Fig. 3
Oocyte-specific Cxxc1 knockout causes meiotic maturation defects. a CFP1 immunohistochemistry on ovarian sections prepared from 3-week-old WT and Cxxc1fl/fl;Gdf9-Cre mice. Scale bar, 50 μm. b Confocal microscopic results of oocytes collected from oviducts of WT and Cxxc1oo−/− mice, at 16 h after hCG injection. PB1 polar body-1. Scale bar, 20 μm. c Rates of germinal vesicle breakdown (GVBD) and PB1 emission in oocytes cultured in vitro. Fully grown GV oocytes were collected from PMSG-primed (44 h) PD23 mice of the indicated genotypes. Error bars, S.E.M. d Confocal microscopic results showing spindle assembly in cultured oocytes at metaphase I (MI) and metaphase II (MII). Scale bar, 20 μm. e Rates of normal spindle assembly in MI oocytes. Error bars, S.E.M. **P < 0.001 and **P < 0.01 by two-tailed Student’s t tests. f Rates of MII oocytes containing abnormal numbers of chromosomes. Error bars, S.E.M. ***P < 0.001 by two-tailed Student’s t tests. g Representative immunofluorescence images of chromosome spreads made from WT and Cxxc1oo−/− oocytes after 18 h of in vitro maturation culture. Numbers of chromosome pairs are indicated. Scale bar, 5 μm. h, i Western blot (h) and immunofluorescence (i) results showing CFP1 and H3K4me3 levels in WT and Cxxc1oo−/− oocytes as well as WT oocytes overexpressing CFP1C379A for 12 h in vitro. Scale bar, 5 μm. j Rates of GVBD, PB1 emission, and normal spindle assembly in oocytes cultured in vitro. Fully grown GV oocytes were microinjected with mRNAs encoding WT and K4-mutated histone H3.3 and were released to resume meiotic maturation at 12 h after microinjection. Error bars, S.E.M. ***P < 0.001, **P < 0.01, and *P < 0.05 by two-tailed Student’s t tests. n.s., non-significant
