Fig. 5. Spatial expression pattern of xtYap during the early develop- ment of Xenopus tropicalis. (A-K) Spatial expression of xtYap was ana- lyzed by whole-mount in situ hybrid- ization. Anterior is at the left of each panel. (A) Unfertilized egg, (B) 8-cell stage, (C) early gastrula, (G) tailbud stage, (H) late tailbud stage, and (I) tadpole stage in lateral view. (D) Late gastrula, (E) neurula stage, and (F) late neurula stage in dorsal view. (J) Transverse section of (E). (K) Trans- verse section of (G). The line position is indicated in (E,G). Scale bars, 50 ïm. Abbreviations: ba, branchial arch; ca, cloaca; cn, center of neural plate; fc, facial connective tissues; hg, hind- gut; mh, midbrain-hindbrain boundary; nc, neural crest; nt, notochord; ov, otic vesicle; ph, pronephros; sc, spinal cord; tb, tailbud.