Figure 4: Gut colonization assayed by a co-feeding assay with GFP or RFP tagged bacteria. Newly emerged mosquitoes were fed on sugar meals mixed with RFP/wt and GFP/waaL-(a) or RFP/waaLand RFP/wt (b) cells in 1:1 ratio for 2 days. Then, the bacterial sugar was replaced with sterile sugar solution for the remaining time of the experiments. At day 3, the mosquitoes were given a blood meal. Panel (A) presents the fluorescent bacteria in the sugar solution; Panel (B) presents the fluorescent bacteria in the gut examined at day 3 post bacterial feeding; Panel (C) presents the fluorescent bacteria in the gut at 24 hr post blood feeding. The images were taken by a fluorescent microscope with 10×40 magnification in (A), and 10×20 magnification in (B) and (C).