1
|
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.
Collapse
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
| |
Collapse
|
2
|
Belyayev A, Kalendar R, Josefiová J, Paštová L, Habibi F, Mahelka V, Mandák B, Krak K. Telomere sequence variability in genotypes from natural plant populations: unusual block-organized double-monomer terminal telomeric arrays. BMC Genomics 2023; 24:572. [PMID: 37752451 PMCID: PMC10521516 DOI: 10.1186/s12864-023-09657-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: 05/16/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND Telomeres are the nucleoprotein complexes that physically cap the ends of eukaryotic chromosomes. Most plants possess Arabidopsis-type telomere sequences (TSs). In addition to terminal TSs, more diverse interstitial TSs exists in plants. Although telomeres have been sufficiently studied, the actual diversity of TSs in land plants is underestimated. RESULTS We investigate genotypes from seven natural populations with contrasting environments of four Chenopodium species to reveal the variability in TSs by analyzing Oxford Nanopore reads. Fluorescent in situ hybridization was used to localize telomeric repeats on chromosomes. We identified a number of derivative monomers that arise in part of both terminal and interstitial telomeric arrays of a single genotype. The former presents a case of block-organized double-monomer telomers, where blocks of Arabidopsis-type TTTAGGG motifs were interspersed with blocks of derivative TTTAAAA motifs. The latter is an integral part of the satellitome with transformations specific to the inactive genome fraction. CONCLUSIONS We suggested two alternative models for the possible formation of derivative monomers from telomeric heptamer motifs of Arabidopsis-type. It was assumed that derivatization of TSs is a ubiquitous process in the plant genome but occurrence and frequencies of derivatives may be genotype-specific. We also propose that the formation of non-canonical arrays of TSs, especially at chromosomal termini, may be a source for genomic variability in nature.
Collapse
Affiliation(s)
- Alexander Belyayev
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic.
| | - Ruslan Kalendar
- Institute of Biotechnology HiLIFE, University of Helsinki, P.O. Box 65, Helsinki, FI-00014, Finland
- National Laboratory Astana, Nazarbayev University, 53 Kabanbay Batyr Ave, Nur- Sultan, 010000, Kazakhstan
| | - Jiřina Josefiová
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Ladislava Paštová
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Farzaneh Habibi
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha, Suchdol, 165 00, Czech Republic
| | - Václav Mahelka
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
| | - Bohumil Mandák
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha, Suchdol, 165 00, Czech Republic
| | - Karol Krak
- Institute of Botany, Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha, Suchdol, 165 00, Czech Republic
| |
Collapse
|
3
|
Hao J, Wang X, Shi Y, Li L, Chu J, Li J, Lin W, Yu T, Hou D. Integrated omic profiling of the medicinal mushroom Inonotus obliquus under submerged conditions. BMC Genomics 2023; 24:554. [PMID: 37726686 PMCID: PMC10507853 DOI: 10.1186/s12864-023-09656-z] [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: 03/27/2023] [Accepted: 09/06/2023] [Indexed: 09/21/2023] Open
Abstract
BACKGROUND The Inonotus obliquus mushroom, a wondrous fungus boasting edible and medicinal qualities, has been widely used as a folk medicine and shown to have many potential pharmacological secondary metabolites. The purpose of this study was to supply a global landscape of genome-based integrated omic analysis of the fungus under lab-growth conditions. RESULTS This study presented a genome with high accuracy and completeness using the Pacbio Sequel II third-generation sequencing method. The de novo assembled fungal genome was 36.13 Mb, and contained 8352 predicted protein-coding genes, of which 365 carbohydrate-active enzyme (CAZyme)-coding genes and 19 biosynthetic gene clusters (BCGs) for secondary metabolites were identified. Comparative transcriptomic and proteomic analysis revealed a global view of differential metabolic change between seed and fermentation culture, and demonstrated positive correlations between transcription and expression levels of 157 differentially expressed genes involved in the metabolism of amino acids, fatty acids, secondary metabolites, antioxidant and immune responses. Facilitated by the widely targeted metabolomic approach, a total of 307 secondary substances were identified and quantified, with a significant increase in the production of antioxidant polyphenols. CONCLUSION This study provided the comprehensive analysis of the fungus Inonotus obliquus, and supplied fundamental information for further screening of promising target metabolites and exploring the link between the genome and metabolites.
Collapse
Affiliation(s)
- Jinghua Hao
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Xiaoli Wang
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Yanhua Shi
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Lingjun Li
- School of Modern Agriculture and Environment, Weifang Institute of Technology, Weifang, 261053, China
| | - Jinxin Chu
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Junjie Li
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China
| | - Weiping Lin
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| | - Tao Yu
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| | - Dianhai Hou
- School of Bioscience and Technology, Weifang Medical University, Weifang, 261053, China.
| |
Collapse
|
4
|
Ma B, Wang H, Liu J, Chen L, Xia X, Wei W, Yang Z, Yuan J, Luo Y, He N. The gap-free genome of mulberry elucidates the architecture and evolution of polycentric chromosomes. HORTICULTURE RESEARCH 2023; 10:uhad111. [PMID: 37786730 PMCID: PMC10541557 DOI: 10.1093/hr/uhad111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/15/2023] [Indexed: 10/04/2023]
Abstract
Mulberry is a fundamental component of the global sericulture industry, and its positive impact on our health and the environment cannot be overstated. However, the mulberry reference genomes reported previously remained unassembled or unplaced sequences. Here, we report the assembly and analysis of the telomere-to-telomere gap-free reference genome of the mulberry species, Morus notabilis, which has emerged as an important reference in mulberry gene function research and genetic improvement. The mulberry gap-free reference genome produced here provides an unprecedented opportunity for us to study the structure and function of centromeres. Our results revealed that all mulberry centromeric regions share conserved centromeric satellite repeats with different copies. Strikingly, we found that M. notabilis is a species with polycentric chromosomes and the only reported polycentric chromosome species up to now. We propose a compelling model that explains the formation mechanism of new centromeres and addresses the unsolved scientific question of the chromosome fusion-fission cycle in mulberry species. Our study sheds light on the functional genomics, chromosome evolution, and genetic improvement of mulberry species.
Collapse
Affiliation(s)
- Bi Ma
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Honghong Wang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Jingchun Liu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Lin Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Xiaoyu Xia
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Wuqi Wei
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Zhen Yang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Jianglian Yuan
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Yiwei Luo
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| | - Ningjia He
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, 400715, China
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
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.
Collapse
Affiliation(s)
| | | | - Josep A. Rosselló
- Jardín Botánico, ICBiBE, Universitat de València, c/Quart 80, E-46008 València, Spain; (A.J.M.); (M.R.)
| |
Collapse
|
9
|
Prušáková D, Peska V, Pekár S, Bubeník M, Čížek L, Bezděk A, Čapková Frydrychová R. Telomeric DNA sequences in beetle taxa vary with species richness. Sci Rep 2021; 11:13319. [PMID: 34172809 PMCID: PMC8233369 DOI: 10.1038/s41598-021-92705-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/14/2021] [Indexed: 02/06/2023] Open
Abstract
Telomeres are protective structures at the ends of eukaryotic chromosomes, and disruption of their nucleoprotein composition usually results in genome instability and cell death. Telomeric DNA sequences have generally been found to be exceptionally conserved in evolution, and the most common pattern of telomeric sequences across eukaryotes is (TxAyGz)n maintained by telomerase. However, telomerase-added DNA repeats in some insect taxa frequently vary, show unusual features, and can even be absent. It has been speculated about factors that might allow frequent changes in telomere composition in Insecta. Coleoptera (beetles) is the largest of all insect orders and based on previously available data, it seemed that the telomeric sequence of beetles varies to a great extent. We performed an extensive mapping of the (TTAGG)n sequence, the ancestral telomeric sequence in Insects, across the main branches of Coleoptera. Our study indicates that the (TTAGG)n sequence has been repeatedly or completely lost in more than half of the tested beetle superfamilies. Although the exact telomeric motif in most of the (TTAGG)n-negative beetles is unknown, we found that the (TTAGG)n sequence has been replaced by two alternative telomeric motifs, the (TCAGG)n and (TTAGGG)n, in at least three superfamilies of Coleoptera. The diversity of the telomeric motifs was positively related to the species richness of taxa, regardless of the age of the taxa. The presence/absence of the (TTAGG)n sequence highly varied within the Curculionoidea, Chrysomeloidea, and Staphylinoidea, which are the three most diverse superfamilies within Metazoa. Our data supports the hypothesis that telomere dysfunctions can initiate rapid genomic changes that lead to reproductive isolation and speciation.
Collapse
Affiliation(s)
- Daniela Prušáková
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Vratislav Peska
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Stano Pekár
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Michal Bubeník
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Lukáš Čížek
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Aleš Bezděk
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radmila Čapková Frydrychová
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05, České Budějovice, Czech Republic.
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
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.
Collapse
|
15
|
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.
Collapse
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
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Yamamoto M. Molecular cytogenetic and epigenetic components of crossing barriers and peculiar reproduction ability in Allium hybrids. THE NUCLEUS 2016. [DOI: 10.1007/s13237-015-0153-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Ji G, Liu K, Chen C, Ruan W, Glytsou C, Yang Y, Okuka M, Song W, Gagos S, Li N, Liu L. Conservation and characterization of unique porcine interstitial telomeric sequences. SCIENCE CHINA-LIFE SCIENCES 2012; 55:1029-37. [PMID: 23233217 DOI: 10.1007/s11427-012-4420-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Accepted: 11/02/2012] [Indexed: 12/18/2022]
Abstract
Telomeres are composed of TTAGGG repeats and located at the ends of chromosomes. Telomeres protect chromosomes from instability in mammals, including mice and humans. Repetitive TTAGGG sequences are also found at intrachromosomal sites, where they are named as interstitial telomeric sequences (ITSs). Aberrant ITSs are implicated in chromosomal instability and found in cancer cells. Interestingly, in pigs, vertebrate telomere sequences TTAGGG (vITSs) are also localized at the centromeric region of chromosome 6, in addition to the end of all chromosomes. Surprisingly, we found that botanic telomere sequences, TTTAGGG (bITSs), also localize with vITSs at the centromeric regions of pig chromosome 6 using telomere fluorescence in situ hybridization (FISH) and by comparisons between several species. Furthermore, the average lengths of vITSs are highly correlated with those of the terminal telomeres (TTS). Also, pig ITSs show a high incidence of telomere doublets, suggesting that pig ITSs might be unstable and dynamic. Together, our results show that pig cells maintain the conserved telomere sequences that are found at the ITSs from of plants and other vertebrates. Further understanding of the function and regulation of pig ITSs may provide new clues for evolution and chromosomal instability.
Collapse
Affiliation(s)
- Guangzhen Ji
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Nkongolo K, Mehes-Smith M. Karyotype evolution in the Pinaceae: implication with molecular phylogeny. Genome 2012. [DOI: 10.1139/g2012-061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The family Pinaceae is made up mostly of diploid species (2n = 24). Systematization of karyotype analysis was developed to make comparison of intra- and interspecific karyotypes among the Pinaceae more accurate and reliable. Considering all parameters, the genera Pseudotsuga and Pseudolarix have the “most derived” (or advanced) and asymmetric karyotypes in the Pinaceae, followed by Larix, Picea, Abies, and Cedrus. The genus Pinus was the “least derived” (or ancestral) of all the genera of the Pinaceae analyzed. Differences in karyotype formulae and asymmetry indices were found among species within the same genera, suggesting that structural changes may have contributed to the diversification of the genus. This review is a detailed analysis of comparative karyotyping based on similar parameters, including numeric data and cytogenetic information. Telomeric sequence repeats and rDNA distribution in the Pinaceae were surveyed. The role of transposition in rDNA chromosome distribution is analyzed. Cytogenetic implications of hybridization between related species are reported. Likewise, the relationships between molecular phylogenetic and karyotype evolution is discussed in light of several reports. Within many genera, chromosomal organization was conserved despite independent molecular divergence and adaptation through the evolutionary history of the species of the Pinaceae.
Collapse
Affiliation(s)
- K.K. Nkongolo
- Department of Biology and Biomolecular Science Program, Laurentian University, Sudbury, ON P3E 2C6, Canada
| | - M. Mehes-Smith
- Department of Biology and Biomolecular Science Program, Laurentian University, Sudbury, ON P3E 2C6, Canada
| |
Collapse
|
23
|
Shibata F, Hizume M. Survey of Arabidopsis- and Human-type Telomere Repeats in Plants Using Fluorescence in situ Hybridisation. CYTOLOGIA 2011. [DOI: 10.1508/cytologia.76.353] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Fukashi Shibata
- Biological Institute, Faculty of Education, Ehime University
| | - Masahiro Hizume
- Biological Institute, Faculty of Education, Ehime University
| |
Collapse
|
24
|
Koo DH, Hong CP, Batley J, Chung YS, Edwards D, Bang JW, Hur Y, Lim YP. Rapid divergence of repetitive DNAs in Brassica relatives. Genomics 2010; 97:173-85. [PMID: 21159321 DOI: 10.1016/j.ygeno.2010.12.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 11/16/2010] [Accepted: 12/02/2010] [Indexed: 11/16/2022]
Abstract
Centromeric, subtelomeric, and telomeric repetitive DNAs were characterized in Brassica species and the related Raphanus sativus and Arabidopsis thaliana. In general, rapid divergence of the repeats was found. The centromeric tandem satellite repeats were differentially distributed in the species studied, suggesting that centromeric repeats have diverged during the evolution of the A/C and B genome lineages. Sequence analysis of centromeric repeats suggested rapid evolution. Pericentromere-associated retrotransposons were identified and showed divergence during the evolution of the lineages as centromeric repeats. A novel subtelomeric tandem repeat from B. nigra was found to be conserved across the diploid Brassica genomes; however, this sequence was not identified in the related species. In contrast to previous studies, interstitial telomere-like repeats were identified in the pericentromeres of Brassica chromosomes, and these repeats may be associated with genomic stability. These results provide insight into genome evolution during polyploidization in Brassica and divergence within the Brassicaceae.
Collapse
Affiliation(s)
- Dal-Hoe Koo
- Department of Biological Science, College of Biological Science and Biotechnology, Chungnam National University, Daejeon 305-764, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
Monocot genomic diversity includes striking variation at many levels. This paper compares various genomic characters (e.g., range of chromosome numbers and ploidy levels, occurrence of endopolyploidy, GC content, chromosome packaging and organization, genome size) between monocots and the remaining angiosperms to discern just how distinctive monocot genomes are. One of the most notable features of monocots is their wide range and diversity of genome sizes, including the species with the largest genome so far reported in plants. This genomic character is analysed in greater detail, within a phylogenetic context. By surveying available genome size and chromosome data it is apparent that different monocot orders follow distinctive modes of genome size and chromosome evolution. Further insights into genome size-evolution and dynamics were obtained using statistical modelling approaches to reconstruct the ancestral genome size at key nodes across the monocot phylogenetic tree. Such approaches reveal that while the ancestral genome size of all monocots was small ( pg), there have been several major increases and decreases during monocot evolution. In addition, notable increases in the rates of genome size-evolution were found in Asparagales and Poales compared with other monocot lineages.
Collapse
|
26
|
Mlinarec J, Chester M, Siljak-Yakovlev S, Papes D, Leitch AR, Besendorfer V. Molecular structure and chromosome distribution of three repetitive DNA families in Anemone hortensis L. (Ranunculaceae). Chromosome Res 2009; 17:331-46. [PMID: 19224381 DOI: 10.1007/s10577-009-9025-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Revised: 12/08/2008] [Accepted: 12/08/2008] [Indexed: 10/21/2022]
Abstract
The structure, abundance and location of repetitive DNA sequences on chromosomes can characterize the nature of higher plant genomes. Here we report on three new repeat DNA families isolated from Anemone hortensis L.; (i) AhTR1, a family of satellite DNA (stDNA) composed of a 554-561 bp long EcoRV monomer; (ii) AhTR2, a stDNA family composed of a 743 bp long HindIII monomer and; (iii) AhDR, a repeat family composed of a 945 bp long HindIII fragment that exhibits some sequence similarity to Ty3/gypsy-like retroelements. Fluorescence in-situ hybridization (FISH) to metaphase chromosomes of A. hortensis (2n = 16) revealed that both AhTR1 and AhTR2 sequences co-localized with DAPI-positive AT-rich heterochromatic regions. AhTR1 sequences occur at intercalary DAPI bands while AhTR2 sequences occur at 8-10 terminally located heterochromatic blocks. In contrast AhDR sequences are dispersed over all chromosomes as expected of a Ty3/gypsy-like element. AhTR2 and AhTR1 repeat families include polyA- and polyT-tracks, AT/TA-motifs and a pentanucleotide sequence (CAAAA) that may have consequences for chromatin packing and sequence homogeneity. AhTR2 repeats also contain TTTAGGG motifs and degenerate variants. We suggest that they arose by interspersion of telomeric repeats with subtelomeric repeats, before hybrid unit(s) amplified through the heterochromatic domain. The three repetitive DNA families together occupy approximately 10% of the A. hortensis genome. Comparative analyses of eight Anemone species revealed that the divergence of the A. hortensis genome was accompanied by considerable modification and/or amplification of repeats.
Collapse
Affiliation(s)
- Jelena Mlinarec
- Department of Molecular Biology, Biology Division, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000, Zagreb, Croatia
| | | | | | | | | | | |
Collapse
|
27
|
Puizina J, Sviben T, Krajacić-Sokol I, Zoldos-Pećnik V, Siljak-Yakovlev S, Papes D, Besendorfer V. Cytogenetic and molecular characterization of the Abies alba genome and its relationship with other members of the Pinaceae. PLANT BIOLOGY (STUTTGART, GERMANY) 2008; 10:256-67. [PMID: 18304200 DOI: 10.1111/j.1438-8677.2007.00018.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Genome size, karyotype structure, heterochromatin distribution, position and number of ribosomal genes, as well as the ITS2 sequence of the internal transcribed spacer (ITS) were analysed in silver fir (Abies alba Mill.). The analysis also included characterization of the Arabidopsis-type of telomeric repeats in silver fir and in related species. The results were compared with results from other species of the Pinaceae, to evaluate phylogeny and chromosomal and molecular evolution in the Pinaceae. Integrated chromosomal data provided insights into chromosome and karyotype evolution in the Pinaceae. The evolutionary trend for GC-rich heterochromatic blocks seems to involve loss of blocks that are not associated with rDNA. Similarly, numerous large blocks of interstitial plant telomeric repeats that are typical for all analysed species of the genus Pinus were not observed in the evolutionarily younger genera, such as Abies, Picea and Larix. On the contrary, the majority of telomeric sequences in these three genera appeared confined to the chromosome ends. We confirmed the current position of Abies and Tsuga in subfamily Abietoideae and the position of Pinus in the subfamily Pinoideae based on ITS2 sequences. Pseudotsuga is placed together with Larix into the subfamily Laricoideae. We conclude that the current position of the genus Picea in the subfamily Abietoideae should be reconsidered and, possibly, the genus Picea should be reclassified as a separate subfamily, Piceoideae, as recently proposed.
Collapse
Affiliation(s)
- J Puizina
- Department of Biology, Faculty of Natural Sciences, Mathematics and Education, University of Split, Split, Croatia
| | | | | | | | | | | | | |
Collapse
|
28
|
Zellinger B, Riha K. Composition of plant telomeres. ACTA ACUST UNITED AC 2007; 1769:399-409. [PMID: 17383025 DOI: 10.1016/j.bbaexp.2007.02.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 02/01/2007] [Accepted: 02/09/2007] [Indexed: 12/15/2022]
Abstract
Telomeres are essential elements of eukaryotic chromosomes that differentiate native chromosome ends from deleterious DNA double-strand breaks (DSBs). This is achieved by assembling chromosome termini in elaborate high-order nucleoprotein structures that in most organisms encompass telomeric DNA, specific telomere-associated proteins as well as general chromatin and DNA repair factors. Although the individual components of telomeric chromatin are evolutionary highly conserved, cross species comparisons have revealed a remarkable flexibility in their utilization at telomeres. This review outlines the strategies used for chromosome end protection and maintenance in mammals, yeast and flies and discusses current progress in deciphering telomere structure in plants.
Collapse
Affiliation(s)
- Barbara Zellinger
- Gregor Mendel Institute of Plant Molecular Biology, Austrian Academy of Sciences, Dr. Bohrgasse 3, A-1030 Vienna, Austria
| | | |
Collapse
|
29
|
Alverca E, Cuadrado A, Jouve N, Franca S, Moreno Díaz de la Espina S. Telomeric DNA localization on dinoflagellate chromosomes: structural and evolutionary implications. Cytogenet Genome Res 2007; 116:224-31. [PMID: 17317964 DOI: 10.1159/000098191] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Accepted: 11/21/2006] [Indexed: 12/25/2022] Open
Abstract
Dinoflagellates are eukaryotic microalgae with distinct chromosomes throughout the cell cycle which lack histones and nucleosomes. The molecular organization of these chromosomes is still poorly understood. We have analysed the presence of telomeres in two evolutionarily distant and heterogeneous dinoflagellate species (Prorocentrum micans and Amphidinium carterae) by FISH with a probe containing the Arabidopsis consensus telomeric sequence. Telomere structures were identified at the chromosome ends of both species during interphase and mitosis and were frequently associated with the nuclear envelope. These results identify for the first time telomere structures in dinoflagellate chromosomes, which are formed in the absence of histones. The presence of telomeres supports the linear nature of dinoflagellate chromosomes.
Collapse
Affiliation(s)
- E Alverca
- Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisboa, Portugal
| | | | | | | | | |
Collapse
|
30
|
Dechyeva D, Schmidt T. Molecular organization of terminal repetitive DNA in Beta species. Chromosome Res 2007; 14:881-97. [PMID: 17195925 DOI: 10.1007/s10577-006-1096-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/19/2007] [Accepted: 10/19/2006] [Indexed: 09/29/2022]
Abstract
We have isolated families of subtelomeric satellite DNA sequences from species of four sections of the genus Beta and from spinach, a related Chenopodiaceae. Twenty-five clones were sequenced and representative repeats of each family were characterized by Southern blotting and FISH. The families of ApaI restriction satellite repeats were designated pAv34, pAc34, the families of RsaI repeats pRp34, pRn34 and pRs34. The repeating units are 344-362 bp long and 45.7-98.8% homologous with a clear species-specific divergence. Each satellite monomer consists of two subrepeats SR1 and SR2 of 165-184 bp, respectively. The repeats of each subrepeat group are highly identical across species, but share only a homology of 40.8-54.8% with members of the other subrepeat group. Two evolutionary steps could be supposed in the phylogeny of the subtelomeric satellite family: the diversification of an ancestor satellite into groups representing SR1 and SR2 in the progenitor of Beta and Spinacea species, followed by the dimerization and diversification of the resulting 360 bp repeats into section-specific satellite DNA families during species radiation. The chromosomal localization of telomeric, subtelomeric and rDNA tandem repeats was investigated by multi-colour FISH. High-resolution analysis by fibre FISH revealed a unique physical organization of B. vulgaris chromosome ends with telomeric DNA and subtelomeric satellites extending over a maximum of 63 kb and 125 kb, respectively.
Collapse
Affiliation(s)
- Daryna Dechyeva
- Institute of Botany, Dresden University of Technology, Zellescher Weg 20b, 01062 Dresden, Germany
| | | |
Collapse
|
31
|
de la Herrán R, Cuñado N, Navajas-Pérez R, Santos JL, Ruiz Rejón C, Garrido-Ramos MA, Ruiz Rejón M. The controversial telomeres of lily plants. Cytogenet Genome Res 2005; 109:144-7. [PMID: 15753570 DOI: 10.1159/000082393] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2003] [Accepted: 02/27/2004] [Indexed: 11/19/2022] Open
Abstract
The molecular structure of the exceptional telomeres of six plant species belonging to the order Asparagales and two species of the order Liliales was analyzed using Southern blot and fluorescence in situ hybridization. Three different situations were found, namely: i) In the two Liliales species, Tulipa australis (Liliaceae) and Merendera montana (Colchicaceae), the chromosome ends display hybridization signals with oligonucleotides resembling telomere repeats of both plants (TTTAGGG)n and vertebrates (TTAGGG)n. ii) Asparagales species such as Phormium tenax (Hemerocallidaceae), Muscari comosum (Hyacinthaceae), Narcissus jonquilla (Amaryllidaceae) and Allium sativum (Alliaceae) lack both the plant telomere repeats and the vertebrate telomere repeats. iii) Two other Asparagales species, Aloe vera (Asphodelaceae) and an Iris hybrid (Iridaceae), display positive hybridization with the vertebrate telomere repeats but not with the plant telomere repeats. Southern blot hybridization revealed concurring results. On this basis, the composition of the telomere structure in this plant group is discussed.
Collapse
Affiliation(s)
- R de la Herrán
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
This paper examines telomeres from an evolutionary perspective. In the monocot plant order Asparagales two evolutionary switch-points in telomere sequence are known. The first occurred when the Arabidopsis-type telomere was replaced by a telomere based on a repeat motif more typical of vertebrates. The replacement is associated with telomerase activity, but the telomerase has low fidelity and this may have implications for the binding of telomeric proteins. At the second evolutionary switch-point, the telomere and its mode of synthesis are replaced by an unknown mechanism. Elsewhere in plants (Sessia, Vestia, Cestrum) and in arthropods, the telomere "typical" of the group is lost. Probably many other groups with "unusual" telomeres will be found. We question whether telomerase is indeed the original end-maintenance system and point to other candidate processes involving t-loops, t-circles, rolling circle replication and recombination. Possible evolutionary outcomes arising from the loss of telomerase activity in alternative lengthening of telomere (ALT) systems are discussed. We propose that elongation of minisatellite repeats using recombination/replication processes initially substitutes for the loss of telomerase function. Then in more established ALT groups, subtelomeric satellite repeats may replace the telomeric minisatellite repeat whilst maintaining the recombination/replication mechanisms for telomere elongation. Thereafter a retrotransposition-based end-maintenance system may become established. The influence of changing sequence motifs on the properties of the telomere cap is discussed. The DNA and protein components of telomeres should be regarded--as with any other chromosome elements--as evolving and co-evolving over time and responding to changes in the genome and to environmental stresses. We describe how telomere dysfunction, resulting in end-to-end chromosome fusions, can have a profound effect on chromosome evolution and perhaps even speciation.
Collapse
Affiliation(s)
- Jirí Fajkus
- Laboratory of Functional Genomics and Proteomics, Faculty of Science, Masaryk University Brno, Královopolská 135, CZ-61265 Brno, Czech Republic.
| | | | | |
Collapse
|
33
|
Schrumpfová P, Kuchar M, Miková G, Skrísovská L, Kubicárová T, Fajkus J. Characterization of two Arabidopsis thaliana myb-like proteins showing affinity to telomeric DNA sequence. Genome 2005; 47:316-24. [PMID: 15060584 DOI: 10.1139/g03-136] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Telomere-binding proteins participate in forming a functional nucleoprotein structure at chromosome ends. Using a genomic approach, two Arabidopsis thaliana genes coding for candidate Myb-like telomere binding proteins were cloned and expressed in E. coli. Both proteins, termed AtTBP2 (accession Nos. T46051 (protein database) and GI:638639 (nucleotide database); 295 amino acids, 32 kDa, pI 9.53) and AtTBP3 (BAB08466, GI:9757879; 299 amino acids, 33 kDa, pI 9.88), contain a single Myb-like DNA-binding domain at the N-terminus, and a histone H1/H5-like DNA-binding domain in the middle of the protein sequence. Both proteins are expressed in various A. thaliana tissues. Using the two-hybrid system interaction between the proteins AtTBP2 and AtTBP3 and self interactions of each of the proteins were detected. Gel-retardation assays revealed that each of the two proteins is able to bind the G-rich strand and double-stranded DNA of plant telomeric sequence with an affinity proportional to a number of telomeric repeats. Substrates bearing a non-telomeric DNA sequence positioned between two telomeric repeats were bound with an efficiency depending on the length of interrupting sequence. The ability to bind variant telomere sequences decreased with sequence divergence from the A. thaliana telomeric DNA. None of the proteins alone or their mixture affects telomerase activity in vitro. Correspondingly, no interaction was observed between any of two proteins and the Arabidopsis telomerase reverse transcriptase catalytic subunit TERT (accession No. AF172097) using two-hybrid assay.
Collapse
Affiliation(s)
- Petra Schrumpfová
- Department of Functional Genomics and Proteomics, Masaryk University Brno, Czech Republic
| | | | | | | | | | | |
Collapse
|
34
|
Abstract
The role model systems have played in understanding telomere biology has been enormous, and understanding has rapidly transferred to human telomere research. Most work using model organisms to study telomerase and nontelomerase-based telomere-maintenance systems has centered on yeasts, ciliates, and insects. But it is now timely to put considerably more effort into plant models for a number of reasons: (i) the rice and Arabidopsis genome sequencing projects make data mining possible; (ii) extensive collections of insertion mutants of Arabidopsis thaliana enable phenotypic effects of protein gene knockouts to be analyzed, including for those genes involved in telomere structure, function (including, for example, in meiosis), and maintenance; and (iii) the variability of plant telomeres is considerable and ranges from the telomerase-mediated synthesis of the Arabidopsis-type (TTTAGGG) and vertebrate-type (TTAGGG) repeats to sequences synthesized by telomerase-independent mechanism(s) that are still to be discovered. Here we describe how the understanding of telomere biology has been advanced by methods used to isolate telomeric sequences and prove that the putative sequences isolated are indeed telomeric. We show how assays designed to prove the activity of telomerase [e.g., telomeric repeat amplification protocol (TRAP)] lead not only to an understanding of telomere structure and function, but also to the understanding of cell activity in development and in the cell cycle. We review how assays designed to reveal protein/protein and protein/nucleic acid interactions promote understanding of the structure and activities of plant telomeres. Together, the data are making significant contributions to telomere biology in general and could have medical implications.
Collapse
Affiliation(s)
- Jirí Fajkus
- Academy of Sciences of the Czech Republic, Brno, Czech Republic.
| | | | | |
Collapse
|
35
|
Puizina J, Weiss-Schneeweiss H, Pedrosa-Harand A, Kamenjarin J, Trinajstic I, Riha K, Schweizer D. Karyotype analysis in Hyacinthella dalmatica (Hyacinthaceae) reveals vertebrate-type telomere repeats at the chromosome ends. Genome 2004; 46:1070-6. [PMID: 14663525 DOI: 10.1139/g03-078] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chromosome analysis of three different populations of Hyacinthella dalmatica (Lallem.) Trinajstić, an endemic species of the coastal region of southeastern Europe, showed a unique chromosome number, 2n = 2x = 20, and bimodal karyotype with one large and nine smaller pairs of chromosomes. Staining with fluorochromes CMA3 (chromomycin A3) and DAPI (4,6-diamidino-2-phenylindole) revealed heterochromatic regions associated with NORs, centromeres, and several interstitial heterochromatic bands on the longest chromosome pair. Double-target FISH with two ribosomal DNA probes revealed one locus of 5S rRNA genes in the pericentromeric region of chromosome pair 3 and one locus of 18S-5.8S-26S rRNA genes on the short arm of chromosome pair 4 in all plants and populations analyzed. Southern hybridization analysis and FISH experiments demonstrated that the distal ends of H. dalmatica chromosomes contain the vertebrate telomere (5'-TTAGGG-3') repeat type rather than the Arabidopsis (5'-TTTAGGG-3') heptamer, and so suggest that this Asparagales species along with Aloe and Othocallis contains the vertebrate-type telomere repeat.
Collapse
Affiliation(s)
- Jasna Puizina
- Gregor Mendel Institute ofMolecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria.
| | | | | | | | | | | | | |
Collapse
|
36
|
Abstract
The stability of eukaryotic genomes is provided in part by the integrity of telomeres, the nucleoprotein caps on the ends of chromosome. Recent studies reveal that proper telomere architecture is required for long-term proliferation capacity. Here we describe molecular mechanisms that protect and maintain chromosome ends and discuss why Arabidopsis is emerging as a powerful new model for elucidating fundamental aspects of telomere biology.
Collapse
Affiliation(s)
- Karel Riha
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, Texas 77843-2128, USA
| | | |
Collapse
|
37
|
Frydrychová R, Grossmann P, Trubac P, Vítková M, Marec F. Phylogenetic distribution of TTAGG telomeric repeats in insects. Genome 2004; 47:163-78. [PMID: 15060613 DOI: 10.1139/g03-100] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We examined the presence of TTAGG telomeric repeats in 22 species from 20 insect orders with no or inconclusive information on the telomere composition by single-primer polymerase chain reaction with (TTAGG)6 primers, Southern hybridization of genomic DNAs, and fluorescence in situ hybridization of chromosomes with (TTAGG)n probes. The (TTAGG)n sequence was present in 15 species and absent in 7 species. In a compilation of new and published data, we combined the distribution of (TTAGG)n telomere motif with the insect phylogenetic tree. The pattern of phylogenetic distribution of the TTAGG repeats clearly supported a hypothesis that the sequence was an ancestral motif of insect telomeres but was lost repeatedly during insect evolution. The motif was conserved in the "primitive" apterous insect orders, the Archaeognatha and Zygentoma, in the "lower" Neoptera (Plecoptera, Phasmida, Orthoptera, Blattaria, Mantodea, and Isoptera) with the exception of Dermaptera, and in Paraneoptera (Psocoptera, Thysanoptera, Auchenorrhyncha, and Sternorrhyncha) with the exception of Heteroptera. Surprisingly, the (TTAGG)n motif was not found in the "primitive" pterygotes, the Palaeoptera (Ephemeroptera and Odonata). The Endopterygota were heterogeneous for the occurrence of TTAGG repeats. The motif was conserved in Hymenoptera, Lepidoptera, and Trichoptera but was lost in one clade formed by Diptera, Siphonaptera, and Mecoptera. It was also lost in Raphidioptera, whereas it was present in Megaloptera. In contrast with previous authors, we did not find the motif in Neuroptera. Finally, both TTAGG-positive and TTAGG-negative species were reported in Coleoptera. The repeated losses of TTAGG in different branches of the insect phylogenetic tree and, in particular, in the most successful lineage of insect evolution, the Endopterygota, suggest a backup mechanism in the genome of insects that enabled them frequent evolutionary changes in telomere composition.
Collapse
|
38
|
Weiss-Schneeweiss H, Riha K, Jang CG, Puizina J, Scherthan H, Schweizer D. Chromosome termini of the monocot plant Othocallis siberica are maintained by telomerase, which specifically synthesises vertebrate-type telomere sequences. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 37:484-93. [PMID: 14756758 DOI: 10.1046/j.1365-313x.2003.01974.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Lack of Arabidopsis-type T3AG3 telomere sequences has recently been reported for the majority of investigated taxa of the monocot order Asparagales. In order to investigate this phenomenon in more detail, we conducted extensive cytogenetic and molecular analyses of the telomeres in Othocallis siberica, a member of this order. Terminal restriction fragment analysis together with Bal31 exonuclease assay showed that chromosome termini in O. siberica are formed by long stretches (more than 10 kbp) of vertebrate-type T2AG3 repeats. In addition, telomerase activity specifically synthesising (T2AG3)n sequence was detected in O. siberica protein extracts by telomerase repeat amplification protocol (TRAP). Fluorescence in situ hybridisation (FISH) revealed the presence of the vertebrate-type T2AG3 telomere sequences at all chromosome termini and at a few additional regions of O. siberica chromosomes, whereas Arabidopsis-type T3AG3 DNA and peptide nucleic acid (PNA) probes did not hybridise to chromosomes of Othocallis, except for polymorphic blocks in chromosomes 2 (interstitial) and 4 (terminal). These interstitial/terminal regions are apparently composed of large blocks of (T2AG3)n and (T3AG3)n DNA and represent a unique example of interspersion of two types of telomeric repeats within one genome. This may be a reflection of the recent evolutionary switch from Arabidopsis- to vertebrate-type telomeric repeats in this plant group.
Collapse
Affiliation(s)
- Hanna Weiss-Schneeweiss
- Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14, A-1030 Vienna, Austria.
| | | | | | | | | | | |
Collapse
|
39
|
Sýkorová E, Lim KY, Kunická Z, Chase MW, Bennett MD, Fajkus J, Leitch AR. Telomere variability in the monocotyledonous plant order Asparagales. Proc Biol Sci 2003; 270:1893-904. [PMID: 14561302 PMCID: PMC1691456 DOI: 10.1098/rspb.2003.2446] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A group of monocotyledonous plants within the order Asparagales, forming a distinct clade in phylogenetic analyses, was reported previously to lack the 'typical' Arabidopsis-type telomere (TTTAGGG)(n). This stimulated us to determine what has replaced these sequences. Using slot-blot and fluorescent in situ hybridization (FISH) to species within this clade, our results indicate the following. 1. The typical Arabidopsis-type telomeric sequence has been partly or fully replaced by the human-type telomeric sequence (TTAGGG)(n). Species in Allium lack the human-type variant. 2. In most cases the human variant occurs along with a lower abundance of two or more variants of the minisatellite sequences (of seven types evaluated), usually these being the consensus telomeric sequence of Arabidopsis, Bombyx (TTAGG)(n) and Tetrahymena (TTGGGG)(n). FISH shows that the variants can occur mixed together at the telomere. 3. Telomerases generate products with a 6 base pair periodicity and when sequenced they reveal predominantly a reiterated human-type motif. These motifs probably form the 'true telomere' but the error rate of motif synthesis is higher compared with 'typical' plant telomerases. The data indicate that the Asparagales clade is unified by a mutation resulting in a switch from synthesis of Arabidopsis-like telomeres to a low-fidelity synthesis of human-like telomeres.
Collapse
Affiliation(s)
- E Sýkorová
- School of Biological Sciences, Queen Mary University of London, London E1 4NS, UK
| | | | | | | | | | | | | |
Collapse
|
40
|
Hajdera I, Siwinska D, Hasterok R, Maluszynska J. Molecular cytogenetic analysis of genome structure in Lupinus angustifolius and Lupinus cosentinii. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2003; 107:988-96. [PMID: 14523528 DOI: 10.1007/s00122-003-1303-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2002] [Accepted: 01/20/2003] [Indexed: 05/10/2023]
Abstract
Molecular cytogenetic analysis of Lupinus angustifolius and Lupinus cosentinii was performed using flow cytometry, fluorescence in situ hybridisation (FISH) and differential chromosome staining. Genome size was determined as 2.07 pg for L. angustifolius and 1.54 pg for L. cosentinii. Analysis of nuclear DNA amount in cells during plant development has shown endopolyploidisation in different organs. The highest level of endopolyploidy was in cotyledons and reached 32C in L. angustifolius and 64C in L. cosentinii. Both of the investigated Lupinus species belong to the polysomatic type of plants. Double FISH with rDNA probes provided chromosomal landmarks for 10 out of 40 chromosomes for L. angustifolius and 8 out of 32 chromosomes for L. cosentinii. In L. angustifolius, the number and localisation of 25S rDNA hybridisation signals precisely corresponded to the chromomycin A3 (CMA(+)) bands, while in L. cosentinii both 25S and 5S rDNA loci overlapped with CMA(+) bands. Silver staining revealed that only 45S rRNA genes located in secondary constriction regions were transcriptionally active. FISH with Arabidopsis-type telomeric arrays revealed the presence of signals at termini of all chromosomes. Despite the application of different DNA probes for FISH and different chromosome staining, a relatively small proportion of chromosomes in the Lupinus karyotypes can be distinguished. Identification of all chromosomes requires the use of more chromosome-specific markers.
Collapse
Affiliation(s)
- Inga Hajdera
- Department of Plant Anatomy and Cytology, University of Silesia, Jagiellonska 28, 40-032 Katowice, Poland
| | | | | | | |
Collapse
|
41
|
Sykorova E, Lim KY, Chase MW, Knapp S, Leitch IJ, Leitch AR, Fajkus J. The absence of Arabidopsis-type telomeres in Cestrum and closely related genera Vestia and Sessea (Solanaceae): first evidence from eudicots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 34:283-291. [PMID: 12713535 DOI: 10.1046/j.1365-313x.2003.01731.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Using slot-blot and fluorescent in situ hybridization (FISH), we found no evidence for the presence of the Arabidopsis-type telomeric sequence (TTTAGGG)n at the chromosome termini in any of the Cestrum species we investigated. Probing for the human-type telomere (TTAGGG)n also revealed no signal. However, polymerase chain reaction experiments indicated that there are short lengths of the sequence TTTAGGG dispersed in the genome but that these sequences are almost certainly too short to act as functional telomeres even if they were at the chromosome termini. An analysis of related genera Vestia and Sessea indicates that they too lack the Arabidopsis-type telomere, and the sequences were lost in the common ancestor of these genera. We found that the Cestrum species investigated had particularly large mean chromosome sizes. We discuss whether this is a consequence of alternative telomere end maintenance systems.
Collapse
Affiliation(s)
- Eva Sykorova
- School of Biological Sciences, Queen Mary University of London, UK
| | | | | | | | | | | | | |
Collapse
|
42
|
Probst AV, Fransz PF, Paszkowski J, Mittelsten Scheid O. Two means of transcriptional reactivation within heterochromatin. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 33:743-749. [PMID: 12609046 DOI: 10.1046/j.1365-313x.2003.01667.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
DNA methylation levels and specific histone modifications of chromatin in interphase nuclei are taken as an indicator of transcriptional activity or silencing. Arabidopsis mutants impaired in maintenance of transcriptional gene silencing (TGS) alleviate TGS with or without affecting DNA methylation. Mutant ddm1, representing the first type, lacks a chromatin remodeling factor that regulates histone and DNA methylation. Mutant mom1, representing the second type, is affected in a different but still unknown silencing mechanism. Both classes of mutation have been studied mainly for their effects on specific loci. Here, we describe the cytological analysis of chromatin in ddm1 and mom1 mutants. The ddm1 mutation causes a striking decondensation of centromeric heterochromatin, a re-distribution of the remaining methylation of DNA, and a drastic change in the pattern of histone modification. A complex transgenic locus, which underwent stable inactivation and became heterochromatin-like, follows similar structural alterations. In contrast, nuclear organization in mom1 appears unaltered, demonstrating an involvement of MOM1 in transcriptional regulation within a heterochromatic environment.
Collapse
Affiliation(s)
- Aline V Probst
- Friedrich Miescher Institute for Biomedical Research, PO Box 2543, CH-4002 Basel, Switzerland.
| | | | | | | |
Collapse
|