Fig. 5. Effective delivery of morpholinos and ubiquitous psr inhibition by PSR-MO. (A) Detection of PSR protein in 24 hpf PSR-MO-injected embryos by western-blot analysis. Note the dose-dependent loss of PSR protein from these embryos (panel a, lanes 3-5). (panel b) Actin internal control. (B) One-cell stage embryos were injected with either 40 ng control-MO or 40 ng PSR-MO, then fixed at either the 36 hpf or 3 dpf stage for in situ hybridization. (a,d) Phase-contrast images of the control-MO group, showing normal embryonic development and psr expression patterns. (b,c,e,f) Phase-contrast images of the PSR-MO group, showing abnormal development, with delayed (b,arrows) or distorted (c, arrows) psr expression patterns. (g-i) Fluorescence microscopy of an Acridine Orange-stained control-MO embryo (g), a weakly defective PSR-MO embryo (h) and a severely defective PSR-MO embryo (i). Accumulated corpse cells are indicated by arrows.