摘要：SummaryThe phytopathogenErwinia carotovora carotovora(Ecc) has been used successfully to decipher some of the mechanisms that regulate the interactions betweenDrosophila melanogasterand bacteria, mostly following forced association between the two species. How doDrosophilanormally perceive and respond to the presence ofEccis unknown. Using a fly feeding two-choice assay and video tracking, we show thatDrosophilaare first attracted but then repulsed by anEcc-contaminated solution. The initial attractive phase is dependent on the olfactory Gr63a and Gαq proteins, whereas the second repulsive phase requires a functional gustatory system. Genetic manipulations and calcium imaging indicate that bitter neurons and gustatory receptors Gr66a and Gr33a are needed for the aversive phase and that the neuropeptide leukokinin is also involved. We also demonstrate that these behaviors are independent of the NF-κB cascade that controls some of the immune, metabolic, and behavioral responses to bacteria.Graphical AbstractDisplay OmittedHighlights•Starved flies are first attracted and then repulsed byErwinia-contaminated solution•Flies' attraction toErwiniais mediated by the olfactory receptor Gr63a and Gαq•Flies repulsion' toErwiniarequires Gr66a neurons and the leukokinin neuropeptide•Feeding onErwinia-contaminated solution potentiates bitter neurons of starved fliesNeuroscience; Behavioral Neuroscience; Sensory Neuroscience
