FIGURE 3.

Phenotypes of morpholino-mediated knockdown of gpbp and gpbpΔ26. A, the position of the target sequence for the translation-blocking morpholino is depicted. The arrow marks the start ATG codon. B, uninjected (wild type, WT) or MO^5′UTR injected embryos at 24 hpf were lysed, and the protein extracts were resolved in reducing 10% acrylamide gels, blotted, and stained with the Mab14 antibody. On the left is the molecular mass expressed in kDa. Arrowheads point to isoforms of Gpbp and GpbpΔ26. C, lateral views of embryos, injected with 5 ng of morpholino (MO^5′UTR) or uninjected controls (WT), were photographed at the indicated times. Arrowheads point to brain edema and to the jaw region. D, wild-type (WT) and MO^5′UTR-injected embryos were fixed at 48 hpf and embedded in plastic resin, sectioned, and stained with toluidine blue. The top four panels show sagittal (left) and cross-sections (right) through the fourth ventricle region of the brain. The arrowhead points to myelinated axonal tracts, and the asterisk marks large brain edema and loss of neuronal tissues. The bottom two panels depict sagittal sections through the mid-trunk region of wild-type and morphant embryos at 48 hpf. The morphant somites are smaller and contain large numbers of dying cells and cellular debris (arrows).