title: Genome-wide DNA replication profile for Drosophila melanogaster: a link between transcription and replication timing.
abstract: Replication of the genome before mitotic cell division is a highly regulated process that ensures the fidelity of DNA duplication. DNA replication initiates at specific locations, termed origins of replication, and progresses in a defined temporal order during the S phase of the cell cycle. The relationship between replication timing and gene expression has been the subject of some speculation. A recent genome-wide analysis in Saccharomyces cerevisiae showed no association between replication timing and gene expression. In higher eukaryotes, the limited number of genomic loci analyzed has not permitted a firm conclusion regarding this association. To explore the relationship between DNA replication and gene expression in higher eukaryotes, we developed a strategy to measure the timing of DNA replication for thousands of genes in a single DNA array hybridization experiment. Using this approach, we generated a genome-wide map of replication timing for Drosophila melanogaster. Moreover, by surveying over 40% of all D. melanogaster genes, we found a strong correlation between DNA replication early in S phase and transcriptional activity. As this correlation does not exist in S. cerevisiae, this interplay between DNA replication and transcription may be a unique characteristic of higher eukaryotes.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002453:Cell Cycle; D002469:Cell Separation; D004261:DNA Replication; D018076:DNA, Complementary / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics*; D005434:Flow Cytometry; D016678:Genome; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D016196:S Phase; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D001973:Bromodeoxyuridine