Figure 3.

siRNA suppression of endogenous gene expression in Xenopus embryos. Both blastomeres of 2-cell stage embryos were mock injected (A), injected with siRNAs (20 µM in 5 nl) targeting Xenopus cyclin B1 (B) or injected with siRNA against cyclin B2 (C). Western blotting (left) and RT–PCR (right) were performed using the indicated antibodies and primers. Injection of 40 µM siRNAs yielded similar results (data not shown). B1 siRNA, cyclin B1-targeting siRNA; B2 siRNA, cyclin B2-targeting siRNA; cycB1, cyclin B1; cycB2, cyclin B2; tub, α-tubulin; H4, histone H4.