Figure 1.

Hypoxic conditions in the guts of conventionally reared and axenic Aedes aegypti larvae. Larvae were reared to the third instar of development and stained with Image-iT Hypoxia Reagent, which fluoresces in anoxic conditions (<5% oxygen). Axenic larvae were reared in the dark to protect light sensitive B-vitamins in the culture medium. A subset of axenic larvae were subsequently verified to be free of microbial contamination by both culture-dependent and culture-independent (16S rRNA and fungal rRNA gene PCR) methods.