Fig. 8

Fig. 8 Aggregation dynamics is influenced by regulation of actomyosin contractility.

Quantitative analysis of aggregation of zebrafish ectoderm cells. a Time-dependent decrease in the mean perimeter of spheroids aggregating from homotypic cell suspensions of either untreated ectoderm cells (ectoderm-ctr, n = 20) or ectoderm cells overexpressing constitutively active ROCK (ectoderm-caROCK, n = 20). Spheroid perimeters are normalized with and plotted as a percentage of initial perimeters, error stripes represent SEM, asterisk (*) at t = 10 h indicates a statistically significant difference with Student’s t-test, p < 0.01. b Representative phase-contrast images from time-lapse videos of spheroids of ectoderm-ctrl cells (left panel) or ectoderm-caROCK cells (right panel) after 10 h of aggregation. Note the difference in spheroid surface roughness. Scale bar: 100 µm. Also, see Supplementary Movie 12. c–f Immunofluorescent detection of phospho-myosin light chain (p-MLC) in spheroids of ectoderm cells. c, d Ectoderm-ctrl spheroid with only p-MLC labeling (c) or merged image of p-MLC (yellow) and NucBlue (blue) labels. e, f A spheroid of ectoderm-caROCK cells labeled for p-MLC (e) or merged image of p-MLC label (yellow) and NucBlue (blue) staining. Cell nuclei are visualized by NucBlue staining. Note that the p-MLC immunofluorescence signal is hardly seen in (c) while it is much more pronounced after the introduction of caROCK in (e). Scale bar: 10 µm in c–f.