Format

Send to

Choose Destination
Genetics. 2006 May;173(1):401-17. Epub 2006 Mar 17.

Natural variation in a subtelomeric region of Arabidopsis: implications for the genomic dynamics of a chromosome end.

Author information

1
Department of Biology, Washington University, St. Louis, Missouri 63130, USA.

Abstract

We investigated genome dynamics at a chromosome end in the model plant Arabidopsis thaliana through a study of natural variation in 35 wild accessions. We focused on the single-copy subtelomeric region of chromosome 1 north (approximately 3.5 kb), which represents the relatively simple organization of subtelomeric regions in this species. PCR fragment-length variation across the subtelomeric region indicated that the 1.4-kb distal region showed elevated structural variation relative to the centromere-proximal region. Examination of nucleotide sequences from this 1.4-kb region revealed diverse DNA rearrangements, including an inversion, several deletions, and an insertion of a retrotransposon LTR. The structures at the deletion and inversion breakpoints are characteristic of simple deletion-associated nonhomologous end-joining (NHEJ) events. There was strong linkage disequilibrium between the distal subtelomeric region and the proximal telomere, which contains degenerate and variant telomeric repeats. Variation in the proximal telomere was characterized by the expansion and deletion of blocks of repeats. Our sample of accessions documented two independent chromosome-healing events associated with terminal deletions of the subtelomeric region as well as the capture of a scrambled mitochondrial DNA segment in the proximal telomeric array. This natural variation study highlights the variety of genomic events that drive the fluidity of chromosome termini.

PMID:
16547105
PMCID:
PMC1461430
DOI:
10.1534/genetics.105.055202
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center