Fig. 2

Effect of CK2 inhibition on the porcine oocyte meiotic progression. a Representative images of cumulus cell expansion and polar body extrusion were shown in control and CK2-inhibited oocytes cultured in vitro for 44 h. Oocytes were denuded following the culture to observe the polar body. COCs, cumulus-oocyte complexes; DOs, denuded oocytes. Scale bar, 500 μm (a, e); 200 μm (b, f); 250 μm (c, g); 30 μm (d, h). b The rate of polar body extrusion was recorded in control and different concentrations of CK2-inhibited groups (1 μmol/L, 5 μmol/L, 10 μmol/L and 20 μmol/L) after for 44 h culture. c Representative images of the chromosome morphology in the different developmental stages of oocyte maturation. DNA was counterstained with PI. Scale bar, 5 μmol/L. d The percentage of different development stages was counted in control and CK2-inhibited oocytes. Data of (b) and (d) were presented as mean percentage (mean ± SEM) of at least three independent experiments. *P < 0.05, ***P < 0.001