Neurobiology of Egg-laying Behavior in <em>Drosophila</em>:<em> </em>Neural Control of the Female Reproductive System

Abstract

Egg-laying is one of the key aspects of female reproductive behavior in insects. Egg-laying has been studied since the dawn of Drosophila melanogaster as a model organism. The female&amp;rsquo;s internal state, hormones, and external factors, including nutrition, light, and social environment, affect egg-laying output. However, only recently has light been shed on certain neurobiological features of egg-laying behavior in both the central and peripheral nervous systems. The central nervous system regulates egg-laying behavior and decision-making, and many studies use fruitless and doublesex, two genes in the sex determination pathway, to identify reproductively important neurons. Neuronal groups like aDNs and pC1clusters modulate egg-laying behavior in the brain, and other neurons like oviINs and oviDNs affect oviposition specifically. In the ventral nerve cord, the abdominal neuromere houses neurons that send information to and from the reproductive tract, including sex peptide abdominal ganglion neurons (SAG) and octopaminergic motor neurons. The reproductive tract itself houses sensory neurons that respond to different aspects of egg maturation and mating, including the male accessory gland products and mechanical stimuli. I conclude this review by summarizing the importance of egg-laying neuronal control in various evolutionary phenomena like cryptic female choice and highlight two Drosophila species and provide intriguing avenues for the future of the field.