Fig. 1

Pulsatile contractions appear following cellular damage and predict extrusion events (A) Left: maximum intensity projection (MIP) of a larva tail 2 h post-MTZ treatment. Epithelial cells express NTR-mCherry (magenta) and LifeAct-GFP (green). Scale bar represents 50 μm. Magnified regions are represented by white square. Right: time-lapse sequence of pulsing epithelial cell until extrusion is shown. White arrowheads indicate pulsing events and red arrowheads extrusion event. Time is in hours and minutes HH:MM. See also Video S1. (B) Scatter dot graph correlating the area fold change of pulsing epithelial cells overtime. Dots represent the average area fold change ± SD of 155 pulses of 29 cells over 9 larvae. Average values of frequency (0.0046 s−1), duration (120 s), relative area loss (2.5%), and relative amplitude (15%) are represented. See also Figure S1E. (C) Scatter dot graph representing the cumulative number of pulses in all epithelial cells (purple line) and the cumulative number of extrusion events (blue line). T = 0 h is when live imaging starts. Analysis was performed in N = 5 larvae, and dots represent average values ± SEM. (D) Scatter dot graph representing single-cell examples of the area fluctuation of an extruding cell, neighboring cell, and non-extruding cell. See also Figure S1J. (E) Quantification of the duration, relative amplitude, relative area loss, and frequency (from left to right) of pulses in extruding, neighboring, and non-extruding cells. Analyses were performed on n = 20 cells/category over N = 5 larvae. (F) Quantification of the number of extruding cells in larvae treated with 10 mM of MTZ for 2 h, 10 mM of MTZ for 1 h, or 5 mM of MTZ for 2 h. Results are expressed as histograms ± SEM with all values. (G) Quantification of the duration, relative amplitude, and relative area loss (from left to right) of extruding cells in larvae treated with 10 mM of MTZ for 2 h (same larvae as in E), 10 mM of MTZ for 1 h, and 5 mM of MTZ for 2 h. Analyses were performed on n = 13–20 cells/category over N = 5 larvae.