At 2 days post-fertilization (dpf),Lyz:dsRed or mpx:GFP larvae were transferred into DMSO ctrl or FK506 (1 μg/ml) containing 0.5 × E2. At 3 dpf, zebrafishlarvae were microinjected with AF eGFP conidia into the hindbrain and mortality, and fungal burden and neutrophil recruitment were assessed. E-G Lyz:dsRedlarvae were infected with ˜50 eGFP-expressing conidia of A. fumigatus and were imaged daily from 24 h p.i. (E) The effects of FK506 on neutrophil recruitment were assessed by integrated density analysis of red fluorescent neutrophils at sites of infection in ImageJ. A representative image showing impaired neutrophil recruitment to the site of infection in immunosuppressed larvae is shown (60 h p.i.). The arrows indicate infectious foci. (F) Neutrophil recruitment was minimal throughout the first 60 h p.i. in immunosuppressed larvae (n = 8 per group). (G) Fungal growth was determined by measurement of the length of individual fluorescent hyphal elements (n = 8 per group). 