Cauliflower mosaic virus replication intermediates are encapsidated into virion-like particles.

We have identified putative cauliflower mosaic virus (CaMV) replication intermediates of first (minus)-strand DNA synthesis which are associated with particles having properties similar to virions. The virion-like particles containing the putative replication intermediates sediment with CaMV virions on sucrose density gradients (L. Marsh, A. Kuzj, and T. Guilfoyle (1985) Virology 143, 212-223), band close to virions on CsCl density gradients, and are precipitable with antibody raised against the CaMV 42-kDa coat protein. The structures of the presumptive intermediates of DNA synthesis are compatible with a reverse transcription model for CaMV. Most or all of the observed minus-strand replication complexes appear to exist as RNA/DNA hybrids. Following RNase A treatment at low salt concentrations, the putative replication intermediates show characteristics of single-stranded DNA in selectively blotting and hybridizing to minus-strand-specific probes without prior denaturation of the blots.