School of Microbiology, University College Cork, Cork, Ireland.
Adv Appl Microbiol. 2014;88:1-29. doi: 10.1016/B978-0-12-800260-5.00001-2.
Photorhabdus is a pathogen of insects that also maintains a mutualistic association with nematodes from the family Heterorhabditis. Photorhabdus colonizes the gut of the infective juvenile (IJ) stage of the nematode. The IJ infects an insect and regurgitates the bacteria and the bacteria reproduce to kill the insect. The nematodes feed on the resulting bacterial biomass until a new generation of IJs emerges from the insect cadaver. Therefore, during its life cycle, Photorhabdus must (1) kill the insect host, (2) support nematode growth and development, and (3) be able to colonize the new generation of IJs. In this review, functional genomic studies that have been aimed at understanding the molecular mechanisms underpinning each of these roles will be discussed. These studies have begun to reveal that distinct gene sets may be required for each of these interactions, suggesting that there is only a minimal genetic overlap between pathogenicity and mutualism in Photorhabdus.
发光杆菌是昆虫的病原体，它还与线虫科的异小杆线虫保持互利共生关系。发光杆菌定植在线虫的感染性幼虫 (IJ) 阶段的肠道内。IJ 感染昆虫并吐出细菌，细菌繁殖以杀死昆虫。线虫以产生的细菌生物量为食，直到昆虫尸体中出现新一代 IJ。因此，在其生命周期中，发光杆菌必须：(1)杀死昆虫宿主，(2)支持线虫的生长和发育，以及 (3)能够定植新一代 IJ。在这篇综述中，将讨论旨在了解这些作用的分子机制的功能基因组研究。这些研究开始揭示，对于这些相互作用中的每一种，可能需要不同的基因集，这表明在发光杆菌中，致病性和共生性之间只有最小的遗传重叠。
