Related Experiment Video

Updated: Aug 17, 2026

Meiotic Spindle Assessment in Mouse Oocytes by siRNA-mediated Silencing
09:16

Meiotic Spindle Assessment in Mouse Oocytes by siRNA-mediated Silencing

Published on: October 11, 2015

Non-spindle microtubule organizing centers in metaphase II-arrested mouse oocytes

B Maro, S K Howlett, M Webb

    The Journal of Cell Biology
    |November 1, 1985
    PubMed

    Insights

    Mouse oocytes organize microtubules using pericentriolar material (PCM) foci. These microtubule-organizing centers (MTOCs) relocate and form new structures during early embryonic development.

    Area of Science:

    • Cell Biology
    • Developmental Biology
    • Microscopy

    Background:

    • Microtubule-organizing centers (MTOCs) are crucial for cell division and organization.
    • Pericentriolar material (PCM) is a key component of MTOCs.
    • Understanding MTOC distribution in early development is essential.

    Purpose of the Study:

    • To investigate the distribution and function of MTOCs in mouse oocytes and early development.
    • To characterize the role of PCM in microtubule nucleation during the first cell cycle.

    Main Methods:

    • Utilized a human autoantiserum (5051) targeting PCM.
    • Observed MTOC distribution in oocytes and during the first cell cycle using microscopy.
    • Manipulated tubulin polymerization dynamics with taxol.

    Main Results:

    • PCM foci were identified at spindle poles and cortical loci in oocytes.
    • Only chromosome-proximal PCM foci acted as MTOCs in metaphase-arrested eggs.
    • Cytoplasmic PCM foci nucleated microtubules after taxol treatment.
    • Cortical PCM foci migrated centrally towards pronuclei post-fertilization.
    • Numerous MTOCs formed and aligned during the first mitotic division.

    Conclusions:

    • PCM distribution is dynamic during oocyte maturation and early embryonic development.
    • Environmental cues and tubulin dynamics influence MTOC activity.
    • MTOCs play a significant role in organizing the first mitotic division in mouse embryos.

    More Related Videos

    Using Mouse Oocytes to Assess Human Gene Function During Meiosis I11:13

    Using Mouse Oocytes to Assess Human Gene Function During Meiosis I

    Published on: April 10, 2018

    Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes08:24

    Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes

    Published on: November 11, 2022

    Related Concept Videos

    Meiosis II01:57

    Meiosis II

    Meiosis II is the second and final stage of meiosis. It relies on the haploid cells produced during meiosis I, each of which contain only 23 chromosomes—one from each homologous initial pair. Importantly, each chromosome in these cells is composed of two joined copies, and when these cells enter meiosis II, the goal is to separate such sister chromatids using the same microtubule-based network employed in other division processes. The result of meiosis II is two haploid cells, each containing...
    The Mitotic Spindle02:27

    The Mitotic Spindle

    The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
    The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
    Spindle Assembly02:50

    Spindle Assembly

    Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
    In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
    Forces Acting on Chromosomes02:11

    Forces Acting on Chromosomes

    During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis. 
    Microtubules and motor proteins exert two types of forces on...
    Meiosis II02:02

    Meiosis II

    Meiosis II entails cell division and segregation of the sister chromatids, resulting in the production of four unique haploid gametes. The steps for meiosis II are similar to mitosis, except that meiosis II occurs in haploid cells, whereas mitosis occurs in diploid cells.
    The timing and cell division patterns of meiosis differ between males and females. In male meiosis, the centrosomes are part of the formation of the meiotic spindle. However, in oocytes, including that of humans, Drosophila,...
    Meiosis vs. Mitosis02:57

    Meiosis vs. Mitosis

    Cell division is necessary for growth and reproduction in organisms. Mitosis aids cell growth and development by dividing somatic cells. In contrast, meiosis causes the division of germ cells and plays an essential role in sexual reproduction. Due to their unique functional requirements, mitosis and meiosis differ from each other in multiple aspects.
    Before the start of mitosis and meiosis I, the cell synthesizes DNA, resulting in two homologous copies of each chromosome. DNA synthesis is...