Local DNA underreplication correlates with accumulation of phosphorylated H2Av in the Drosophila melanogaster polytene chromosomes.
Chromosome Res
; 16(6): 851-62, 2008.
Article
en En
| MEDLINE
| ID: mdl-18704724
ABSTRACT
DNA in Drosophila melanogaster polytene chromosomes is known to be locally underreplicated in both pericentric and intercalary heterochromatin. When the SuUR gene is mutant, complete and partial suppression of underreplication are observed in intercalary and pericentric heterochromatin, respectively; in contrast, overexpression of SuUR results in stronger underreplication. Using antibodies against phosphorylated histone H2Av and flies with different levels of SuUR expression, we demonstrated a clear correlation between the extent of underreplication in specific chromosome regions and the accumulation of H2Av phosphorylated at S137 (gamma-H2AX) at the same sites. Phosphorylated H2Av is a well-established marker of DNA double-stranded breaks (DSB). Our data thus argue that DNA underreplication leads to DSBs and that DSBs accumulate as salivary gland cells progress throughout repeated endocycles. We speculate that ligation of free double-stranded DNA termini causes the formation of ectopic contacts between the underreplicated regions in heterochromatin.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
/
Histonas
/
Cromosomas
/
Replicación del ADN
/
Drosophila melanogaster
Límite:
Animals
Idioma:
En
Revista:
Chromosome Res
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2008
Tipo del documento:
Article
País de afiliación:
Rusia