Fig. 5. Growth and patterning defects of posterior cranial nerves in RA-rescued Raldh2^–/– mutants. Whole-mount anti-neurofilament stainings of E11.5 embryos were examined after removal of the surface ectoderm to expose the nerve tracts. (A) wild-type embryo. (B-D) Raldh2^–/– embryos with increasingly severe phenotypic defects. Cranial nerves are indicated in Arabic numerals (5-12). g9-g10, distal sensory ganglia of the 9th and 10th nerves, respectively. The arrowhead in D points to an aborted 9th-11th common axonal tract.