In the early phase of courtship, female fruit flies exhibit an acute rejection response to avoid unfavorable mating. This pre-mating rejection response is evolutionarily paralleled across species, but the molecular and neuronal basis of that behavior is unclear. Here, we show that a putative incoherent feedforward circuit comprising ellipsoid body neurons, cholinergic R4d, and its repressor GABAergic R2/R4m neurons regulates the pre-mating rejection response in the virgin female Drosophila melanogaster. Both R4d and R2/R4m are positively regulated, via specific dopamine receptors, by a subset of neurons in the dopaminergic PPM3 cluster. Genetic deprivation of GABAergic signal via GABAA receptor RNA interference in this circuit induces a massive rejection response, whereas activation of GABAergic R2/R4m or suppression of cholinergic R4d increases receptivity. Moreover, glutamatergic signaling via N-methyl-d-aspartate receptors induces NO-mediated retrograde regulation potentially from R4d to R2/R4m, likely providing flexible control of the behavioral switching from rejection to acceptance. Our study elucidates the molecular and neural mechanisms regulating the behavioral selection process of the pre-mating female.

中文翻译：

---

前馈回路调节女性果蝇中交配前行为的动作选择。

在求爱的早期，雌果蝇表现出急性排斥反应，以避免不利的交配。这种交配前的排斥反应在进化上跨物种平行，但这种行为的分子和神经基础尚不清楚。在这里，我们显示了一个推定的非相干前馈电路，该电路包含椭球体神经元，胆碱能R4d及其阻遏物GABAergic R2 / R4m神经元，可调节处女雌性果蝇的交配前排斥反应。R4d和R2 / R4m都通过特定的多巴胺受体受到多巴胺能PPM3簇中一部分神经元的正调控。在此电路中，通过GABAA受体RNA干扰对GABA能信号的遗传剥夺引起大量排斥反应，而激活GABA能R2 / R4m或抑制胆碱能R4d则增加了接受性。此外，通过N-甲基-d-天冬氨酸受体的谷氨酸能信号传导可能诱导NO介导的从R4d到R2 / R4m的逆行调节，可能提供从拒绝到接受的行为转换的灵活控制。我们的研究阐明了调控早产女性行为选择过程的分子和神经机制。