Skip to main content
. Author manuscript; available in PMC: 2011 Jan 1.
Published in final edited form as: Cytoskeleton (Hoboken). 2010 Jan;67(1):13–22. doi: 10.1002/cm.20412

Figure 4.

Figure 4

Evidence for functionality of isolated cytokinetic apparatus. A) Number of Myo1-GFP rings was measured for isolated rings alone, rings incubated with ATP and cytokinetic extracts; and rings incubated with cytokinetic extract and a highly active ATPase, apyrase, for ATP depletion. Consistent with in vitro ring contraction, ring titers declined in an energy-dependent fashion. Incubation time was in excess of that required for full contraction of rings in vivo. Rings were titered by pelleting onto slides and counted by fluorescence microscopy. “Fields” here refers to ocular fields using a 100× objective. Only morphologically distinct rings were counted. B) Size distribution of isolated Myo1-GFP rings in the absence of activation by ATP and cytokinetic extract (i.e. 0 minutes contraction time) was measured for rings incubated with cytokinetic extract & apyrase. C) Size distribution of isolated rings after incubation with ATP and cytokinetic extract for approximately half the time necessary for ring contraction in vivo. In B & C) ring sizes were determined by photographing pelleted rings and measuring them using ImageJ software. “Fields” here refers to CCD camera fields using a 100× objective. In both B & C) 3 sets of 15 fields were measured. Error bars represent the standard error of the mean.