Figure 5.
Ectopic expression of vnd suppresses the identity of intermediate and dorsal NE and Nbs. (A,B) Vnd suppresses Hkb expression in the intermediate and dorsal neuroblasts. (A) In stage 11 wild-type embryos, Hkb protein is strongly expressed by Nb 2-4 (arrowhead), Nb 4-2 (arrow), Nb 4-4, and Nb 5-4. (B) In sca–GAL4; UAS–vnd embryos, the Hkb-positive Nb4-2 and Nb2-4 are missing. Other Hkb-positive Nbs are out of focus and are weakly stained. (C) Kr–GAL4; UAS–vnd embryos double stained for Lbe and Engrailed. Outside the Kr domain, Nb 5-6 expressing Lbe (arrow) is detected just above the Engrailed stripe. Within the Kr domain, Lbe expression in Nb 5-6 is abolished. (D) Kr–GAL4; UAS–vnd embryos carrying a msh–lacZ insertion and stained for β-gal to detect msh expression. Early msh expression in the dorsal column of the NE is abolished within the Kr domain.