Homology-dependent repair is involved in 45S rDNA loss in plant CAF-1 mutants.
Veronika Muchová,Simon Amiard,Iva Mozgová,Martina Dvořáčková,Maria Eugenia Gallego,Charles I. White,Jiří Fajkus +6 more
TLDR
The results suggest that the repair of double-stranded breaks present in the transcribed rDNA region is RAD51B dependent and that this contributes to rDNA repeat loss in fas mutants, presumably via the single-stranding annealing recombination pathway.Abstract:
Arabidopsis thaliana mutants in FAS1 and FAS2 subunits of chromatin assembly factor 1 (CAF1) show progressive loss of 45S rDNA copies and telomeres. We hypothesized that homology-dependent DNA damage repair (HDR) may contribute to the loss of these repeats in fas mutants. To test this, we generated double mutants by crossing fas mutants with knock-out mutants in RAD51B, one of the Rad51 paralogs of A. thaliana. Our results show that the absence of RAD51B decreases the rate of rDNA loss, confirming the implication of RAD51B-dependent recombination in rDNA loss in the CAF1 mutants. Interestingly, this effect is not observed for telomeric repeat loss, which thus differs from that acting in rDNA loss. Involvement of DNA damage repair in rDNA dynamics in fas mutants is further supported by accumulation of double-stranded breaks (measured as γ-H2AX foci) in 45S rDNA. Occurrence of the foci is not specific for S-phase, and is ATM-independent. While the foci in fas mutants occur both in the transcribed (intranucleolar) and non-transcribed (nucleoplasmic) fraction of rDNA, double fas rad51b mutants show a specific increase in the number of the intranucleolar foci. These results suggest that the repair of double-stranded breaks present in the transcribed rDNA region is RAD51B dependent and that this contributes to rDNA repeat loss in fas mutants, presumably via the single-stranded annealing recombination pathway. Our results also highlight the importance of proper chromatin assembly in the maintenance of genome stability.read more
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Allium telomeres unmasked: the unusual telomeric sequence (CTCGGTTATGGG)(n) is synthesized by telomerase
Petr Fajkus,Petr Fajkus,Vratislav Peška,Zdeňka Sitová,Jana Fulnečková,Martina Dvořáčková,Martina Dvořáčková,Roman Gogela,Eva Sýkorová,Jan Hapala,Jiří Fajkus,Jiří Fajkus +11 more
TL;DR: To characterize the unknown Allium telomeres, a combination of bioinformatic processing of transcriptomic and genomic data with standard approaches in telomere biology is applied, opening up the possibility of studying the molecular details of the evolutionary genetic change in Alliumtelomeres and its possible role in speciation.
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DNA Damage Repair in the Context of Plant Chromatin
TL;DR: This Update compares the knowledge of the role of chromatin and chromatin-modifying factors during DDR in plants with equivalent systems in yeast and humans to emphasize plant-specific elements and discuss possible implications.
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Chromatin dynamics of plant telomeres and ribosomal genes
Martina Dvořáčková,Martina Dvořáčková,Martina Dvořáčková,Miloslava Fojtová,Miloslava Fojtová,Miloslava Fojtová,Jiří Fajkus,Jiří Fajkus,Jiří Fajkus +8 more
TL;DR: The structural and functional inter-connectivity of telomeres and rDNA is discussed, with a focus on recent results obtained in plants.
Journal ArticleDOI
Arabidopsis ATRX Modulates H3.3 Occupancy and Fine-Tunes Gene Expression
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TL;DR: This study characterize the Arabidopsis thaliana Alpha Thalassemia-mental Retardation X-linked (ATRX) ortholog and show that ATRX is involved in histone H3.3 deposition and emphasize the role of histone chaperones in adjusting genome expression.
Journal ArticleDOI
Variation of 45S rDNA intergenic spacers in Arabidopsis thaliana
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TL;DR: This study presents for the first time a comprehensive and representative set of complete IGS sequences, obtained by conventional cloning and by Pacific Biosciences sequencing, and is the first study combining IGS sequencing data with RFLP analysis of genomic DNA.
References
More filters
Journal ArticleDOI
A plant DNA minipreparation: Version II
TL;DR: The topic of this report is rap,d m,croscale methods for,solat,on of plant D N A without tile use of ul tracentr ,fugatlon wEth CsCI, which is of moderately high molecular weight and serves as a satisfactory substrate for most restrlctum cndonucleases and is statable for genom,c blot analys,s.
Journal ArticleDOI
Genome-Wide Insertional Mutagenesis of Arabidopsis thaliana
Jose M. Alonso,Anna Stepanova,Thomas J. Leisse,Christopher J. Kim,Huaming Chen,Paul Shinn,Denise K. Stevenson,Justin Zimmerman,Pascual Barajas,Rosa Cheuk,Carmelita Gadrinab,Collen Heller,Albert Jeske,Eric Koesema,Cristina C. Meyers,Holly Parker,Lance Prednis,Yasser Ansari,Nathan Choy,Hashim Deen,Michael Geralt,Nisha Hazari,Emily Hom,Meagan Karnes,Celene Mulholland,Ral Ndubaku,Ian Thomas Schmidt,Plinio Guzmán,Laura Aguilar-Henonin,Markus Schmid,Detlef Weigel,David E. Carter,Trudy Marchand,Eddy Risseeuw,Debra Brogden,Albana Zeko,William L. Crosby,Charles C. Berry,Joseph R. Ecker +38 more
TL;DR: Genome-wide analysis of the distribution of integration events revealed the existence of a large integration site bias at both the chromosome and gene levels, and insertion mutations were identified in genes that are regulated in response to the plant hormone ethylene.
Journal ArticleDOI
How Shelterin Protects Mammalian Telomeres
Wilhelm Palm,Titia de Lange +1 more
TL;DR: Recent experiments have revealed how shelterin represses the ATM and ATR kinase signaling pathways and hides chromosome ends from nonhomologous end joining and homology-directed repair.
Journal ArticleDOI
Regulation of homologous recombination in eukaryotes
TL;DR: The factors and mechanistic stages of recombination that are subject to regulation are reviewed and it is suggested that recombination achieves flexibility and robustness by proceeding through metastable, reversible intermediates.
Journal ArticleDOI
Mammalian telomeres resemble fragile sites and require TRF1 for efficient replication
Agnel Sfeir,Settapong T. Kosiyatrakul,Dirk Hockemeyer,Sheila L. MacRae,Jan Karlseder,Carl L. Schildkraut,Titia de Lange +6 more
TL;DR: The TTAGGG repeat arrays of mammalian telomeres pose a challenge to the DNA replication machinery, giving rise to replication-dependent defects that resemble those of aphidicolin-induced common fragile sites.