An image of a live jsIs821 animal expressing GFP-RAB-3 in six mechanosensory neurons under the control of the mec-7 ß-tubulin promoter. RAB3 associates with synaptic vesicles that accumulate at synapses. In this animal, a cluster of synapses in the nerve ring and a pair of synaptic puncta in the ventral nerve cord are easily visible. Dimmer autofluorescence derived from the intestine can also be seening along most of the length of the animal. These types of transgenic animals permit us to examine select synapses in live animals . In some cases, like in the case of jsIs821, even under a dissecting microscope. We utilize synaptic-GFP tags extensively in the laboratory to study synapse formation. This image was taken using a 20 X 0.5 na objective on an Olympus compound microscope.