Figure 7
From: Periderm invasion contributes to epithelial formation in the teleost pharynx
Interpretative scheme, showing development of the pharyngeal lining. (A) Before 30 hpf, peridermal (krt4+) cells are only seen covering the embryo; internal krt4+ cells are only present in the midline at the level of P1-P2. (B) Around 32 hpf peridermal cells start to invade P2. The domain of midline krt4+ cells starts to spread posteriorly and laterally towards P2. (C) Peridermal cells invade P2 until halfway and midline krt4+ cells extend outwards reaching peridermal krt4+ cells. Also midline krt4+ cells continue to extend through the pharynx midline until the level of P3. (D) The invasion and expansion of both peridermal and midline krt4+ cells continue, following the same pattern seen for P2. (E) Finally, the entire pharynx midline is invested by krt4+ cells and all the pouches, until halfway, are covered in peridermal cells. The domain of midline krt4+ cells also expands anteriorly until the mouth, and posteriorly until the end of the esophagus. P2: pouch 2; P3: pouch 3; P4: pouch 4; P5: pouch 5; P6: pouch 6.
