Fig. 5

Effect of lower oxygen conditions on pre-implantation embryonic development cultured in vitro. a Representative images of pre-implantation embryos at 2-cell (2-cell), 4-cell (4-cell), morula (Morula), and blastocyst (Blast) stages in the atmospheric oxygen, oxygen gradient and hypoxia groups. Scale bars: 50 μm. b Quantification of developmental rate from 2-cell to blastocyst stage (n = 64 in atmospheric oxygen group; n = 63 in oxygen gradient group; n = 66 in hypoxia group, 3 independent experiments). The mean value for 2-cell was set as 1 and relative values for all other samples were calculated accordingly. Data are presented as mean ± SEM. Statistical analysis was carried out using two-way ANOVA followed by Tukey's multiple comparisons test. ⁎⁎p < 0.01; ⁎⁎⁎p < 0.001; ⁎⁎⁎⁎p < 0.0001