Figure 1.

Cisplatin-treated GN-WT MEFs exhibiting SIGRUNB. (A) Expression of GFP-nucleolin in healthy GN-WT MEFs is confined to the nucleus. Hoechst 33342 was added to the culture medium of GN-WT MEFs and GFP-nucleolin and Hoechst fluorescence were monitored in live cells. GN-WT MEFs were treated with 25 μM cisplatin and after 15–24 h were subjected to live-cell imaging at 30-s intervals. (B) Appearance and subsequent rupture of GFP-nucleolin-containing nuclear bubble. The still images shown were taken from Vid. S1. Arrow indicates a bubble. The indicated time points (min:s) are expressed relative to the first image selected for presentation (t = 00:00), which corresponds to the image captured 34 min into the recording. (C) Stress-induced nuclear bubbles do not contain DNA. Hoechst 33342 was added to the culture medium 18 h after cisplatin treatment. Results shown (still images from time lapse imaging) are from the same field visualized separately for detection of GFP-nucleolin (upper panel) and Hoechst 33342 (lower panel). Dashed oval indicates the position of the nuclear bubble that lacks Hoechst 33342 staining. Indicated time points (min:s) are expressed as described in A. t = 00:00 corresponds to the image captured 43 min into the recording. The images shown are from representative experiments from 3, 8 and 8 independent experiments for A, B and C respectively.