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Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
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Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient

Published on: September 3, 2014

THYMIDINE INCORPORATION BY MITOCHONDRIA IN PHYSARUM POLYCEPHALUM

E GUTTES, S GUTTES

    Science (New York, N.Y.)
    |September 4, 1964
    PubMed

    Insights

    Slime mold particles incorporate thymidine into DNA within mitochondria. This DNA is resistant to acid and RNase but sensitive to DNase, confirming its mitochondrial origin.

    Area of Science:

    • Cell Biology
    • Molecular Biology
    • Mycology

    Background:

    • The slime mold Physarum polycephalum, a model organism in cell biology research.
    • Understanding the subcellular localization and metabolic processes within eukaryotic cells.

    Purpose of the Study:

    • To investigate the nature of cytoplasmic particles in Physarum polycephalum that incorporate thymidine.
    • To determine the biochemical properties and subcellular location of these thymidine-incorporating particles.

    Main Methods:

    • Incubation of Physarum polycephalum with tritiated thymidine.
    • Biochemical assays including acid and ribonuclease insolubility, and deoxyribonuclease solubility.
    • Microscopic analysis of particle distribution, size, and staining characteristics.

    Main Results:

    • Cytoplasmic particles were found to incorporate tritiated thymidine.
    • The incorporated thymidine was insoluble in acid and ribonuclease, indicating DNA.
    • The incorporated thymidine was soluble in deoxyribonuclease, confirming DNA.
    • Particle distribution, size, and staining supported a mitochondrial identity.

    Conclusions:

    • The thymidine-incorporating particles in Physarum polycephalum are mitochondria.
    • Mitochondria in Physarum polycephalum actively synthesize DNA.
    • This study provides evidence for mitochondrial DNA synthesis in slime molds.
    Keywords:
    DNAEXPERIMENTAL LAB STUDYMETABOLISMMITOCHONDRIAMYXOMYCETESTHYMIDINETRITIUM

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