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Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
07:03

Mouse Oocyte Microinjection, Maturation and Ploidy Assessment

Published on: July 23, 2011

Changes in mouse oocyte membrane potential and permeability during meiotic maturation

R D Powers

    The Journal of Experimental Zoology
    |July 1, 1982
    PubMed

    Insights

    Mouse oocytes undergo spontaneous meiotic maturation, involving significant changes in cell membrane potential. Reduced potassium permeability is identified as the primary driver of membrane depolarization during this process.

    Area of Science:

    • Cell Biology
    • Reproductive Biology
    • Membrane Physiology

    Background:

    • Mouse oocytes mature spontaneously in vitro, a process involving critical cellular changes.
    • Understanding the electrophysiological events during oocyte maturation is crucial for reproductive science.

    Purpose of the Study:

    • To investigate the changes in cell surface membrane potential during mouse oocyte meiotic maturation.
    • To determine the ionic basis of membrane potential changes and their relationship with germinal vesicle breakdown (GVBD).

    Main Methods:

    • Measurement of cell surface membrane potential at different meiotic stages (GV, GVBD, PB).
    • Radioisotope tracer flux experiments to quantify potassium (K) transport parameters.
    • Pharmacological manipulation using dibutyryl cyclic AMP to block GVBD.

    Main Results:

    • Membrane potential depolarized from -46 mV (GV stage) to -17 mV (PB stage).
    • Potassium (K) efflux rate coefficient and permeability were determined at the GV stage.
    • A decrease in K permeability was linked to membrane depolarization.
    • Blocking GVBD with dibutyryl cyclic AMP prevented depolarization, suggesting a linkage.
    • Oocyte depolarization via high K+ medium did not induce GVBD.

    Conclusions:

    • Membrane potential depolarization during mouse oocyte maturation is primarily due to decreased K+ permeability.
    • While linked to GVBD, membrane depolarization alone is insufficient to trigger GVBD.

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