Chromosomal duplications and cointegrates generated by the bacteriophage lamdba Red system in Escherichia coli K-12.
Chromosomal duplications and cointegrates generated by the bacteriophage lamdba Red system in Escherichia coli K-12.
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DOI：
10.1186/1471-2199-5-22
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发表时间：
2004-12-13
影响因子：
--
通讯作者：
Nadkarni A
中科院分区：
文献类型：
--
作者：
Poteete AR;Fenton AC;Nadkarni A
在大肠杆菌菌株中，RecBCD已被噬菌体λ Red系统遗传取代，其染色体和与染色体共享序列的线性双链DNA种类之间进行有效重组。以往的研究主要集中在基因重组型事件上，即由cat基因和lac操纵子组成的3.5kbp双链DNA与大肠杆菌重组。大肠杆菌染色体，以产生氯霉素抗性Lac-重组体。dsDNA作为非复制λ载体的染色体的一部分被递送到细胞中，在感染细胞中通过限制性内切酶的作用将其释放。这项研究的特点的遗传要求和结果的各种额外的红色促进同源重组事件生产紫胶+重组。对染色体和线性DNA之间的重组事件进行了一些观察：（1）Lac+和Lac-重组体的形成依赖于相同的重组功能。(2)高多样性和高染色体拷贝数有利于Lac+重组体的形成。(3)Lac+重组体不稳定，分离Lac-后代。(4)在远离猫的噬菌体染色体上的一个位点上的四环素抗性标记不常与猫共遗传。（5）线性DNA中的噬菌体序列与染色体中的隐蔽原噬菌体之间的重叠是大多数观察到的Lac+重组体的原因。此外，还观察到染色体和环状DNA之间的重组事件：（6）重组体的形成依赖于RecA，在较小程度上也依赖于Red。(7)在这种情况下，连锁的四环素耐药标记经常共同遗传。Lac+重组体产生于这样的事件，其中进入的线性DNA与染色体中的lac和隐蔽原噬菌体序列之间的同源重组产生细菌染色体的部分复制。当进入的DNA种类是环状而不是线性时，共整合体是最常见的重组类型。
An Escherichia coli strain in which RecBCD has been genetically replaced by the bacteriophage λ Red system engages in efficient recombination between its chromosome and linear double-stranded DNA species sharing sequences with the chromosome. Previous studies of this experimental system have focused on a gene replacement-type event, in which a 3.5 kbp dsDNA consisting of the cat gene and flanking lac operon sequences recombines with the E. coli chromosome to generate a chloramphenicol-resistant Lac- recombinant. The dsDNA was delivered into the cell as part of the chromosome of a non-replicating λ vector, from which it was released by the action of a restriction endonuclease in the infected cell. This study characterizes the genetic requirements and outcomes of a variety of additional Red-promoted homologous recombination events producing Lac+ recombinants. A number of observations concerning recombination events between the chromosome and linear DNAs were made: (1) Formation of Lac+ and Lac- recombinants depended upon the same recombination functions. (2) High multiplicity and high chromosome copy number favored Lac+ recombinant formation. (3) The Lac+ recombinants were unstable, segregating Lac- progeny. (4) A tetracycline-resistance marker in a site of the phage chromosome distant from cat was not frequently co-inherited with cat. (5) Recombination between phage sequences in the linear DNA and cryptic prophages in the chromosome was responsible for most of the observed Lac+ recombinants. In addition, observations were made concerning recombination events between the chromosome and circular DNAs: (6) Formation of recombinants depended upon both RecA and, to a lesser extent, Red. (7) The linked tetracycline-resistance marker was frequently co-inherited in this case. The Lac+ recombinants arise from events in which homologous recombination between the incoming linear DNA and both lac and cryptic prophage sequences in the chromosome generates a partial duplication of the bacterial chromosome. When the incoming DNA species is circular rather than linear, cointegrates are the most frequent type of recombinant.
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影响因子：
--
作者：
Murphy KC;Campellone KG
通讯作者：
Campellone KG
DOI：
10.1073/pnas.121164898
发表时间：
2001-06-05
影响因子：
11.1
作者：
Ellis, HM;Yu, DG;Court, DL
通讯作者：
Court, DL
影响因子：
3.1
作者：
Day, WA;Maurelli, AT
通讯作者：
Maurelli, AT
影响因子：
5.6
作者：
WANG, JC;DAVIDSON, N
通讯作者：
DAVIDSON, N
影响因子：
14.9
作者：
Muyrers, JPP;Zhang, YM;Stewart, AF
通讯作者：
Stewart, AF