Fig 4.

Comparison of the entire 3′ UTR of B3 to those of B1 (A) and B2 (B). Nucleotides are numbered from the 3′ end. The diagnostic nucleotides (shown in gray font) used to distinguish the 3′ end of B3 (shown in black font) from those of B1 and B2 are shown. Roman numerals I to VI and I to IV indicate nucleotide domains of B1 and B2, respectively, that are involved in template switching of the BMV RdRp to generate recombinant sequences. Recombinant clones shown below each domain (e.g., GRI-1) correspond to those shown in Fig. 3. ^a, homologous recombinants; ^b, nonhomologous recombinants.