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CHLOROPLAST MUTAGENESIS: EFFECT OF N-METHYL-N'NITRO-N-NITROSOGUANIDINE AND SOME OTHER AGENTS ON EUGLENA

D R MCCALLA

    Science (New York, N.Y.)
    |April 23, 1965
    PubMed

    Insights

    N-methyl-N'-nitro-N-nitrosoguanidine permanently bleaches Euglena gracilis, preventing chloroplast formation in nearly all organisms. This induced bleaching is stable for over 100 generations, with other tested agents proving ineffective.

    Area of Science:

    • Cell Biology
    • Molecular Biology
    • Genetics

    Background:

    • Euglena gracilis is a single-celled photosynthetic organism.
    • Chloroplasts are essential organelles for photosynthesis.
    • Understanding factors affecting chloroplast development is crucial for cell biology research.

    Purpose of the Study:

    • To investigate the effects of N-methyl-N itro-N-nitrosoguanidine (MNNG) on Euglena gracilis chloroplast formation.
    • To determine the stability and reversibility of MNNG-induced bleaching.
    • To compare the efficacy of MNNG with other potential bleaching agents.

    Main Methods:

    • Treatment of Euglena gracilis with N-methyl-N itro-N-nitrosoguanidine.
    • Culturing of treated organisms for over 100 generations.
    • Testing the effects of various chemical agents (alkylating agents, azaserine, mitomycin C, acridines, nitrous acid, hydroxylamine) and gamma-irradiation.

    Main Results:

    • MNNG treatment resulted in a near 100% permanent loss of chloroplasts (bleaching) in Euglena gracilis.
    • Bleached strains remained stable for over 100 generations with no observed reversion.
    • Other tested agents were largely ineffective in causing significant bleaching, even at lethal concentrations.

    Conclusions:

    • MNNG is a highly effective agent for inducing permanent chloroplast loss in Euglena gracilis.
    • The stability of the induced bleaching suggests a significant impact on chloroplast genetic material.
    • Differential susceptibility may relate to variations in nuclear and chloroplast DNA base composition.
    Keywords:
    ACRIDINESAZASERINEBUTADIENECHLOROPHYLLCHLOROPLASTSCOBALT ISOTOPESDNAEUGLENAEXPERIMENTAL LAB STUDYFLAVINSGENETICSGUANIDINESHYDROXYLAMINESLACTONESMECHLORETHAMINEMITOMYCINMUTATIONNITRITESPHARMACOLOGYRADIATION EFFECTSSULFATESTRIETHYLENE MELAMINE

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