(
A–H) Confocal images of third instar NMJ4 boutons from control and various
tnc and
mys/βPS manipulations stained for α-Spectrin (green) and HRP (magenta). Neuronal knockdown of
tnc significantly increases the α-Spectrin levels; muscle knockdown mildly decreases the α-Spectrin signals (quantified in D). Thus synaptic α-Spectrin generally follows the levels of synaptic Tnc (compare with
Figure 4—figure supplement 2). The recruitment of α-Spectrin appears to be dependent on Tnc/integrin complexes, since muscle knockdown of
mys/βPS drastically reduces α-Spectrin accumulation at synaptic terminals (quantified in H). The number of NMJs examined is indicated in each bar. Bars indicate mean ±SEM. ns (p>0.05), ***p<0.001, **p<0.01. Scale bars: 5 μm. Genotypes:
N > tncRNAi (BG380-Gal4/+; UAS-tncRNAi/+); M > tncRNAi (UAS-tncRNAi/+; 24B-Gal4/+); N > mys RNAi (BG380-Gal4/+; UAS-mys RNAi/UAS-Dcr-2); M > mys RNAi (UAS-mys RNAi/UAS-Dcr-2; 24B-Gal4/+).