DEV034322 Supplementary Material

Files in this Data Supplement:

• Supplemental Figure S1 -

  Fig. S1. Neuropilin expression by NCC subpopulations in the 9.5 dpc wild-type mouse trunk. (A) Schematic representation of the 9.5 dpc mouse embryo trunk, containing a portion of neural tube (nt), dorsal aorta (da), posterior cardinal veins (pcv) as well as one somite consisting of sclerotome and dermomyotome; the planes of sectioning used in this study are indicated. Transverse sections are shown in Figs 1 and 3, longitudinal sections in Figs 2, 3 and 4. (B) Schematic representation of neuroglial NCC subpopulations, as defined by NRP1 and NRP2 expression. The neuropilin-negative early NCC wave migrates through the intersomitic furrow and seeds the sympathetic ganglia (Schwarz et al., 2009). The intermediate wave of NCCs contains the majority of neuroglial NCCs and migrates through the anterior sclerotome. Many NCCs in this wave express NRP1 (Schwarz et al., 2009), but the intermediate wave also contains NCCs with high NRP2 expression levels (see Fig. 2). NRP1-positive NCCs, but not NRP2-positive NCCs, differentiate into sympathetic neurons; NRP2-positive NCCs differentiate instead into sensory neurons (see Fig. 1). The final wave of NCCs gives rise to melanocytes, but is not included in this figure.

• Supplemental Figure S2 -

  Fig. S2. Peripheral nervous system organisation in the absence of semaphorin signalling through neuropilins. Whole-mount neurofilament labelling of 11.5 dpc mouse embryo trunk; rostral is to the right. (A) Wild types contain well-separated DRGs, and thoracic spinal nerves emerge at the level of each somite in a metameric pattern (red dots); each spinal nerve contains a dorsal and ventral ramus supplying sensory axons to the skin. (B) In compound Nrp1^Sema Nrp2 null mutants, DRGs form a continuous band. Even though sensory axons appear non-segmented in the vicinity of the DRGs, the sensory nerves supplying the skin emerge in a metameric pattern from the dorsal and ventral rami (red dots), indicating that the spinal nerves are segmented. Note that sensory axons defasciculated and spread further in mutants than in wild types. df, dorsal funiculus; dr and vr, dorsal and ventral ramus, respectively, of a spinal nerve; fl, forelimb. Scale bar: 250 µm.