High-frequency phage-mediated gene transfer in freshwater environments determined at single-cell level
High-frequency phage-mediated gene transfer in freshwater environments determined at single-cell level
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DOI：
10.1038/ismej.2009.145
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发表时间：
2010-05-01
期刊：
影响因子：
11
通讯作者：
Nasu, Masao
中科院分区：
文献类型：
--
作者：
Kenzaka, Takehiko;Tani, Katsuji;Nasu, Masao
细菌的横向基因转移对细菌的遗传多样性有重要贡献。为了准确地确定噬菌体介导的基因转移的频率和范围，重要的是要了解微生物之间的DNA运动。使用原位DNA扩增技术（循环引物原位扩增-荧光原位杂交; CPRINS-FISH），我们研究了噬菌体介导的基因转移在淡水环境中的单细胞水平的倾向。噬菌体P1、T4和分离的大肠杆菌噬菌体EC 10用作载体。所有E. coli质粒介导的基因转移。大肠杆菌对空斑形成和非空斑形成的肠杆菌科菌株的频率为0.3-8 × 10 ~（-3）/空斑形成单位（PFU），而使用选择性琼脂培养基的培养方法不能检测非空斑形成菌株中的转导子。当天然细菌群落为受体时，通过噬菌体EC 10的DNA转移频率范围从检测不到到9 × 10 - 2/PFU（检测不到到2 × 10 - 3/总直接计数）。直接活细胞计数结合CPRINS-FISH显示，在大多数情况下，超过20%的携带转移基因的细胞保留了它们的活力。这些结果表明，细菌之间的DNA序列交换频繁发生，并在广泛的细菌，并可能促进淡水环境中的原核基因组的快速进化。The ISME Journal（2010）4，648-659; doi：10.1038/ismej.2009.145; 2010年1月21日在线发表
Lateral gene transfer by phages has contributed significantly to the genetic diversity of bacteria. To accurately determine the frequency and range of phage-mediated gene transfer, it is important to understand the movement of DNA among microbes. Using an in situ DNA amplification technique (cycling primed in situ amplification-fluorescent in situ hybridization; CPRINS-FISH), we examined the propensity for phage-mediated gene transfer in freshwater environments at the single-cell level. Phage P1, T4 and isolated Escherichia coli phage EC10 were used as vectors. All E. coli phages mediated gene transfer from E. coli to both plaque-forming and non-plaque-forming Enterobacteriaceae strains at frequencies of 0.3-8 x 10(-3) per plaque-forming unit (PFU), whereas culture methods using selective agar media could not detect transductants in non-plaque-forming strains. The DNA transfer frequencies through phage EC10 ranged from undetectable to 9 x 10(-2) per PFU (undetectable to 2 x 10(-3) per total direct count) when natural bacterial communities were recipients. Direct viable counting combined with CPRINS-FISH revealed that more than 20% of the cells carrying the transferred gene retained their viability in most cases. These results indicate that the exchange of DNA sequences among bacteria occurs frequently and in a wide range of bacteria, and may promote rapid evolution of the prokaryotic genome in freshwater environments. The ISME Journal (2010) 4, 648-659; doi:10.1038/ismej.2009.145; published online 21 January 2010