(A) Schematic demonstration of illumination time windows at the end of blastoderm stage. Illumination starts at certain time before gastrulation and ends at the onset of gastrulation as indicated by blue bars. (B–F, B’–F’ and B’’–F’’) Embryos illuminated in different time windows as indicated at the left side of each panel are fixed by the end of GBE and stained for En (B–F), Deformed (Dfd, white) and Scr (magenta) (B’–F’), Scr (magenta) and Abd-B (cyan)(B’’–F’’); (B–F) Colored dots represent embryonic segments. Red, clypeolabrum; orange, stomodeum; yellow, mandibular lobe; light green, maxillary lobe; dark green, labial lobe; light blue, prothorax; dark blue, mesothorax; dark purple, metathorax; and light purple, abdominal segments. (E’’ and F’’) Arrows, ectopic Abd-B expression. n = 5–10 embryos per condition. Scale bar, 50 µm. (B’’’–F’’’) Schematic representation of hox gene expression maps.