Fig. 5: Intraluminal sheets control crystal orientation.

a Low magnification cryo-SEM image of the mirror in a juvenile scallop eye (Fig. 1b). Inserts: representative cryo-SEM images of iridosomes from the regions of interest, demonstrating the orientation of the sheets follows the curvature of the mirror. b Histograms representing the directionality of the templating sheets in the juvenile, from the three highlighted regions of interest in (b). c Representative in situ μspot wide-angle X-ray diffraction (WAXS) patterns from corresponding regions of the adult mirror showing the preferred orientation of the guanine (100) peak across the mirror. Throughout the figure, the colors correspond to the different regions of the mirror: yellow—left, blue—center, and pink—right. Scale bars: 200 nm.