Circuit and Behavioral Mechanisms of Sexual Rejection by Drosophila Females

• Published in: Current biology Vol. 30; no. 19; pp. 3749 - 3760.e3
• Main Authors: Wang, Fei, Wang, Kaiyu, Forknall, Nora, Parekh, Ruchi, Dickson, Barry J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 05.10.2020
• Subjects: courtship song; descending neurons; Drosophila; mating behavior; neural circuit; ovipositor extrusion; ovulation; receptivity; rejection; neural circuit; receptivity; descending neurons; ovipositor extrusion; Drosophila; courtship song; rejection; mating behavior; ovulation
• ISSN: 0960-9822; 1879-0445; 1879-0445
• DOI: 10.1016/j.cub.2020.07.083

The mating decisions of Drosophila melanogaster females are primarily revealed through either of two discrete actions: opening of the vaginal plates to allow copulation, or extrusion of the ovipositor to reject the male. Both actions are triggered by the male courtship song, and both are dependent upon the female’s mating status. Virgin females are more likely to open their vaginal plates in response to song; mated females are more likely to extrude their ovipositor. Here, we examine the neural cause and behavioral consequence of ovipositor extrusion. We show that the DNp13 descending neurons act as command-type neurons for ovipositor extrusion, and that ovipositor extrusion is an effective deterrent only when performed by females that have previously mated. The DNp13 neurons respond to male song via direct synaptic input from the pC2l auditory neurons. Mating status does not modulate the song responses of DNp13 neurons, but rather how effectively they can engage the motor circuits for ovipositor extrusion. We present evidence that mating status information is mediated by ppk+ sensory neurons in the uterus, which are activated upon ovulation. Vaginal plate opening and ovipositor extrusion are thus controlled by anatomically and functionally distinct circuits, highlighting the diversity of neural decision-making circuits even in the context of closely related behaviors with shared exteroceptive and interoceptive inputs. [Display omitted] •Mated Drosophila females extrude their ovipositors to reject courting males•The DNp13 descending neurons are command neurons for ovipositor extrusion•DNp13 neurons respond to male courtship song via pC2l auditory neurons•Ovulation, triggered by a prior mating, enhances DNp13 motor output After an initial mating, female flies often reject courtship from other males. Here, Wang et al. characterize the neural circuitry that controls a specific rejection behavior, ovipositor extrusion. Ovipositor extrusion occurs in response to a male’s courtship song, provided the female has ovulated as a consequence of a previous mating.