Effect of the Fv-1 locus on the titration of murine leukemia viruses.
Titration of N- and B-tropic murine leukemia viruses on sensitive and resistant cell lines has been studied by direct XC plaque assay and infective center assay. The titration of cloned B-tropic virus by infective center assay on BALB/3T3 (Fv-1b/b) and NIH/3T3 (Fv-1n/n) cells gave one-hit patterns, with 100-fold less infected NIH/3T3 cells than BALB/3T3 cells. The titration of B-tropic virus on DBA/2 cells (Fv-1n/n) was also a one-hit. The titration of a one-hit curve, and there were about 100-fold less infected BALB/3T3 cells than NIH/3T3 cells. Comparable results were obtained by titrating the cloned N-tropic virus on congenic SIM (Fv-1n/n) and SIM.R (Fv-1b/b) cells or the Gross N-tropic virus on BALB/3T3 cells. Therefore, our data indicate that the multiple-hit phenomenon described previously may not be an essential part of the Fv-1 gene restriction.
D000818:Animals; D002460:Cell Line; D005796:Genes; D009052:Leukemia Virus, Murine / Q000254:growth & development* / Q000302:isolation & purification; D051379:Mice; D008807:Mice, Inbred BALB C; D008815:Mice, Inbred Strains; D013045:Species Specificity; D010948:Viral Plaque Assay