Fig. 4: Nematic orientation field of the outer CL of the ventricle of the zebrafish heart.
From: Capturing nematic order on tissue surfaces of arbitrary geometry
a 2D image of the ventricle at 120 hpf. The signal within a distance of 8 μm to the surface was max-projected onto a 2D plane. The cell boundaries (dark areas) of the heart indicate the fluorescence signal of the membrane (myl7:BFP-CAAX). The image is superimposed with the 2D nematic directors (red lines) representing the orientation field of the cells. b Result of our 3D surface analysis that displays the correct orientation field of the cells. c, d Ventricles at 72 and 120 hpf, superimposed with nematic directors, see also Supplementary Movie 2 and Supplementary Movie 3. The color code of the nematic directors corresponds to the local nematic order parameter. Red indicates high alignment of cells (i.e., order of 1) and blue misalignment (i.e., order of 0). The distance between the directors is about 10 μm. Region I and II (cyan dots, encircled in cyan) were used for further analysis. e, f Distribution of the local nematic order parameter and the absolute value of the Gaussian curvature of the two different regions of zebrafish hearts, as shown in panels (c, d). Each box plot contains data points of these regions of zebrafish hearts at 72 and 120 hpf, NI,72hpf = 66, NII,72hpf = 59, NI,120hpf = 62, NII,120hpf = 63. In each case, we use data from five different hearts. The black dots are the mean values of selected data points per analyzed heart. Each box shows the median (red line), 25th and 75th percentiles (box), maximum and minimum without outliers (whiskers), and 95% confidence interval of the median (notches). P-values were calculated from Dunn’s test of multiple comparisons after a significant Kruskal-Wallis test.
