Abstract
Ibaraki virus core particles were purified from infected BHK-21 cells. The core particles displayed RNA transcriptase activity while the virion did not. The RNA transcriptase activity was stimulated about 15- fold by addition of S-adenosyl-L-methionine. The reaction product was single-stranded RNA which could be hybridized with heat-denatured Ibaraki virus RNA. The hybrids possessed the same electrophoretic mobility as Ibaraki virus double-stranded RNA.