Mitomycin C-induced pairing of heterochromatin reflects initiation of DNA repair and chromatid exchange formation.
J Cell Sci
; 118(Pt 8): 1757-67, 2005 Apr 15.
Article
en En
| MEDLINE
| ID: mdl-15797924
Chromatid interchanges induced by the DNA cross-linking agent mitomycin C (MMC) are over-represented in human chromosomes containing large heterochromatic regions. We found that nearly all exchange breakpoints of chromosome 9 are located within the paracentromeric heterochromatin and over 70% of exchanges involving chromosome 9 are between its homologues. We provide evidence that the required pairing of chromosome 9 heterochromatic regions occurs in G(0)/G(1) and S-phase cells as a result of an active cellular process initiated upon MMC treatment. By contrast, no pairing was observed for a euchromatic paracentromeric region of the equal-sized chromosome 8. The MMC-induced pairing of chromosome 9 heterochromatin is observed in a subset of cells; its percentage closely mimics the frequency of homologous interchanges found at metaphase. Moreover, the absence of pairing in cells derived from XPF patients correlates with an altered spectrum of MMC-induced exchanges. Together, the data suggest that the heterochromatin-specific pairing following MMC treatment reflects the initiation of DNA cross-link repair and the formation of exchanges.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Intercambio de Cromátides Hermanas
/
Daño del ADN
/
Heterocromatina
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Mitomicina
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Emparejamiento Cromosómico
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Reparación del ADN
Límite:
Humans
Idioma:
En
Revista:
J Cell Sci
Año:
2005
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Reino Unido