Figure 9. Tracts associated with posterior lineages (CP, BLP, DPLp).

(A, B): Digital 3D models of posterior lineages and tracts of a single L1 brain hemisphere. Lateral view (A), posterior view (B). At the top of each panel, lineages are shown in relationship to mushroom body (blue-grey) for spatial orientation; bottom of panels shows higher magnification of lineages and neuropil tracts (light blue). Numbered hatched circles in (A) and other panels represent entry portals of lineage-associated tracts. Double-headed arrow in (B) indicates brain midline. (C–L) Z-projections of frontal confocal sections of lateral half of brain hemisphere of L1 larva (24h; C–H), L2 larva (48h; I–J’), and early L3 larva (56h; K–L). Lateral in all panels is to the left. Antero-posterior levels shown by z-projections are indicated by letters (CAant, CApost) at lower left corner (for definition of levels, see Figure 2). Primary neurons and tracts are labeled by anti-Neuroglian (BP104; white in panels C–D, I, J; magenta in all other panels). Primary neurons representing the Type II lineages CP2 and CP3 are labeled by 9D11-Gal4>UAS-mcd8::GFP (green in E–F); from L2 onward, the same marker labels secondary neurons of these lineages (green in panels I’–J’). Primary neurons of CP1 are labeled by R76A11-Gal4>UAS-mcd8::GFP (green in G–H). Secondary neurons are globally labeled by insc-Gal4>UAS-chRFP-Tub (green in K–L). For abbreviations of compartments and fiber tracts see Table 1; for numbering of entry portals see Table 2. Bar: 20µm (C–L)