Treatment with ML-7 causes cleavage furrow regression. (A) Time-course of a dividing Drosophila spermatocyte treated with 80 μM ML-7 just after the time-point depicted in the second panel. The cell was washed with Insect Ringer's buffer just after the time-point depicted in the fourth panel. Bar, 10 μm. (B) Plot of the change in cell diameter (ordinate) over time (abscissa) for the Drosophila spermatocyte shown in A. Time-points of ML-7 addition (left arrow) and washout (right arrow) are indicated [see Additional file 9].