Fig. 3
From: Establishment of the mayfly Cloeon dipterum as a new model system to investigate insect evolution
Representative phases of C. dipterum embryogenesis. Upper panels show embryo morphology detectable through DAPI staining (white). Lower panels show DAPI (nuclei, blue), Actin (cell contour cRed) and mitosis (anti-PH3, green). a–a′ Blastoderm formation (stage 2: st. 2) bcd: blastoderm cells are replicating, shown by PH3 staining (a′), in green. The asterisk highlights a DAPI-rich region located opposite to the embryo with unknown function. b–b′ Germ disc (gd) formation (st. 3). The asterisk highlights a DAPI-rich region located opposite the embryo which we have not identified. It disappears during subsequent stages. c–c′ S-shaped embryo (st. 6). The germ band elongates through active cell proliferation, shown by PH3 staining (abr: abdominal region; hl: head lobe). d–d′ Segmentation of the embryo (st. 8) starts from the cephalic (hl) and thoracic regions, which segments are already visible, towards the abdominal regions (abr). e–e′ Proctodaeum formation (st. 9). Segmentation progresses, appendages enlarge and get segmented (an: antenna, md: mandible, mx: maxilla, lb: labium, pl: pro-leg). f–f′ The abdominal regions are already segmented (abs: abdominal segments). Cercei (ce) are already visible. Dorsal closure proceeds. Scale bars: 50 μm