Bacterial-driven odorant receptor expression shifts alter olfactory behavior in the oriental fruit fly

This work reveals a previously unknown mechanism by which gut microbiota
modulate insect sensory ecology, demonstrating that Enterobacter sp. MU-1,
a gut symbiont of the invasive pest Bactrocera dorsalis, reprograms host
olfactory behavior through specific suppression of odorant receptor OR67c.
Our integrated approach combining behavioral assays, transcriptomics, and
functional validation establishes a novel paradigm of tripartite interplay
between gut microbiota, chemoreceptor tuning, and behavioral adaptation.
Key findings include: MU-1 colonization converts avoidance behavior to
attraction in axenic flies (P < 0.01, Figure 1), while
RNAi-mediated knockdown of OR67c reverses this behavioral shift (55% gene
downregulation, P < 0.05, Figure 4). Temporal qPCR analysis
confirms that MU-1 specifically suppresses OR67c expression (FPKM >
2-fold change in antibiotic-treated vs. recolonized flies, Figure 3), with
no equivalent effects on other olfactory receptors. This
microbiota-chemosensory axis represents a significant advance in
understanding how symbiotic bacteria fine-tune insect behavioral
plasticity—a phenomenon with critical implications for developing novel
management strategies against this globally invasive species.