Nuf functions within the RhoA pathway to promote furrow integrity. (A and B) 1 mg/ml C3 transferase was injected at cycle-13 early prophase. (A) GFP-Dlg–marked furrow membrane (green) was progressively lost and eventually led to spindle fusions (red, asterisks). See Video 8 . (B) 2 min after C3 injection, most of the F-actin has been lost from the furrow (bottom). In contrast, membrane loss has just started (top). (C) 1 mg/ml RhoA(Q63L) was injected into nuf embryos at cycle-13 early interphase. Green, GFP-Moesin; red, tubulin. At metaphase (18:00), normal furrow structures were maintained in the region close to injection site (arrow); however, loss of F-actin at the furrows is evident further away from the site of injection (arrowheads). See Video 9 . Bars: (A) 10 μm; (B) 5 μm; (C) 20 μm.