Champalimaud Center for the Unknown, Lisbon 1400-038, Portugal.
Centre for Neural Circuits and Behaviour, University of Oxford, Oxford OX1 3SR, UK.
Curr Biol. 2020 Oct 5;30(19):3736-3748.e5. doi: 10.1016/j.cub.2020.06.071. Epub 2020 Aug 13.
Communication between male and female fruit flies during courtship is essential for successful mating, but, as with many other species, it is the female who decides whether to mate. Here, we show a novel role for ovipositor extrusion in promoting male copulation attempts in virgin and mated females and signaling acceptance in virgins. We first show that ovipositor extrusion is only displayed by sexually mature females, exclusively during courtship and in response to the male song. We identified a pair of descending neurons that controls ovipositor extrusion in mated females. Genetic silencing of the descending neurons shows that ovipositor extrusion stimulates the male to attempt copulation. A detailed behavioral analysis revealed that during courtship, the male repeatedly licks the female genitalia, independently of ovipositor extrusion, and that licking an extruded ovipositor prompts a copulation attempt. However, if the ovipositor is not subsequently retracted, copulation is prevented, as it happens with mated females. In this study, we reveal a dual function of the ovipositor: while its extrusion is necessary for initiating copulation by the male, its retraction signals female acceptance. We thus uncover the significance of the communication between male and female that initiates the transition from courtship to copulation.
在求偶过程中，雌雄果蝇之间的交流对成功交配至关重要，但与许多其他物种一样，是否交配是由雌性决定的。在这里，我们展示了产卵器伸出在促进处女蝇和交配雌蝇中的雄性交配尝试以及在处女蝇中发出接受信号的新作用。我们首先表明，产卵器伸出仅由性成熟的雌性表现出来，仅在求偶期间并且对雄性歌声作出反应。我们鉴定出一对控制交配雌蝇产卵器伸出的下行神经元。对下行神经元的基因沉默表明，产卵器伸出会刺激雄性尝试交配。详细的行为分析表明，在求偶过程中，雄性会反复舔雌性生殖器，而与产卵器伸出无关，并且舔伸出的产卵器会促使雄性尝试交配。但是，如果随后不缩回产卵器，则会阻止交配，就像交配后的雌蝇一样。在这项研究中，我们揭示了产卵器的双重功能：虽然它的伸出对于雄性启动交配是必要的，但它的缩回则表示雌性接受。因此，我们揭示了启动从求偶到交配的雌雄之间交流的重要性。
