Figure 5

In vivo analysis of axonal growth in Necdin mutant embryos. (A) Whole-mount immunostaining of E13.5 wild type and mutant embryos with TuJ1, a neuronal specific marker illustrating the parameter used for quantification (lcb). (B) Quantitative analysis of the length of the lateral cutaneous branches of the nerves innervating the trunk at E12.5 and E13.5. No significant differences in the length of spinal nerves were observed in mutant embryos compared to wild type. Six peripheral axon bundles, from five mice, for each genotype, were analyzed. Statistical analysis was carried out using the Mann-Whitney test. (C, D) Parvalbumin immunostaining on transverse section at E17.5 showing a decrease of Necdin mutant proprioceptive afferences (D) in spinal cord compared to wild type (C). (E) Representative scheme of defect observed in (C) and (D). (F-I) CGRP immunostaining on coronal section, at adulthood, showing a similar innervation pattern of TrkA fibers in the hindpaw pad (F-G) around an hair follicle or (H-I) in the epidermis under nail of the second toe in NdnKO (G, I) or wild type (F-H) mice. We notice a decrease in the number of fibers in Ndn KO. ab, anterior bud; Ep, epidermis; HF, hair follicle; lcb, lateral cutaneous branch. Scale bar: 500 μm (A); 100 μm (C, D and F-I).