Fig. 1: Apical-to-basal RNA gradient in outer cells of live 16-cell stage mouse embryos.

a–c Live mouse embryos labelled with Membrane-GFP show RNA localisation patterns in 3D (top) and 2D (bottom) view at a 8-cell stage, b early 16-cell stage and c late 16-cell stage, which includes close-up view of asymmetric RNA localisation at basolateral regions (white arrowheads in 2D view; yellow dashed line in inset). d Schematic representation of an 8-cell stage embryo; blastomeres have a cell-contact free portion (surface facing the external perivitelline space; light blue) and a cell-contact portion surrounded by neighbour blastomeres (yellow). e Schematic representation of an 16-cell stage embryo illustrating inner (orange) and outer blastomeres, with apical (light blue) and basal (yellow) portion. f RNA intensity profiles in 8-, early and late 16-cell stage embryos. Data are presented as mean ± SEM; thick lines indicate mean, transparent shadows depict SEM. g Distance between RNA foci in 8-, early and late 16-cell stage embryos. h RNA intensity profiles in inner cells. Data are presented as mean ± SEM; thick lines indicate mean, transparent shadows depict SEM. i RNA fluorescence intensity between outer and inner cells at late 16-cell stage. Box plots display minimum, lower quartile, median, upper quartile and maximum. Mann-Whitney two-tailed t-tests were used to identify statistical differences. Scale bars 3D and 2D embryos 10 μm; inset 5 μm. Source data are provided as a Source data file.