L-cell virion ribonucleic acid.

"L-cell virion," obtained from chronically infected 929 L-cell lines, was purified on 70% sucrose pads and its ribonucleic acid (RNA) was extracted and analyzed on sucrose gradients. Two RNA components were isolated from the virion, a rapidly sedimenting species (82S) and a more slowly sedimenting species (6S). When the fast-moving component was heated to 45 C, it yielded a homogeneous peak which now sedimented at approximately 72S. Upon heating to 70 C, the peak dissociates into a smaller homogeneous RNA species with a sedimentation coefficient of approximately 33S. Ribonuclease treatment and base composition analysis revealed that the fast-moving species is a single-stranded molecule. Base ratio analysis also revealed that the small (6S) RNA component is similar in its base composition to L-cell ribosomal RNA and distinctly different from the base composition of the large (72S) RNA component. Actinomycin D inhibits production of the L-cell virion by the L-cell line.