title: Yeast killer mutants with altered double-stranded ribonucleic acid.
abstract: Killer strains of Saccharomyces cerevisiae contain two species of double-stranded ribonucleic acid (dsRNA) with molecular weights estimated at 2.5 x 10(6) (L) and 1.4 x 10(6) (M). The M component appears to have a high adenine content. All mutants of killer which are defective for both the toxin and immunity functions lack the M dsRNA. One of these mutants has a novel dsRNA with a molecular weight of 5 x 10(5). Another class of killer mutants contains strains which are defective for either the toxin or the immunity function. They include temperature-sensitive killers, superkillers, and immunity-minus strains. The dsRNA profile of temperature-sensitive killers resembles that of the standard killer. The superkiller has 2.5 times more of the M dsRNA (1.4 x 10(6) daltons) than does the standard killer. Immunity-minus killers have, in addition to the two dsRNAs species of standard killer, a novel dsRNA with a molecular weight of 2.5 x 10(5). The data are consistent with the hypothesis that the M RNA controls toxin production. In addition, the two RNAs, L and M, seem to be regulated together. When the M RNA is missing, the amount of L is either greatly elevated or greatly reduced.
mesh_terms: D000225:Adenine / Q000032:analysis; D002498:Centrifugation; D011232:Chemical Precipitation; D002854:Chromatography, Paper; D003513:Cycloheximide / Q000494:pharmacology; D003596:Cytosine / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D006147:Guanine / Q000032:analysis; D008970:Molecular Weight; D009154:Mutation; D009183:Mycotoxins / Q000096:biosynthesis; D010641:Phenotype; D010761:Phosphorus Radioisotopes; D012313:RNA / Q000032:analysis* / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D013696:Temperature; D014498:Uracil / Q000032:analysis
chemical_list: D009183:Mycotoxins; D010761:Phosphorus Radioisotopes; D014498:Uracil; D006147:Guanine; D012313:RNA; D003596:Cytosine; D003513:Cycloheximide; D000225:Adenine