Fig. 5. Heterochronic transplantation of tail bud regions to early embryos. (A) Tissue caudal to the node or tail bud regions from stage 15 HH embryos were grafted into 6-somite (stage 8 HH) hosts and incubated for 48 hours. (B) An embryo immediately after grafting. Line indicates level of the section. (B') Mid-sagittal section of host embryo two hours after grafting. Arrow, Hensen's node. (C-F') Embryos and transverse sections 48 hours after (C,C') homotopic graft of caudal node tissue; (D,D') heterochronic graft of CNH; (E,E') heterochronic graft of the dpTB; (F,F') heterochronic graft of the vTB. Blue, nuclear stain. Scale bars: B,C,D,E, 0.5 mm; C',D',E', 0.1 mm.