Figure 1

Figure 1 p60-katanin impairs the axon pathfinding of secondary motor neurons.

(A) Immunolabelling of sMN tracts in 72-hpf Tg(Hb9:GFP) larvae injected with control morpholino (MO^Ctl; n = 32), p60-katanin morpholino (MO^{p60Kat/1.3pmol}, n = 32 and MO^{p60Kat/3.4pmol}, n = 32) or co-injected with p60-katanin morpholino and human KATNA1 mRNA (MO^{p60Kat/1.3pmol} + mRNA^KATNA1, n = 32; MO^{p60Kat/3.4pmol} + mRNA^KATNA1, n = 32) using Zn-5 and GFP antibodies. Dotted lines mark lateral myosepta. (B–D) Mean number of misguided dorsal projections (B), missing dorsal projections (C) and misguided rostral nerves (D) per larva. (E) Percentage of larvae with ectopic sorting of sMN axons from the spinal cord. (F) Immunolabelling of sMN axons in 72-hpf controls (katna1^+/+, n = 34), as well as heterozygous (katna1^+/-, n = 53), homozygous zygotic (katna1^−/−Z, n = 33) and maternal zygotic (katna1^{-/- MZ}, n = 12) mutant larvae using Zn-5 antibody. Insets are higher magnifications of the dorsal nerve. (G) Percentage of larvae with dorsal nerve defects. (H) Mean number of misguided dorsal projections. (I) Percentage of larvae with rostral nerve defects. (A, F) Lateral views of the trunk, anterior to the left. Full arrowheads and full arrows show normal rostral and dorsal nerves, respectively. Empty arrowheads and empty arrows indicate misguided rostral and split/misguided dorsal projections, respectively. Asterisks indicate missing dorsal nerves while the red arrowhead points at aberrant exit points of sMN axons from the spinal cord. Scale bars: 25 µm, inset: 10 µm (F). (B–E, G–I) Non-blind quantifications were performed on 24 spinal hemisegments around the yolk tube per larva. Analysed larvae were pooled from three independent experiments. (B–D, H) Violin Plots; horizontal bars indicate the median ± the 1st and 3rd quartiles. Kruskal–Wallis ANOVA test with Dunn’s post hoc test. (E, G, I) Chi² test. P values are displayed on graphs. Source data are available online for this figure.