English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  The mitochondrial genome of higher plants is unusually dynamic, with recombination and nonhomologous end-joining (NHEJ) activities producing variability in size and organization. Plant mitochondrial DNA also generally displays much lower nucleotide substitution rates than mammalian or yeast systems. Arabidopsis displays these features and expedites characterization of the mitochondrial recombination surveillance gene  MSH1  (MutS 1 homolog), lending itself to detailed study of  de novo  mitochondrial genome activity. In the present study, we investigated the underlying basis for unusual plant features as they contribute to rapid mitochondrial genome evolution.    Results  We obtained evidence of double-strand break (DSB) repair, including NHEJ, sequence deletions and mitochondrial asymmetric recombination activity in Arabidopsis wild-type and  msh1  mutants on the basis of data generated by Illumina deep sequencing and confirmed by DNA gel blot analysis. On a larger scale, with mitochondrial comparisons across 72 Arabidopsis ecotypes, similar evidence of DSB repair activity differentiated ecotypes. Forty-seven repeat pairs were active in DNA exchange in the  msh1  mutant. Recombination sites showed asymmetrical DNA exchange within lengths of 50- to 556-bp sharing sequence identity as low as 85%.  De novo  asymmetrical recombination involved heteroduplex formation, gene conversion and mismatch repair activities. Substoichiometric shifting by asymmetrical exchange created the appearance of rapid sequence gain and loss in association with particular repeat classes.    Conclusions  Extensive mitochondrial genomic variation within a single plant species derives largely from DSB activity and its repair. Observed gene conversion and mismatch repair activity contribute to the low nucleotide substitution rates seen in these genomes. On a phenotypic level, these patterns of rearrangement likely contribute to the reproductive versatility of higher plants.

Double-strand break repair processes drive evolution of the mitochondrial genome in Arabidopsis