Refining the Roots of the Beewolf-Streptomyces Symbiosis: Antennal Symbionts in the Rare Genus Philanthinus (Hymenoptera, Crabronidae)
Refining the Roots of the Beewolf-Streptomyces Symbiosis: Antennal Symbionts in the Rare Genus Philanthinus (Hymenoptera, Crabronidae)
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DOI：
10.1128/aem.06809-11
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发表时间：
2012-02-01
影响因子：
4.4
通讯作者：
Strohm, Erhard
中科院分区：
文献类型：
--
作者：
Kaltenpoth, Martin;Yildirim, Erol;Strohm, Erhard
昆虫与多种多样的有益微生物共生。虽然大多数研究充分的共生体都有营养基础，但已知有几种情况是细菌保护其宿主免受病原体感染。Philanthus属和Tracypus属的独居黄蜂（蜂狼; Hyattera，Crabronidae）在专门的触角腺水库中培养放线菌“Philanthus Streptomyces philanthi”。共生体被转移到幼虫茧中，在那里它们通过产生至少九种不同的抗生素来提供对病原真菌的保护。在这里，我们调查了Philanthus和Tracypus的近亲，罕见的属Philanthinus，触角腺水库和共生链霉菌的存在。分子分析鉴定出"Ca.四星菲兰尼斯菌（Philanthinus quattuordecimpunctatus）的贮存器中的"菲兰尼斯链霉菌"。基于16S rRNA基因的系统发育表明，P. quattuordecimpunctatus可能已经获得了"Ca.通过从其他蜂狼物种水平转移而产生的"嗜花链霉菌"。在组织学切片和三维重建中，触角腺水库被发现占据六个触角节（而Philanthus和Tracypus只有五个），并且在结构上不如进化上更衍生的蜂狼属复杂。的存在”。Philanthinus触角腺中的“Streptomyces philanthi”表明蜂狼和链霉菌细菌之间的共生关系比以前认为的要古老得多。它可能沿着通向单系族Philanthini的分支进化，因为它似乎仅限于Philanthus属，Tracypus属和Philanthinus属，它们共同组成了172种已描述的独居黄蜂。
Insects engage in symbiotic associations with a large diversity of beneficial microorganisms. While the majority of well-studied symbioses have a nutritional basis, several cases are known in which bacteria protect their host from pathogen infestation. Solitary wasps of the genera Philanthus and Trachypus (beewolves; Hymenoptera, Crabronidae) cultivate the actinomycete "Candidatus Streptomyces philanthi" in specialized antennal gland reservoirs. The symbionts are transferred to the larval cocoon, where they provide protection against pathogenic fungi by producing at least nine different antibiotics. Here we investigated the closest relatives of Philanthus and Trachypus, the rare genus Philanthinus, for the presence of antennal gland reservoirs and symbiotic streptomycetes. Molecular analyses identified "Ca. Streptomyces philanthi" in reservoirs of Philanthinus quattuordecimpunctatus. Phylogenies based on the 16S rRNA gene suggest that P. quattuordecimpunctatus may have acquired "Ca. Streptomyces philanthi" by horizontal transfer from other beewolf species. In histological sections and three-dimensional reconstructions, the antennal gland reservoirs were found to occupy six antennal segments (as opposed to only five in Philanthus and Trachypus) and to be structurally less complex than those of the evolutionarily more derived genera of beewolves. The presence of "Ca. Streptomyces philanthi" in antennal glands of Philanthinus indicates that the symbiosis between beewolves and Streptomyces bacteria is much older than previously thought. It probably evolved along the branch leading to the monophyletic tribe Philanthini, as it seems to be confined to the genera Philanthus, Trachypus, and Philanthinus, which together comprise 172 described species of solitary wasps.