The nature of messenger RNA in the early stages of sea urchin development.

Abstract

MRNA synthesized in the developing sea urchin through the blastula stage is essentially the same as that in the unfertilized egg. Between the blastula and gastrula stages, about 40% of this population disappears and is replaced by different mRNA, characteristic of later stages of development. This major shift in mRNA population arising from a combination of gene activation and deactivation leaves unchanges the maintenance of functions common to all stages programmed by an invariant portion of the mRNA population.