Extended Data Fig. 2: Crypts fold through actomyosin-driven apical constriction.
a, Top row: 3D tractions of the crypts treated with the indicated concentration of blebbistatin (Bleb). Yellow vectors represent components tangential to the substrate and the colour map represents the component normal to the substrate. Bottom row: lateral views of the organoids along the crypt midline. Representative images from 3 independent experiments. Yellow vectors represent tractions. Scale bar, 20 μm. Scale vector, 200 Pa. b-c, Crypt indentation (b), and normal traction (c) as a function of the distance to the crypt centre for crypts treated with the indicated concentrations of blebbistatin for 3 h. Data are represented as mean ± s.e.m. of n = 18 (DMSO), 24 (0.5 µM), 19 (1.5 µM) 22 (5 µM) and 20 (15 µM) crypts from 3 independent experiments. d, Olfm4 immunostaining in membrane–tdTomato organoids at baseline conditions and 11 h after blebbistatin removal. Representative images from 2 independent experiments. Scale bar, 20 μm. e, Radial distribution of the apical (blue) and basal (red) F-actin intensity as a function of the distance to the crypt centre on 0.7 kPa substrates. Scale bars, 20 μm. Data are presented as mean ± s.d. of n = 12 crypts from 3 independent experiments. f, Bottom: Recoil velocity maps immediately after ablation of two crypts along the red lines on 0.7 kPa substrates. Left: a cut inside the TA. Right: a cut outside the TA. Scale vector, 1.5 μm/s. Top: the two crypts before ablation. Representative images from 3 independent experiments. Scale bar, 20 μm. g, Radial recoil velocity as a function of distance to crypt centre for cuts between stem cell compartment and transit amplifying zone (green) and between transit amplifying zone and villus-like ___domain (blue) on 0.7 kPa substrates. Data are represented as mean ± s.d. of n = 14 (cut Stem / TA) and 10 (cut TA / Villus-like) crypts from 3 independent experiments. h, Representative kymographs of circumferentially averaged radial velocity as a function of the distance to the crypt centre on 0.7 kPa (Top) and 5 kPa (bottom) substrates. Left: cut inside TA; right: Cut outside TA. The dashed black line indicates the time and position of the cut. Negative velocities point towards crypt centre.
