Figure 3. Disruption of the presynaptic microtubule cytoskeleton in iav¹.

(A) Confocal image of an NMJ from wild-type (WT) larvae stained with antibodies against Futsch (magenta).

(B) Magnification of the boxed region in (A). White arrow points to a synaptic Futsch loop.

(C) Same as (A) but in iav¹ larvae. Scale bar shown in (A) also applies to (C).

(D) Same as (B) but in iav¹ larvae. Red arrows point to synaptic Futsch punctae.

(E) Quantification of the number of Futsch loops per NMJ in the indicated genotypes. *, p = 3.6×10⁻⁴, Student’s t-test, n = 10-14 NMJs per genotype.

(F) 3-D reconstruction of a wild-type (WT) synaptic bouton stained with antibodies against HRP (green) and tubulin (magenta).

(G) Magnification of the boxed region in (F). Dashed-lines represent synaptic microtubule loops.

(H) Same as (F) but in iav¹ larvae. Arrows point to fragmented microtubules. Scale bar shown in (F) also applies to (H).

(I) Schematic depicting the role of Futsch phosphorylation status on the regulation of presynaptic microtubule stability.

All values represent mean ±SEM. Abbreviations: MAP-1b, microtubule associated protein-1b; P, phosphorylation.