Anti‐Centromere Protein A Antibody Disrupts the Competence of Mouse Oocytes Matured In Vitro

ABSTRACT 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.