Genomic plasticity drives olfactory adaptation in a pest fly

Area of Science:

• * Insect olfaction and sensory ecology.
• * Evolutionary biology and genomics.

Background:

• * Olfactory system changes drive insect preference shifts, but mechanisms are unclear.
• * The pest fruit fly, *Drosophila suzukii*, oviposits in ripe fruits, offering a model for studying these shifts.
• * Understanding these mechanisms is crucial for pest control strategies.

Purpose of the Study:

• * To investigate the mechanisms underlying olfactory preference shifts in *Drosophila suzukii*.
• * To identify specific olfactory receptor neurons involved in this behavioral adaptation.
• * To explore the genomic basis of these sensory changes.

Main Methods:

• * Comparative analysis of olfactory receptor neuron function between *D. suzukii* and *D. biarmipes*.
• * Investigation of olfactory receptor gene expression and sequence divergence.
• * Functional characterization of olfactory receptor neurons ab2B, ab3A, ab4B, and ab10A.

Main Results:

• * Functional remodeling in four olfactory receptor neurons (ab2B, ab3A, ab4B, ab10A) underlies the preference shift in *D. suzukii*.
• * Species-specific adaptations were observed in ab2B and ab4B neurons.
• * Novel mechanisms, including receptor co-expression and partitioned expression of paralogs, were identified.

Conclusions:

• * Genomic plasticity in chemosensory gene families enables rapid sensory adaptation.
• * These adaptations facilitate niche transitions, as seen in *D. suzukii*'s shift to ovipositing in ripe fruits.
• * The study provides insights into the molecular basis of olfactory-driven behavioral evolution.