Shadowing the Actions of a Predator: Backlit Fluorescent Microscopy Reveals Synchronous Nonbinary Septation of Predatory Bdellovibrio inside Prey and Exit through Discrete Bdelloplast Pores
Shadowing the Actions of a Predator: Backlit Fluorescent Microscopy Reveals Synchronous Nonbinary Septation of Predatory Bdellovibrio inside Prey and Exit through Discrete Bdelloplast Pores
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DOI：
10.1128/jb.00914-10
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发表时间：
2010-12-01
影响因子：
3.2
通讯作者：
Sockett, R. E.
中科院分区：
文献类型：
--
作者：
Fenton, A. K.;Kanna, M.;Sockett, R. E.
蛭弧菌是微型“活抗生素”捕食性细菌，它们会侵入、重新密封和消化其他较大的革兰氏阴性细菌，包括病原体。蛭弧菌复制的营养完全来自单个入侵细菌的消化，现在称为蛭体，它与原始猎物的外膜结合。蛭弧菌细菌是猎物细胞的高效消化者，消化单个猎物细胞时平均产生 4 至 6 个后代，其基因组大小与蛭弧菌细胞本身相似。蛭弧菌的细菌内发育周期在很大程度上是未知的，并且从未被“现场”观察到。使用具有非常明确的 z 轴控制和工程化周质荧光猎物的最新电动 xy 平台，首次可以仅使用猎物细胞的内部资源在几个小时内实现准确的返回和可视化，而无需对发育中的蛭弧菌细胞进行猎物漂白。我们表明，蛭弧菌并不遵循常见的细菌细胞二元裂变分裂模式。相反，它们同步分隔以产生奇数和偶数数量的子代，即使两个独立的蛭弧菌细胞侵入并在单个猎物细菌内发育，产生两个不同数量的子代。这种新颖的分隔模式的进化，允许奇怪的后代产量，允许优化利用有限的猎物细胞资源来产生最大程度的复制捕食性细菌。当复制完成后，蛭弧菌细胞会离开精疲力尽的猎物，并通过离散的孔离开，而不是通过猎物的整个外膜破裂离开。
The Bdellovibrio are miniature "living antibiotic" predatory bacteria which invade, reseal, and digest other larger Gram-negative bacteria, including pathogens. Nutrients for the replication of Bdellovibrio bacteria come entirely from the digestion of the single invaded bacterium, now called a bdelloplast, which is bound by the original prey outer membrane. Bdellovibrio bacteria are efficient digesters of prey cells, yielding on average 4 to 6 progeny from digestion of a single prey cell of a genome size similar to that of the Bdellovibrio cell itself. The developmental intrabacterial cycle of Bdellovibrio is largely unknown and has never been visualized "live." Using the latest motorized xy stage with a very defined z-axis control and engineered periplasmically fluorescent prey allows, for the first time, accurate return and visualization without prey bleaching of developing Bdellovibrio cells using solely the inner resources of a prey cell over several hours. We show that Bdellovibrio bacteria do not follow the familiar pattern of bacterial cell division by binary fission. Instead, they septate synchronously to produce both odd and even numbers of progeny, even when two separate Bdellovibrio cells have invaded and develop within a single prey bacterium, producing two different amounts of progeny. Evolution of this novel septation pattern, allowing odd progeny yields, allows optimal use of the finite prey cell resources to produce maximal replicated, predatory bacteria. When replication is complete, Bdellovibrio cells exit the exhausted prey and are seen leaving via discrete pores rather than by breakdown of the entire outer membrane of the prey.