Figure 10.

frazzled LOF mutant anatomy, physiology, and presynaptic Innexin levels. A, Heterozygous frazzled control animals (fra³/+) exhibited normal GF terminal anatomy. B, Innexin labeling (green) in frazzled heterozygous mutant GFs (magenta) colocalized in GF terminals (white) at the GF-PSI synapse and the GF terminal (image is a single slice of a TIFF stack with 0.5 μm steps and dotted lines represent the terminal in other sections of the TIFF stack). C, Control physiological recordings were normal. D, frazzled LOF trans-heterozygous animals (fra³/fra⁴) often exhibited bifurcated axon terminals (left giant fiber shown). E, Innexin labeling (green) in the GF (magenta) was greatly reduced and colocalized Innexin in the terminal was undetectable (image is a single slice of a TIFF stack as in B). F, This correlated with the mutant physiological phenotype shown by long response latency and inability of the circuit to follow high-frequency stimulation of 100 Hz. Scale bars, 5 μm.