Figure 1.

SF subpopulations align along principal curvature directions on a surface with negative Gaussian curvature. (A) A scanning electron micrograph of SWS surface is shown. Scale bar, 50 μm. (B) This diagram shows the alignment of apical (red) and basal (yellow) SFs on an SWS skirt. (C) A representative MEF is shown on an SWS skirt. Orthogonal sections reveal chords formed by apical SFs. The apical SF image is a projection of 16 slices. The basal SF image is a single slice. Gray coloring represents phalloidin, and green coloring represents FNs. Scale bar, 20 μm. (D) A projection of phalloidin staining of another MEF on a different SWS skirt is shown. The red line is a 50-μm-long reslice line oriented along and centered at an apical SF. Cyan lines are radial reslice lines. Scale bar, 20 μm. (E) The curvature of the surface based on FN signals beneath the cell in (D) is shown. Red and cyan dots correspond to the radial reslice lines in (D). (F) SF subpopulation orientation angles are shown as a function of δc. The values are the average for each cell. (G) The average curvature under apical SFs divided by the average maximal curvature for radially resliced apical SFs is shown. (H) The average curvature under basal SFs divided by the average minimal curvature for radially resliced basal SFs is shown. 13 cells are shown on small δc surfaces, and 31 cells are shown on large δc surfaces. The results in (G) and (H) are the mean and SE, ^∗∗p ≤ 0.01, ^∗∗∗p ≤ 0.001 (Student’s t-test). Az., azimuthal; deg, degree; Max., maximal; Min., minimal; Rad., radial. To see this figure in color, go online.