Figure 6. Ato⁺/Dac⁺ neuroblasts terminally divide to produce two sister GMCs with different Notch identities.

(A) First temporal window Dichaete⁺ and second temporal window Ato⁺ NBs localized the Notch inhibitor Numb to the basal cortex during cell division.

(B) Newborn Ato⁺/Pros⁺ GMCs that did not inherit Numb transiently expressed the Notch reporter mγGFP (arrowheads).

(C,D) Notch mutant MARCM clones visualized with T4/T5-Gal4 produced four T4 neurons projecting to the same retinotopic location, both of subtype b in the horizontal system (C), or subtype d for the vertical system (D) (see also Figure S2).

(E) Schematic illustrating Ato⁺/Dac⁺ neurogenesis. Two Notch binary fate decisions specify neuronal identity.