Fig. 5. Repression of Ubx in postembryonic neuroblasts does not require larval Grh activity. All panels show the pattern of Ubx expression in MARCM neuroblast clones in the posterior thorax (n-ßgal driven by elav-GAL4) at the stages indicated on the left. (A-D) Wild-type clones do not express Ubx in the neuroblast or GMCs at any of the stages shown, but it is progressively upregulated within adult-specific neurons. At 72 hours, few if any cells are Ubx positive (in A, projected sections produce false overlap), by 96 hours early-born adult-specific neurons become Ubx positive (B), and, by 104 hours, the majority of neurons in many of the lineages become Ubx positive, but not the GMCs (arrowheads) or neuroblasts (C,D). (E-G) grh^B37 mutant clones do not express Ubx in the neuroblast or adult-specifc neurons at 72 hours (E). By 96 (F) and 104 hours (G), although clone size is small and the large neuroblast is absent, Ubx is upregulated in a subset of adult-specific neurons in some but not all clones (in G, two clones are shown).