Biochemical Characteristics of Rat C-Type Virus WF-1

Abstract

The discovery and morphological-immunological properties of the rat C-type virus WF-1, infectious for normal rat embryo cell cultures, have been previously described (1 , 2). This presumably endogenous C-type virus was spontaneously released by a cell line (WF-1) derived from normal Wistar-Furth rat embryos. The virus was also shown to be antigenically related to two C-type viruses (RMTDV and R-35) produced by cell lines derived from rat mammary tumors (3).Although all three viruses are similar morphologically and antigenically, only RMTDV had been found to produce some leukemogenic effects when inoculated into rats (4).It was therefore of interest to determine the pertinent biochemical characteristics of the WF-1 virus, non-oncogenic for rats, and to compare them with those of known oncogenic RNA viruses of other animal species. The results of this study are presented in this report. Materials and methods. Reagents. TNE buffer (0.01 M Tris, 0.1 M NaCl, and 0.001 M EDTA, pH 7.2), TNM buffer (0.01 M Tris, 0.1 M NaCl, and 0.001 M MgCI2), and sucrose solutions prepared in TNE buffer were sterilized by filtration (0.45-pm porosity, Millipore Corp., Bedford, Mass .) . Ribonuclease-free sucrose, [3H]uridine (sp act 25 to 28 Ci/mmole), [14C]uridine (sp act