Investigating a Link Between Cold Stress and Bacterial Leak from the Gut of Locusta Migratoria

Abstract

Following prolonged low temperature exposure, chill-susceptible insects can incur chilling injuries that manifest as motor deficits and tissue damage. This is thought to be a driven by a loss of ion and water homeostasis partly resulting from gut leak of solutes. The insect gut, however, also houses an abundant microbial community. Recent studies have reported immune activation following cold stress in insects, which has yet to be fully explained. Here, I hypothesize that prolonged cold stress results in immune activation as a result of bacterial leakage across the gut and into the surrounding fluid of locusts, using fluorescent bacteria as a marker to test it. Surprisingly, no leakage of the fluorescent bacteria was observed regardless of cold exposure duration. My research suggests that gut barrier integrity is maintained after cold stresses, and this open up other possible explanations as to why cold-induced immune activation occurs in insects.