Fig. 8. Pl-Otx2 expression during posterior and anterior regeneration. (A,C,E-G) Lateral views; (B) ventral view; (D) dorsal view. See Fig. 5 for explanation of expression diagrams (left). (A,B) Mid-stage posterior regeneration: Pl-Otx2 is expressed in ventral cells of the blastema (arrows), primarily in regions where the ventral nerve cord of new segments is forming. (C,D) Early anterior regeneration: Pl-Otx2 is expressed intensely in lateral crescents on each side of the developing blastema (arrows). (E) Mid-stage anterior regeneration: deep cells of the developing foregut strongly express Pl-Otx2 (arrowhead), and a lateral cluster of unidentified cells near the anterior margin of the blastema transiently expresses Pl-Otx2 (small arrow). (F,G) Late anterior regeneration: foregut expression (F, arrowhead) persists, localizing specifically to the pharynx. In addition, Pl-Otx2 becomes expressed in scattered ventral cells of the blastema (F, arrow), mostly in the developing ventral nerve cord, and in a bilaterally symmetrical cluster of dorsolateral cells (G, arrow), possibly associated with an eyespot (see text). Vertical scale bar: 50 µm.
