Self-annealing of Subgroup 2 Myxovirus RNAs

Abstract

THE myxoviruses of subgroup 2, Newcastle disease virus (NDV)¹ and Sendai virus², have been shown to contain a homogeneous component of RNA which has a sedimentation coefficient (S_20,w) of 57S, and the properties of single stranded RNA. Cells infected with these viruses synthesize viral specific RNA, 70 to 90 per cent of which anneals exclusively with virion RNA to form highly ordered complexes suggesting that most of the intracellular RNA is complementary in base sequence to virion RNA^2–4. Several distinct components of viral specific RNA are synthesized in infected cells and one of these (57S) is indistinguishable from virion RNA in sedimentation rate². The 57S RNA in infected cells has been shown to be almost completely in the form of viral nucleocapsid (C. D. Blair and W. S. R., manuscript in preparation) and annealing studies have shown that this RNA component anneals extensively when incubated with virion RNA (unpublished results of W. S. R.). Because of this observation, annealing experiments were done with 57S RNA isolated from purified Sendai virus and Newcastle disease virus, and the results I report here indicate that a large fraction of the single stranded 57S RNA from these virusesself anneals.