Extended Data Fig. 1: Post-implantation embryo growth and basement membrane morphology.
From: Basement membrane remodelling regulates mouse embryogenesis

a, Tracked bright-field stills from a time-lapse video of an E5.5–E5.75 embryo showing egg-cylinder growth along the embryo proximal–distal axis. Tracks are arbitrarily colour-coded and follow growth in xy dimensions of specific anatomical characteristics. Red, ectoplacental cone–extraembryonic ectoderm boundary; magenta–cyan, extraembryonic ectoderm; green, epiblast–extraembryonic ectoderm boundary; white–yellow, epiblast; blue, distal epiblast. n = 5 embryos. b, E5.5 embryos cultured for 8 h in the presence or absence of collagenase IV. c, Egg-cylinder aspect ratio comparison in control and collagenase IV-treated embryos. Unpaired Student’s t-test; ****P < 0.0001; mean ± s.e.m. In b and c, n = 11 (control) and 11 (collagenase IV-treated) embryos. d, Representative example of an E5.5 embryo stained for different components of basement membrane. Basement membrane perforations can be identified with all markers. n = 10 embryos. e, Representative examples of E5.5 embryos (n = 20) showing the size of basement membrane perforations relative to the size of nuclei. Asterisks, visceral endoderm nuclei; arrowheads, basement membrane perforations. f, Quantification of basement membrane perforations and cell nuclei area. n = 1,501 perforations and 100 nuclei from 6 embryos. Two-sided unpaired Student’s t-test; ****P < 0.0001; mean ± s.e.m. g, Quantification of basement membrane perforation size during post-implantation development. Average perforation size remains the same in early post-implantation stages but increases in the pre-gastrula stages. n = 423 (E5.0), n = 1,046 (E5.25), n = 1,327 (E5.5), n = 1,501 (E5.75), n = 1,615 (E6.0–E6.5). One way ANOVA; ****P < 0.0001; mean ± s.e.m. Scale bars, 20 μm.