Dynamic organization of DNA replication in one-cell mouse embryos: relationship to transcriptional activation.
We have analyzed the spatial and temporal relationship between transcription and replication sites during the first cell cycle in mouse embryos. Embryos were microinjected with both 5-bromouridine-5'-triphosphate and digoxygenin-11-deoxyuridine-5'-triphosphate to visualize transcription and replication sites respectively. We detected six different phases of replication during S phase and dated the onset of zygotic transcription at the end of the S phase. Using confocal microscopy, we showed that there is essentially no colocalization of replication and transcription sites at this stage of development. Moreover, studies on aphidicolin-treated embryos demonstrated that inhibition of DNA replication does not hinder transcriptional activation at the 1-cell stage.
Bouniol-Baly
C
C
Laboratoire Associé Institut National de la Santé et de la Recherche Médicale (INSERM), Institut National de la Recherche Agronomique (INRA), Paris, France. bouniol@.ibpc.fr
Nguyen
E
E
Besombes
D
D
Debey
P
P
D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D002467:Cell Nucleus / Q000502:physiology; D004247:DNA / Q000032:analysis / Q000096:biosynthesis; D004261:DNA Replication / Q000502:physiology*; D004076:Digoxigenin; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008845:Microinjections; D016196:S Phase / Q000502:physiology; D014158:Transcription, Genetic / Q000187:drug effects / Q000502:physiology*; D014544:Uridine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D015053:Zygote / Q000166:cytology* / Q000502:physiology*
D004791:Enzyme Inhibitors; C018009:5-bromouridine triphosphate; D016590:Aphidicolin; D004247:DNA; D004076:Digoxigenin; D014544:Uridine Triphosphate