HYBRIDIZATION BETWEEN SV40 DNA AND CELLULAR DNAS

In DNA-DNA hybridization tests, Simian virus 40 DNA was bound by monkey and mouse cell DNA but not by DNA from chicken livers, Escherichia coli or T4 phage. The capacity of SV40 DNA to bind to monkey cell DNA was not abolished after fractionation of the SV40† † Abbreviations used: SV40, simian virus 40; MAK, methylated albumin-kieselguhr; F-dUrd, fluorodeoxyuridine; Br-dUrd, bromodeoxyuridine; p.f.u., plaque-forming unit. DNA by MAK chromatography, by equilibrium centrifugation in cesium chloride-ethidium bromide density-gradients, or by band sedimentation in neutral and alkaline cesium chloride solutions. In contrast, polyoma DNA, purified by MAK chromatography, was bound to only a very small extent, if at all, by mouse cell DNA. Double labeling experiments with [14C]-Br-dUrd before infection and [3H]thymidine after infection showed that the apparent homology between SV40 DNA and monkey cell DNA cannot be accounted for by the presence in viral capsids of host cell DNA unlinked to viral DNA. © 1969.