Fig. 4. Kette regulates actin foci dissolution during Drosophila myoblast fusion. (A-A'') Lateral views of live stage 14 twip-GFP-actin, apME-NLS-dsRed; kette^J4-48 embryo. Each column of panels represents a time point from a timelapse sequence. Each image is an optical projection displaying 9 µm of the z-axis, allowing visualization of several cell layers simultaneously and tracking of all relevant cell movements. Large actin foci form (arrowheads) but do not dissolve as in wild type (compare with Fig. 1E). No incorporation of new red nuclei is seen, consistent with the kette fusion block. Scale bar: 5 µm. (B) Actin foci persist significantly longer in kette^J4-48 null mutants compared to wild type. Focus duration (mean±s.d.): wild type=10.9±6.9 minutes, kette^J4-48=36.0±17.6 minutes. This difference is significant by a two-tail unpaired Student's t-test (P<0.0001, n=25 foci).