DNA TRANSFECTION OF ECOTROPIC MURINE LEUKEMIA VIRUSES IN MOUSE CELL-CULTURES

Abstract

DNA were isolated from cells chronically infected with N-, B- or NB-tropic murine leukemia viruses and tested for infectious activity in various mouse cell cultures. Early detection of the DNA transfection is facilitated by growing the DNA-recipient cells in medium containing 10-6 M hydrocortisone. Appropriate shearing of the DNA preparations may increase the efficiency of the transfection. With these procedures virus production of the transfected cells can be detected by [rat sarcoma] XC [cell] plaque assay as early as 4 days after DNA inoculation in [mouse fibroblast] NIH 3T3 cells. Susceptibility of the mouse cell cultures to DNA transfection does not parallel their susceptibility to virion infection. Progeny virues derived from the transfection show the same N- or B-tropic host range property as do the parent viruses.