An approach to the understanding of messenger ribonucleic acid synthesis, processing and regulation in eukaryotes.

Eukaryotic mRNA isolation is now relatively simple, and molecular probes allow analysis of gene number and specific gene expression by nucleic acid hybridization. Compelling evidence is accumulating for high-molecular-weight nuclear precursors of mRNA species, but little is known of their processing or detailed molecular structure. This should become clear when heterogeneous nuclear RNA molecules containing only one mRNA sequence are analysed.