The seabird tick, Ixodes uriae, uses uric acid in penguin guano as a kairomone and guanine in tick feces as an assembly pheromone on the Antarctic Peninsula
The seabird tick, Ixodes uriae, uses uric acid in penguin guano as a kairomone and guanine in tick feces as an assembly pheromone on the Antarctic Peninsula
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DOI：
10.1007/s00300-008-0485-1
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发表时间：
2008-11-01
期刊：
影响因子：
1.7
通讯作者：
Denlinger, David L.
中科院分区：
文献类型：
--
作者：
Benoit, Joshua B.;Lopez-Martinez, Giancarlo;Denlinger, David L.
在南极洲的帕尔默站附近，在阿德利企鹅栖息地周边的岩石下，海鸟蜱（Ixodes uriae）形成了大量的聚集。当成年企鹅在筑巢季节开始时返回繁殖地时，蜱虫离开它们的非宿主聚集地，附着在企鹅身上进食一段时间，然后返回聚集地。在这项研究中，我们寻找蜱虫可能用来定位它们聚集地点的化学线索，以及寻找企鹅的线索。蜱虫排泄物和蜱虫聚集地下的土壤提取物中含有一种信息素，可以诱导未喂食的幼虫、若虫和成虫的聚集行为。鸟嘌呤是蜱的主要排泄产物，引起了组装行为，因此鸟嘌呤可能是参与组装的活性成分。非喂食阶段也对企鹅的鸟粪和尿酸（企鹅的主要排泄产物）有积极的反应，这表明尿酸和企鹅鸟粪的其他成分是非喂食阶段的蜱虫用来定位宿主的一种激素。喂食后，未成熟的蜱虫对组装和kairomones的反应被关闭了几天，蜱虫只有在蜕皮后才会恢复反应。被喂食的成年雌虫产卵后死去，再也没有恢复反应能力。因此，尿球菌依靠两种密切相关的化学物质来调节其生命的两个关键方面：组装和寻找宿主。蜱排泄物中的鸟嘌呤和其他成分是一种集合信息素，促进离宿主聚集物的形成，而企鹅粪便中的尿酸和其他成分则是蜱用来定位宿主的kairomone。
In the vicinity of Palmer Station, Antarctica, the seabird tick, Ixodes uriae, forms large aggregations under rocks at the periphery of Adelie penguin rookeries. When the adult penguins return to the rookeries at the beginning of the nesting season the ticks leave their off-host aggregation site, attach to the penguins for a period of feeding, and then subsequently return to the aggregation site. In this study, we searched for chemical cues that may be used by the ticks to locate their aggregation sites as well as cues involved in finding penguins. Tick excreta and soil extracts from beneath tick aggregations contained a pheromone that elicited assembly behavior in unfed larvae, non-fed nymphs and non-fed adults. Guanine, the major excretory product of ticks, elicited assembly behavior, thus, guanine is likely an active component involved in assembly. Non-fed stages also responded positively to penguin guano and uric acid, the primary excretory product of penguins, suggesting that uric acid and other components of penguin guano function as a kairomone used by the non-fed ticks to locate their host. After feeding, the immature ticks' response to both the assembly and kairomones is switched off for several days, and the ticks regain responsiveness only after they have molted. Fed adult females lay eggs and die without ever regaining responsiveness. Thus, I. uriae relies on two closely related chemicals to regulate two critical aspects of its life: assembly and host-finding. Guanine and other components of tick excreta function as an assembly pheromone in promoting the formation of off-host aggregations, while uric acid and other components of penguin guano function as a kairomone used by the tick to locate its host.