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...诸多物种的雄性个体可借助社交线索预判精子竞争态势，并针对性调整生殖策略，包括射精投入与行为投入等。尽管这类可塑性生殖策略广泛分布，但其背后的核心调控机制仍未被完全阐明。行为可塑性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）在接触同性竞争者后，会通过延长交配时长来应对精子竞争威胁的加剧。该行为在环境变化与行为响应之间存在滞后性，这提示其涉及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：嗅觉学习记忆通路可能在调控该可塑性行为中发挥关键作用。本研究针对已知参与学习记忆过程的基因与脑结构的功能展开了评估……