Fig. 8. Lateral vegetal ectoderm contributes to tail rather than trunk spinal cord in chordino mutant embryos. (A-H) Wild-type (wt), and chordino mutant (din^-/-) gastrula stage embryos, with or without injection of fgf3, stained initially to show eve1 expression (red; A,B,E,F) and subsequently to show sox3 expression (purple; C,D,G,H). Arrowheads in A and B indicate the position of vegetal lateral ectoderm, where eve1 expression is absent in wild type (A) while expanded in din^-/- (B). The arrowhead in F indicates the dorsal most ectoderm where eve1 expression is absent. (I-N) Lateral views of gastrula (I,L) and 1-day-old (J,K,M,N) wild-type (I-K) and chordin morphant (din MO; L-N) in which fluorescein was uncaged in lateral vegetal ectoderm (I,L, arrowheads) and fates of fluorescent cells were traced on the next day (J,K,M,N). In the wild-type embryo, vegetal lateral ectoderm cells mostly give rise to trunk neural tube (J,K, arrowheads), whereas in the chordin morphant, the cells occupy the tail, including the caudal spinal cord (M,N, arrowheads). White lines in I,L indicate the vegetal limit of the germ ring.