Confocal image stacks of GFP expression in Drosophila forelegs driven by Gal4 driver expression in foreleg motor neurons

Like the vertebrate spinal cord, the insect ventral nerve cord (VNC) mediates limb sensation and motor control. We applied automated tools for electron microscopy volume alignment, neuron segmentation, and synapse prediction toward creating a connectome of an adult female Drosophila VNC. To interpret a connectome, it is crucial to know its relationship with the rest of the body. We therefore mapped the muscle targets of leg and wing motor neurons in the connectome by comparing their morphology to genetic driver lines, dye fills, and X-ray nano-tomography of the fly leg and wing. The dataset made available here contains the confocal image stacks of the legs of each driver line. We imaged only driver lines for which we found an image of a single motor neuron labeled by MCFO, from the collection on the https://neuronbridge.janelia.org website. Thus, the dendritic morphology of the MNs that are visible in these images stacks can be found by cross referencing the alphanumeric code for the Ga..., Confocal imaging
Fly prothoracic (front) legs were immersed in a 4% formaldehyde (PFA) PBS solution for 20 minutes, followed by three rinses in PBS with 0.2% Triton X-100 (PBT). The legs were then incubated in a PBS solution containing 1:50 phalloidin (Alexa-phalloidin-647, Fisher A222287) and the following reagents that improve tissue penetrance: 1% Triton X-100, 0.5% DMSO, 0.05 mg/ml Escin (Sigma-Aldrich, E1378), and 3% normal goat serum. Legs were incubated for one week at 4 °C with occasional rocking. After staining, legs were rinsed 3x with PBS-Tx, 1 rinse with PBS, and were mounted onto slides in Vectashield. To image MNs innervating the coxal muscles in the thorax, the fly was fixed as above, then hemisected along the parasagital plane with a fine razor blade in Tissue-Tek O.C.T. compound (Sakura 4583) frozen for 10 seconds on dry ice. Hemisected thoraces were rinsed 3x in PBT and stained as above.
Mounted legs or thoraxes were imaged on a Confocal Olympus FV1000. At least one im..., , # Confocal image stacks of GFP expression in Drosophila forelegs driven by Gal4 lines labelling foreleg motor neurons

[https://doi.org/10.5061/dryad.k0p2ngfg0](https://doi.org/10.5061/dryad.k0p2ngfg0)

Like the vertebrate spinal cord, the insect ventral nerve cord (VNC) mediates limb sensation and motor control. We applied automated tools for electron microscopy volume alignment, neuron segmentation, and synapse prediction toward creating a connectome of an adult female *Drosophila* VNC. To interpret a connectome, it is crucial to know its relationship with the rest of the body. We therefore mapped the muscle targets of leg and wing motor neurons in the connectome by comparing their morphology to genetic driver lines, dye fills, and X-ray nano-tomography of the fly leg and wing. The dataset made available here contains the confocal image stacks of the legs of each driver line. 

## Description of the data and file structure

Meissner et al. ([https://doi.org/10.7554/eLife.80660](https:...