Data from: Flexible memory controls sperm competition responses to male Drosophila melanogaster

Males of many species use social cues to predict sperm competition and tailor their reproductive strategies, such as ejaculate or behavioural investment, accordingly. Whilst these plastic strategies are widespread, the underlying mechanisms remain largely unknown. Plastic behaviour requires individuals to learn and memorise cues associated with environmental change before using this experience to modify behaviour. Drosophila melanogaster respond to an increase in sperm competition threat by extending mating duration after exposure to a rival male. This behaviour shows lag times between environmental change and behavioural response suggestive of acquisition and loss of memory. Considering olfaction is important for a male’s ability to assess the sperm competition environment, we hypothesised that an olfactory learning and memory pathway may play a key role in controlling this plastic behaviour. We assessed the role of genes and brain structures known to be involved in learning and memory. We show that sperm competition responses depend on anaesthesia sensitive memory, specifically the genes rut and amn. We also show that the γ lobes of the mushroom bodies are integral to the control of plastic mating behaviour. These results reveal the genetic and neural properties required for reacting to changes in the sperm competition environment.诸多物种的雄性个体可借助社会线索预测精子竞争（sperm competition）风险，并据此调整生殖策略，例如射精投入或行为投入。尽管这类可塑性生殖策略分布广泛，但其背后的调控机制仍未被完全阐明。可塑性行为要求个体先学习并记忆与环境变化相关的线索，再依托此类经验调整自身行为。黑腹果蝇（Drosophila melanogaster）在暴露于竞争对手雄性后，会通过延长交配时长来应对精子竞争威胁的升高。该行为在环境变化与行为响应之间存在时间滞后性，这暗示了记忆的获取与消退过程。鉴于嗅觉对于雄性评估精子竞争环境至关重要，我们提出假说：嗅觉学习记忆通路或许在调控该可塑性行为中发挥关键作用。我们针对已知参与学习记忆过程的基因与脑结构，评估了其在该行为中的调控作用。我们证实，精子竞争响应依赖于麻醉敏感记忆（anaesthesia sensitive memory），具体涉及rut与amn两个基因。我们还证实，蘑菇体（mushroom bodies）的γ叶对于可塑性交配行为的调控不可或缺。本研究结果揭示了响应精子竞争环境变化所需的遗传与神经基础。