Fig. 6
Induction of endodermal marker genes induced by ectopic mezzo in wild-type embryos, MZoep mutants and casanova mutants. (A,E) animal pole views. (B-D,F-H) Side views. Embryos were injected at the 2- to 16-cell stage with 40 pg of GFP (A) or 40 pg of mezzo mRNA and examined at the shield (A,B,E,F) or at 80% epiboly (C,D,G,H) for the expression of sox17 (B,C,D,E,G,H) or casanova (F). Ectopic mezzo induces robust expression of sox17 (B,D,E) or casanova (F). These cells were typically large and scattered like the endogenous endoderm precursors; however, most of those cells remained in the epiblast. Overexpression of mezzo rescues sox17-expressing cells in MZoep (G) and weakly induces ectopic expression of sox17 in casanova (H).