Figure 3
From: Double Strand Break DNA Repair occurs via Non-Homologous End-Joining in Mouse MII Oocytes
Morphometric analysis of arrested two cell embryos generated from the etoposide-treated MII oocytes. (a–d) Embryos borne of ETP-exposed MII oocytes were characterised by significant fragmentation and unequal cytoplasm partitioning, accompanied by an increase in diameter in the notably larger blastomeres (greater than 25% difference). (c–e) Accordingly, nuclear integrity was also analysed, revelaing that daughter cells derived from ETP-treated MII oocytes contained additional multinucleate structures in addition to the pronucleus. (f) Localisation of the actin and tubulin networks of the preimplantation zygote and 2 cell embryos were analysed for their potential contribution to the unequal cytoplasmic partitioning. However, neither embryonic stage exhibited apparent modifications in labelling intensity or distribution patterns of tubulin or actin irrespective of the treatment they received. Statistical significance was determined using ANOVA and Student’s t-tests. *p ≤ 0.05, **p ≤ 0.01 and ***p ≤ 0.001. Each experiment was conducted on a minimum of three biological replicates, with each replicate comprising a minimum of 30 oocytes. All data are expressed as means ± S.E.M. Scale bar = 80 μm.
