Figure 2.

Directed expression of viral protein U makes flies highly susceptible to fungal infections. Directed expression of viral protein U (Vpu) but not Vpu2/6 makes flies susceptible to fungal infection (B–D) but does not affect resistance to Gram-negative bacterial infection (A). Female adults were pricked with a needle that was previously dipped into (A) a pellet of Erwinia carotovora, or concentrated solutions of spores of (C) Aspergillus fumigatus or (D) Neurospora crassa, or were naturally infected with Beauveria bassiana (B). The spatzle (spz) gene is required to resist fungal infections (B–D), whereas mutations in dredd make flies highly susceptible to Gram-negative bacterial infection (A).