Images of live mutant embryos. Anterior is left, dorsal is top in all pictures, except in G-I, which are dorsal views. (A) 24-hour old wild-type embryo. (B) flhtk241 embryo; a small patch of floor plate in the ventral neural tube is indicated by an arrowhead. (C) momth211 embryo. (D) ntl embryo with the strongest allele, ntltc41. (E) ntlts260, the weak allele produces a reduced ventral tailfin. (F) doctt258 embryo. (G-I) Dorsal view of 10-somite stage embryos: (G) wild type, (H) momth211 and (I) doctt258. (J-K) Heads of 48-hour (J) wild-type and (K) mom larvae in a lateral view. (L) Tailtip of a 60 hour doctt258 larva.