Fig. 2.

The rate of progression to GVBD was assessed for each test compound relative to the time taken for 50% of DMSO-treated control oocytes to complete GVBD (GVBD₅₀). A value of 1.0 indicates that the compound did not differ from DMSO-treated control oocytes. A value greater than 1.0 indicates an acceleration to maturation, with a value of 2.0 indicating spontaneous progression to GVBD without added progesterone. A value less than 1.0 indicates a delay to maturation, with a value of 0.0 indicating that no maturation occurred. Only compounds differing by more than 20% from DMSO-treated control oocytes were assessed further. Select compounds are identified by labels above their respective data point. Compounds 5c and 6c induced spontaneous maturation in the absence of added progesterone. Compounds 6b, 6e, 6g, and 6i accelerated progesterone-stimulated maturation by more than 20% relative to DMSO-treated controls. Compounds 5b and 6f were effective inhibitors of progesterone-stimulated maturation. None of the other compounds tested (including compounds 5f, 7 and parthenolide (PTL)) exerted any reproducibly significant phenotypic effects upon progression to GVBD during oocyte maturation.