Coexpression of SID-1(S536I) with wild-type SID-1 interferes with soaking RNAi. (A) Cotransfection of SID-1(S536I) with wild-type SID-1 reduces luciferase silencing. S2 cells were cotransfected with a constant amount of firefly luciferase plasmid and the indicated ratios of plasmids that express wild-type SID-1 and SID-1(S536I). A range of concentrations of 500 bp firefly luciferase dsRNA was then added to the growth medium. (B) SID-1(S536I) does not sequester dsRNA from wild-type SID-1 when expressed in different cells. S2 cells coexpressing firefly luciferase and wild-type SID-1 were cocultured at the indicated ratios with S2 cells expressing SID-1(S536I) with a range of concentrations of 500 bp firefly luciferase dsRNA added to the growth medium. For cells expressing SID-1(S536I) alone (0:1 ratio), firefly luciferase plasmid was cotransfected with the SID-1(S536I) expressing plasmid. Error bars = 1 standard deviation, n = 3.
