Dynamics of chromosome replication and its relationship to predatory attack lifestyles in Bdellovibrio bacteriovorus
Dynamics of chromosome replication and its relationship to predatory attack lifestyles in Bdellovibrio bacteriovorus
复制标题
食菌蛭弧菌染色体复制动态及其与捕食性攻击生活方式的关系
DOI：
10.1101/519983
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Makowski L
中科院分区：
文献类型：
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作者：
Makowski L
噬菌蛭弧菌是一种小的革兰氏阴性专性捕食细菌，主要存在于潮湿的有氧环境中（例如，土壤）。这种细菌攻击和入侵其他革兰氏阴性细菌，包括动物和植物病原体。有趣的B生命周期。食菌菌性细菌包括两个阶段：自由生活的非复制性攻击阶段，在此阶段，捕食性细菌寻找其猎物，和繁殖阶段，在此阶段，B.噬菌降解宿主的大分子，并将其重新用于自身的生长和染色体复制。虽然这种捕食性细菌的细胞生物学近年来引起了相当大的兴趣，但我们对其染色体复制的动力学几乎一无所知。在此，我们对复制体在B单细胞中的亚细胞定位进行了实时研究。食菌动物结果表明，在B.噬菌性细菌的染色体复制仅发生在生殖阶段，并表现出一种新的时空排列的复制体。复制过程从被捕食细胞内的捕食性细菌的侵入极开始，一直进行到几个染色体拷贝完全合成。染色体复制与捕食者细胞分裂不一致，它在同步捕食者丝分隔发生前不久终止。此外，我们证明了，如果这个B。虽然噬菌体的生命周期在大肠杆菌的某些细胞中失败，但它们可以使用第二个猎物细胞来完成其生命周期。重要信息需要新的策略来对抗多重耐药细菌感染。捕食性细菌噬菌蛭弧菌（Bdellovibrio bacteriovorus）可杀死包括病原体在内的其他细菌，其应用被认为有望防治细菌感染。B。噬菌菌的生命周期包括两个阶段，自由生活的侵入攻击阶段和细胞内繁殖阶段，在这一阶段，这种捕食性细菌降解宿主的大分子并将其重新用于自身生长。了解B的用法。作为一种“活抗生素”，首先有必要解剖其生命周期，包括染色体复制。在这里，我们提出了一个实时调查到亚细胞定位染色体复制在一个单一的细胞B。食菌动物这个过程起始于B的侵入极点。噬菌菌体的染色体复制，并继续进行，直到几个拷贝的染色体已经完全合成。有趣的是，我们发现B.食菌动物需要两个被捕食细胞来完成它们的生命周期。
Bdellovibrio bacteriovorus is a small Gram-negative, obligate predatory bacterium that is largely found in wet, aerobic environments (e.g., soil). This bacterium attacks and invades other Gram-negative bacteria, including animal and plant pathogens. The intriguing life cycle of B. bacteriovorus consists of two phases: a free-living nonreplicative attack phase, in which the predatory bacterium searches for its prey, and a reproductive phase, in which B. bacteriovorus degrades a host’s macromolecules and reuses them for its own growth and chromosome replication. Although the cell biology of this predatory bacterium has gained considerable interest in recent years, we know almost nothing about the dynamics of its chromosome replication. Here, we performed a real-time investigation into the subcellular localization of the replisome(s) in single cells of B. bacteriovorus. Our results show that in B. bacteriovorus, chromosome replication takes place only during the reproductive phase and exhibits a novel spatiotemporal arrangement of replisomes. The replication process starts at the invasive pole of the predatory bacterium inside the prey cell and proceeds until several copies of the chromosome have been completely synthesized. Chromosome replication is not coincident with the predator cell division, and it terminates shortly before synchronous predator filament septation occurs. In addition, we demonstrate that if this B. bacteriovorus life cycle fails in some cells of Escherichia coli, they can instead use second prey cells to complete their life cycle.IMPORTANCENew strategies are needed to combat multidrug-resistant bacterial infections. Application of the predatory bacterium Bdellovibrio bacteriovorus, which kills other bacteria, including pathogens, is considered promising for combating bacterial infections. The B. bacteriovorus life cycle consists of two phases, a free-living, invasive attack phase and an intracellular reproductive phase, in which this predatory bacterium degrades the host’s macromolecules and reuses them for its own growth. To understand the use of B. bacteriovorus as a “living antibiotic,” it is first necessary to dissect its life cycle, including chromosome replication. Here, we present a real-time investigation into subcellular localization of chromosome replication in a single cell of B. bacteriovorus. This process initiates at the invasion pole of B. bacteriovorus and proceeds until several copies of the chromosome have been completely synthesized. Interestingly, we demonstrate that some cells of B. bacteriovorus require two prey cells sequentially to complete their life cycle.