Figure 2.

Normal Development and Survival of Nmnat2^gtE/gtE;Sarm1^−/− Mice

(A) Neurofilament-L immunostaining of diaphragms from E18.5 Nmnat2^gtE/gtE and Nmnat2^gtE/gtE;Sarm1^−/− embryos (montages representative of n = 3 for each genotype). Boxed areas are magnified (right). Distal branches of phrenic nerves were present in wild-type, Nmnat2^+/gtE, Sarm1^−/−, and Nmnat2^+/gtE;Sarm1^−/− embryos as expected (not shown).

(B) DiI-labeled intercostal nerves in ribcages from P0 Nmnat2^gtE/gtE and Nmnat2^gtE/gtE;Sarm1^−/− pups (montages, representative of n = 3 for each genotype). Nerve truncation was seen in all Nmnat2^gtE/gtE pups but was rescued in all Nmnat2^gtE/gtE;Sarm1^−/− pups.

(C) Quantification of radial neurite outgrowth over 7 days for E18.5 SCG explant cultures of the genotypes listed. Means ± SEM are plotted (n = 3–6 embryos of each genotype, average of both ganglia). Extension of the majority of Nmnat2^gtE/gtE neurites (mass) and a more robust sub-population (max) are both shown.

(D) Representative images of Nmnat2^gtE/gtE and Nmnat2^gtE/gtE;Sarm1^−/− neurite outgrowth at 7 days in vitro in E18.5 SCG explant cultures. Mass and max extension of Nmnat2^gtE/gtE neurites are marked (continuous and dashed lines).

(E) Viability of offspring from Nmnat2^+/gtE or Nmnat2^+/gtE;Sarm1^−/− crosses.

(F) Weights of 10-week-old male or female Nmnat2^gtE/gtE;Sarm1^−/− mice relative to indicated control groups. Both individual weights and means ± SEM are plotted. The weights of different genotypes in control groups do not vary significantly.

(G) Representative RT-PCR analysis of Nmnat2, Sarm1, and Actb (sample control) mRNA levels in E18.5 embryo brains of the indicated genotypes. Quantification of normalized Nmnat2 levels (to Actb), relative to wild-type levels, is shown below. Means ± SEM are plotted (n = 3).

(H) Representative immunoblots (of n = 3) showing NMNAT2, SARM1, and ßIII-tubulin (sample control) expression in brains from E18.5 embryo of the indicated genotypes.