Analysis of 5'-termini of early intermediates of Okazaki fragments accumulated in thymocytes after emetine treatment of mice.
Nascent Hg-DNA synthesized by the incorporation of Hg-dCTP in reversibly permeable cells of murine thymocytes has been characterized earlier. Here we describe the analysis of 5' ends of oligonucleotides isolated from thymocytes 48 hr after a single dose of emetine administration to mice. This small-molecular-weight population of nascent DNA shorter than Okazaki fragments was absent in control cells. More than 90% of the terminally 32P-labeled oligonucleotides carried a terminally phosphorylated RNA moiety at the 5' end, as demonstrated by alkaline hydrolysis. The size of the short nascent DNA fragments carrying RNA primers ranged between 9 and 50 nucleotides with an average chain length of 15 nucleotides. These oligomers are regarded as the precursors of the Okazaki fragments.
Csuka
I
I
Institute of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University Medical School, Budapest, Hungary.
Banfalvi
G
G
D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D004247:DNA / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D004261:DNA Replication / Q000187:drug effects*; D004587:Electrophoresis, Agar Gel; D004640:Emetine / Q000494:pharmacology*; D008297:Male; D008628:Mercury; D051379:Mice; D008815:Mice, Inbred Strains; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D012313:RNA / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
C022262:Okazaki fragments; D010761:Phosphorus Radioisotopes; D012313:RNA; D004247:DNA; D008628:Mercury; D004640:Emetine