Abstract
DNA extracted from frog virus 3 has a GC mol fraction of about 0.56. The mol. wt. of the DNA is about 100 x 106 (97 x 106 by neutral sucrose gradient sedimentation; 102 x 106 from renaturation kinetics). Analysis by neutral sucrose sedimentation indicated that the DNA exists as a single heteroduplex in the virus particle. Alkaline sucrose gradient sedimentation indicated that single strand alkali labile interruptions probably occur in both strands of the heteroduplex. Renaturation kinetic analysis also indicated that about 7% of the genome contains repeated sequences. Quantitative analyses of DNADNA homology showed no sequence homology between frog virus 3 DNA and the DNA extracted from iridescent virus types 2, 6 or 9. This lack of sequence homology reflects the markedly distinct profiles on acrylamide gels of the structural polypeptides of frog virus 3 and the iridescent viruses.
* Present address: N.E.R.C. Unit of Invertebrate Virology, Commonwealth Forestry Institute, University of Oxford, South Parks Road, Oxford, OX1 3RB, Oxfordshire, U.K.