Fig. 3.

Wld^S confers sustained protection against JNK axon degeneration that is Nmnat enzyme-independent. (A,B) Graphs quantifying JNK axon degeneration in neuroblast (A) or single cell clones (B) expressing Wld^S in 5- and 28-day-old adults. P-values were highly significant comparing age-matched bsk^147e neuroblast clones with those in the presence of Wld^S::Myc. (C–F) Wld^S expression blocks JNK axon degeneration and terminal loss phenotypes in bsk neuroblast (C,D) and single cell clones (E,F), respectively. (G) Quantification of axon degeneration in 28-day-old bsk neuroblast clones expressing mNmnat1, mNmnat2, mNmnat3 or Wld^S-dead. Fisher's exact test between age-matched bsk^147e neuroblast clones and those in the presence of the Wld^S::Myc lines (#1 and #2), Wld^S-dead, Nmnat1::Myc and Nmnat3::Myc were highly significant, but not significant for Nmnat2::Myc. (H–K) Representative images of genotypes. Yellow and blue arrows indicate axonal degeneration in β- and γ-axons, respectively. (L) Quantification of the terminal loss in 28-day-old JNK single-cell clones expressing Wld^S, Wld^S-dead, mNmnat1, mNmnat2 and mNmnat3. (M–P) Representative images of clones. Blue arrow indicates where axon terminal loss has occurred. Green, CD8-GFP; magenta, FasII. Scale bar: 20 µm. (Q) Box-and-whisker representation of the axon degeneration phenotype, measuring the distance of single axon terminus from the midline. Significant differences were found between 5- and 28-day-old age-matched bsk^147e single γ-axons compared with bsk clones with Wld^S::Myc. (R) Similar plots with other Nmnat lines, including Wld^S-dead, Nmnat1::Myc and Nmnat3::Myc, also showed significant differences compared with bsk^147e mutants alone. By contrast, bsk^147e clones expressing Nmnat2::Myc exhibited no significant difference. **P<0.01; ***P<0.001; N.S., P>0.05.