Adult fruit flies (Drosophila melanogaster) are more tolerant of environments devoid of oxygen than their larvae. In fact, they are able to survive up to 12 hours without oxygen by becoming paralyzed, which enables them to dramatically reduce metabolism and the need for oxygen. In contrast, Drosophila larvae expend a lot of energy trying to escape and are only able to tolerate a couple of hours without oxygen. This is surprising as adults typically spend more time flying in the air whereas larvae develop in rotting fruit with little oxygen.
A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology examined differences in the metabolism of adult Drosophila and larvae exposed to short durations without oxygen. What they found was that lactate concentrations increased rapidly in larvae, which may lower their pH and cause them to become more acidic. In contrast, adults increased concentrations of metabolites that might protect tissues in their body from damage due to the drop in environmental oxygen. The drop in metabolism along with an increase in these protective protein may explain why adult Drosophila are better able to deal with low environmental oxygen concentrations.
For humans, impaired oxygen delivery to tissues can happen during strokes, heart attacks and even sleep apnea. Unlike Drosophila, however, neonatal humans can tolerate decreases in oxygen better than adults.
JB Campbell, S Werkhoven, J Harrison. Metabolomics of anoxia tolerance in Drosophila melanogaster: evidence against substrate limitation and for roles of protective metabolites and paralytic hypometabolism. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. 317(3): R442-R450, 2019. https://doi-org.ezproxy1.lib.asu.edu/10.1152/ajpregu.00389.2018