FIG. 6.

Schematic representation of Tn insertions into the HCMV virion glycoprotein genes. Mutants were characterized by appropriate restriction enzyme digests and direct sequencing on BACs prior to transfection. >, insertion of a Tn sequence resulting in the disruption of that gene. For gB many more candidates are present in the library, but these have not been confirmed by sequencing (grey symbols). Transfection results for insertion mutants are summarized at the right. When upon repeated transfection no viral progeny could be obtained (−), plaque formation could reproducibly be rescued by cotransfection of subgenomic fragments of HCMV DNA (4 to 5 kbp) spanning the insertion site. ∗, mutant with revertant genome constructed by allelic exchange in bacteria and found to be infectious.