Figure 2.

SIGRUNB preceded the appearance of typical late onset features of apoptosis (A) SIGRUNB occurs before the appearance of membrane blebbing and bubbling and nuclear condensation. The still images shown were taken from Vid. S2. Arrow indicates a cell undergoing SIGRUNB. Arrowhead points to a GFP-nucleolin-containing nuclear bubble. Indicated time points (min:s) are expressed as described in Figure 1. t = 00:00 corresponds to the image captured 50 min into the recording. (B) SIGRUNB occurs before loss of plasma-membrane integrity. PI was added to the culture medium 17 h after cisplatin treatment. The still images shown were taken from Vid. S3 and are from the same field visualized separately for detection of GFP-nucleolin (upper panel) and PI (lower panel). The images show a GFP-nucleolin-expressing cell which developed nuclear bubble (arrowhead) that burst shortly thereafter. No PI staining was observed in this cell at any of the time points shown. The position of the cell nucleus undergoing SIGRUNB is shown by dashed oval and is also superimposed on the PI images. Arrows indicate PI stained apoptotic nuclei of neighboring GFP-nucleolin-negative cells (the position of those cells is shown both in the PI panel and also when superimposed on the GFP-nucleolin images). Indicated time points (min:s) are expressed as describe in Figure 1. t = 00:00 corresponds to the image captured at the beginning of the recording. The images shown are from representative experiments from 8 and 3 independent experiments for A and B respectively. Bar = 10 μm.