Figure 4. A collection of fly strains to genetically control every proboscis muscle.

Confocal stacks of split GAL4 lines showing the proboscis muscles (magenta) targeted by the motor neurons of the collection (left images; green). (Note: cuticular structures can also autofluoresce green). Scale bar: 50 µm. Gain and contrast adjusted. Right images: location of those muscles in the head schematic from Figure 3, at a reduced scale.

Figure 4—figure supplement 1. Sparse lines providing genetic access to specific proboscis motor neurons.

Confocal maximum projections of brains (above) and VNCs (below) of split GAL4 lines targeting proboscis motor neurons. Targeted neurons: green (GFP). Counterstain: magenta (nc82). Most lines contain a single motor neuron type in SEZ; a few contain more than one (numbers in Table 1, along with split GAL4s used). Gain and contrast adjusted. Scale bar: 50 µm.

Figure 4—figure supplement 2. Completeness of motor neuron coverage in split GAL4 collection.

(A) Example proboscis stained for muscles (phalloidin, red), genetically targeted motor neuron (mn9, GFP, green), and neuromuscular junctions (nc82, blue), to determine whether all synaptic sites on the appropriate muscle are occupied by the incoming green axon(s) in that line. (More examples of this staining are shown in Video 9 and in B). Frontal view, dorsal at top. (B) Partial stack projections cropped in the region of each muscle showing neuromuscular junction synapses (nc82, left panels within each group, magenta in overlay) and motor neuron terminals (GFP, middle panels, green in overlay). Gain and contrast adjusted. Scale bars: 50 µm.