Escherichia coli with a linear genome
Escherichia coli with a linear genome
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DOI：
10.1038/sj.embor.7400880
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发表时间：
2007-02-01
期刊：
影响因子：
7.7
通讯作者：
Horiuchi, Takashi
中科院分区：
文献类型：
--
作者：
Cui, Tailin;Moro-oka, Naoki;Horiuchi, Takashi
真核生物的染色体是线性的，而大多数原核生物(但不是全部)的染色体是环形的。为了探索拥有线性基因组对原核细胞的影响，我们使用溶原性Lambda样噬菌体N15线性化了大肠杆菌基因组。线形基因组大肠杆菌为活菌，基因组结构稳定。具有线性或环形基因组的细胞在生长速度、细胞和类核形态、全基因组基因表达(少数例外情况)以及依赖DNA旋转酶和拓扑异构酶IV的生长方面没有明显差异。然而，在不同缺陷的条件下，只有具有环形基因组的细胞才表现出异常的表型。显微镜显示，线形基因组的末端是分离的，而不是环状基因组，它们位于新生细胞的两端。当将ToS-线性化所需的顺式元件-插入不同的染色体位置时，那些基因组末端离dif较远的菌株显示出更大的生长缺陷。
Chromosomes in eukaryotes are linear, whereas those of most, but not all, prokaryotes are circular. To explore the effects of possessing a linear genome on prokaryotic cells, we linearized the Escherichia coli genome using the lysogenic lambda-like phage N15. Linear genome E coli were viable and their genome structure was stable. There were no appreciable differences between cells with linear or circular genomes in growth rates, cell and nucleoid morphologies, genome-wide gene expression (with a few exceptions), and DNA gyrase- and topoisomerase IV-dependent growth. However, under dif-defective conditions, only cells with a circular genome developed an abnormal phenotype. Microscopy indicated that the ends of the linear genome, but not the circular genome, were separated and located at each end of a new-born cell. When tos-the cis-element required for linearization-was inserted into different chromosomal sites, those strains with the genome termini that were more remote from dif showed greater growth deficiencies.