Table 1. Quantification of Aae fra knockdown phenotype penetrance and severity.

	AnteriorWT	Mild	Strong	PosteriorWT	Mild	Strong
Control	91 (100%)	0 (0%)	0 (0%)	91(100%)	0 (0%)	0 (0%)
fra siRNA-A	22 (29%)	26 (35%)	27 (36%)	15 (20%)	22 (29%)	38 (51%)

Embryos stained with anti-acetylated tubulin were scored at 54 hrs. post-injection of fra siRNA-A or scrambled control siRNA. The number and percentage of total segments bearing wild-type (WT), mild, or strong phenotypes in the anterior and posterior commissures are reported. Mild phenotypes correspond to thinning commissures, and severe phenotypes correspond to near or complete absence of commissural axons.