PENETRATION OF BDELLOVIBRIO-BACTERIOVORUS INTO HOST-CELLS
PENETRATION OF BDELLOVIBRIO-BACTERIOVORUS INTO HOST-CELLS
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DOI：
10.1128/jb.118.2.663-680.1974
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发表时间：
1974-01-01
影响因子：
3.2
通讯作者：
CHOU, D
中科院分区：
文献类型：
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作者：
ABRAM, D;CASTROEM.J;CHOU, D
电子显微镜观察发现，蜈蚣弧菌感染后，在宿主细胞壁形成通道孔后，分化后的寄生虫穿透极与宿主原生质体相连。这种牢固的接触在整个寄生虫渗透过程中和这一过程完成后持续存在。在被穿透的宿主中，这种接触在位相显微镜下也很明显。另一方面，寄生虫的细胞壁和寄主之间的联系是暂时的，蜈蚣弧菌不会穿透通过质壁分离的原生质体和细胞壁的宿主，或者膜-壁关系受到低膨胀压力影响的宿主。因此，结论是，为了发生穿透，寄主原生质体必须在寄生虫能够接触到的范围内，这样才能在它们之间建立牢固的联系。提出了一种渗透机制，该机制受受感染宿主包膜结构变化所产生的水和溶质通量所产生的力的影响。这些力量导致宿主原生质体和细胞壁的不同扩张，并在进入部位周围彼此分离，而寄生虫仍然牢牢地锚定在宿主原生质体上。结果，寄生虫最终被包围在扩大的寄主周质中。因此，实际的进入是寄生虫的被动行为。
Electron microscopy reveals that, inBdellovibrioinfection, after the formation of a passage pore in the host cell wall, the differentiated parasite penetration pole is associated with the host protoplast. This firm contact persists throughout the parasite penetration and after this process is completed. In penetrated hosts this contact is also apparent by phase microscopy. The association between the walls of the parasite and the host at the passage pore, on the other hand, is transient.Bdellovibriodo not penetrate hosts whose protoplast and cell walls are separated by plasmolysis, or in which the membrane-wall relationship is affected by low turgor pressure. It is concluded, therefore, that for penetration to occur it is essential that the host protoplast be within reach of the parasite, so that a firm contact can be established between them. A penetration mechanism is proposed that is effected by forces generated by fluxes of water and solutes due to structural changes in the infected host envelope. These forces cause a differential expansion of the host protoplast and cell wall and their separation from each other around the entry site, while the parasite remains firmly anchored to the host protoplast. Consequently, the parasite ends up enclosed in the expanded host periplasm. The actual entry, therefore, is a passive act of the parasite.