ABSTRACT
The transcription and/or subsequent processing of pre-tRNA molecules, which carry 5'-flanking and 3'-trailing sequences and may or may not possess an intervening sequences (IVS), will take place in several in vitro systems. The requirement of the in vitro splicing reaction for ATP provides a means to uncouple excision, cleavage at either end of the IVS, from ligation, rejoining of the novel termini of the precursor created by excision. Determination of the sizes of the poly(A)-containing RNA molecules labeled in vitro and protected against nuclease Sl-digestion by hybridization to specific, cloned, restriction endonuclease fragments of adenovirus DNA has demonstrated that the cleavages of the primary Ad2 late transcript to generate sites of poly(A) addition occur in vitro at the sites utilized in vivo. A final complexity that must be included when considering splicing of pre-messenger ribonucleic acid species is its potential for regulation of gene expression.
