The mechanism of formation of adenovirus-2 late messenger RNAs from nuclear viral primary transcripts will be studied. Small restriction fragments of Ad2 DNa will be identified which encode the 3' terminal regions of late viral mRNA species. These fragments are anticipated to encode portions of primary transcripts which are recognized by RNA processing enzymes. The structures of these DNA fragments will be analyzed for nucleotide sequences which are signals for RNA processing events. BIBLIOGRAPHIC REFERENCES: Sedat, J., Ziff, E. and Galibert, F. (1976). J. Mol. Biol. 197, 391-416. Aiv, G.M., Blackburn, E.H., Coulson, A.R., Galibert, F., Sanger, F., Sedat, J.W. and Ziff, E.B. (1976). J. Mol. Biol. 107, 445-458.