The Xenorhabdus nematophila nilABC genes confer the ability of Xenorhabdus spp. to colonize Steinernema carpocapsae nematodes
The Xenorhabdus nematophila nilABC genes confer the ability of Xenorhabdus spp. to colonize Steinernema carpocapsae nematodes
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DOI：
10.1128/jb.00123-08
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发表时间：
2008-06-01
影响因子：
3.2
通讯作者：
Goodrich-Blair, Heidi
中科院分区：
文献类型：
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作者：
Cowles, Charles E.;Goodrich-Blair, Heidi
线虫的斯氏线虫属的成员被细菌的Xabridus属的成员相互定殖。在自然界中，Steinernema carpocapsae线虫总是与嗜热小杆菌细菌相关联。因此，这种相互作用，像许多微生物-宿主协会，似乎是物种特异性的。X.嗜盐菌需要nilA、nilB和nilC基因来定殖S。果荚类在这项工作中，我们发现，在所有的Xabhabdus物种检查，只有X。嗜水气单胞菌具有nilA、nilB和nilC基因。通过暴露S. carpocapsae到其他Xelobdus spp.，我们确定只有X.嗜水气单胞菌能够定殖于S. carpocapsae;因此，S.果荚藻X.互作是种特异性的。此外，我们还发现，将nilA、nilB和nilC基因导入其他的黄杆菌属物种，使它们能够在相同的沙门氏菌中定居。通常被X.喜食草最后，序列分析支持nil基因是水平获得的观点。我们的研究结果表明，一个单一的遗传位点决定宿主特异性，在这种细菌-动物互利共生和宿主范围的扩大，可以通过收购一个小的遗传因素。
Members of the Steinernema genus of nematodes are colonized mutualistically by members of the Xenorhabdus genus of bacteria. In nature, Steinernema carpocapsae nematodes are always found in association with Xenorhabdus nematophila bacteria. Thus, this interaction, like many microbe-host associations, appears to be species specific. X. nematophilia requires the nilA, nilB, and nilC genes to colonize S. carpocapsae. In this work, we showed that of all the Xenorhabdus species examined, only X. nematophila has the nilA, nilB, and nilC genes. By exposing S. carpocapsae to other Xenorhabdus spp., we established that only X. nematophila is able to colonize S. carpocapsae; therefore, the S. carpocapsae-X. nematophila interaction is species specific. Further, we showed that introduction of the nilA, nilB, and nilC genes into other Xenorhabdus species enables them to colonize the same S. carpocapsae host tissue that is normally colonized by X. nematophila. Finally, sequence analysis supported the idea that the nil genes were horizontally acquired. Our findings indicate that a single genetic locus determines host specificity in this bacteria-animal mutualism and that host range expansion can occur through the acquisition of a small genetic element.