The uptake and development of reovirus in strain L cells followed with labeled viral ribonucleic acid and ferritin-antibody conjugates

Abstract

Reovirus possesses an outer capsid and a subjacent shell, presumably necessitating the rupture of two separate protective coats to release the genome. This may occur intracellularly within phagocytic viral inclusions where whole particles are sequestered and gradually lose their coats. Cells infected with purified virus particles containing labeled RNA were sampled at intervals during a 12-hour experimental period, and then subjected to light and electron microscopic autoradiography. The label was conserved in a macromolecular form throughout this period. Because of asynchrony in the release of parental genomes and lack of identifiable, partially degraded forms of the virus outside the phagocytic inclusions, it was not possible to reconstruct the sequence of stages during the penetration of inoculum RNA to its site of function. However, about 14% of the parental label was finally transferred to foci where progeny virus was being formed. Evidence, derived from experiments with infected cells and tagging by means of Ferritin-antibody conjugates specific for reovirus protein, is presented which relates virus morphogenesis with the presence of mitotic-spindle tubules and a cytoplasmic filamentous component.