Figure 7. Neuronal octopamine signaling, followed by Oamb-Ca²⁺-Mmp2 signaling, regulates the mating-induced GSC increase.

The illustration is the proposed working model from our findings here. SP signaling and SP sensory neurons activate dsx⁺ Tdc2 neurons via acetylcholine signaling. The octopamine released from dsx⁺ Tdc2 neurons is received by the Oamb in escort cells and then activates intracellular Ca²⁺ flux. The OA-mediated signaling increases pMad levels in GSCs to evoke mating-induced GSC increase via Mmp2.