Figure 1. Overexpression of dp53 suppresses ectopic neuroblast formation in numb mutant or Numb-TS4D overexpression backgrounds.

(A–C) Inhibition of ectopic neuroblast formation in numb mutant by dp53. The UAS-dp53-WT transgenes were introduced into numb¹⁵ null mutant MARCM clones marked with GFP (green). Type II neuroblasts were identified as Miranda-positive (Mira⁺, red) and Asense-negative (Ase^-, blue) cells with a diameter of around 10 µm and were labeled with asterisks. The smaller Mira⁺ cells are intermediate progenitors. Note that the clone in B and B' is of bigger size than that in A and C as indicated by the scale bars. The number of type II neuroblasts in dp53-expressing numb mutant (C) is much less than that of numb¹⁵ mutant alone (B). The genotypes of each panel are FRT40A (A), FRT40A, numb¹⁵ (B), and FRT40A, numb¹⁵, UAS-dp53-WT; 1407-Gal4 (C), respectively. (D–F) dp53-WT (E), but not dp53-H159N (F), inhibits the ectopic neuroblast formation phenotype induced by Numb-TS4D. The corresponding transgenes were overexpressed in neuroblasts using the 1407-Gal4 driver. Neuroblasts are identified by Mira immunostaining (green). Quantification of neuroblast number is shown in F. Eight animals from each genotype were analyzed. Scale bars, 10 µm.