Global Health Labs, Bellevue, WA, 98007, USA.
Intellectual Ventures Global Good Fund, Bellevue, WA, 98007, USA.
Sci Rep. 2022 Jun 22;12(1):10570. doi: 10.1038/s41598-022-15021-z.
Vector control strategies are among the most effective measures to combat mosquito-borne diseases, such as malaria. These strategies work by altering the mosquito age structure through increased mortality of the older female mosquitoes that transmit pathogens. However, methods to monitor changes to mosquito age structure are currently inadequate for programmatic implementation. Female mosquitoes generally mate a single time soon after emergence and draw down spermatozoa reserves with each oviposition cycle. Here, we demonstrate that measuring spermatozoa quantity in female Anopheles mosquitoes is an effective approach to assess mosquito age. Using multiplexed qPCR targeted at male spermatozoa, we show that Y-linked genes in female mosquitoes are exclusively found in the spermatheca, the organ that houses spermatozoa, and the quantity of these gene sequences significantly declines with age. The method can accurately identify mosquitoes more than 10 days old and thus old enough to potentially transmit pathogens harbored in the salivary glands during blood feeding. Furthermore, mosquito populations that differ by 10% in daily survivorship have a high likelihood of being distinguished using modest sample sizes, making this approach scalable for assessing the efficacy of vector intervention control programs.
病媒控制策略是防治蚊媒疾病（如疟疾）最有效的措施之一。这些策略通过增加传播病原体的老年雌性蚊子的死亡率来改变蚊子的年龄结构。然而，目前监测蚊子年龄结构变化的方法还不足以进行方案实施。雌性蚊子通常在刚出现后交配一次，并在每次产卵周期中耗尽精子储备。在这里，我们证明测量雌性疟蚊中的精子数量是评估蚊子年龄的有效方法。我们使用靶向雄性精子的多重 qPCR 表明，Y 连锁基因仅存在于容纳精子的交配囊中，这些基因序列的数量随年龄的增长而显著下降。该方法可以准确识别超过 10 天的蚊子，因此它们已经足够老，有可能在吸血时传播存在于唾液腺中的病原体。此外，每天存活率相差 10%的蚊子种群很有可能通过适度的样本量来区分，因此这种方法可用于评估病媒干预控制计划的效果。
