Fig. 7. Response to THC 10⁻⁷ M during oocyte maturation (17 h) measured as rates of metaphase II oocytes (MII), fertilized oocytes, 2 cell-stage embryos and blastocysts after IVF. The Fig. shown the embryo development observed for oocytes incubated with vehicle (DMSO) (white) and incubated with THC 10⁻⁷ M (black). The sperm always came from WT mice and the oocytes came from A) wild type (WT) mice, B) Cnr1^−/− mice, C) Cnr2^−/− mice and D) Cnr1^−/−/Cnr2^−/− mice. Results are the mean of % ± SEM of 10 independent experiments. Significant differences between treatments are indicated with different letters; p<0.005 in all cases.