Monastrol concentrations permissive for cell division led to aberrant cytokinesis assayed at 48 h AF. (A) 0.2% DMSO. By 48 h AF, control zygotes had divided several times in a stereotypical pattern. Arrowhead indicates first division plane. (B-C) 25 μM monastrol. Asterisks mark aberrant division planes. (D) Percent of divided zygotes with abnormal first cytokinesis, as assessed by >30 degree deviance from perpendicular to the long axis of the cell, or by curved cell plates. Standard error bars shown. Scale bars equal 10 μm.