Figure 1

19H09-Gal4 labels a subset of type II neuroblasts and their progeny. (A) Type II NB lineage summary, modified from [4]. (B-D) Confocal images of third instar larval brains expressing nls::GFP (B) or mCD8::GFP (C) under 19H09-Gal4 stained for indicated markers (white box). Low magnification images of single brain lobes are presented in (B,C) and high magnification images of boxed areas are presented in (B',C'), respectively. (D) A high magnification image of a type II NB and associated progeny from a different brain. The white dotted outlines represent the green fluorescent protein (GFP)-labeled areas. Type II NB are large Dpn+ Ase- cells (white arrows). Ase- Dpn- immature INPs next to type II NBs are indicated with asterisks, Ase+ Dpn- immature INPs close to type II NBs are indicated with arrowheads and mature INPs are indicated with yellow arrows. The type II lineage shown in (D) is diagrammed below indicating the different kinds of cells in the lineage. The birth order of the cells was inferred from their relative position to the parental NB: newly born cells (5) are in direct contact with the type II NB while earlier-born cells (1) and their progeny are displaced and found further away. (E,E') Three-dimensional reconstruction of medial (E) and lateral (E') views of a 120 h ALH (after larval hatching) brain lobe expressing mCD8::GFP under control of 19H09-Gal4. Type II lineages and their axonal projections are in white, the mushroom body, visualized by FasII, in magenta, and type I lineages and their projections in red. Additionally, a subset of neurons that project to the mushroom body are visualized by the driver. The optic lobes have been removed and the brain cropped for a clearer view. Brains (gray outline) are in the orientations shown in the insets, with imaged lobes indicated with a white dashed line and their mushroom bodies shown. The rest of the brain apart from the imaged lobes is indicated in white outline. Split axon tracts of type II lineages are indicated with white arrows, the yellow arrow points at a commissural projection from a type II lineage, and the red arrow points at a type I projection. Orientation: d, dorsal; v, ventral; p, posterior; l, lateral; m, medial. Scale bars: (B,C) 50 μM; (B',C',D) 10 μM; (E,E') 40 μM.