Fig. 7. Effects of Arbacia cyclin B 
90 on oocytes injected with 100 ng of anti B1/B4 antisense oligonucleotide. (A) Images of progesterone-treated oocytes 3 hours after GVBD (6 hours after addition of progesterone). Control, uninjected oocytes; Antisense, 100 ng anti B1/B4 antisense oligonucleotide injected 15 minutes after addition of progesterone; Antisense + cyclin B 90, as before with 100 ng cyclin B 90 injected 1.5 hours after GVBD. (B) RNase protection assay of mRNA cleavage in these oocytes; C, uninjected controls; S, sense; AS, antisense injected. (C) Histone H1 kinase assays and c-mos immunoblots of the oocytes. Cyclin B 90 levels were as indicated above each lane. (D) Meiotic spindles; Control, 6 hours after progesterone addition in an uninjected oocyte; Antisense + cyclin B 90, oocytes injected with 100 ng anti B1/B4 antisense oligonucleotide 15 minutes after progesterone addition and 100 ng cyclin B 90 1.5 hours after GVBD, sampled 1.5 hours later; Cyclin B 90, as before without antisense. Scale bar, 10 µm.
