Fig. 1. Inactivation of the centralspindlin complex prevents furrowing without affecting astral microtubule dynamics. (A) Western blot analysis of protein levels after RNAi treatment. Tubulin::GFP cells were incubated with dsRNAs directed against PAV (pav RNAi), RacGAP50C (GAP RNAi) or no dsRNA as a control. After 48 hours, the proteins were extracted and separated on a 10% SDS gel, transferred onto a PVDF membrane and probed with antibodies against PAV, RacGAP50 and -tubulin. (B) Selected images from time-lapse recordings of Drosophila S2 cells expressing a Tubulin::GFP transgene. Cells were treated for 48 hours with dsRNAs directed against the two members of the centralspindlin complex: PAV (pav RNAi) and RacGAP50C (GAP RNAi) or no dsRNA as a control. The arrowheads indicate the astral microtubules contacting the equatorial cortex. Time is in minutes:seconds relative to anaphase onset. Bar, 10 µm.