RNA interference (RNAi) plays a role in the defense against viral infection in plants, but does it play a similar role in animals? The evidence from tissue culture cells and Caenorhabditis elegans-based systems has suggested that this is so, but definitive evidence in a system that uses endogenous viruses and whole animals has been lacking. Wang et al. now show that both Drosophila embryos and adult flies mount a substantial innate immune response to insect viruses that requires the RNAi machinery and that this innate defense is separable from the innate bacterial defense provided by the Toll and immune-deficiency pathways.
X.-H. Wang, R. Aliyari, W.-X. Li, H.-W. Li, K. Kim, R. Carthew, P. Atkinson, S.-W. Ding, RNA interference directs innate immunity against viruses in adult Drosophila. Science 312, 452-454 (2006). [Abstract] [Full Text]