Murine cytomegalovirus with a transposon insertional mutation at open reading frame M35 is defective in growth in vivo.

We had previously constructed a pool of murine cytomegalovirus (MCMV) mutants that contained a Tn3-based transposon sequence randomly inserted in the viral genome. In the study reported here, one of the mutants, RvM35, which contains the transposon insertion at open reading frame M35, was characterized both in vitro in tissue cultures and in immunocompetent Balb/c and immunodeficient SCID mice. Our results provide the first direct evidence to suggest that M35 is not essential for viral replication in vitro in NIH 3T3 cells.

In vitro and in vivo characterization of a murine cytomegalovirus with a mutation at open reading frame m166.

We have recently generated a pool of murine cytomegalovirus (MCMV) mutants by using a Tn3-based transposon mutagenesis approach. In this study, one of the mutants, Rvm166, which contained the transposon sequence at open reading frame m166, was characterized both in tissue culture and in immunocompetent BALB/c mice and immunodeficient SCID mice. The viral mutant replicated as well as the wild-type Smith strain in vitro in NIH 3T3 cells, whereas the transposon insertion precluded the expression of >65% of the m166 open reading frame.

Genetic analyses of gene function and pathogenesis of murine cytomegalovirus by transposon-mediated mutagenesis.

Murine cytomegalovirus (MCMV) has a linear genome of 230 kb and encodes more than 170 genes, many of which have not been extensively studied for their functions in pathogenesis in vivo. A Tn3-based transposon was constructed and used to generate MCMV mutants by disrupting viral gene targets. The functions of the mutated genes were investigated by studying the viral mutants in cultured cells and in immunocompetent Balb/c and immunodeficient SCID mice.