PLK-1 suppresses centrosome maturation and microtubule polymerization to ensure faithful oocyte meiosis
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Updated: Sep 17, 2025
Multi-Photon Laser Ablation of Cytoplasmic Microtubule Organizing Centers in Mouse Oocytes
Published on: November 11, 2022
Juhi G Narula1, Sarah M Wignall1
1Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
Abstract:
Sexual reproduction relies on meiosis, a specialized cell division program that produces haploid gametes. Oocytes of most organisms lack centrosomes, and therefore chromosome segregation is mediated by acentrosomal spindles. Here, we explore the role of Polo-like kinase 1 (PLK-1) in Caenorhabditiselegans oocytes, revealing mechanisms that ensure the fidelity of this unique form of cell division. Previously, PLK-1 was shown to be required for nuclear envelope breakdown and chromosome segregation in oocytes. We now find that PLK-1 is also required for establishing and maintaining acentrosomal spindle organization and for preventing excess microtubule polymerization in these cells. Additionally, our studies revealed an unexpected new role for this essential kinase. While PLK-1 is known to be required for centrosome maturation during mitosis, we found that either removal of PLK-1 from oocytes or inhibition of its kinase activity caused premature recruitment of pericentriolar material to the sperm-provided centrioles following fertilization. Thus, PLK-1 suppresses centrosome maturation during oocyte meiosis, which is opposite to its role in mitosis. Taken together, our work identifies PLK-1 as a key player that promotes faithful acentrosomal meiosis in oocytes and demonstrates that its catalytic activity is required for carrying out these important roles.
Insights
Polo-like kinase 1 (PLK-1) ensures accurate chromosome segregation during oocyte meiosis by organizing acentrosomal spindles and suppressing premature centrosome maturation, crucial for faithful cell division.
Area of Science:
- Cell Biology
- Developmental Biology
- Genetics
Background:
- Sexual reproduction depends on meiosis to produce haploid gametes.
- Oocytes typically lack centrosomes, utilizing acentrosomal spindles for chromosome segregation.
- Polo-like kinase 1 (PLK-1) is essential for nuclear envelope breakdown and chromosome segregation in oocytes.
Purpose of the Study:
- Investigate the role of Polo-like kinase 1 (PLK-1) in Caenorhabditis elegans oocytes.
- Elucidate mechanisms ensuring fidelity in acentrosomal spindle organization and function.
- Determine PLK-1's function in centrosome maturation during oocyte meiosis.
Main Methods:
- Utilized genetic manipulation (removal of PLK-1) in Caenorhabditis elegans oocytes.
- Employed kinase activity inhibition assays for PLK-1.
- Observed microtubule polymerization and pericentriolar material recruitment following fertilization.
Main Results:
- PLK-1 is required for establishing and maintaining acentrosomal spindle organization.
- PLK-1 prevents excessive microtubule polymerization in oocytes.
- PLK-1 suppresses premature centrosome maturation by inhibiting pericentriolar material recruitment to sperm centrioles.
Conclusions:
- PLK-1 is a key regulator promoting faithful acentrosomal meiosis in oocytes.
- PLK-1's catalytic activity is essential for its roles in oocyte meiosis.
- PLK-1 exhibits opposing functions in oocyte meiosis (suppressing centrosome maturation) versus mitosis (promoting maturation).
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