<i>Zfp36</i> mRNA overexpression does not prevent mesoderm induction nor myogenic factor expression.

<p>(A) Two-cell stage embryos were injected with 250 pg of the different <i>Xenopus zfp36</i> mRNAs or mouse <i>zfp36</i> mRNA (<i>mzfp36</i>) and animal caps were explanted at stage 8.5–9 then treated with 10 ng/ml of activin before analysis by RT-PCR for <i>xbra</i> expression when control embryos reached stage 12. Stage 12 embryo (Emb) or untreated animal caps (-) were assayed by RT-PCR in parallel. <i>Odc</i> was used as control of loading and a reaction was performed in the absence of reverse transcriptase to check for genomic DNA contamination (-RT). (B) 250 pg of <i>Xenopus zfp36</i> (a, b) and <i>zfp36l1</i> (c, d) or mouse <i>Zfp36</i> (<i>mZfp36</i>, e, f) mRNAs were injected in one blastomere of two-cell stage embryos and developing embryos were fixed at stage 28 and analyzed by <i>in situ</i> hybridization for <i>myod</i> expression.