Overexpression of Cerberus mRNA or knockdown of Blimp1 ventralizes and posteriorizes amphioxus embryos. Side views. Anterior at left. Expression of gene markers as noted. (A-H) Overexpression of Cerberus eliminates dorsal, anterior structures. Early mid-neurulae (15 hrs). (A-D) Injection of control mRNA. (E-H) Injected with Cerberus mRNA. (I-X) MO knockdown of Blimp eliminates the anterior part of the head. (I,M,K,O,Q,U,S,W) Early mid-neurulae (15 hrs). (J,N,L,P,R,V,T,X) Early larva (36 hrs). (I-L,Q-T) Embryos injected with control MO. (M-P,U-X) Injected with Blimp1 MO.