Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit.
Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit.
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DOI：
10.1371/journal.pbio.1002318
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发表时间：
2015-12
期刊：
影响因子：
9.8
通讯作者：
Knaden M
中科院分区：
文献类型：
--
作者：
Ebrahim SA;Dweck HK;Stökl J;Hofferberth JE;Trona F;Weniger K;Rybak J;Seki Y;Stensmyr MC;Sachse S;Hansson BS;Knaden M
检测危险是神经系统的首要任务之一。幼虫寄生蜂对果蝇构成明显的危险，因为在自然界中高达80%的蝇幼虫被寄生。我们表明，果蝇幼虫和成年人避免网站的主要寄生虫的敌人，Leptopilina黄蜂的气味。这种回避是通过高度特异性的嗅觉感觉神经元（OSN）类型介导的。虽然幼虫OSN表达嗅觉受体Or49a，并调谐到Leptopilina气味iridomyrmecin，成人既表达Or49a和Or85f，此外检测黄蜂气味猕猴桃和荆芥内酯。这些信息通过投射神经元传递到侧角的一个特定部位，该部位参与了回避的调节。因此，果蝇已经发展出一种专门的电路，根据其化学信息素的气味来检测威胁生命的敌人。这种探测敌人的嗅觉回路以前只在老鼠和线虫身上发现过。果蝇对主要寄生蜂Leptopilina产生的化学信息物质有一个专门的嗅觉回路，帮助果蝇执行回避行为。探测危险是动物的一项基本任务。拟寄生蜂幼虫对醋蝇D.在自然界中，高达80%的蝇幼虫被黑腹果蝇寄生。我们表明，果蝇幼虫会从闻起来像主要寄生虫敌人薄翼蜂的地方爬走。此外，果蝇成年雌性避免在这些地方产卵。这种回避是通过一种高度特异性的嗅觉感觉神经元类型来介导的，该神经元类型被调谐以检测寄生虫的三种气味，包括黄蜂性信息素iridomyrmecin。我们确定的神经元类型，受体，和气味配体，介导这种行为，也表明，这种神经元系统是必要的和足够的管理寄生虫回避行为。我们还发现证据表明，这种基于气味的Leptopilina黄蜂回避是保守的几个果蝇物种。
Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes. A dedicated olfactory circuit helps the fruit fly to implement avoidance behavior in response to semiochemicals produced by its main parasitoid enemy – wasps of the genus Leptopilina. Detecting danger is a fundamental task for an animal. Larval parasitoids constitute clear danger to the vinegar fly D. melanogaster as up to 80% of fly larvae become parasitized in nature. We show that Drosophila larvae crawl away from places that smell like the main parasitoid enemies, Leptopilina wasps. Furthermore, Drosophila adult females avoid laying eggs at those places. This avoidance is mediated via a highly specific olfactory sensory neuron type that is tuned to detect three odors of the parasitoid, including the wasps sex pheromone iridomyrmecin. We identify the neuron type, the receptors, and the odor ligands that mediate this behavior and also show that this neuronal system is both necessary and sufficient to govern the parasitoid avoidance behavior. We also find evidence that this odor-based Leptopilina wasp avoidance is conserved across several Drosophila species.