Dengue Virus RNA Structure Specialization Facilitates Host Adaptation
Figure 5
Requirements of DEN-SLI and DEN-SLII for viral replication in mosquito and human cells.
(A) RNAs of reporter DENVs with deletions ΔSLI, ΔSLII or ΔSLI-II were transfected along with WT and replication impaired NS5M controls into C6/36, BHK and human A549 cells. Normalized luciferase levels are shown using a logarithmic scale at 48 h post transfection. The luciferase values are the mean +/- SD, n = 4. (B) Schematic representation of mutations in the DEN-SLII introduced in the reporter DENV. Red lines indicate substitutions and the circle indicates a deletion. (C) Viral RNA replication as in (A) for DEN-SLII mutants. The luciferase values are the mean +/- SD, n = 4. (D) Competition experiments in A. albopictus mosquitoes indicate a fitness advantage of variants with DEN-SLII mutations. Mosquitoes were injected with a mixture of the two viruses (WT: M132) at a 9:1 ratio and on day 10 individual mosquitoes were collected for viral RNA extraction and sequencing analysis of viral 3’UTRs. Pie charts with frequencies of viruses obtained from each mosquito are shown.