Fig. 5: Time-lapse pulsed-SBS imaging of C. elegans embryo development.

Brillouin shift (top) and brightfield (bottom) images over a 3-h time span and at 13-min time interval (representative of n = 3 embryos). The pixel steps in x and y directions are 0.5 µm and the pixel time is 20 ms (total time per image 288 s). Scale bars in all the images are 10 µm. The embryo at the start of the time lapse is at the late ‘ball-stage’, slightly before the bean stage, or approximately at 300 min post-fertilization (mpf). Imaging time lapses presented here conclude at ~480 mpf, when embryos start their first spontaneous muscle contractions, known as ‘twitching’. Embryonic axes: top right is anterior, bottom left is posterior, right is ventral and left is dorsal.