Fig. 1. Dislocation of TH-positive sympathetic neurons in the neuropilin 1 and Sema3A mutant embryos. (A-F) Frontal sections of the wild-type (A), neuropilin 1 homozygous mutant (B) and Sema3A homozygous mutant (C) embryos at E12.5, immunostained with anti-TH antibody. (D,F) High-magnification views of the boxed areas in A and B, respectively. (E) A high-magnification view of the medial part of an embryo in a section adjacent to B. Arrows in C indicate TH-positive neurons in the upper arm and axilla. (G) A double immunostaining of a section from the Nrp-1^–/– embryo at E12.5, with anti-TH antibody (red) and anti-neurofilament antibody 2H3 (green). (H,I) The wild-type (H) and homozygous neuropilin 1 mutant (I) embryos at E12.5, immunostained in whole-mount with anti-TH antibody. Arrows indicate TH-positive neurons at ectopic positions. nt, the neural tube; da, the dorsal aorta; SCG, the superior cervical ganglion; fl, the forelimb. Scale bar: 200 µm (A-C); 200 µm (D,E); 100 µm (F,G); 500 µm (H,I).