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Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes
Published on: September 13, 2022
Cdc6 is required for meiotic spindle assembly in Xenopus oocytes
Yadushyla Narasimhachar1, Daniel R Webster, David L Gard
1Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA. shyla.narasimhan@gmail.com
Cell Cycle (Georgetown, Tex.)
|January 21, 2012
Summary
Cell division protein Cdc6 is essential for DNA replication and also plays a crucial role in spindle formation during Xenopus oocyte maturation and cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Developmental Biology
Background:
- Cdc6 protein is known to be essential for DNA replication competence during Xenopus oocyte maturation.
- Cdc6 is expressed prior to the completion of meiosis I (MI), indicating potential roles beyond DNA replication during this meiotic phase.
Purpose of the Study:
- To investigate the potential non-replicative functions of Cdc6 during Xenopus oocyte maturation.
- To explore the role of Cdc6 in spindle assembly and organization during meiosis and mitosis.
Main Methods:
- Confocal immunofluorescence microscopy was used to visualize Cdc6 protein localization during Xenopus oocyte maturation.
- Antisense oligonucleotides targeting Cdc6 mRNA were microinjected to assess the impact of Cdc6 depletion on spindle formation.
- Co-localization studies with γ-tubulin were performed in interphase somatic cells and mitotic COS cells.
Main Results:
- Cdc6 protein localized to the spindle precursor during germinal vesicle breakdown (GVBD) and to spindle poles during prometaphase and metaphase arrest.
- Depletion of Cdc6 via antisense oligonucleotides led to significant spindle assembly defects, including delayed assembly, misoriented spindles, and abnormal microtubule structures.
- Cdc6 co-localized with γ-tubulin in centrosomes in interphase cells and associated with spindle poles in mitotic cells.
Conclusions:
- Cdc6 plays a critical role in spindle formation and organization during meiosis and mitosis in Xenopus.
- These findings reveal a novel function for Cdc6 in microtubule dynamics and spindle assembly, in addition to its established role in DNA replication.
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