EVOLUTIONARY CONSERVATION OF SEQUENCE ELEMENTS CONTROLLING CYTOPLASMIC POLYADENYLYLATION

Cytoplasmic polyadenylylation is an evolutionarily conserved mechanism involved in the translational activation of a set of maternal messeng er RNAs (mRNAs) during early development, In this report, we show by i nterspecies injections that Xenopus and mouse use the same regulatory sequences to control cytoplasmic poly(A) addition during meiotic matur ation. Similarly, Xenopus and Drosophila embryos exploit functionally conserved signals to regulate polyadenylylation during early post-fert ilization development. These experiments demonstrate that the sequence elements that govern cytoplasmic polyadenylylation, and hence one for m of translational activation, function across species. We infer that the requisite regulatory sequence elements, and likely the trans-actin g components with which they interact, have been conserved since the d ivergence of vertebrates and arthropods.