Figure 9.

Comparison of mouse oocyte activation rates between sham, sham + BSA, recombinant (r)WBP2NL (PAWP), rWBP2, rWBP2 + PPXY, rWBP2 + PPXA and sperm heads (CTRL ICSI) 9–10 h after microinjection into metaphase II arrested oocytes (three or more replicates were done for each experimental group except for sham (without BSA) where only 2 replicates were done). In the positive control (ICSI), metaphase II arrested oocytes that were injected with sperm heads had an average activation rate of 86%, based on the formation of male and female pronuclei. Recombinant WBP2NL (0.0075 μg/μl) and rWBP2 (0.0075 μg/μl) injections produced average activation rates over 50%, based on the formation of a female pronucleus. Coinjection of PPXY peptide with rWBP2 significantly reduced the activation rate obtained with rWBP2 alone, while coinjection PPXA peptide with rWBP2 had no significant effect. The negative control, sham + BSA, had a 4% activation rate with most oocytes remaining arrested in metaphase II while sham had a 0% activation rate. Representative DAPI stained images of pronuclei progression within oocytes or ova for respective microinjection regime are found directly below bar graphs. Pronuclei, arrows; metaphase II plate, asterisk; bar = 20 μm. Superscript letters (a, b, c) indicate significant differences at P < 0.05 and error bars denote standard error.