Fig. 2. Influence of aphidicolin on the phosphorylation state of RPB1. Aphidicolin (100 µg/ml) was added (+) or not (-) at the two-cell stage and development was allowed to proceed at 25°C. Batches of ten unfertilised eggs (0) or embryos from the same female sampled respectively at 4.5, 6.5, 8.5 and 11.5 hours post fertilisation (h.p.f.) were analysed by western blot using the POL3/3 antibody. The positions of the IIa and the IIo forms are indicated.