A metagenomic approach from aphid's hemolymph sheds light on the potential roles of co-existing endosymbionts.
A metagenomic approach from aphid's hemolymph sheds light on the potential roles of co-existing endosymbionts.
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DOI：
10.1186/s40168-015-0130-5
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发表时间：
2015-12-15
期刊：
影响因子：
15.5
通讯作者：
Massart S
中科院分区：
文献类型：
--
作者：
De Clerck C;Fujiwara A;Joncour P;Léonard S;Félix ML;Francis F;Jijakli MH;Tsuchida T;Massart S
已知蚜虫与特定的细菌共生，称为内共生体，其可以被分类为专性或辅助性。蚜虫共生体是蚜虫体内唯一的专性共生体，为寄主提供植物韧皮部所缺少的必需营养。香蕉束顶病毒是香蕉上危害最严重的病毒之一，黑脉五核虫是其主要传播媒介。这只蚜虫携带着两种共生体：B。蚜虫属（BPn）和沃尔巴克氏体属（wPn）。沃尔巴克氏体在香蕉蚜虫中的高发生率提出了关于它在这种昆虫中所起作用的问题。本研究的目的是进一步了解这两种共生体在黑脉黑脉海葵中所起的作用。为此，进行了显微注射试验，以观察wPn消除对宿主的影响，然后，血淋巴的高通量测序用于分析共生体的基因含量。我们观察到wPn的消除系统地导致蚜虫的死亡，这表明细菌可以发挥互利互惠的作用。此外，我们通过高通量测序分别鉴定和注释了wPn和BPn的587和250个基因。对这些基因的分析表明，这两种细菌共同生产几种必需的营养素。最引人注目的例子是溶素和核黄素，它们通常由B提供。蚜虫对寄主的影响在香蕉蚜虫中，参与这些代谢物产生途径的基因在两种细菌之间共享，使它们对蚜虫宿主的生存都至关重要。我们的研究结果表明，共专性共生之间的B。蚜虫和沃尔巴克氏体中的两种细菌共同作用，为宿主提供必需的营养。据我们所知，这是第一次报道沃尔巴克氏体在蚜虫中发挥重要作用。本文的在线版本（doi：10.1186/s40168-015-0130-5）包含补充材料，可供授权用户使用。
Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory symbiont present in aphids, supplying essential nutrients that are missing in the plants phloem to its host. Pentalonia nigronervosa is the main vector of the banana bunchy top virus, one of the most damageable viruses in banana. This aphid is carrying two symbionts: B. aphidicola (BPn) and Wolbachia sp. (wPn). The high occurrence of Wolbachia in the banana aphid raises questions about the role it plays in this insect. The goal of this study was to go further in the understanding of the role played by the two symbionts in P. nigronervosa. To do so, microinjection tests were made to see the effect of wPn elimination on the host, and then, high-throughput sequencing of the haemolymph was used to analyze the gene content of the symbionts. We observed that the elimination of wPn systematically led to the death of aphids, suggesting that the bacterium could play a mutualistic role. In addition, we identify and annotate 587 and 250 genes for wPn and BPn, respectively, through high-throughput sequencing. Analysis of these genes suggests that the two bacteria are working together for the production of several essential nutrients. The most striking cases are for lysin and riboflavin which are usually provided by B. aphidicola alone to the host. In the banana aphid, the genes involved in the production pathways of these metabolites are shared between the two bacteria making them both essential for the survival of the aphid host. Our results suggest that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid, the two bacteria acting together to supply essential nutrients to the host. This is, to our knowledge, the first time Wolbachia is reported to play an essential role in aphids. The online version of this article (doi:10.1186/s40168-015-0130-5) contains supplementary material, which is available to authorized users.