FIG. 6.

Effect of the deletion of the RNA2 5′ and/or 3′ UTR on Δ31 RNA2 replication. (A) Schematic representation of recombinant baculoviruses for the synthesis of replicating Δ31 RNA2 (AcΔ31δ) and nonreplicating Δ31 RNA2 (AcΔ31[−3′UTR]). These baculoviruses are identical to AcR2δ and AcR2[−3′UTR] (Fig. 4A), respectively, with the exception that the cDNA encoding residues 2 through 31 of FHV capsid protein was deleted (indicated by a break in the lines). Electrophoretic analysis (B) and Northern blot analysis (C) of total cellular RNA isolated from Sf21 cells infected with AcR1δ and either AcΔ31δ or AcΔ31[−3′UTR] at an MOI of 10. Aliquots of either 3 μg or 100 ng total cellular RNA were run on a denaturing agarose gel for electrophoretic and Northern blot analysis, respectively. Northern blot analysis was performed with a negative-sense RNA2 probe. The positions of RNA1, RNA2, Δ31 RNA2 (Δ31), and RNA3 are indicated to the right. RNA isolated from authentic FHV particles (vRNA) and in vitro-synthesized Δ31 RNA2 transcripts (Δ31ts) were run for comparison in lanes 3 and 4, respectively. The molecular sizes of RNA markers (in nucleotides) are indicated to the left.