Contribution of maternal mRNA for maintenance of Ca²⁺-dependent reaggregating activity in dissociated cells of Xenopus laevis embryos

Dissociated Xenopus laevis blastula cells, where reaggregation was inhibited in Ca²⁺-free medium, reaggregated immediately after the addition of Ca²⁺. This reaggregation was not inhibited by cordycepin or actinomycin D treatment during culture, although cycloheximide and puromycin were inhibitory. The reaggregation was not inhibited even when fertilized eggs were microinjected with cordycepin and their RNA synthesis was continuously inhibited through cleavage to blastula stages. In neurula cells, cordycepin treatment induced significant reduction in sizes of aggregates formed. These results suggest that the Ca²⁺-dependent reaggregating activity of blastula cells is maintained by the translation of maternal, rather than newly synthesized, mRNA.