title: Transcription and division inhibitors in the medium of stationary phase cultures of the slime mold Dictyostelium discoideum.
abstract: When cell-free medium of a stationary phase culture is added to an exponentially multiplying culture, it blocks further cell division and depresses the level of nuclear transcription. Furthermore, when cell-free medium of a stationary phase culture is added directly to an in vitro transcription system containing nuclei isolated from exponentially multiplying amebae, it completely inhibits "late" incorporation (20-60 min reaction time), which is predominantly alpha-amanitin resistant (ribosomal-like). The stationary phase medium however, affects neither "early" alpha-amanitin resistant incorporation (0-20 min reaction time) nor alpha-amanitin sensitive incorporation. Inhibition of late in vitro transcription is not due to a nucleotidase, nor is it due to changes in the pH, ionic strength, or osmolarity of the reaction mixture.
mesh_terms: D001487:Basidiomycota; D002455:Cell Division / Q000187:drug effects*; D002474:Cell-Free System; D004352:Drug Resistance, Microbial; D006863:Hydrogen-Ion Concentration; D009183:Mycotoxins / Q000494:pharmacology; D009235:Myxomycetes / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D009994:Osmolar Concentration; D010456:Peptides, Cyclic / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014529:Uridine / Q000378:metabolism
chemical_list: D009183:Mycotoxins; D009842:Oligopeptides; D010456:Peptides, Cyclic; D014529:Uridine