FIG. 1.

(A) Structure of the transposon construct used for mutagenesis. TR, terminal repeat; Tet, tetracycline resistance gene; gpt, gene that encodes guanine phosphoribosyltransferase (gpt); poly(A), transcription termination signal; T, the 3′ terminus of viral genome. (B) Transposon insertion in the recombinant virus. The m166 coding sequence is shown as an open arrow, whereas the transposon is represented as a filled bar. The numbers represent the sizes of the DNA fragments of the viruses that were generated by digestion with HindIII (H) and EcoRI (E). (C) Southern analyses of the recombinant viruses. The DNA fractions were isolated from cells infected with the wild-type (WT) virus, Rvm166 (Rvm166) or Rqm166 (Rqm166). The DNA samples (20 μg) were digested with HindIII (H), separated on 0.8% agarose gels, transferred to a Zeta-Probe membrane, and hybridized to a DNA probe that contained the MCMV DNA fragment inserted with the transposon sequence.