Fig. 9.

F-actin dynamics during CAT-mediated cell fusion are unaffected by benomyl treatment. Shown are pairs of Lifeact-RFP-expressing conidia of N. crassa during pre- and postfusion stages. (A) In the untreated control, fluorescence intensities of actin cables and patches are concentrated at the CAT tips during homing and peak as cell-to-cell contact is established. (B) After cytoplasmic continuity has been achieved by fusion pore formation, the fluorescence intensity has decreased, and the remaining patches are dispersed. (C and D) In the presence of 3 μg/ml benomyl, germ tubes are unable to become elongated, and the macroconidia show extended isotropic growth and become swollen. The localization and abundance of actin cables and patches remained essentially unchanged after benomyl treatment. Arrows mark sites of CAT contact/fusion. Scale bars, 5 μm.