Heat seeking is cool Mosquitoes seek hosts using several cues, one of which is body heat. Greppi et al. hypothesized that cooling-activated receptors could be used for locating mammalian hosts if they were rewired downstream for repulsion responses (see the Perspective by Lazzari). A gene family conserved in insects and known to be responsible for sensing changes in temperature in fruit flies was the starting point. Genome-wide analyses and labeled CRISPR-Cas9 mutants allowed visualization of the receptor in neurons of Anopheles gambiae mosquitoes' antennae and assessment of adult female mosquitoes with a disrupted copy of the receptor. This ancestral insect temperature regulatory system has been repurposed for host-finding by malaria mosquitoes. Science, this issue p. 681; see also p. 628 Mosquitoes rely on an ancestral cooling receptor to drive heat seeking, a behavior important for blood feeding. Mosquitoes transmit pathogens that kill >700,000 people annually. These insects use body heat to locate and feed on warm-blooded hosts, but the molecular basis of such behavior is unknown. Here, we identify ionotropic receptor IR21a, a receptor conserved throughout insects, as a key mediator of heat seeking in the malaria vector Anopheles gambiae. Although Ir21a mediates heat avoidance in Drosophila, we find it drives heat seeking and heat-stimulated blood feeding in Anopheles. At a cellular level, Ir21a is essential for the detection of cooling, suggesting that during evolution mosquito heat seeking relied on cooling-mediated repulsion. Our data indicate that the evolution of blood feeding in Anopheles involves repurposing an ancestral thermoreceptor from non–blood-feeding Diptera.

中文翻译：

---

蚊子的寻热是由祖先的冷却感受器驱动的


寻热很酷 蚊子利用多种线索寻找宿主，其中之一就是体温。格雷皮等人。假设冷却激活受体可以用于定位哺乳动物宿主，如果它们被重新连接到下游以产生排斥反应（参见拉扎里的观点）。昆虫中保守且已知负责感知果蝇温度变化的基因家族是起点。全基因组分析和标记的 CRISPR-Cas9 突变体允许对冈比亚按蚊触角神经元中的受体进行可视化，并利用受体的破坏副本对成年雌性蚊子进行评估。这种祖先昆虫温度调节系统已被重新用于疟疾蚊子寻找宿主。科学，本期第 14 页。第681章另见 p. 628 蚊子依靠祖先的冷却感受器来驱动寻热，这是一种对吸血很重要的行为。蚊子传播的病原体每年导致 3E700,000 人死亡。这些昆虫利用体热来定位并以温血宿主为食，但这种行为的分子基础尚不清楚。在这里，我们确定了离子型受体 IR21a（一种在昆虫中保守的受体），作为疟疾媒介冈比亚按蚊中寻热的关键介质。尽管 Ir21a 介导果蝇的避热作用，但我们发现它会驱动按蚊的寻热和热刺激血液摄食。在细胞水平上，Ir21a 对于检测冷却至关重要，这表明在进化过程中蚊子的寻热依赖于冷却介导的排斥。我们的数据表明，按蚊吸血的进化涉及重新利用非吸血双翅目的祖先温度感受器。