Phenotypic reversion in fas mutants of Arabidopsis thaliana by reintroduction of FAS genes: variable recovery of telomeres with major spatial rearrangements and transcriptional reprogramming of 45S rDNA genes
Language English Country Great Britain, England Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
27377564
DOI
10.1111/tpj.13257
Knihovny.cz E-resources
- Keywords
- rDNA, CAF-1, chromatin assembly, genome instability, rRNA gene regulation, telomeres,
- MeSH
- Arabidopsis genetics metabolism MeSH
- Chromatin genetics metabolism MeSH
- Genome, Plant genetics MeSH
- Arabidopsis Proteins genetics metabolism MeSH
- DNA, Ribosomal genetics metabolism MeSH
- Telomere genetics metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Chromatin MeSH
- Arabidopsis Proteins MeSH
- DNA, Ribosomal MeSH
Arabidopsis thaliana mutants dysfunctional in the evolutionarily conserved protein complex chromatin assembly factor-1 (CAF-1), which deposits the canonical histone H3 variant H3.1 during DNA synthesis-dependent chromatin assembly, display complex phenotypic changes including meristem and growth alterations, sensitivity to DNA-damaging agents, and reduced fertility. We reported previously that mutants in the FAS1 subunit of CAF-1 progressively lose telomere and 45S rDNA repeats. Here we show that multiple aspects of the fas phenotype are recovered immediately on expression of a reintroduced FAS1 allele, and are clearly independent of the recovery of rDNA copy-numbers and telomeres. In reverted lines, 45S rDNA genes are recovered to diverse levels with a strikingly different representation of their variants, and the typical association of nucleolar organizing region 4 with the nucleolus is perturbed. One of 45S rDNA variants (VAR1), which is silenced in wild-type (WT) plants without mutation history (Col-0 WT), dominates the expression pattern, whereas VAR2 is dominant in Col-0 WT plants. We propose an explanation for the variability of telomere and 45S rDNA repeats associated with CAF-1 function, suggesting that the differences in nuclear partitioning and expression of the rDNA variants in fas mutants and their revertants provide a useful experimental system to study genetic and epigenetic factors in gene dosage compensation.
References provided by Crossref.org
The rDNA Loci-Intersections of Replication, Transcription, and Repair Pathways
Large tandem duplications affect gene expression, 3D organization, and plant-pathogen response
G4 Structures in Control of Replication and Transcription of rRNA Genes
Variation of 45S rDNA intergenic spacers in Arabidopsis thaliana
