(a) Compound muscle action potential (CMAP) measurements in gastrocnemius muscle of mice. Statistics by two-sided, one-way ANOVA post hoc Tukey’s multiple comparisons test. P = 0.0131; P = 0.0252 at 3 months; P = 0.0045. (b-c) Neurofilament light (NF-L) levels in serum at different time-points in Stmn2+/+, Stmn2+/− and Stmn2−/− mice in the C57/BL6J (b) and FVB (c) backgrounds. (d-e) Phosphorylated neurofilament heavy (pNF-H) levels in serum at different time-points in Stmn2+/+, Stmn2+/− and Stmn2−/− mice in the C57/BL6J (d) and FVB (e) backgrounds. (b-e) Statistics by two-sided, two-way ANOVA post hoc Tukey’s multiple comparison test. (f) Hindlimb clasping test of Stmn2+/+/Sarm1+/+, Stmn2+/+/Sarm1−/− and Stmn2−/−/Sarm1−/− mice in C57/BL6J background for 20 weeks. Statistics by two-sided, two-way ANOVA post hoc Tukey’s multiple comparison test. **P = 0.0018; **** P <0.0001 when comparing to Stmn2+/+/Sarm1+/+. ##
P = 0.0069 when comparing between Stmn2+/+/Sarm1−/− and Stmn2−/−/Sarm1−/−. (g-h) Von Frey analysis for the sensory response in hindlimbs of Stmn2+/+, Stmn2+/− and Stmn2−/− mice in C57/BL6J background at 9 and 12 month of age, (P <0.0001) (g), and in FVB background at 6, 9 and 12 month of age. P value range from P = 0.0037 to P <0.0001 (h). Statistics by two-sided, one-way ANOVA Kruskal-Wallis with Dunn’s multiple comparison test. Number of animals used were n=28 for Stmn2+/+; n=30 for Stmn2+/− and n=32 for Stmn2−/− at 9 months, and n=29 for Stmn2+/+; n=30 for Stmn2+/− and n=13 for Stmn2−/− at 12 months (g). Number of animals used were n=24 for Stmn2+/+; n=23 for Stmn2+/− and n=20 for Stmn2−/− at 6 months and 9 months; n=23 for Stmn2+/+; n=23 for Stmn2+/− and n=14 for Stmn2−/− at 12 months (h). (i) Lumbar spinal cord dorsal section of Stmn2+/+, Stmn2+/− and Stmn2−/− mice immunostained for stathmin-2 (green), CGRP (magenta) and isolectin B4 (IB4) in blue. N=3 animals/genotype were imaged. (a,g,h) Each data point represents an individual mouse. All panels: Error bars plotted as SEM. ****, P <0.0001; ***, P < 0.001; **, P < 0.01; *, P <0.05; ns, P >0.05.