The nuclear experience of CPE-containing mRNAs mediates tight translational repression. (A) Diagram of experimental procedure for comparing CPE-dependent translational repression with or without the nucleus experience. (B) Time course of translational efficiency of reporters (luciferase activity/RNA) containing or lacking CPEs derived from plasmid DNA-injected oocytes (top). Time course of translational efficiency of the constructs noted above that were synthesized in vitro and then injected into the cytoplasms of oocytes (bottom). (C) Comparison of the translational efficiencies from panel B of plasmid-injected nuclei versus RNA-injected cytoplasm (dark gray bars). Also shown is a comparison of the translational efficiencies between RNA-injected nuclei versus cytoplasm (light gray bars). The RNA was collected 12 to 16 h after injection, and the translation efficiency was determined as in B. The bars represent the fold difference of translational efficiency of RNA lacking the CPE (mt) divided by that of RNA containing the CPE (WT). Statistical analysis was by a one-tailed paired t-test.
