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. Author manuscript; available in PMC: 2012 Dec 8.
Published in final edited form as: Neuron. 2011 Dec 8;72(5):760–775. doi: 10.1016/j.neuron.2011.09.031

Figure 8. Mitochondria Are Required Locally for Axonal and Synapse Degeneration.

Figure 8

(A and B) Mutations in either the Drosophila JNK homolog bsk or in the NFκβ homolog dorsal do not suppress synaptic degeneration caused by a disrupted spectrin/ankyrin skeleton. dnJNK = elavC155-GAL4; dnbsk (n = 100 NMJs); α-spec = elavC155-GAL4; α-spec-RNAi (n = 57 NMJs); α-spec; dnJNK = elavC155-GAL4; α-spec-RNAi/+; dnbsk/+ (n = 106 NMJs); dl = dl1/dl1 (n = 100 NMJs); ank2 = ank22001/ank22001 (n = 75 NMJs); dl1; ank2 = dl1/dl1; ank22001/ank22001 (n = 77 NMJs).

(C) Mutations in miro suppress the synaptic degeneration caused by neuronally expressed α-spectrin-RNAi (p < 0.001). miro = elavC155-GAL4; miro B682/miro B682 (n = 88 NMJs); α-spec = elavC155-GAL4; α-spectrin-RNAi (n = 58 NMJs); α-spec; miro = elavC155-GAL4; α-spectrin-RNAi/+; miro B682/miro B682 (n = 209 NMJs).

(D) Representative images of third-instar muscle 6/7 NMJs stained with the presynaptic active zone marker Brp (green) and the postsynaptic marker Dlg (red). Neuronally expressed α-spectrin RNAi causes neuronal degeneration (top panel) and this is suppressed by the miro mutation (bottom panel).

(E–H) Mutations in known components of mitochondrial-dependent caspase signaling suppress ankyrin-dependent synaptic degeneration. (E) Mutations in debcl suppress ankyrin-dependent degeneration. debcl = debcl[E26]/debcl[E26] (n = 60); ank2 = ank22001/ank22001 (n = 151); decbl; ank = debcl[E26]/debcl[E26]; ank22001/ank22001(n = 103). (F) Representative images stained with presynaptic Brp (green) and postsynaptic Dlg (red). debcl mutant animal NMJs do not have any noticeable morphological abnormalities or synaptic degeneration (top panel); however, there is a significant suppression of ankyrin-dependent degeneration (bottom panel). (G) Mutations in dark suppress ankyrin2-dependent degeneration. dark = darkCD4/dark CD4 (n = 80); ank2 = ank22001/ank22001 (n = 60); dark; ank = darkCD4/dark CD4; ank22001/ank22001 (n = 160). (H) Representative images stained with presynaptic Brp (green) and postsynaptic Dlg (red). Animals mutant for dark that produce NMJs do not have any noticeable morphological abnormalities or synaptic degeneration (top panel); however, there is a significant suppression of ankyrin-dependent degeneration (bottom panel). Degeneration severity is measured as above.

Error bars represent SEM. p values were determined using one-way ANOVA with post hoc Tukey-Kramer: *p < 0.05; ***p < 0.001. Statistical differences remain when comparisons are made using Student’s t test. n.s., not significant.