Fig. 3. In vivo fertilization rate as assessed by the percentage of fertilized eggs retrieved from mated wild-type and conditional knockout females. Five wild-type and three knockout females were treated with gonadotropins and mated with wild-type males immediately following hCG injection. 40 hours post-hCG, unfertilized eggs and two-cell embryos were released from oviducts and observed under the light microscope to score for the number of two-cell embryos. Error bars represent s.e.m.