Actin accumulation and severing of budded yeast in myosin-II-null cells. In mutant cells deficient in myosin-II heavy chains, filamentous actin is labeled with LimEΔ- GFP. Time series showing (a) complete uptake with actin accumulation at the neck of the particle; (b) a case of severing. Brightfield images showing particle shape are superimposed on the fluorescence images at 11 seconds in (a) and at 0 and 377 seconds in (b). In these frames, the mother cell and bud of the yeast are denoted by circles and dots, respectively. Time is indicated in seconds. The complete series is shown in Additional file 11. Bar = 10 μm for all images.