title: The effect of cytosine arabinoside on the synthesis of rapidly labeled RNA during DNA replicating and non-DNA replicating periods of the cell cycle.
abstract: The effects of various concentrations of cytosine arabinoside (Ara-C) on the rates of DNA and RNA synthesis were investigated during the peak of DNA synthesis, using a naturally synchronized culture of Aedes aegypti (mosquito) cells. During this stage of the cell cycle, the synthesis of both DNA and RNA was found to be progressively inhibited with increasing concentrations of Ara-C. When the same concentrations of Ara-C were added to the culture at a time period when no DNA was being synthesized, it was found that the synthesis of RNA was not inhibited. Rapidly labeled polysomal RNA species were isolated from cultured cells in which DNA was being synthesized. The synthesis of these RNA species is inhibited completely in the presence of a concentration of Ara-C which inhibits 90% of DNA synthesis. It is suggested that during periods of DNA replication, Ara-C is a selective inhibitor of the synthesis of rapidly labeled RNA species or of the processing of these RNA species from the nucleus to the polysomes.
mesh_terms: D000330:Aedes; D000818:Animals; D002453:Cell Cycle; D002478:Cells, Cultured; D003561:Cytarabine / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication; D004591:Electrophoresis, Polyacrylamide Gel; D011132:Polyribosomes / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis*
chemical_list: D003561:Cytarabine; D012313:RNA; D004247:DNA