Visualizing Late Insect Embryogenesis: Extraembryonic and Mesodermal Enhancer Trap Expression in the Beetle Tribolium castaneum
Figure 4
EGFP expression in the G04609 line across embryogenesis.
Micrographs labeled with the same letter are of the same embryo(s). Views are in lateral (A–B) or dorsal-lateral (C) aspect, with anterior left (A–B) or up (C, except left-most embryo, where the head is labeled: H). (A) Onset of expression from blastoderm through germband extension stages (4.8–24.8 hAEL, n = 11), including in the yolk and dorsal-anterior serosa. (B) Increasing EGFP signal through the completion of dorsal closure (17.9–64.2 hAEL, n = 7), in lateral segmental muscle blocks, distal leg regions, and the cardioblast cell row. See also Movie S2. (C) Overview of expression from dorsal closure through hatching of the larvae (n = 11). Images A1–A2 show expression in yolk globules, where the schematic in A2 tracks all globules visible at each of the three ages indicated for the entire duration that a given globule is visible. In all subsequent panels, colored annotations indicate: EGFP expression in the serosa (blue, arcs and arrowheads: A3,B1–B3,C1), in the segmental muscle blocks (yellow arrows: A4,B1–B4,C1–C3), and in the cardioblast cell row (red double-headed arrows: B1–B4,C1–C3). In B1–B4, only the segmental muscle block on abdominal segment 5 is indicated. Percentage values (A–B) are normalized EGFP signal intensity values relative to the maximum intensity achieved during embryogenesis. Time stamps show embryo minimum age (A–B, at 30°C) or elapsed time from start of filming (C, 30°C then room temperature). All scale bars, shown in the first panels only, are 100 µm except for 200 µm in C3.