Evidence for particle-induced horizontal gene transfer and serial transduction between bacteria
Evidence for particle-induced horizontal gene transfer and serial transduction between bacteria
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DOI：
10.1111/j.1574-6941.2011.01077.x
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发表时间：
2011-06-01
影响因子：
4.2
通讯作者：
Velimirov, Branko
中科院分区：
文献类型：
--
作者：
Chiura, Hiroshi Xavier;Kogure, Kazuhiro;Velimirov, Branko
氨基酸缺乏菌株大肠杆菌AB1157与从少营养环境中收获的颗粒孵育显示水平基因转移（HGT）的证据，在可逆细胞中恢复所有缺陷，频率高达1.94 x 10-5。没有任何标记被优先转移，表明DNA转移是通过广义转导进行的。单个标记的基因转移频率最高，可达1.04 × 10-2。所有的还原剂都能产生大小相当的颗粒，出现在固定相的开始。用电子显微镜检查回复剂显示出具有电子致密体的芽状结构。显示膜囊结构特征的颗粒再次感染大肠杆菌AB1157，产生能够传递遗传信息的新感染性颗粒，这种现象称为序列转导。因此，来自海水的< 0.2 μ m颗粒馏分包含了具有高基因转移潜力的粒径馏分。偏压正弦场凝胶电泳显示，颗粒的DNA含量为370 kbp，高于已知的膜泡。这些发现为一种新的HGT方法提供了证据，在这种方法中，可移动的DNA通过颗粒从供体细胞运输到受体细胞。
Incubation of the amino acid-deficient strain Escherichia coli AB1157 with particles harvested from an oligotrophic environment revealed evidence of horizontal gene transfer (HGT) with restoration of all deficiencies in revertant cells with frequencies up to 1.94 x 10-5. None of the markers were preferentially transferred, indicating that the DNA transfer is performed by generalized transduction. The highest gene transfer frequencies were obtained for single markers, with values up to 1.04 x 10-2. All revertants were able to produce particles of comparable size, appearing at the beginning of the stationary phase. Examination of the revertants using electron microscopy showed bud-like structures with electron-dense bodies. The particles that display the structural features of membrane vesicles were again infectious to E. coli AB1157, producing new infectious particles able to transduce genetic information, a phenomenon termed serial transduction. Thus, the < 0.2-mu m particle fraction from seawater contains a particle size fraction with high potential for gene transfer. Biased sinusoidal field gel electrophoresis indicated a DNA content for the particles of 370 kbp, which was higher than that of known membrane vesicles. These findings provide evidence of a new method of HGT, in which mobilizable DNA is trafficked from donor to recipient cells via particles.