FIG. 9.

Effect of actinomycin D on RNA encapsidation by Δγ405 coat protein. Monolayers of Drosophila cells (approximately 1.2 × 10⁸ cells) were transfected with wt RNA1 and in vitro-synthesized, capped Δγ405 RNA, as described in Materials and Methods. At 4 h after transfection, actinomycin D was added to the culture medium at a final concentration of 5 μg/ml, and incubation was continued for 20 h. Particles were then gradient purified, and RNA was extracted with phenol and chloroform. An aliquot was analyzed on a denaturing 1% agarose-formaldehyde gel followed by staining with ethidium bromide. Lane 1, RNA molecular size markers; lane 2, RNA extracted from Δγ405 particles grown in the absence of actinomycin D; lane 3, RNA extracted from Δγ405 particles grown in the presence of actinomycin D; lane 4, RNA extracted from wt FHV particles.