Abstract
After infection of Sac(-) cells with the murine coronavirus JHM the synthesis of seven major and two minor RNA species was induced. These RNAs were polyadenylated and single-stranded. Their mol. wt. were estimated by electrophoresis in agarose gels containing methylmercury hydroxide. The values for the major species were 6.67 x 10(6) for RNA of genome size (RNA 1), 3.42 x 10(6) for RNA 2, 2.76 x 10(6) for RNA 3, 1.35 x 10(6) for RNA 4, 1.19 x 10(6) for RNA 5, 0.93 x 10(6) for RNA 6 and 0.62 x 10(6) for RNA 7. The minor species have a size of 4.7 x 10(6) (RNA a) and 1.5 x 10(6) (RNA b). The same number of species were found by electrophoresis after denaturation with glyoxal-dimethyl sulphoxide. No gross difference in number of RNAs and the amount of each species was found between total cytoplasmic RNA, polyadenylated cytoplasmic RNA and RNA extracted from pelleted polysomes.