Translational blocking of pePNAs after injection of gfp mRNA into medaka embryos. The pePNAs were coinjected with gfp mRNA into medaka embryos at the one cell stage. 24 hours later the intensity of the gfp fluorescence was qualified as weak (B), moderate (C; mod) or strong (D). (A) Shows an uninjected embryo (no signal, corresponding to a complete knock down of gfp). The embryos are shown in a dorsal view, anterior to the top. A graph summarizing the experiments for optimisation of the PNA length is shown in (E). The names of the PNAs are explained in Figure 2. The embryos were injected with a mixture of 10 ng/μl gfp mRNA and 200 μM PNAs preincubated for 30 minutes on ice. After 24 hours the embryos were divided into groups according to their gfp signal intensity. Above the columns the calculated average gfp intensity in percent is indicated (see text for calculation). Similarly the results for mixed PNAs are shown in (F). Injections and evaluations were performed as in (E), except that 20 ng/μl mRNA were used. Note that the increased amount of mRNA results in higher numbers of average gfp intensity for comparable antisense function.