Fig. 4

Transient Hunchback in neuroblasts is sufficient to specify early-born neuronal identity. a Wild type (y w) stage aCC/pCC sibling neurons (circle) are Eve+ Hb+ and Zfh2-. b hunchback CNS null mutant aCC/pCC sibling neurons (circle) are Eve+ Hb- and Zfh2+. Note that loss of Hb throughout the neuroblast lineage results in zfh2 de-repression. c hunchback CNS null mutant with sca-gal4 UAS-hb driving expression of Hb in neuroblasts. aCC/pCC sibling neurons (circle) are Eve+ Hb- and Zfh2-. The Hb protein made in the parental neuroblast is not maintained in the aCC/pCC neuronal progeny. Note that Hb expression in the neuroblast maintains zfh2 repression despite lack of Hb in the neurons. In all panels, stage 15 embryo, three segments shown, anterior to top, ventral midline at center of panel. Scale bars, 5 μm. d Quantification