Replication timing of human telomeres is chromosome arm-specific, influenced by subtelomeric structures and connected to nuclear localization.
PLoS Genet
; 6(4): e1000920, 2010 Apr 22.
Article
in En
| MEDLINE
| ID: mdl-20421929
ABSTRACT
The mechanisms governing telomere replication in humans are still poorly understood. To fill this gap, we investigated the timing of replication of single telomeres in human cells. Using in situ hybridization techniques, we have found that specific telomeres have preferential time windows for replication during the S-phase and that these intervals do not depend upon telomere length and are largely conserved between homologous chromosomes and between individuals, even in the presence of large subtelomeric segmental polymorphisms. Importantly, we show that one copy of the 3.3 kb macrosatellite repeat D4Z4, present in the subtelomeric region of the late replicating 4q35 telomere, is sufficient to confer both a more peripheral localization and a later-replicating property to a de novo formed telomere. Also, the presence of beta-satellite repeats next to a newly created telomere is sufficient to delay its replication timing. Remarkably, several native, non-D4Z4-associated, late-replicating telomeres show a preferential localization toward the nuclear periphery, while several early-replicating telomeres are associated with the inner nuclear volume. We propose that, in humans, chromosome arm-specific subtelomeric sequences may influence both the spatial distribution of telomeres in the nucleus and their replication timing.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cell Nucleus
/
Telomere
/
DNA Replication
Limits:
Humans
Language:
En
Journal:
PLoS Genet
Journal subject:
GENETICA
Year:
2010
Document type:
Article
Affiliation country:
France