FIG. 10.

Identification of seven sequence insertions (duplications) of various sizes at the junction between domains II-1 and II-2 in the genomic RNAs of MUTΔ1-284-derived pseudorevertants. The original recombinant viral stock was obtained after transfection of BHK-21 cells with the RNA transcripts derived from MUTΔ1-284 cDNA (passage 0); this virus stock was then passaged three times in naïve BHK-21 cells at an MOI of 0.1 (passages 1 to 3). The 3′-terminal sequences of the genomic RNAs at passages 0, 1, and 3 were determined as described in Materials and Methods. (A) Relative locations of the seven sequence insertions (Ins1 to Ins7) duplicated from upstream sequences of domain II-2 in the genomic RNAs of MUTΔ1-284-derived pseudorevertants. At the top is a schematic presentation of the genomic RNA derived from the MUTΔ1-284 cDNA; given below is an expanded view of the 290-nt 3′NCR containing only the three 3′-proximal domains (II-1, II-2, and III), with the three CSs (CS1, CS2, and RCS2) and the 3′SL indicated. (B and C) Nucleotide sequences of the seven sequence insertions (Ins1 to Ins7) of various sizes. (B) The number of clones containing each identified nucleotide sequence/the total number of clones containing the insert that we examined is indicated. (C) The nucleotides of the seven sequence insertions (duplications) were aligned; the RCS2 motif is highlighted with a gray box. Open arrowheads indicate the translation stop codon UAG.