A host beetle pheromone regulates development and behavior in the nematode Pristionchus pacificus.
A host beetle pheromone regulates development and behavior in the nematode Pristionchus pacificus.
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DOI：
10.7554/elife.03229
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发表时间：
2014-10-15
期刊：
影响因子：
7.7
通讯作者：
Hong RL
中科院分区：
文献类型：
--
作者：
Cinkornpumin JK;Wisidagama DR;Rapoport V;Go JL;Dieterich C;Wang X;Sommer RJ;Hong RL
线虫和昆虫是两个种类最丰富的动物门，线虫-昆虫共生体包含着广泛的生物学相互作用。为了剖析化学信号和介导这种关联的基因，我们研究了东方甲虫性信息素对太平洋棱纹瓢虫线虫的发育和行为的影响。我们发现，虽然甲虫信息素是吸引的太平洋大蠊成虫，信息素逮捕胚胎发育，麻痹J2幼虫，并抑制退出的dauer幼虫。为了揭示调节昆虫信息素敏感性的机制，一种新发现的突变体Ppa-obi-1被用来揭示改变对甲虫信息素的吸引力以及对其麻痹作用的超敏性之间的分子联系。ppa-obi-1编码脂质结合结构域，并在各种细胞类型中达到最高表达，包括两栖类神经鞘和排泄细胞。我们的数据表明，甲虫宿主信息素可能是一个物种特有的挥发性synomone，共同进化的necromeny。太平洋棱纹线虫可以作为一种寄生虫生活在东方甲虫体内，在那里它等待甲虫死亡，这样它就可以以甲虫腐烂尸体上的细菌为食。这种生态上重要的相互作用被称为坏死。太平洋拟步行虫被甲虫产生的性信息素吸引到一个新的宿主，但是使这种相互作用发生的基因和生物学机制还没有被详细了解。为了确定这种相互作用的遗传基础，Cinkornpumin等人鉴定并检查了一种不能感知甲虫性信息素的太平洋拟步行虫突变体。这表明，虽然这种信息素吸引了成年线虫，但它阻止了太平洋太平洋虫胚胎的发育，并可能使幼虫瘫痪。Cinkornpumin等人认为，信息素很可能进化出这种能力，以抵消线虫的传播。这一结果意味着被太平洋拟步行虫入侵使甲虫的生活比以前想象的更困难。对太平洋比目鱼突变体中受损基因的进一步研究表明，它编码一种蛋白质，该蛋白质可能与称为脂质的分子结合，而脂质是形成细胞膜所需的，并用于细胞信号传导。除了帮助线虫检测性信息素外，脂质结合蛋白似乎还有助于保护蠕虫免受信息素的有害影响。Cinkornpumin等人观察到，脂质结合蛋白的基因在几种组织中被激活，包括在一些检测化学信号的神经周围形成鞘的细胞。这种组织是否负责脂质结合蛋白的化学传感能力，以及这些组织是否负责保护线虫免受信息素的破坏作用，仍有待发现。DOI：www.example.com网站
Nematodes and insects are the two most speciose animal phyla and nematode–insect associations encompass widespread biological interactions. To dissect the chemical signals and the genes mediating this association, we investigated the effect of an oriental beetle sex pheromone on the development and behavior of the nematode Pristionchus pacificus. We found that while the beetle pheromone is attractive to P. pacificus adults, the pheromone arrests embryo development, paralyzes J2 larva, and inhibits exit of dauer larvae. To uncover the mechanism that regulates insect pheromone sensitivity, a newly identified mutant, Ppa-obi-1, is used to reveal the molecular links between altered attraction towards the beetle pheromone, as well as hypersensitivity to its paralyzing effects. Ppa-obi-1 encodes lipid-binding domains and reaches its highest expression in various cell types, including the amphid neuron sheath and excretory cells. Our data suggest that the beetle host pheromone may be a species-specific volatile synomone that co-evolved with necromeny. DOI: http://dx.doi.org/10.7554/eLife.03229.001 The nematode worm Pristionchus pacificus can live as a parasite inside the oriental beetle, where it waits for the beetle to die so it can feed off the bacteria that live on the beetle's decomposing carcass. This ecologically important interaction is called necromeny. P. pacificus is attracted to a new host by a sex pheromone produced by the beetle, but the genes and biological mechanisms that enable this interaction to occur are not understood in much detail. To identify the genetic basis of this interaction, Cinkornpumin et al. identified and examined a mutant form of P. pacificus that cannot sense the beetle sex pheromone. This revealed that although this pheromone attracts the adult nematodes, it stops P. pacificus embryos developing and can paralyze larvae. Cinkornpumin et al. suggest that the pheromone has likely evolved this ability in order to counteract the spread of the nematodes. This result implies that being invaded by P. pacificus makes life more difficult for the beetles than was previously thought. Further investigation of the gene damaged in the P. pacificus mutants revealed that it encodes a protein that may bind to molecules called lipids, which are needed to form cell membranes and are used in cell signaling. As well as helping the nematodes to detect the sex pheromone, the lipid-binding protein also appears to help protect the worms from the pheromone's detrimental effects. Cinkornpumin et al. observed that the gene for the lipid-binding protein is activated in several tissues, including the cells that form a sheath around some of the nerves that detect chemical signals. Whether this tissue is responsible for the chemical-sensing abilities of the lipid-binding protein, and whether these same tissues are responsible for protecting the nematodes from the damaging effects of the pheromone, remains to be discovered. DOI: http://dx.doi.org/10.7554/eLife.03229.002