
The discovery of telomeric repeats in interstitial regions of plant chromosomes (ITRs) through molecular cytogenetic techniques was achieved several decades ago. However, the information is scattered and has not been critically evaluated from an evolutionary perspective. Based on the analysis of currently available data, it is shown that ITRs are widespread in major evolutionary lineages sampled. However, their presence has been detected in only 45.6% of the analysed families, 26.7% of the sampled genera, and in 23.8% of the studied species. The number of ITR sites greatly varies among congeneric species and higher taxonomic units, and range from one to 72 signals. ITR signals mostly occurs as homozygous loci in most species, however, odd numbers of ITR sites reflecting a hemizygous state have been reported in both gymnosperm and angiosperm groups. Overall, the presence of ITRs appears to be poor predictors of phylogenetic and taxonomic relatedness at most hierarchical levels. The presence of ITRs and the number of sites are not significantly associated to the number of chromosomes. The longitudinal distribution of ITR sites along the chromosome arms indicates that more than half of the ITR presences are between proximal and terminal locations (49.5%), followed by proximal (29.0%) and centromeric (21.5%) arm regions. Intraspecific variation concerning ITR site number, chromosomal locations, and the differential presence on homologous chromosome pairs has been reported in unrelated groups, even at the population level. This hypervariability and dynamism may have likely been overlooked in many lineages due to the very low sample sizes often used in cytogenetic studies.
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Affiliation(s)
| | | | - Josep A. Rosselló
- Jardín Botánico, ICBiBE, Universitat de València, c/Quart 80, E-46008 València, Spain; (A.J.M.); (M.R.)
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15
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Garrido-Ramos MA. The Genomics of Plant Satellite DNA. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 60:103-143. [PMID: 34386874 DOI: 10.1007/978-3-030-74889-0_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The twenty-first century began with a certain indifference to the research of satellite DNA (satDNA). Neither genome sequencing projects were able to accurately encompass the study of satDNA nor classic methodologies were able to go further in undertaking a better comprehensive study of the whole set of satDNA sequences of a genome. Nonetheless, knowledge of satDNA has progressively advanced during this century with the advent of new analytical techniques. The enormous advantages that genome-wide approaches have brought to its analysis have now stimulated a renewed interest in the study of satDNA. At this point, we can look back and try to assess more accurately many of the key questions that were left unsolved in the past about this enigmatic and important component of the genome. I review here the understanding gathered on plant satDNAs over the last few decades with an eye on the near future.
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Peska V, Fajkus P, Bubeník M, Brázda V, Bohálová N, Dvořáček V, Fajkus J, Garcia S. Extraordinary diversity of telomeres, telomerase RNAs and their template regions in Saccharomycetaceae. Sci Rep 2021; 11:12784. [PMID: 34140564 PMCID: PMC8211666 DOI: 10.1038/s41598-021-92126-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/03/2021] [Indexed: 01/08/2023] Open
Abstract
Telomerase RNA (TR) carries the template for synthesis of telomere DNA and provides a scaffold for telomerase assembly. Fungal TRs are long and have been compared to higher eukaryotes, where they show considerable diversity within phylogenetically close groups. TRs of several Saccharomycetaceae were recently identified, however, many of these remained uncharacterised in the template region. Here we show that this is mainly due to high variability in telomere sequence. We predicted the telomere sequences using Tandem Repeats Finder and then we identified corresponding putative template regions in TR candidates. Remarkably long telomere units and the corresponding putative TRs were found in Tetrapisispora species. Notably, variable lengths of the annealing sequence of the template region (1–10 nt) were found. Consequently, species with the same telomere sequence may not harbour identical TR templates. Thus, TR sequence alone can be used to predict a template region and telomere sequence, but not to determine these exactly. A conserved feature of telomere sequences, tracts of adjacent Gs, led us to test the propensity of individual telomere sequences to form G4. The results show highly diverse values of G4-propensity, indicating the lack of ubiquitous conservation of this feature across Saccharomycetaceae.
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Affiliation(s)
- Vratislav Peska
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.
| | - Petr Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Michal Bubeník
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Václav Brázda
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic
| | - Natália Bohálová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, 62500, Czech Republic
| | - Vojtěch Dvořáček
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic
| | - Jiří Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, 61265, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, 62500, Czech Republic
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC, Ajuntament de Barcelona), Passeig del Migdia s/n, 08038, Barcelona, Catalonia, Spain.
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Fajkus P, Peška V, Fajkus J, Sýkorová E. Origin and Fates of TERT Gene Copies in Polyploid Plants. Int J Mol Sci 2021; 22:1783. [PMID: 33670111 PMCID: PMC7916837 DOI: 10.3390/ijms22041783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/14/2022] Open
Abstract
The gene coding for the telomerase reverse transcriptase (TERT) is essential for the maintenance of telomeres. Previously we described the presence of three TERT paralogs in the allotetraploid plant Nicotiana tabacum, while a single TERT copy was identified in the paleopolyploid model plant Arabidopsis thaliana. Here we examine the presence, origin and functional status of TERT variants in allotetraploid Nicotiana species of diverse evolutionary ages and their parental genome donors, as well as in other diploid and polyploid plant species. A combination of experimental and in silico bottom-up analyses of TERT gene copies in Nicotiana polyploids revealed various patterns of retention or loss of parental TERT variants and divergence in their functions. RT-qPCR results confirmed the expression of all the identified TERT variants. In representative plant and green algal genomes, our synteny analyses show that their TERT genes were located in a conserved locus that became advantageous after the divergence of eudicots, and the gene was later translocated in several plant groups. In various diploid and polyploid species, translocation of TERT became fixed in target loci that show ancient synapomorphy.
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Affiliation(s)
- Petr Fajkus
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; (P.F.); (V.P.)
| | - Vratislav Peška
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; (P.F.); (V.P.)
| | - Jiří Fajkus
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; (P.F.); (V.P.)
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Eva Sýkorová
- Institute of Biophysics of the Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; (P.F.); (V.P.)
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18
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Aguilar M, Prieto P. Telomeres and Subtelomeres Dynamics in the Context of Early Chromosome Interactions During Meiosis and Their Implications in Plant Breeding. FRONTIERS IN PLANT SCIENCE 2021; 12:672489. [PMID: 34149773 PMCID: PMC8212018 DOI: 10.3389/fpls.2021.672489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 05/08/2023]
Abstract
Genomic architecture facilitates chromosome recognition, pairing, and recombination. Telomeres and subtelomeres play an important role at the beginning of meiosis in specific chromosome recognition and pairing, which are critical processes that allow chromosome recombination between homologs (equivalent chromosomes in the same genome) in later stages. In plant polyploids, these terminal regions are even more important in terms of homologous chromosome recognition, due to the presence of homoeologs (equivalent chromosomes from related genomes). Although telomeres interaction seems to assist homologous pairing and consequently, the progression of meiosis, other chromosome regions, such as subtelomeres, need to be considered, because the DNA sequence of telomeres is not chromosome-specific. In addition, recombination operates at subtelomeres and, as it happens in rye and wheat, homologous recognition and pairing is more often correlated with recombining regions than with crossover-poor regions. In a plant breeding context, the knowledge of how homologous chromosomes initiate pairing at the beginning of meiosis can contribute to chromosome manipulation in hybrids or interspecific genetic crosses. Thus, recombination in interspecific chromosome associations could be promoted with the aim of transferring desirable agronomic traits from related genetic donor species into crops. In this review, we summarize the importance of telomeres and subtelomeres on chromatin dynamics during early meiosis stages and their implications in recombination in a plant breeding framework.
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Affiliation(s)
- Miguel Aguilar
- Área de Fisiología Vegetal, Universidad de Córdoba, Córdoba, Spain
| | - Pilar Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
- *Correspondence: Pilar Prieto, ; orcid.org/0000-0002-8160-808X
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19
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Červenák F, Sepšiová R, Nosek J, Tomáška Ľ. Step-by-Step Evolution of Telomeres: Lessons from Yeasts. Genome Biol Evol 2020; 13:6127219. [PMID: 33537752 PMCID: PMC7857110 DOI: 10.1093/gbe/evaa268] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 12/23/2022] Open
Abstract
In virtually every eukaryotic species, the ends of nuclear chromosomes are protected by telomeres, nucleoprotein structures counteracting the end-replication problem and suppressing recombination and undue DNA repair. Although in most cases, the primary structure of telomeric DNA is conserved, there are several exceptions to this rule. One is represented by the telomeric repeats of ascomycetous yeasts, which encompass a great variety of sequences, whose evolutionary origin has been puzzling for several decades. At present, the key questions concerning the driving force behind their rapid evolution and the means of co-evolution of telomeric repeats and telomere-binding proteins remain largely unanswered. Previously published studies addressed mostly the general concepts of the evolutionary origin of telomeres, key properties of telomeric proteins as well as the molecular mechanisms of telomere maintenance; however, the evolutionary process itself has not been analyzed thoroughly. Here, we aimed to inspect the evolution of telomeres in ascomycetous yeasts from the subphyla Saccharomycotina and Taphrinomycotina, with special focus on the evolutionary origin of species-specific telomeric repeats. We analyzed the sequences of telomeric repeats from 204 yeast species classified into 20 families and as a result, we propose a step-by-step model, which integrates the diversity of telomeric repeats, telomerase RNAs, telomere-binding protein complexes and explains a propensity of certain species to generate the repeat heterogeneity within a single telomeric array.
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Affiliation(s)
- Filip Červenák
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Bratislava, Slovakia
| | - Regina Sepšiová
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Bratislava, Slovakia
| | - Jozef Nosek
- Department of Biochemistry, Comenius University in Bratislava, Faculty of Natural Sciences, Bratislava, Slovakia
| | - Ľubomír Tomáška
- Department of Genetics, Comenius University in Bratislava, Faculty of Natural Sciences, Bratislava, Slovakia
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Schrumpfová PP, Fajkus J. Composition and Function of Telomerase-A Polymerase Associated with the Origin of Eukaryotes. Biomolecules 2020; 10:biom10101425. [PMID: 33050064 PMCID: PMC7658794 DOI: 10.3390/biom10101425] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/19/2022] Open
Abstract
The canonical DNA polymerases involved in the replication of the genome are unable to fully replicate the physical ends of linear chromosomes, called telomeres. Chromosomal termini thus become shortened in each cell cycle. The maintenance of telomeres requires telomerase—a specific RNA-dependent DNA polymerase enzyme complex that carries its own RNA template and adds telomeric repeats to the ends of chromosomes using a reverse transcription mechanism. Both core subunits of telomerase—its catalytic telomerase reverse transcriptase (TERT) subunit and telomerase RNA (TR) component—were identified in quick succession in Tetrahymena more than 30 years ago. Since then, both telomerase subunits have been described in various organisms including yeasts, mammals, birds, reptiles and fish. Despite the fact that telomerase activity in plants was described 25 years ago and the TERT subunit four years later, a genuine plant TR has only recently been identified by our group. In this review, we focus on the structure, composition and function of telomerases. In addition, we discuss the origin and phylogenetic divergence of this unique RNA-dependent DNA polymerase as a witness of early eukaryotic evolution. Specifically, we discuss the latest information regarding the recently discovered TR component in plants, its conservation and its structural features.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- Correspondence:
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic;
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65 Brno, Czech Republic
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21
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Peska V, Mátl M, Mandáková T, Vitales D, Fajkus P, Fajkus J, Garcia S. Human-like telomeres in Zostera marina reveal a mode of transition from the plant to the human telomeric sequences. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:5786-5793. [PMID: 32589715 DOI: 10.1093/jxb/eraa293] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/16/2020] [Indexed: 05/26/2023]
Abstract
A previous study describing the genome of Zostera marina, the most widespread seagrass in the Northern hemisphere, revealed some genomic signatures of adaptation to the aquatic environment such as the loss of stomatal genes, while other functions such as an algal-like cell wall composition were acquired. Beyond these, the genome structure and organization were comparable with those of the majority of plant genomes sequenced, except for one striking feature that went unnoticed at that time: the presence of human-like instead of the expected plant-type telomeric sequences. By using different experimental approaches including fluorescence in situ hybridization (FISH), genome skimming by next-generation sequencing (NGS), and analysis of non-coding transcriptome, we have confirmed its telomeric location in the chromosomes of Z. marina. We have also identified its telomerase RNA (TR) subunit, confirming the presence of the human-type telomeric sequence in the template region. Remarkably, this region was found to be very variable even in clades with a highly conserved telomeric sequence across their species. Based on this observation, we propose that alternative annealing preferences in the template borders can explain the transition between the plant and human telomeric sequences. The further identification of paralogues of TR in several plant genomes led us to the hypothesis that plants may retain an increased ability to change their telomeric sequence. We discuss the implications of this occurrence in the evolution of telomeres while introducing a mechanistic model for the transition from the plant to the human telomeric sequences.
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Affiliation(s)
- Vratislav Peska
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Martin Mátl
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czech Republic
| | - Terezie Mandáková
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czech Republic
- Laboratory of Plant Molecular Genetics, Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Daniel Vitales
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s/n, Barcelona, Catalonia, Spain
| | - Petr Fajkus
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czech Republic
| | - Jiří Fajkus
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Passeig del Migdia s/n, Barcelona, Catalonia, Spain
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22
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Adamusová K, Khosravi S, Fujimoto S, Houben A, Matsunaga S, Fajkus J, Fojtová M. Two combinatorial patterns of telomere histone marks in plants with canonical and non-canonical telomere repeats. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:678-687. [PMID: 31834959 DOI: 10.1111/tpj.14653] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 11/21/2019] [Accepted: 11/28/2019] [Indexed: 05/24/2023]
Abstract
Telomeres, nucleoprotein structures at the ends of linear eukaryotic chromosomes, are crucial for the maintenance of genome integrity. In most plants, telomeres consist of conserved tandem repeat units comprising the TTTAGGG motif. Recently, non-canonical telomeres were described in several plants and plant taxons, including the carnivorous plant Genlisea hispidula (TTCAGG/TTTCAGG), the genus Cestrum (Solanaceae; TTTTTTAGGG), and plants from the Asparagales order with either a vertebrate-type telomere repeat TTAGGG or Allium genus-specific CTCGGTTATGGG repeat. We analyzed epigenetic modifications of telomeric histones in plants with canonical and non-canonical telomeres, and further in telomeric chromatin captured from leaves of Nicotiana benthamiana transiently transformed by telomere CRISPR-dCas9-eGFP, and of Arabidopsis thaliana stably transformed with TALE_telo C-3×GFP. Two combinatorial patterns of telomeric histone modifications were identified: (i) an Arabidopsis-like pattern (A. thaliana, G. hispidula, Genlisea nigrocaulis, Allium cepa, Narcissus pseudonarcissus, Petunia hybrida, Solanum tuberosum, Solanum lycopersicum) with telomeric histones decorated predominantly by H3K9me2; (ii) a tobacco-like pattern (Nicotiana tabacum, N. benthamiana, C. elegans) with a strong H3K27me3 signal. Our data suggest that epigenetic modifications of plant telomere-associated histones are related neither to the sequence of the telomere motif nor to the lengths of the telomeres. Nor the phylogenetic position of the species plays the role; representatives of the Solanaceae family are included in both groups. As both patterns of histone marks are compatible with fully functional telomeres in respective plants, we conclude that the described specific differences in histone marks are not critical for telomere functions.
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Affiliation(s)
- Kateřina Adamusová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| | - Solmaz Khosravi
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Seeland, Germany
| | - Satoru Fujimoto
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, 06466, Seeland, Germany
| | - Sachihiro Matsunaga
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
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23
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Peska V, Garcia S. Origin, Diversity, and Evolution of Telomere Sequences in Plants. FRONTIERS IN PLANT SCIENCE 2020; 11:117. [PMID: 32153618 PMCID: PMC7046594 DOI: 10.3389/fpls.2020.00117] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/27/2020] [Indexed: 05/18/2023]
Abstract
Telomeres are basic structures of eukaryote genomes. They distinguish natural chromosome ends from double-stranded breaks in DNA and protect chromosome ends from degradation or end-to-end fusion with other chromosomes. Telomere sequences are usually tandemly arranged minisatellites, typically following the formula (TxAyGz)n. Although they are well conserved across large groups of organisms, recent findings in plants imply that their diversity has been underestimated. Changes in telomeres are of enormous evolutionary importance as they can affect whole-genome stability. Even a small change in the telomere motif of each repeat unit represents an important interference in the system of sequence-specific telomere binding proteins. Here, we provide an overview of telomere sequences, considering the latest phylogenomic evolutionary framework of plants in the broad sense (Archaeplastida), in which new telomeric sequences have recently been found in diverse and economically important families such as Solanaceae and Amaryllidaceae. In the family Lentibulariaceae and in many groups of green algae, deviations from the typical plant telomeric sequence have also been detected recently. Ancestry and possible homoplasy in telomeric motifs, as well as extant gaps in knowledge are discussed. With the increasing availability of genomic approaches, it is likely that more telomeric diversity will be uncovered in the future. We also discuss basic methods used for telomere identification and we explain the implications of the recent discovery of plant telomerase RNA on further research about the role of telomerase in eukaryogenesis or on the molecular causes and consequences of telomere variability.
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Affiliation(s)
- Vratislav Peska
- Department of Cell Biology and Radiobiology, The Czech Academy of Sciences, Institute of Biophysics, Brno, Czechia
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB, CSIC-Ajuntament de Barcelona), Barcelona, Spain
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24
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Fajkus P, Peška V, Závodník M, Fojtová M, Fulnečková J, Dobias Š, Kilar A, Dvořáčková M, Zachová D, Nečasová I, Sims J, Sýkorová E, Fajkus J. Telomerase RNAs in land plants. Nucleic Acids Res 2019; 47:9842-9856. [PMID: 31392988 PMCID: PMC6765143 DOI: 10.1093/nar/gkz695] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/26/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023] Open
Abstract
To elucidate the molecular nature of evolutionary changes of telomeres in the plant order Asparagales, we aimed to characterize telomerase RNA subunits (TRs) in these plants. The unusually long telomere repeat unit in Allium plants (12 nt) allowed us to identify TRs in transcriptomic data of representative species of the Allium genus. Orthologous TRs were then identified in Asparagales plants harbouring telomere DNA composed of TTAGGG (human type) or TTTAGGG (Arabidopsis-type) repeats. Further, we identified TRs across the land plant phylogeny, including common model plants, crop plants, and plants with unusual telomeres. Several lines of functional testing demonstrate the templating telomerase function of the identified TRs and disprove a functionality of the only previously reported plant telomerase RNA in Arabidopsis thaliana. Importantly, our results change the existing paradigm in plant telomere biology which has been based on the existence of a relatively conserved telomerase reverse transcriptase subunit (TERT) associating with highly divergent TRs even between closely related plant taxa. The finding of a monophyletic origin of genuine TRs across land plants opens the possibility to identify TRs directly in transcriptomic or genomic data and/or predict telomere sequences synthesized according to the respective TR template region.
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Affiliation(s)
- Petr Fajkus
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic.,Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic
| | - Vratislav Peška
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic
| | - Michal Závodník
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Miloslava Fojtová
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic.,Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Jana Fulnečková
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic.,Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic
| | - Šimon Dobias
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic.,Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic
| | - Agata Kilar
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Dagmar Zachová
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Ivona Nečasová
- Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
| | - Jason Sims
- Max Perutz Labs, University of Vienna, Dr. Bohr Gasse 9, A-1030, Vienna, Austria
| | - Eva Sýkorová
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic
| | - Jiří Fajkus
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, v.v.i., Brno CZ-61265, Czech Republic.,Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Brno CZ-61137, Czech Republic.,Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno CZ-62500, Czech Republic
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25
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Abstract
Conventional approaches to identify a telomere motif in a new genome are laborious and time-intensive. An efficient new methodology based on next-generation sequencing (NGS), de novo sequence repeat finder (SERF) and fluorescence in situ hybridization (FISH) is presented. Unlike existing heuristic approaches, SERF utilizes an exhaustive analysis of raw NGS reads or assembled contigs for rapid de novo detection of conserved tandem repeats representing telomere motifs. SERF was validated using the NGS data from Ipheion uniflorum and Allium cepa with known telomere motifs. The analysis program was then used on NGS data to investigate the telomere motifs in several additional plant species and together with FISH proved to be an efficient approach to identify as yet unknown telomere motifs.
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26
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Goffová I, Vágnerová R, Peška V, Franek M, Havlová K, Holá M, Zachová D, Fojtová M, Cuming A, Kamisugi Y, Angelis KJ, Fajkus J. Roles of RAD51 and RTEL1 in telomere and rDNA stability in Physcomitrella patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:1090-1105. [PMID: 30834585 DOI: 10.1111/tpj.14304] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/21/2019] [Accepted: 02/27/2019] [Indexed: 05/11/2023]
Abstract
Telomeres and ribosomal RNA genes (rDNA) are essential for cell survival and particularly sensitive to factors affecting genome stability. Here, we examine the role of RAD51 and its antagonist, RTEL1, in the moss Physcomitrella patens. In corresponding mutants, we analyse their sensitivity to DNA damage, the maintenance of telomeres and rDNA, and repair of double-stranded breaks (DSBs) induced by genotoxins with various modes of action. While the loss of RTEL1 results in rapid telomere shortening, concurrent loss of both RAD51 genes has no effect on telomere lengths. We further demonstrate here the linked arrangement of 5S and 45S rRNA genes in P. patens. The spacer between 5S and 18S rRNA genes, especially the region downstream from the transcription start site, shows conspicuous clustering of sites with a high propensity to form quadruplex (G4) structures. Copy numbers of 5S and 18S rDNA are reduced moderately in the pprtel1 mutant, and significantly in the double pprad51-1-2 mutant, with no progression during subsequent cultivation. While reductions in 45S rDNA copy numbers observed in pprtel1 and pprad51-1-2 plants apply also to 5S rDNA, changes in transcript levels are different for 45S and 5S rRNA, indicating their independent transcription by RNA polymerase I and III, respectively. The loss of SOL (Sog One-Like), a transcription factor regulating numerous genes involved in DSB repair, increases the rate of DSB repair in dividing as well as differentiated tissue, and through deactivation of G2/M cell-cycle checkpoint allows the cell-cycle progression manifested as a phenotype resistant to bleomycin.
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Affiliation(s)
- Ivana Goffová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Radka Vágnerová
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Vratislav Peška
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65, Brno, Czech Republic
| | - Michal Franek
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Kateřina Havlová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Marcela Holá
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Dagmar Zachová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Miloslava Fojtová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Andrew Cuming
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Yasuko Kamisugi
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Karel J Angelis
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65, Brno, Czech Republic
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27
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Crhák T, Zachová D, Fojtová M, Sýkorová E. The region upstream of the telomerase reverse transcriptase gene is essential for in planta telomerase complementation. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 281:41-51. [PMID: 30824060 DOI: 10.1016/j.plantsci.2019.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/29/2018] [Accepted: 01/03/2019] [Indexed: 06/09/2023]
Abstract
Telomerase is essential for the maintenance of telomeres, structures located at the ends of linear eukaryotic chromosomes that are crucial for genomic stability. Telomerase has been frequently explored in mammals because of its activity in many types of cancers, but knowledge in plants is rather sketchy despite plants representing useful models due to peculiarities in their telomeres and telomerase biology. We studied in planta complementation of telomerase in Arabidopsis thaliana mutant plants with disrupted expression of the gene encoding the telomerase protein subunit (AtTERT) and significantly shortened telomeres. We found that the upstream region of AtTERT, previously identified as a putative minimal promoter, was essential for reconstitution of telomerase function, as demonstrated by the full or partial recovery of the telomere phenotype in mutants. In contrast, transformation by the full length AtTERT gene construct resulted in more progressive telomere shortening in mutants and even in wild type plants, despite the high level of AtTERT transcript and telomerase activity detected by in vitro assay. Thus, the telomerase protein subunit putative promoter is essential for in planta telomerase reconstitution and restoration of its catalytical activity. Contributions from other factors, including those tissue-specific, for proper telomerase function are discussed.
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Affiliation(s)
- Tomáš Crhák
- The Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic; Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Dagmar Zachová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Miloslava Fojtová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Eva Sýkorová
- The Czech Academy of Sciences, Institute of Biophysics, Brno, Czech Republic.
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28
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Peška V, Mandáková T, Ihradská V, Fajkus J. Comparative Dissection of Three Giant Genomes: Allium cepa, Allium sativum, and Allium ursinum. Int J Mol Sci 2019; 20:E733. [PMID: 30744119 PMCID: PMC6387171 DOI: 10.3390/ijms20030733] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/31/2019] [Accepted: 02/02/2019] [Indexed: 02/07/2023] Open
Abstract
Knowledge of the fascinating world of DNA repeats is continuously being enriched by newly identified elements and their hypothetical or well-established biological relevance. Genomic approaches can be used for comparative studies of major repeats in any group of genomes, regardless of their size and complexity. Such studies are particularly fruitful in large genomes, and useful mainly in crop plants where they provide a rich source of molecular markers or information on indispensable genomic components (e.g., telomeres, centromeres, or ribosomal RNA genes). Surprisingly, in Allium species, a comprehensive comparative study of repeats is lacking. Here we provide such a study of two economically important species, Allium cepa (onion), and A. sativum (garlic), and their distantly related A. ursinum (wild garlic). We present an overview and classification of major repeats in these species and have paid specific attention to sequence conservation and copy numbers of major representatives in each type of repeat, including retrotransposons, rDNA, or newly identified satellite sequences. Prevailing repeats in all three studied species belonged to Ty3/gypsy elements, however they significantly diverged and we did not detect them in common clusters in comparative analysis. Actually, only a low number of clusters was shared by all three species. Such conserved repeats were for example 5S and 45S rDNA genes and surprisingly a specific and quite rare Ty1/copia lineage. Species-specific long satellites were found mainly in A. cepa and A. sativum. We also show in situ localization of selected repeats that could potentially be applicable as chromosomal markers, e.g., in interspecific breeding.
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Affiliation(s)
- Vratislav Peška
- Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.
| | - Terezie Mandáková
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic.
| | - Veronika Ihradská
- Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic.
| | - Jiří Fajkus
- Institute of Biophysics, The Czech Academy of Sciences, Královopolská 135, 612 65 Brno, Czech Republic.
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic.
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29
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Aksenova AY, Mirkin SM. At the Beginning of the End and in the Middle of the Beginning: Structure and Maintenance of Telomeric DNA Repeats and Interstitial Telomeric Sequences. Genes (Basel) 2019; 10:genes10020118. [PMID: 30764567 PMCID: PMC6410037 DOI: 10.3390/genes10020118] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 02/07/2023] Open
Abstract
Tandem DNA repeats derived from the ancestral (TTAGGG)n run were first detected at chromosome ends of the majority of living organisms, hence the name telomeric DNA repeats. Subsequently, it has become clear that telomeric motifs are also present within chromosomes, and they were suitably called interstitial telomeric sequences (ITSs). It is well known that telomeric DNA repeats play a key role in chromosome stability, preventing end-to-end fusions and precluding the recurrent DNA loss during replication. Recent data suggest that ITSs are also important genomic elements as they confer its karyotype plasticity. In fact, ITSs appeared to be among the most unstable microsatellite sequences as they are highly length polymorphic and can trigger chromosomal fragility and gross chromosomal rearrangements. Importantly, mechanisms responsible for their instability appear to be similar to the mechanisms that maintain the length of genuine telomeres. This review compares the mechanisms of maintenance and dynamic properties of telomeric repeats and ITSs and discusses the implications of these dynamics on genome stability.
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Affiliation(s)
- Anna Y Aksenova
- Laboratory of Amyloid Biology, St. Petersburg State University, 199034 St. Petersburg, Russia.
| | - Sergei M Mirkin
- Department of Biology, Tufts University, Medford, MA 02421, USA.
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30
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Telomeres in Plants and Humans: Not So Different, Not So Similar. Cells 2019; 8:cells8010058. [PMID: 30654521 PMCID: PMC6356271 DOI: 10.3390/cells8010058] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 01/07/2019] [Accepted: 01/07/2019] [Indexed: 01/01/2023] Open
Abstract
Parallel research on multiple model organisms shows that while some principles of telomere biology are conserved among all eukaryotic kingdoms, we also find some deviations that reflect different evolutionary paths and life strategies, which may have diversified after the establishment of telomerase as a primary mechanism for telomere maintenance. Much more than animals, plants have to cope with environmental stressors, including genotoxic factors, due to their sessile lifestyle. This is, in principle, made possible by an increased capacity and efficiency of the molecular systems ensuring maintenance of genome stability, as well as a higher tolerance to genome instability. Furthermore, plant ontogenesis differs from that of animals in which tissue differentiation and telomerase silencing occur during early embryonic development, and the “telomere clock” in somatic cells may act as a preventive measure against carcinogenesis. This does not happen in plants, where growth and ontogenesis occur through the serial division of apical meristems consisting of a small group of stem cells that generate a linear series of cells, which differentiate into an array of cell types that make a shoot and root. Flowers, as generative plant organs, initiate from the shoot apical meristem in mature plants which is incompatible with the human-like developmental telomere shortening. In this review, we discuss differences between human and plant telomere biology and the implications for aging, genome stability, and cell and organism survival. In particular, we provide a comprehensive comparative overview of telomere proteins acting in humans and in Arabidopsis thaliana model plant, and discuss distinct epigenetic features of telomeric chromatin in these species.
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31
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Tanee T, Sudmoon R, Siripiyasing P, Suwannakud KS, Monkheang P, Chaveerach A. New Karyotype Information of Hymenocallis littoralis, Amaryllidaceae. CYTOLOGIA 2018. [DOI: 10.1508/cytologia.83.437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Tawatchai Tanee
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
- Faculty of Environment and Resource Studies, Mahasarakham University
| | - Runglawan Sudmoon
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
- Faculty of Law, Khon Kaen University
| | - Pornarong Siripiyasing
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
- Faculty of Science and Technology, Mahasarakham Rajabhat University
| | - Kittiya Silawong Suwannakud
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
- Graduate School, Khon Kaen University
| | - Pansa Monkheang
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
| | - Arunrat Chaveerach
- Genetics and Environmental Toxicology Research Group, Khon Kaen University
- Department of Biology, Faculty of Science, Khon Kaen University
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32
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Rosato M, Álvarez I, Feliner GN, Rosselló JA. Inter- and intraspecific hypervariability in interstitial telomeric-like repeats (TTTAGGG)n in Anacyclus (Asteraceae). ANNALS OF BOTANY 2018; 122:387-395. [PMID: 29800070 PMCID: PMC6110349 DOI: 10.1093/aob/mcy079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/24/2018] [Indexed: 05/18/2023]
Abstract
Background and Aims Interstitial telomeric repeat (ITR) sites, consisting of tandem repeats of telomeric motifs localized at intrachromosomal sites, have been reported in a few unrelated organisms including plants. However, the causes for the occurrence of ITRs outside of the chromosomal termini are not fully understood. One possible explanation are the chromosomal rearrangements involving telomeric sites, which could also affect the location of other structural genome elements, such as the 45S rDNA. Taking advantage of the high dynamism in 45S rDNA loci previously found in Anacyclus (Asteraceae, Anthemideae), the occurrence and patterns of variation of ITRs were explored in this genus with the aim of finding common underlying causes. Methods In total, 132 individuals from 44 populations of nine species were analysed by fluorescence in situ hybridization using an Arabidopsis-type telomeric sequence as a probe. Key results Variable presence of ITR sites was detected in six out of nine species of Anacyclus, ranging from two to 45 sites and showing contrasting chromosomal locations and a differential presence of the ITR site on homologous chromosome pairs. At the intraspecific level, the ranges were as large as 0-12 ITR sites. Although only 26 % of the total observed ITR sites were localized in chromosomes bearing 45S rDNA loci, all cases of interstitial 45S rDNA reported in a previous work co-occurred with ITRs in close proximity in the same chromosome arms. Conclusions High levels of ITR polymorphism within a single species have not been previously reported in plants and suggest that this pattern might have been overlooked due to insufficient sampling. Although ancient Robertsonian translocations or the amplification of terminal 45S rDNA sites cannot, on their own, explain all of the levels of variability in ITRs reported here, there are suggestions that they may have been involved in the evolutionary history of this genus or its ancestors in Anthemideae.
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Affiliation(s)
- Marcela Rosato
- Jardín Botánico, ICBIBE-Unidad Asociada CSIC, Universidad de Valencia, Spain
| | - Inés Álvarez
- Real Jardín Botánico (CSIC), Plaza de Murillo, Spain
| | | | - Josep A Rosselló
- Jardín Botánico, ICBIBE-Unidad Asociada CSIC, Universidad de Valencia, Spain
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Waminal NE, Pellerin RJ, Kim NS, Jayakodi M, Park JY, Yang TJ, Kim HH. Rapid and Efficient FISH using Pre-Labeled Oligomer Probes. Sci Rep 2018; 8:8224. [PMID: 29844509 PMCID: PMC5974128 DOI: 10.1038/s41598-018-26667-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/17/2018] [Indexed: 12/29/2022] Open
Abstract
Fluorescence in situ hybridization (FISH) is used to visualize the distribution of DNA elements within a genome. Conventional methods for FISH take 1-2 days. Here, we developed a simplified, rapid FISH technique using pre-labeled oligonucleotide probes (PLOPs) and tested the procedure using 18 PLOPs from 45S and 5S rDNA, Arabidopsis-type telomere, and newly-identified Panax ginseng-specific tandem repeats. The 16 developed rDNA PLOPs can be universally applied to plants and animals. The telomere PLOPs can be utilized in most plants with Arabidopsis-type telomeres. The ginseng-specific PLOP can be used to distinguish P. ginseng from related Panax species. Differential labeling of PLOPs allowed us to simultaneously visualize different target loci while reducing the FISH hybridization time from ~16 h to 5 min. PLOP-FISH is efficient, reliable, and rapid, making it ideal for routine analysis, especially of newly sequenced genomes using either universal or specific targets, such as novel tandem repeats identified from whole-genome sequencing data.
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Affiliation(s)
- Nomar Espinosa Waminal
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea.,Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Remnyl Joyce Pellerin
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea
| | - Nam-Soo Kim
- Department of Molecular Biosciences, Kangwon National University, Chuncheon, 24341, Korea
| | - Murukarthick Jayakodi
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jee Young Park
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Tae-Jin Yang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.
| | - Hyun Hee Kim
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea.
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Garrido-Ramos MA. Satellite DNA: An Evolving Topic. Genes (Basel) 2017; 8:genes8090230. [PMID: 28926993 PMCID: PMC5615363 DOI: 10.3390/genes8090230] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 09/12/2017] [Accepted: 09/13/2017] [Indexed: 12/22/2022] Open
Abstract
Satellite DNA represents one of the most fascinating parts of the repetitive fraction of the eukaryotic genome. Since the discovery of highly repetitive tandem DNA in the 1960s, a lot of literature has extensively covered various topics related to the structure, organization, function, and evolution of such sequences. Today, with the advent of genomic tools, the study of satellite DNA has regained a great interest. Thus, Next-Generation Sequencing (NGS), together with high-throughput in silico analysis of the information contained in NGS reads, has revolutionized the analysis of the repetitive fraction of the eukaryotic genomes. The whole of the historical and current approaches to the topic gives us a broad view of the function and evolution of satellite DNA and its role in chromosomal evolution. Currently, we have extensive information on the molecular, chromosomal, biological, and population factors that affect the evolutionary fate of satellite DNA, knowledge that gives rise to a series of hypotheses that get on well with each other about the origin, spreading, and evolution of satellite DNA. In this paper, I review these hypotheses from a methodological, conceptual, and historical perspective and frame them in the context of chromosomal organization and evolution.
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Affiliation(s)
- Manuel A Garrido-Ramos
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
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Pereira TNS, Neto MF, de Souza MM, da Costa Geronimo IG, de Melo CAF, Pereira MG. Cytological Characterization of Brazilian Green Dwarf Coconut (<i>Cocos nucifera</i> L.) <i>via</i> Meiosis and Conventional and Differential Karyotyping. CYTOLOGIA 2017. [DOI: 10.1508/cytologia.82.167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Telma Nair Santana Pereira
- Universidade Estadual do Norte Fluminense, Centro de Ciências e Tecnologias Agropecuárias, Laboratório de Melhoramento Genético Vegetal
| | - Monique Freitas Neto
- Universidade Estadual do Norte Fluminense, Centro de Ciências e Tecnologias Agropecuárias, Laboratório de Melhoramento Genético Vegetal
| | | | - Ingrid Gaspar da Costa Geronimo
- Universidade Estadual do Norte Fluminense, Centro de Ciências e Tecnologias Agropecuárias, Laboratório de Melhoramento Genético Vegetal
| | | | - Messias Gonzaga Pereira
- Universidade Estadual do Norte Fluminense, Centro de Ciências e Tecnologias Agropecuárias, Laboratório de Melhoramento Genético Vegetal
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Uzlíková M, Fulnečková J, Weisz F, Sýkorová E, Nohýnková E, Tůmová P. Characterization of telomeres and telomerase from the single-celled eukaryote Giardia intestinalis. Mol Biochem Parasitol 2017; 211:31-38. [DOI: 10.1016/j.molbiopara.2016.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/08/2016] [Accepted: 09/12/2016] [Indexed: 10/21/2022]
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Monkheang P, Chaveerach A, Sudmoon R, Tanee T. Karyotypic features including organizations of the 5S, 45S rDNA loci and telomeres of Scadoxus multiflorus (Amaryllidaceae). COMPARATIVE CYTOGENETICS 2016; 10:637-646. [PMID: 28123684 PMCID: PMC5237775 DOI: 10.3897/compcytogen.v10i4.9958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/07/2016] [Indexed: 05/26/2023]
Abstract
Scadoxus multiflorus Martyn, 1795 is an ornamental plant with brilliantly colored flowers. Even though its chromosomes are rather large, there is no karyotype description reported so far. Therefore, conventional and molecular cytogenetic studies including fluorescence in situ hybridization (FISH) with 45S and 5S rDNA, and human telomere sequence (TTAGGG)n probes (Arabidopsis-type telomere probes yielded negative results) were carried out. The chromosome number is as reported previously, 2n = 18. The nine chromosome pairs include two large submetacentric, five large acrocentric, one medium acrocentric, two small metacentric and eight small submetacentric chromosomes. Hybridization sites of the 45S rDNA signals were on the short arm ends of chromosomes #1, #3 and #8, while 5S rDNA signals appeared on the long arm of chromosome 3, in one homologue as a double signal. The telomere signals were restricted to all chromosome ends. Three chromosome pairs could be newly identified, chromosome pair 3 by 5S rDNA and chromosomes #1, #3 and #8 by 45S rDNA loci. In addition to new information about rDNA locations we show that the ends of Scadoxus multiflorus chromosomes harbor human instead of Arabidopsis-type telomere sequences. Overall, the Scadoxus multiflorus karyotype presents chromosomal heteromorphy concerning size, shape and 45S and 5S rDNA positioning. As Scadoxus Rafinesque, 1838 and related species are poorly studied on chromosomal level the here presented data is important for better understanding of evolution in Amaryllidaceae.
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Affiliation(s)
- Pansa Monkheang
- Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
- Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Arunrat Chaveerach
- Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
- Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Runglawan Sudmoon
- Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand
- Faculty of Law, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Tawatchai Tanee
- Genetics and Environmental Toxicology Research Group, Khon Kaen University, Khon Kaen 40002, Thailand
- Faculty of Environment and Resource Studies, Mahasarakham University, Maha Sarakham 44150, Thailand
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Peška V, Sitová Z, Fajkus P, Fajkus J. BAL31-NGS approach for identification of telomeres de novo in large genomes. Methods 2016; 114:16-27. [PMID: 27595912 DOI: 10.1016/j.ymeth.2016.08.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/22/2016] [Accepted: 08/31/2016] [Indexed: 10/21/2022] Open
Abstract
This article describes a novel method to identify as yet undiscovered telomere sequences, which combines next generation sequencing (NGS) with BAL31 digestion of high molecular weight DNA. The method was applied to two groups of plants: i) dicots, genus Cestrum, and ii) monocots, Allium species (e.g. A. ursinum and A. cepa). Both groups consist of species with large genomes (tens of Gb) and a low number of chromosomes (2n=14-16), full of repeat elements. Both genera lack typical telomeric repeats and multiple studies have attempted to characterize alternative telomeric sequences. However, despite interesting hypotheses and suggestions of alternative candidate telomeres (retrotransposons, rDNA, satellite repeats) these studies have not resolved the question. In a novel approach based on the two most general features of eukaryotic telomeres, their repetitive character and sensitivity to BAL31 nuclease digestion, we have taken advantage of the capacity and current affordability of NGS in combination with the robustness of classical BAL31 nuclease digestion of chromosomal termini. While representative samples of most repeat elements were ensured by low-coverage (less than 5%) genomic shot-gun NGS, candidate telomeres were identified as under-represented sequences in BAL31-treated samples.
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Affiliation(s)
- Vratislav Peška
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic
| | - Zdeňka Sitová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Petr Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic; Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265 Brno, Czech Republic; Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500 Brno, Czech Republic.
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Souza G, Vanzela ALL, Crosa O, Guerra M. Interstitial telomeric sites and Robertsonian translocations in species of Ipheion and Nothoscordum (Amaryllidaceae). Genetica 2016; 144:157-66. [PMID: 26869260 DOI: 10.1007/s10709-016-9886-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 02/04/2016] [Indexed: 10/22/2022]
Abstract
The genera Nothoscordum and Ipheion (Allioideae, Amaryllidaceae) are cytologically characterized by a dysploid series with variable numbers of metacentric and acrocentric chromosomes typical of karyotypes rearranged by Robertsonian translocations (RT). Since they have large chromosomes, low diploid numbers, and possess two telomeric motifs [the vertebrate-type (TTAGGG) n and the Arabidopsis-type (TTTAGGG) n ] they are suitable for investigating the occurrence and possible role of interstitial telomeric sites (ITS) associated with RT. We analyzed the distributions of telomeric sites in 12 species of Nothoscordum and Ipheion and found that both telomeric probes colocalized in all chromosome termini. Cloning and sequencing PCR products obtained using both telomeric primers simultaneously revealed long stretches of (TTAGGG) n and (TTTAGGG) n sequences together with degenerated telomeric sequences. Most acrocentric chromosomes have a 45S rDNA site at the terminal region of the short arms adjacent to the most distal telomeric sites. Telomeric signals were found at all chromosome ends, but ITS were also detected in a few proximal and subterminal regions in some Nothoscordum species. Although RT are common in this group of plants, our findings suggest that proximal positioning of telomeric motifs are not necessarily related to that kind of rearrangement. Rather, transposition of telomeric sequences followed by amplification, could better explain the presence of (TTAGGG) n and (TTTAGGG) n repeats at those sites. Furthermore, a few small interstitial sites found in some Nothoscordum species indicate that dispersion of these sequences was not restricted to the proximal region.
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Affiliation(s)
- Gustavo Souza
- Laboratory of Plant Cytogenetics and Evolution, Centro de Ciências Biológicas, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil.
| | - Andre L L Vanzela
- Laboratory of Cytogenetics and Plant Diversity, Department of General Biology, State University of Londrina, Londrina, Paraná, Brazil
| | - Orfeo Crosa
- Laboratory of Genetics, Department of Plant Biology, Faculty of Agronomy, University of the Republic, Montevideo, Uruguay
| | - Marcelo Guerra
- Laboratory of Plant Cytogenetics and Evolution, Centro de Ciências Biológicas, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
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Fajkus P, Peška V, Sitová Z, Fulnečková J, Dvořáčková M, Gogela R, Sýkorová E, Hapala J, Fajkus J. Allium telomeres unmasked: the unusual telomeric sequence (CTCGGTTATGGG)n is synthesized by telomerase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 85:337-47. [PMID: 26716914 DOI: 10.1111/tpj.13115] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 12/17/2015] [Accepted: 12/22/2015] [Indexed: 05/25/2023]
Abstract
Phylogenetic divergence in Asparagales plants is associated with switches in telomere sequences. The last switch occurred with divergence of the genus Allium (Amaryllidaceae) from the other Allioideae (formerly Alliaceae) genera, resulting in uncharacterized telomeres maintained by an unknown mechanism. To characterize the unknown Allium telomeres, we applied a combination of bioinformatic processing of transcriptomic and genomic data with standard approaches in telomere biology such as BAL31 sensitivity tests, terminal restriction fragment analysis, the telomere repeat amplification protocol (TRAP), and fluorescence in situ hybridization (FISH). Using these methods, we characterize the unusual telomeric sequence (CTCGGTTATGGG)n present in Allium species, demonstrate its synthesis by telomerase, and characterize the telomerase reverse transcriptase (TERT) subunit of Allium cepa. Our findings open up the possibility of studying the molecular details of the evolutionary genetic change in Allium telomeres and its possible role in speciation. Experimental studies addressing the implications of this change in terms of the interplay of telomere components may now be designed to shed more light on telomere functions and evolution in general.
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Affiliation(s)
- Petr Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
- Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Vratislav Peška
- Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Zdeňka Sitová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Jana Fulnečková
- Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Martina Dvořáčková
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
- Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Roman Gogela
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Eva Sýkorová
- Institute of Biophysics, Czech Academy of Sciences, Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Jan Hapala
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
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Procházková Schrumpfová P, Schořová Š, Fajkus J. Telomere- and Telomerase-Associated Proteins and Their Functions in the Plant Cell. FRONTIERS IN PLANT SCIENCE 2016; 7:851. [PMID: 27446102 PMCID: PMC4924339 DOI: 10.3389/fpls.2016.00851] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 05/31/2016] [Indexed: 05/20/2023]
Abstract
Telomeres, as physical ends of linear chromosomes, are targets of a number of specific proteins, including primarily telomerase reverse transcriptase. Access of proteins to the telomere may be affected by a number of diverse factors, e.g., protein interaction partners, local DNA or chromatin structures, subcellular localization/trafficking, or simply protein modification. Knowledge of composition of the functional nucleoprotein complex of plant telomeres is only fragmentary. Moreover, the plant telomeric repeat binding proteins that were characterized recently appear to also be involved in non-telomeric processes, e.g., ribosome biogenesis. This interesting finding was not totally unexpected since non-telomeric functions of yeast or animal telomeric proteins, as well as of telomerase subunits, have been reported for almost a decade. Here we summarize known facts about the architecture of plant telomeres and compare them with the well-described composition of telomeres in other organisms.
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Affiliation(s)
- Petra Procházková Schrumpfová
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
- *Correspondence: Petra Procházková Schrumpfová,
| | - Šárka Schořová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
| | - Jiří Fajkus
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk UniversityBrno, Czech Republic
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk UniversityBrno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i.Brno, Czech Republic
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Tran TD, Cao HX, Jovtchev G, Neumann P, Novák P, Fojtová M, Vu GTH, Macas J, Fajkus J, Schubert I, Fuchs J. Centromere and telomere sequence alterations reflect the rapid genome evolution within the carnivorous plant genus Genlisea. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 84:1087-99. [PMID: 26485466 DOI: 10.1111/tpj.13058] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 10/07/2015] [Accepted: 10/15/2015] [Indexed: 05/25/2023]
Abstract
Linear chromosomes of eukaryotic organisms invariably possess centromeres and telomeres to ensure proper chromosome segregation during nuclear divisions and to protect the chromosome ends from deterioration and fusion, respectively. While centromeric sequences may differ between species, with arrays of tandemly repeated sequences and retrotransposons being the most abundant sequence types in plant centromeres, telomeric sequences are usually highly conserved among plants and other organisms. The genome size of the carnivorous genus Genlisea (Lentibulariaceae) is highly variable. Here we study evolutionary sequence plasticity of these chromosomal domains at an intrageneric level. We show that Genlisea nigrocaulis (1C = 86 Mbp; 2n = 40) and G. hispidula (1C = 1550 Mbp; 2n = 40) differ as to their DNA composition at centromeres and telomeres. G. nigrocaulis and its close relative G. pygmaea revealed mainly 161 bp tandem repeats, while G. hispidula and its close relative G. subglabra displayed a combination of four retroelements at centromeric positions. G. nigrocaulis and G. pygmaea chromosome ends are characterized by the Arabidopsis-type telomeric repeats (TTTAGGG); G. hispidula and G. subglabra instead revealed two intermingled sequence variants (TTCAGG and TTTCAGG). These differences in centromeric and, surprisingly, also in telomeric DNA sequences, uncovered between groups with on average a > 9-fold genome size difference, emphasize the fast genome evolution within this genus. Such intrageneric evolutionary alteration of telomeric repeats with cytosine in the guanine-rich strand, not yet known for plants, might impact the epigenetic telomere chromatin modification.
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Affiliation(s)
- Trung D Tran
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
| | - Hieu X Cao
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
| | - Gabriele Jovtchev
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
| | - Pavel Neumann
- Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
| | - Petr Novák
- Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
| | - Miloslava Fojtová
- Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Giang T H Vu
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
| | - Jiří Macas
- Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, Branišovská 31/1160, 37005, České Budějovice, Czech Republic
| | - Jiří Fajkus
- Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
- Institute of Biophysics, Academy of Sciences of the Czech Republic v.v.i., Královopolská 135, 61265, Brno, Czech Republic
| | - Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
- Central European Institute of Technology (CEITEC) and Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
| | - Joerg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstrasse 3, D-06466, Stadt Seeland, Germany
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Fulnečková J, Ševčíková T, Lukešová A, Sýkorová E. Transitions between the Arabidopsis-type and the human-type telomere sequence in green algae (clade Caudivolvoxa, Chlamydomonadales). Chromosoma 2015; 125:437-51. [PMID: 26596989 DOI: 10.1007/s00412-015-0557-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 11/25/2022]
Abstract
Telomeres are nucleoprotein structures that distinguish native chromosomal ends from double-stranded breaks. They are maintained by telomerase that adds short G-rich telomeric repeats at chromosomal ends in most eukaryotes and determines the TnAmGo sequence of canonical telomeres. We employed an experimental approach that was based on detection of repeats added by telomerase to identify the telomere sequence type forming the very ends of chromosomes. Our previous studies that focused on the algal order Chlamydomonadales revealed several changes in telomere motifs that were consistent with the phylogeny and supported the concept of the Arabidopsis-type sequence being the ancestral telomeric motif for green algae. In addition to previously described independent transitions to the Chlamydomonas-type sequence, we report that the ancestral telomeric motif was replaced by the human-type sequence in the majority of algal species grouped within a higher order clade, Caudivolvoxa. The Arabidopsis-type sequence was apparently retained in the Polytominia clade. Regarding the telomere sequence, the Chlorogonia clade within Caudivolvoxa bifurcates into two groups, one with the human-type sequence and the other group with the Arabidopsis-type sequence that is solely formed by the Chlorogonium species. This suggests that reversion to the Arabidopsis-type telomeric motif occurred in the common ancestral Chlorogonium species. The human-type sequence is also synthesized by telomerases of algal strains from Arenicolinia, Dunaliellinia and Stephanosphaerinia, except a distinct subclade within Stephanosphaerinia, where telomerase activity was not detected and a change to an unidentified telomeric motif might arise. We discuss plausible reasons why changes in telomeric motifs were tolerated during evolution of green algae.
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Affiliation(s)
- Jana Fulnečková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic.,Faculty of Science, and CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Tereza Ševčíková
- Department of Biology and Ecology, Life Science Research Centre & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Chittussiho 10, CZ-71000, Ostrava, Czech Republic
| | - Alena Lukešová
- Institute of Soil Biology, Biology Centre Academy of Sciences of the Czech Republic, v.vi., Na Sádkách 7, CZ-37005, České Budějovice, Czech Republic
| | - Eva Sýkorová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic. .,Faculty of Science, and CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic.
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Nelson ADL, Shippen DE. Evolution of TERT-interacting lncRNAs: expanding the regulatory landscape of telomerase. Front Genet 2015; 6:277. [PMID: 26442096 PMCID: PMC4564757 DOI: 10.3389/fgene.2015.00277] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/17/2015] [Indexed: 12/17/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) evolve rapidly and are functionally diverse. The emergence of new lncRNAs is driven by genome disturbance events, including whole genome duplication, and transposition. One of the few lncRNAs with a conserved role throughout eukaryotes is the telomerase RNA, TER. TER works in concert with the telomerase reverse transcriptase (TERT) to maintain telomeres. Here we discuss recent findings from Arabidopsis thaliana and its relatives illustrating the remarkable evolutionary flexibility within TER and the potential for non-canonical TERT-lncRNA interactions. We highlight the two TERs in A. thaliana. One is a conventional telomerase template. The other lncRNA negatively regulates telomerase activity in response to DNA damage, a function mediated by co-option of a transposable element. In addition, we discuss evidence for multiple independent TER loci throughout the plant family Brassicaceae, and how these loci not only reflect rapid convergent evolution, but also the flexibility of having a lncRNA at the core of telomerase. Lastly, we discuss the propensity for TERT to bind a suite of non-templating lncRNAs, and how such RNAs may facilitate telomerase regulation and off-telomere functions.
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Affiliation(s)
| | - Dorothy E Shippen
- Department of Biochemistry and Biophysics, Texas A&M University , College Station, TX, USA
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Garrido-Ramos MA. Satellite DNA in Plants: More than Just Rubbish. Cytogenet Genome Res 2015; 146:153-170. [PMID: 26202574 DOI: 10.1159/000437008] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2015] [Indexed: 11/19/2022] Open
Abstract
For decades, satellite DNAs have been the hidden part of genomes. Initially considered as junk DNA, there is currently an increasing appreciation of the functional significance of satellite DNA repeats and of their sequences. Satellite DNA families accumulate in the heterochromatin in different parts of the eukaryotic chromosomes, mainly in pericentromeric and subtelomeric regions, but they also span the functional centromere. Tandem repeat sequences may spread from subtelomeric to interstitial loci, leading to the formation of chromosome-specific loci or to the accumulation in equilocal sites in different chromosomes. They also appear as the main components of the heterochromatin in the sex-specific region of sex chromosomes. Satellite DNA, required for chromosome organization, also plays a role in pairing and segregation. Some satellite repeats are transcribed and can participate in the formation and maintenance of heterochromatin structure and in the modulation of gene expression. In addition to the identification of the different satellite DNA families, their characteristics and location, we are interested in determining their impact on the genomes, by identifying the mechanisms leading to their appearance and amplification as well as in understanding how they change over time, the factors affecting these changes, and the influence exerted by the evolutionary history of the organisms. On the other hand, satellite DNA sequences are rapidly evolving sequences that may cause reproductive barriers between organisms and promote speciation. The accumulation of experimental data collected in recent years and the emergence of new approaches based on next-generation sequencing and high-throughput genome analysis are opening new perspectives that are changing our understanding of satellite DNA. This review examines recent data to provide a timely update on the overall information gathered about this part of the genome, focusing on the advances in the knowledge of its origin, its evolution, and its potential functional roles.
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Peška V, Fajkus P, Fojtová M, Dvořáčková M, Hapala J, Dvořáček V, Polanská P, Leitch AR, Sýkorová E, Fajkus J. Characterisation of an unusual telomere motif (TTTTTTAGGG)n in the plant Cestrum elegans (Solanaceae), a species with a large genome. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:644-54. [PMID: 25828846 DOI: 10.1111/tpj.12839] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 05/26/2023]
Abstract
The characterization of unusual telomere sequence sheds light on patterns of telomere evolution, maintenance and function. Plant species from the closely related genera Cestrum, Vestia and Sessea (family Solanaceae) lack known plant telomeric sequences. Here we characterize the telomere of Cestrum elegans, work that was a challenge because of its large genome size and few chromosomes (1C 9.76 pg; n = 8). We developed an approach that combines BAL31 digestion, which digests DNA from the ends and chromosome breaks, with next-generation sequencing (NGS), to generate data analysed in RepeatExplorer, designed for de novo repeats identification and quantification. We identify an unique repeat motif (TTTTTTAGGG)n in C. elegans, occurring in ca. 30 400 copies per haploid genome, averaging ca. 1900 copies per telomere, and synthesized by telomerase. We demonstrate that the motif is synthesized by telomerase. The occurrence of an unusual eukaryote (TTTTTTAGGG)n telomeric motif in C. elegans represents a switch in motif from the 'typical' angiosperm telomere (TTTAGGG)n . That switch may have happened with the divergence of Cestrum, Sessea and Vestia. The shift in motif when it arose would have had profound effects on telomere activity. Thus our finding provides a unique handle to study how telomerase and telomeres responded to genetic change, studies that will shed more light on telomere function.
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Affiliation(s)
- Vratislav Peška
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Petr Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Miloslava Fojtová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Martina Dvořáčková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Jan Hapala
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Vojtěch Dvořáček
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
| | - Pavla Polanská
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Eva Sýkorová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Jiří Fajkus
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, CZ-61265, Brno, Czech Republic
- Faculty of Science, and CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
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Školáková P, Foldynová-Trantírková S, Bednářová K, Fiala R, Vorlíčková M, Trantírek L. Unique C. elegans telomeric overhang structures reveal the evolutionarily conserved properties of telomeric DNA. Nucleic Acids Res 2015; 43:4733-45. [PMID: 25855805 PMCID: PMC4482068 DOI: 10.1093/nar/gkv296] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 03/25/2015] [Indexed: 11/16/2022] Open
Abstract
There are two basic mechanisms that are associated with the maintenance of the telomere length, which endows cancer cells with unlimited proliferative potential. One mechanism, referred to as alternative lengthening of telomeres (ALT), accounts for approximately 10–15% of all human cancers. Tumours engaged in the ALT pathway are characterised by the presence of the single stranded 5′-C-rich telomeric overhang (C-overhang). This recently identified hallmark of ALT cancers distinguishes them from healthy tissues and renders the C-overhang as a clear target for anticancer therapy. We analysed structures of the 5′-C-rich and 3′-G-rich telomeric overhangs from human and Caenorhabditis elegans, the recently established multicellular in vivo model of ALT tumours. We show that the telomeric DNA from C. elegans and humans forms fundamentally different secondary structures. The unique structural characteristics of C. elegans telomeric DNA that are distinct not only from those of humans but also from those of other multicellular eukaryotes allowed us to identify evolutionarily conserved properties of telomeric DNA. Differences in structural organisation of the telomeric DNA between the C. elegans and human impose limitations on the use of the C. elegans as an ALT tumour model.
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Affiliation(s)
- Petra Školáková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska, 135, 612 65 Brno, Czech Republic
| | - Silvie Foldynová-Trantírková
- Central European Institute of Technology, Masaryk University, Kamenice 735/5, 625 00 Brno, Czech Republic Institute of Parasitology, Academy of Sciences of the Czech Republic, Branisovska, 31, 375 05 Ceske Budejovice, Czech Republic
| | - Klára Bednářová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska, 135, 612 65 Brno, Czech Republic Central European Institute of Technology, Masaryk University, Kamenice 735/5, 625 00 Brno, Czech Republic
| | - Radovan Fiala
- Central European Institute of Technology, Masaryk University, Kamenice 735/5, 625 00 Brno, Czech Republic
| | - Michaela Vorlíčková
- Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Kralovopolska, 135, 612 65 Brno, Czech Republic Central European Institute of Technology, Masaryk University, Kamenice 735/5, 625 00 Brno, Czech Republic
| | - Lukáš Trantírek
- Central European Institute of Technology, Masaryk University, Kamenice 735/5, 625 00 Brno, Czech Republic
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Fojtová M, Sýkorová E, Najdekrová L, Polanská P, Zachová D, Vagnerová R, Angelis KJ, Fajkus J. Telomere dynamics in the lower plant Physcomitrella patens. PLANT MOLECULAR BIOLOGY 2015; 87:591-601. [PMID: 25701469 DOI: 10.1007/s11103-015-0299-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/16/2015] [Indexed: 06/04/2023]
Abstract
A comparative approach in biology is needed to assess the universality of rules governing this discipline. In plant telomere research, most of the key principles were established based on studies in only single model plant, Arabidopsis thaliana. These principles include the absence of telomere shortening during plant development and the corresponding activity of telomerase in dividing (meristem) plant cells. Here we examine these principles in Physcomitrella patens as a representative of lower plants. To follow telomerase expression, we first characterize the gene coding for the telomerase reverse transcriptase subunit PpTERT in P. patens, for which only incomplete prediction has been available so far. In protonema cultures of P. patens, growing by filament apical cell division, the proportion of apical (dividing) cells was quantified and telomere length, telomerase expression and activity were determined. Our results show telomere stability and demonstrate proportionality of telomerase activity and expression with the number of apical cells. In addition, we analyze telomere maintenance in mre11, rad50, nbs1, ku70 and lig4 mutants of P. patens and compare the impact of these mutations in double-strand-break (DSB) repair pathways with earlier observations in corresponding A. thaliana mutants. Telomere phenotypes are absent and DSB repair kinetics is not affected in P. patens mutants for DSB factors involved in non-homologous end joining (NHEJ). This is compliant with the overall dominance of homologous recombination over NHEJ pathways in the moss, contrary to the inverse situation in flowering plants.
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Affiliation(s)
- Miloslava Fojtová
- Faculty of Science and CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic
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Nelson ADL, Forsythe ES, Gan X, Tsiantis M, Beilstein MA. Extending the model of Arabidopsis telomere length and composition across Brassicaceae. Chromosome Res 2015; 22:153-66. [PMID: 24846723 DOI: 10.1007/s10577-014-9423-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Telomeres are repetitive TG-rich DNA elements essential for maintaining the stability of genomes and replicative capacity of cells in almost all eukaryotes. Most of what is known about telomeres in plants comes from the angiosperm Arabidopsis thaliana, which has become an important comparative model for telomere biology. Arabidopsis tolerates numerous insults to its genome, many of which are catastrophic or lethal in other eukaryotic systems such as yeast and vertebrates. Despite the importance of Arabidopsis in establishing a model for the structure and regulation of plant telomeres, only a handful of studies have used this information to assay components of telomeres from across land plants, or even among the closest relatives of Arabidopsis in the plant family Brassicaceae. Here, we determined how well Arabidopsis represents Brassicaceae by comparing multiple aspects of telomere biology in species that represent major clades in the family tree. Specifically, we determined the telomeric repeat sequence, measured bulk telomere length, and analyzed variation in telomere length on syntenic chromosome arms. In addition, we used a phylogenetic approach to infer the evolutionary history of putative telomere-binding proteins, CTC1, STN1, TEN1 (CST), telomere repeat-binding factor like (TRFL), and single Myb histone (SMH). Our analyses revealed conservation of the telomeric DNA repeat sequence, but considerable variation in telomere length among the sampled species, even in comparisons of syntenic chromosome arms. We also found that the single-stranded and double-stranded telomeric DNA-binding complexes CST and TRFL, respectively, differ in their pattern of gene duplication and loss. The TRFL and SMH gene families have undergone numerous duplication events, and these duplicate copies are often retained in the genome. In contrast, CST components occur as single-copy genes in all sampled genomes, even in species that experienced recent whole genome duplication events. Taken together, our results place the Arabidopsis model in the context of other species in Brassicaceae, making the family the best characterized plant group in regard to telomere architecture.
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Affiliation(s)
- Andrew D L Nelson
- School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
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