vg expression in the Tribolium embryo. (A–D) vg expression during Tribolium embryogenesis. Black arrow denotes T3. Mandible (blue arrow in B), maxilla (red arrow in B), and central nervous system (arrowhead in D) express vg. For A–C, two images were composed into one to show the whole embryo. (E) Close-up of the thoracic region of C focused dorsally, showing additional vg staining in all three thoracic segments (asterisks). (F) Confocal image of vg expression (purple) with DAPI nuclear staining (green) in the thoracic segments. Asterisks indicate additional vg expression in the thoracic segments dorsal to the leg primordia. Tergal vg expression is indicated by an arrow. Dorsal and ventral sides of the image are indicated in the upper right side of F by “D” and “V”, respectively.