Drosophila's sensory responses to bacterial peptidoglycan integrates positive and negative signals

Abstract

Interactions between animals, including humans, and surrounding microbes are governed by a delicate balance, crucial for survival. Animals must distinguish and respond adequately to beneficial and harmful microbes to maintain homeostasis. Recent research suggests that bacterial components such as lipopolysaccharide and peptidoglycan (PGN) influence host behavior by modulating neuronal activity. PGN detection by specific neurons can prompt infected female flies to reduce oviposition or trigger avoidance behaviors via gustatory neurons. Using behavioral assays and calcium imaging, we found that PGNs can also act as attractants, activating the sweet taste circuit in a concentration-dependent manner. Our findings demonstrate that flies integrate PGN-derived positive and negative signals to make ad hoc decisions. This dual response underlines the need for Drosophila to distinguish between different concentrations of compounds in their environment, integrating sensory data to navigate efficiently in microbe-co-inhabited environments. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/626038v3_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@8aab21org.highwire.dtl.DTLVardef@1e90d09org.highwire.dtl.DTLVardef@156f1d4org.highwire.dtl.DTLVardef@11ed69c_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Bacterial PGN is attractive to flies - Gr5a sweet gustatory neurons are activated by PGN - Adult PER to PGN is not directly influenced by larval life - Fly gustatory response to PGN integrates both attractive and aversive signals