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Killer double-stranded ribonucleic acid synthesis in cell division cycle mutants of Saccharomyces cerevisiae

C Shalitin, I Weiser

    Journal of Bacteriology
    |September 1, 1977
    PubMed

    Insights

    Killer yeast strains with defects in initiating DNA replication or nuclear division overproduce double-stranded RNA (dsRNA) at restrictive temperatures. This overproduction requires the complete dsRNA genome, highlighting its role in DNA replication control.

    Area of Science:

    • Molecular Biology
    • Yeast Genetics
    • RNA Synthesis

    Background:

    • Killer Saccharomyces cerevisiae possess double-stranded RNA (dsRNA) viruses.
    • Cell division cycle (cdc) mutants affect DNA replication and nuclear division.
    • Understanding dsRNA synthesis regulation is crucial for yeast genetics.

    Purpose of the Study:

    • Investigate the relationship between cell division cycle mutations and killer dsRNA synthesis.
    • Determine which stages of DNA replication and nuclear division impact dsRNA overproduction.
    • Identify the role of the complete dsRNA genome in this phenomenon.

    Main Methods:

    • Utilized seven distinct Saccharomyces cerevisiae cell division cycle mutants.
    • Assessed dsRNA synthesis levels at restrictive temperatures.
    • Examined killer sensitive strains to confirm genome requirements.

    Main Results:

    • Overproduction of killer dsRNA observed in mutants defective in DNA replication initiation (cdc28, cdc4, cdc7) and nuclear division (cdc23, cdc14).
    • No dsRNA overproduction occurred in mutants defective in DNA chain elongation (cdc8, cdc21).
    • Complete killer dsRNA genome essential for temperature-induced overproduction.

    Conclusions:

    • Specific defects in DNA replication initiation and nuclear division trigger killer dsRNA overproduction.
    • DNA replication elongation stages are not linked to this dsRNA overproduction.
    • The killer dsRNA genome plays a critical role in regulating its own synthesis in response to cell cycle perturbations.

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