Fig. 5. Phenotypes of zebrafish embryos injected with mkp3 and mkp3::C292S RNA. (A-C) Somitogenesis stages of zebrafish embryos uninjected (A), injected with mkp3 (B) or with mkp3::C292S (C). Injected embryos display anterior defects (red arrowhead). (D-I) At 24 hpf, mkp3-injected embryos (E) exhibit anterior truncation and expanded trunk-tail region, while mkp3::C292S-injected embryos, show trunk-tail defects (F) (compare with uninjected in D). (G-I) Staining for gata1 at 24 hpf reveals ventralization of mkp3-injected (H) and dorsalization in mkp3::C292S-injected embryos (I); arrows indicate region of gata1 staining (compare with G, uninjected). (J-Q) Early dorsoventral markers are disrupted in injected embryos. bmp4 is activated in mkp3-injected embryos (J,K, 70% epiboly), while chordin expression is suppressed (L,M, shield stage). Conversely, ectopic expression of mkp3::C292S expands expression of chordin at shield stage (N,O; arrowheads indicate the boundary of chd expression), and expression of neural markers en3 and krox20 (P,Q) at one-somite stage. MHB, mid/hindbrain boundary; r3 and r5, rhombomeres 3 and 5.