||FIG. 2. Patterns of contactin mRNA expression in tailbud embryos, revealed by whole-mount in situ hybridization. (A and B) Lateral
views of the embryos at stage 24 (A) and stage 32 (B), with the anterior to the left. Weak contactin signals (arrowheads) are detectable in
the anterior spinal cord, the hindbrain, and the trigeminal nerves in (A). Intensity of the overall contactin signal increases and the areas of
expression expand by stage 32 (B). (C and D) Cross sections of the whole-mount hybridized stage 32 embryo at the levels of the midbrain
(C) and spinal cord (D). Contactin mRNA is detected in the trigeminal nerve (small arrowheads), the fasciculus longitudinalis medialis, and
the ventral fascicles (large arrowheads) in the midbrain section (C). It is also detectable in RB neurons (arrowheads), lateral fascicles (lf), and
ventral fascicles (vf) in the spinal cord section (D). hb, hindbrain; nc, notochord; sp, spinal cord; tgn, trigeminal nerve. Scale bars, 100 mm.