Figure 2
From: Double Strand Break DNA Repair occurs via Non-Homologous End-Joining in Mouse MII Oocytes
Physiological consequences of etoposide exposure. The developmental competence of ETP exposed MII oocytes was directly assessed via in vitro fertilisation and early embryonic development assays. For this purpose oocytes were co-cultured with approximately 2 × 105 capacitated spermatozoa for 4 h at 37 °C. (a) ETP-treated MII oocytes retained their competence to participate in fertilisation. (b) However, ETP-treated MII oocytes were not able to support embryonic development through to blastocyst formation (i.e. 5 days post-fertilisation) whereby 40–60% of embryos failed to progress beyond the two cell stage of development. Statistical significance was determined using ANOVA, and Tukey–Kramer HSD. *p ≤ 0.05, **p ≤ 0.01 and ***p ≤ 0.001. Each experiment was conducted on a minimum of three biological replicates, with the total number of embryos assessed across these replicates being: vehicle = 95; untreated = 93; 100 µg/ml ETP = 95; 200 µg/ml ETP = 86. All data are expressed as means ± S.E.M. Scale bar = 80 μm.
