Dong Linhan, Bradford Elisabeth F, Barnett Jord M, Duvall Laura B
Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Barnard College, New York, NY 10027, USA.
bioRxiv. 2025 Jun 27:2025.06.25.661507. doi: 10.1101/2025.06.25.661507.
The global spread and increasing populations of disease vector mosquitoes expose hundreds of millions of people to mosquito-borne illnesses each year. Female mosquitoes, global vectors of dengue, require protein from host blood to support egg development and undergo repeated cycles of blood-feeding and egg-laying. After biting, females temporarily alter their behavioral state and suppress host-seeking while using blood-derived nutrients to develop eggs. Host-seeking suppression ends once eggs are laid. While this period has generally been thought of as one of behavioral inactivity, we reveal that it instead reflects behavioral reprogramming, during which females transition from post-blood-meal inactivity into active searching for egg-laying sites. Females with mature eggs show a distinct behavioral state characterized by increased locomotor activity and a shift in circadian behavioral timing, leading to nocturnal humidity-seeking and egg-laying in an otherwise diurnal species. We show that the circadian clock gene is critical for regulating this transition; its absence disrupts the timing of oviposition behaviors, leading to poor site selection and reduced predicted offspring survival. These findings suggest that during egg development, circadian clock-dependent behavioral reprogramming triggers nocturnal hyperactivity and oviposition site search, an essential process for mosquito reproduction and population viability.
疾病传播媒介蚊子在全球范围内的扩散以及数量的增加，每年使数亿人面临蚊媒疾病的威胁。雌性蚊子是登革热的全球传播媒介，需要从宿主血液中获取蛋白质来支持卵子发育，并经历反复的吸血和产卵周期。叮咬后，雌性蚊子会暂时改变其行为状态，抑制寻找宿主行为，同时利用血液中的营养物质来发育卵子。一旦产卵，寻找宿主的抑制作用就会结束。虽然这段时间通常被认为是行为不活跃期，但我们发现它实际上反映了行为重编程，在此期间，雌性蚊子从吸血后的不活跃状态转变为积极寻找产卵地点。怀有成熟卵子的雌性蚊子表现出一种独特的行为状态，其特征是运动活动增加以及昼夜行为时间的转变，导致在原本昼行性的物种中出现夜间寻找湿度和产卵的行为。我们表明，生物钟基因对于调节这种转变至关重要；该基因的缺失会扰乱产卵行为的时间，导致产卵地点选择不佳，并降低预期后代的存活率。这些发现表明，在卵子发育过程中，依赖生物钟的行为重编程会引发夜间多动和产卵地点搜索，这是蚊子繁殖和种群生存能力的一个重要过程。
