An evolutionarily conserved function of Ptenb regulates C/ebpα and α-catenin levels and prevents myelodysplasia in zebrafish embryos. (A) Western blot analysis of C/ebpα and α-catenin proteins in embryos injected with the indicated morpholino oligonucleotides at 22 hpf. Note that the polyclonal antibody used detected only zebrafish wild-type p38-kDa C/ebpα protein. (B-D) Morphology of embryos and appearance of EGFP⁺ myeloid progenitors in Tg(zpu.1:EGFP) transgenic embryos injected with the indicated morpholinos at 22 hpf. hb indicates hindbrain; and s, somite. (E-G) EGFP⁺ myeloid progenitors in Tg(zpu.1:EGFP) transgenic embryos injected with the indicated morpholinos at 28 hpf. hb indicates hindbrain; and s, somite. All embryos are shown in lateral view with the head to the left. (H-I) Whole-mount mRNA in situ hybridization analysis of l-plastin expression in control and ptenb-deficient embryos at 22 hpf.