Fig. 2. Pax2 expression and DiI-labeling of cranial neural crest cells at the midbrain and rostral-most hindbrain. (A) Lamprey Pax2 expression at stage 23. Pax2 is expressed at the mid-hindbrain boundary (mhb) and within the otic vesicle (ov). (B) DiI-labeled cells originating from the midbrain region have migrated into the first (mandibular) arch of a stage 23 embryo. (C) Cells originating from the rostral hindbrain have migrated into the mandibular arch. d indicates plane of section shown in D. (D) transverse section through mandibular arch of embryo shown in C in which labeled cells are positioned both medial and lateral to the mesodermal core. (E) Pax2 expression continued in the mid-hindbrain boundary and otic vesicle at stage 25. (F) Stage 25 embryo labeled in the midbrain; DiI-labeled cells are found in the upper (ul) and lower (ll) lips; g,h indicate planes of section shown in G and H, respectively. (G) Horizontal section indicating labeled cells contributed to the ophthalmic (V₁) and maxillomandibular (V₂) lobes of the trigeminal ganglion. (H) Plane of section through developing lips indicates labeled cells present both medial and lateral to mesodermal core. (I) Stage 26 embryo in which cells originating from midbrain persist in the upper and lower lips. Scale bar: 200 µm.

Return to article