Fig. 4.

A–F, Embryonic expression pattern of Voila¹visualized by the lacZ reporter. A, B, At embryonic stage 10, staining appears in the entire germ band, with a strongly expressing cluster of cells in the head region (arrowheads). C, At stage 11, large neuroblast-like cells (arrowheads) are seen in each segment. D, E, At subsequent stages (D, stage 13; E, stage 14), strong label appears at three sites: in the CNS, in a segmental, dorsoventral stripe of cells (arrowheads), probably part of the PNS, and in twin spots at the anterior tip of the head (arrows), very likely the precursors of the antennomaxillary complex.F, At stage 16, staining intensity in the CNS begins to fade. Scale bar, 50 μm.