Extended Data Fig. 9: Morphogenetic processes in C. riparius head ectoderm: relative chronology, temporal distribution of divisions, expression pattern of Cri-Insc, and cell apical area changes.
From: Divergent evolutionary strategies pre-empt tissue collision in gastrulation
a, Timeline of early developmental events (yellow: D. melanogaster; magenta: C. riparius) in absolute time (in min) post gastrulation onset, defined as the onset of PMG in D. melanogaster and the onset of ventral-ward tissue flow in C. riparius. The onset of mitotic rounding was determined by the first cell displaying rounding in the domains analyzed (MD1 in D. melanogaster, MD2o in C. riparius). Complementary, the degree of GBE by % egg length (EL) in this timeframe is given for each fly. b, Distribution of C. riparius cells dividing out-of-plane (magenta/MD2o) and in-plane (red/MD2i) in the 5 embryos analyzed. c, Spread of divisions over time in C. riparius MD2o and MD2i in time post onset of gastrulation. Top panel, bars represent the average number of cells entering telophase within a 90 s window. Error bars, standard error. Bottom panel, bars show data from individual embryos (n = 5). d, In situ hybridization showing a broad expression pattern for Cri-insc in the head domain (n = 3). Red vertical line, anterior boundary of the eve1 region at 33%EL. Scale bar, 25 µm. e, f, Time course of an event of in-plane (e) or out-of-plane division (f) with T0 defined the same way as that in Fig. 5e, i.e., the onset of telophase. Cells are chosen from a representative embryo, e from MD2i and f from MD2o. The dashed lines in the schematics indicate the plane of the epithelium, and the LUT bar at the bottom indicates the color-code used for cell apical area. Scale bars 5 µm.
