MPEG1 and infection: To further dissect the kinetics of infection at the BRB (retinal vascular endothelium), we infected double-transgenic (cross-bred for kdrl and mpeg1: BB) larvae with wild-type (WT) Mm. We noted that until 3 dpi, 83.3% (10 of 12) of the Mm were extracellular and within the lumen of the blood vessel (Figure 3A,B).