Table 1.

Virus production after transfection of permissive cells with wild-type or mutant MVM DNA clonesa

Indicator cell lineVirus titers (hybridization U/transfected culture) for producer cell line and virus DNA clone
A98 × 105 ND9 × 105 4 × 105 ND4 × 105
NBK9 × 105 ND9 × 105 8 × 105 ND9 × 105
  • a Cultures of 106 A9 or NBK cells were transfected with 10 μg of DNA of the wild-type (pMVM) or mutant (pMVM-E2F and pMVM-Ets) MVM genomic clones. Cells and supernatants were collected 7 days after transfection and sonicated in order to release progeny viruses. After elimination of cell debris, virus titers were determined by single-cell DNA hybridization, with A9 or NBK indicator cultures. Data shown are average values from five independent experiments (standard deviation < 10%). The background value detected with the replication-deficient MVM genomic clone (pMVMori) was subtracted. ND, nondetectable (<3 U/transfected culture).