Fig. 6. Serial transplantation of the CNH. (A) Serial grafting experiments between stage 15 HH and stage 20 HH embryos. (B-D) Embryos immediately after grafting (left) and after incubation (right). (B) CNH from a stage 15 HH GFP⁺ embryo grafted to a host embryo and incubated for 20 hours. (C) CNH region from the first host was grafted to a stage 15 HH host and incubated for 20 hours. (D) CNH region from the second host was grafted to a stage 15 HH host and incubated for 48 hours. (E) Transverse section of the third host embryo immunostained for the neuronal marker TUJ1 (red), which labels some GFP⁺ cells (arrow). Blue, nuclear stain. Scale bars: B-D, 0.5 mm; E, 0.1 mm.