[The translation regulation of the synthesis of proteins responsible for dorsoventral differentiation of clawed toad embryos].

We studied the distribution of mRNAs involved in dorsoventral differentiation of Xenopus laevis embryos (Xbra, chordin, Xnot, Xvent1, Xvent2, and Xwnt11) among polyribosomes (the translated form of mRNA) and informosomes (the nontranslated form of mRNA). It was shown using molecular hybridization that all of the studied templates are in the informosomes until the midgastrula stage, thus suggesting regulation at the level of translation. At the midgastrula stage (stage 11), translation begins on mRNAs of chordin, Xnot2, Xvent1, and Xbra, although mRNAs of Xvent1 and Xbra are partially located in the informosomes. The matrices of Xwnt11 are localized predominantly in the informosomes at the midgastrula stage, while those of Xvent2 are not seen in the polyribosomes until the end of gastrulation. We propose that the fate of different mRNAs is determined by different mechanisms of r-translational regulation in different cell lineages. It cannot be excluded that the Xvent2 transcript is not involved in translation and fulfills its morphogenetic functions in the form of RNA or RNP.