Extended Data Figure 2. Serial confocal preBötC sections showing Nmb-GFP projections contain puncta of NMB.

a-d, Serial confocal optical sections (0.6 μm apart) through preBötC brain region of Nmb-GFP mouse immunostained for GFP (green), NMB (red), preBötC marker SST (white), and DAPI (blue) as in Figure 2h. Note the GFP-positive projection with a puncta of NMB (yellow, open arrows in b,c) directly abutting an SST positive neuron (asterisk). Most NMB puncta (open arrowheads) were detected within GFP-positive projections as expected, and only a small fraction of NMB puncta (closed arrowhead) were detected outside them; NMB outside Nmb-GFP projections could be secreted protein or the rare Nmb-expressing cells that do not co-express the Nmb-GFP transgene (see Extended Data Figure 1e-h). Bar, 20 μm.