Meeting Abstract
Atmospheric oxygen has wide ranging effects on insect physiology including changes in body size, development, lifespan, and fecundity. Recently, several studies have shown an effect of oxygen on the tracheal system of insects. A limitation of these studies has been a focus on the supply side and only imaging the large conducting tracheae or a small area of the tracheoles Here we have used confocal imaging to image both the oxygen supply side (the tracheal system) and the oxygen demand side (the mitochondria) of the flight muscle in Drosophila melanogaster that have been reared in oxygen levels ranging from 12kPa to 31kPa. Using genetically modified D. melanogaster that have a yellow-fluorescing protein (YFP) inserted into their mitochondrial membrane, we have been able to create 3D renderings of both the mitochondrial and tracheolar networks, which auto-fluoresce in the green spectrum. This allows us to simultaneously analyze the effect of developmental oxygen on the relative volume investment and network patterns of both components. Using this technique and analyzing the images in Image Pro Premier, we have been able to co-localize the mitochondrial network with the tracheolar network and show that mitochondrial to tracheolar distances vary with rearing oxygen. Interestingly, it appears both tracheolar investment and mitochondrial investment are inversely correlated with rearing oxygen. This suggests that insects invest more in their respiratory network to ensure adequate oxygen delivery. At the same time, they invest more in their mitochondrial system to ensure metabolic efficiency during periods of high performance. The results of these studies demonstrate that atmospheric oxygen availability strongly affects both the supply and demand side of insect respiratory systems.
