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Updated: Oct 1, 2025
Evaluation of the Spindle Assembly Checkpoint Integrity in Mouse Oocytes
Published on: September 13, 2022
Using ZINC08918027 inhibitor to determine Aurora kinase-chromosomal passenger complex isoforms in mouse oocytes
Caroline Kratka1, David Drutovic2, Cecilia S Blengini1,3
1Department of Genetics, Rutgers University, The State University of New Jersey, 145 Bevier Rd, Piscataway, NJ, 08854, USA.
Objective:
Miscarriages affect 10% of women aged 25-29, and 53% of women over 45. The primary cause of miscarriage is aneuploidy that originated in eggs. The Aurora kinase family has three members that regulate chromosome segregation. Therefore, distinguishing the roles of these isoforms is important to understand aneuploidy etiology. In meiosis, Aurora kinase A (AURKA) localizes to spindle poles, where it binds TPX2. Aurora kinase C (AURKC) localizes on chromosomes, where it replaces AURKB as the primary AURK in the chromosomal passenger complex (CPC) via INCENP binding. Although AURKA compensates for CPC function in oocytes lacking AURKB/C, it is unknown whether AURKA binds INCENP in wild type mouse oocytes. ZINC08918027 (ZC) is an inhibitor that prevents the interaction between AURKB and INCENP in mitotic cells. We hypothesized that ZC would block CPC function of any AURK isoform.
Results:
ZC treatment caused defects in meiotic progression and spindle building. By Western blotting and immunofluorescence, we observed that activated AURKA and AURKC levels in ZC-treated oocytes decreased compared to controls. These results suggest there is a population of AURKA-CPC in mouse oocytes. These data together suggest that INCENP-dependent AURKA and AURKC activities are needed for spindle bipolarity and meiotic progression.
Insights
A novel inhibitor revealed that Aurora kinase A (AURKA) and Aurora kinase C (AURKC) activities, dependent on INCENP, are crucial for proper spindle formation and meiotic progression in oocytes.
Area of Science:
- Reproductive biology
- Cell biology
- Genetics
Background:
- Aneuploidy in oocytes is a major cause of miscarriage, particularly in older women.
- The Aurora kinase (AURK) family regulates chromosome segregation during meiosis.
- Understanding the specific roles of AURK isoforms, like AURKA and AURKC, is vital for addressing aneuploidy.
Purpose of the Study:
- To investigate the role of INCENP-binding Aurora kinases in mouse oocyte meiosis.
- To test if the inhibitor ZINC08918027 (ZC) blocks chromosomal passenger complex (CPC) function for any AURK isoform.
Main Methods:
- Treatment of mouse oocytes with ZC, an inhibitor of AURK-INCENP interaction.
- Analysis of meiotic progression and spindle formation.
- Western blotting and immunofluorescence to assess activated AURKA and AURKC levels.
Main Results:
- ZC treatment disrupted meiotic progression and spindle assembly in oocytes.
- Activated AURKA and AURKC levels were reduced in ZC-treated oocytes.
- Evidence suggests a population of AURKA-CPC exists in mouse oocytes.
Conclusions:
- INCENP-dependent activities of AURKA and AURKC are essential for maintaining spindle bipolarity and successful meiotic progression.
- These findings highlight potential targets for understanding and preventing aneuploidy-related miscarriages.
