| pubmed-article:6305003 | pubmed:abstractText | Previous genetic and molecular data suggest that adenovirus genomes can undergo several rounds of recombination before being encapsidated (C. S. H. Young and S. J. Silverstein, Virology 101, 503-515). Two predictions of this hypothesis have been tested. The first is that infection with three differentially marked parental viruses should lead to the appearance of recombinants with genetic contributions from all three parents. In a triparental cross, involving two strains with different ts mutations in chimeric Ad5/Ad2+ND1 backgrounds, and a third strain containing both ts mutations in an Ad5 background, it was demonstrated that multiple recombinations, involving distinguishable restriction endonuclease sites and host range markers from all three parents, were common. The second prediction, from previous kinetic data, is that cells are recombinationally proficient from the eclipse period well into the exponential rise period. This has been tested by superinfecting singly infected cultures, both during eclipse and in early exponential phase. Recombinant viruses were produced in these superinfections, demonstrating that the early to late switch in the replicative cycle does not inhibit recombination. From the temporal appearance of recombinants moreover, it seems likely that recombination functions, and the DNA structures necessary to initiate recombination, are present well into the late phase of replication. | lld:pubmed |
