Table 1.

Quantitation of filopodial orientation from live imaging before and after the 52 hpf transition^a

GFP		WT-α2-chn		G228S-α2-chn
Before	After	Before	After	Before	After
25.97	61.14*	36.93	54.90*	34.01	33.86

^aPercentage of filopodia oriented within the rostroventral quadrant (Fig. 4C) between 180° and 270°, before and after the 52 hpf transition point, in neurons expressing the GFP, WT-α2-chn, or G228S-α2-chn mutant constructs (based on movies of 9, 4, and 5 neurons, respectively, for before and 10, 8, and 6 neurons after; numbers of filopodia were in the range of 70–173 per condition). This quadrant represents the area where the MR and IR muscle targets lie. Distribution was compared by two-way ANOVA. There was a significant difference in filopodial orientation between “Before” and “After” in both GFP- or WT-α2-chn-expressing neurons (p < 0.001 in both cases). There was no difference in filopodial orientation “Before” in any situation; or between “Before” and “After” in G228S-α2-chn-expressing neurons (p > 0.05). Filopodial distribution of G228S-α2-chn-expressing neurons “After” was significantly different compared with that of GFP- or WT-α2-chn-expressing neurons “After,” however (p = 0.009 and p = 0.033, respectively).

*Significant distribution difference.