Fig. 9. Cyclin stability and spindle appearance in oocytes treated with CHX 30 minutes after injection of indestructible cyclin B1 mRNA. (A) Destruction assays in oocytes using 35S-labelled cyclin B1, either wild type (WT) or destruction-box mutant (dm) injected into the indicated oocytes 3 hours after GVBD. Control, oocytes with no other treatment; CHX, cycloheximide added 2 hours after GVBD; Cyclin B1 dm + CHX as before, with indestructible cyclin B1 mRNA injected 1.5 hours after GVBD. (B) Control MII spindles in a progesterone-treated oocyte and images of spindles from 3 oocytes treated with CHX after translation of indestructible cyclin B1. Scale bar, 10 µm.