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Updated: Jun 5, 2025
Mouse Oocyte Microinjection, Maturation and Ploidy Assessment
Published on: July 23, 2011
Anti-Centromere Protein A Antibody Disrupts the Competence of Mouse Oocytes Matured In Vitro
Masashi Shioya1,2, Keiichi Takahashi1, Shun Nakano1
1Takahashi Women's Clinic, Chuo-ku, Chiba, Japan.
Introduction:
Anticentromere autoantibodies are associated with refractory IVF/ET failure, but causality is unclear. Experimental models are needed.
Methods:
Immature oocytes collected from 23-day-old mice were matured in vitro for 18 h in a culture medium containing an anti-human centromere protein A (CENP-A) polyclonal antibody, and those oocytes' maturity and chromosome/spindle structure were assessed.
Results:
Antibody exposure did not affect the germinal vesicle breakdown ratio but reduced the first polar body formation ratio by 13% at the highest concentration (70.0 µg/mL). Metaphase II (MII) oocytes were stained for chromosomes/spindles and grouped into aligned/barrel-like (AB), scattered/weakly-stained (SW), and condensed/absent (CA). Antibody exposure decreased AB and increased SW and CA in a dose-dependent manner. The AB/SW/CA percentages were 86/14/0, 86/14/0, 35/65/0, and 0/0/100 in the 0, 17.5, 35.0, and 70.0 µg/mL antibody groups, respectively (underlined values represent p < 0.05 compared with 0 µg/mL). Next, metaphase II oocytes were subjected to intracytoplasmic sperm injection, and the number of pronucleus/pronuclei (PN) was counted 6 h later. Antibody exposure decreased two pronuclei oocytes and increased non-two pronuclei oocytes dose-dependently. The percentages of 0/1/2/3 pronuclei oocytes were 43/0/57/0, 37/0/21/42, 16/28/48/8, and 91/4/4/0 in the 0, 17.5, 35.0, and 70.0 µg/mL groups, respectively.
Conclusions:
Anti-CENP-A antibody impaired a linear alignment of chromosomes at metaphase II and enhanced one or three PN formation after ICSI, which are similar to findings reported for infertile women with anticentromere autoantibodies.
Insights
Anticentromere autoantibodies, specifically anti-centromere protein A (CENP-A) antibodies, disrupt oocyte maturation and chromosome alignment, potentially explaining infertility in women with these antibodies.
Area of Science:
- Reproductive biology
- Immunology
- Infertility research
Background:
- Anticentromere autoantibodies are linked to in vitro fertilization (IVF) failure.
- The causal relationship and underlying mechanisms remain unclear.
- There is a need for experimental models to investigate this association.
Purpose of the Study:
- To investigate the direct effect of anti-centromere protein A (CENP-A) antibodies on mouse oocyte maturation and chromosome structure.
- To establish an experimental model for understanding the impact of these antibodies on reproductive outcomes.
Main Methods:
- Immature mouse oocytes were matured in vitro with varying concentrations of anti-human CENP-A polyclonal antibody.
- Oocyte maturity, chromosome/spindle structure, and first polar body formation were assessed.
- Metaphase II oocytes were subjected to intracytoplasmic sperm injection (ICSI) to evaluate pronuclei formation.
Main Results:
- Anti-CENP-A antibody exposure reduced first polar body formation and impaired chromosome alignment in a dose-dependent manner.
- The antibody increased abnormal chromosome configurations (scattered/weakly-stained and condensed/absent) at metaphase II.
- Following ICSI, antibody exposure decreased the rate of two-pronuclei formation and increased abnormal pronuclei development.
Conclusions:
- Anti-CENP-A antibodies disrupt crucial aspects of oocyte maturation and fertilization.
- Impaired chromosome alignment and abnormal pronuclei formation mirror findings in infertile women with anticentromere autoantibodies.
- This study provides an experimental basis for the association between anticentromere antibodies and IVF failure.
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