Table 1.

Leukemogenicity of MCF viruses in AKR/J mice

VirusaNo. of diseased mice/no. injectedbMean latency period (days)cIncidence of leukemia (%)d
Controle 0/26NAf 0
MCF 247-W (supF)31/32117 ± 2797
MCF 1dr (supF)16/33140 ± 1748
MCF 2dr (Not9)38/55135 ± 2969
  • a Virus stocks were prepared fromM. dunni cells transfected with cloned viral DNAs. Mice were injected with virus stocks having titers that varied less than one-half of a log unit, as determined by reverse transcriptase activity assay.

  • b The number of mice with disease is compared with the total number of mice injected with a specific virus.

  • c The mean latency period calculated is expressed as the mean of all mice observed with advanced disease ± the standard error.

  • d Percent incidence was calculated as (number of mice with advanced disease at 180 days)/(number of mice injected) × 100.

  • e Control mice indicate the incidence of spontaneous leukemia prior to 180 days.

  • f NA, not applicable.