title: Discontinuous DNA replication of Drosophila melanogaster is primed by octaribonucleotide primer.
abstract: To investigate the precise structure of eucaryotic primer RNA made in vivo, short DNA chains isolated from nuclei of Drosophila melanogaster embryos were analyzed. Post-labeling of 5' ends of short DNA chains with polynucleotide kinase and [gamma-32P]ATP revealed that 7% of the DNA fragments were covalently linked with mono- to octaribonucleotide primers at their 5' ends. Octaribonucleotides, the major component (ca. 30%), formed the cap structure in the reaction with vaccinia guanylyltransferase and [alpha-32P]GTP, indicating that they were the intact primer RNA with tri- (or di-) phosphate termini, and the shorter ribooligomers were degradation intermediates. The intact primers started with purine (A/G ratio, 4:1), and the starting few ribonucleotide residues were rich in A.
mesh_terms: D000818:Animals; D004261:DNA Replication; D003851:Deoxyribonucleases; D004331:Drosophila melanogaster / Q000196:embryology / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism*; D009843:Oligoribonucleotides / Q000378:metabolism*; D012315:RNA Caps / Q000378:metabolism; D012265:Ribonucleotides / Q000032:analysis
chemical_list: D009841:Oligonucleotides; D009843:Oligoribonucleotides; D012315:RNA Caps; D012265:Ribonucleotides; D003851:Deoxyribonucleases