Table 1.

Effect of Ribeye a depletion on synaptic ribbons

	Ribbons in OPL			Ribbons in IPL
Injection	Number (μm2)	Length (nm)	Number (μm2)
Mis4+	0.0089 ± 0.0016 (n = 26)	226 ± 32 (n = 20)	0.018 ± 0.002 (n = 63)
MO1-	0.0069 ± 0.0013 (n = 28)	111 ± 20 (n = 21)	0.001 ± 0.001 (n = 66)
t test	p > 0.05	p < 0.005	p < 0.0001

Retinas from two larvae of each phenotype were sectioned and analyzed by electron microscopy. MO1-injected larvae tested negative for OKR. In the OPL, ribbons were counted in images of 108 μm² area at a resolution of 5 nm/pixel. We used 26 images from Mis- and 28 images from MO1-injected larvae. Electron dense structures were recognized as ribbons if they were juxtaposed to synaptic membranes. Length measurements did not include the arciform density. In the IPL, ribbons were counted in images of 38 μm² area and resolution of 3 nm/pixel. Ribbons were recognized by their pentalaminar structure as in Figure 6C. Sixty-three images from Mis- and 66 images from MO1- injected larvae.