Two chimeric chromosomes of Streptomyces coelicolor A3(2) generated by single crossover of the wild-type chromosome and linear plasmid SCP1
Two chimeric chromosomes of Streptomyces coelicolor A3(2) generated by single crossover of the wild-type chromosome and linear plasmid SCP1
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DOI：
10.1128/jb.186.19.6553-6559.2004
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发表时间：
2004-10-01
影响因子：
3.2
通讯作者：
Kinashi, H
中科院分区：
文献类型：
--
作者：
Yamasaki, M;Kinashi, H
天蓝色链霉菌A3(2)菌株2106除了携带一条7.2-Mb的线性染色体外，还携带一条1.85-Mb的线性质粒SCP1‘-cysD。宏观限制性内切酶分析表明，这两个线形DNA都是野生型染色体和线形质粒SCP1两侧的杂交产物。对融合连接的核苷酸测序显示，重组区域之间没有同源性。SCP1‘-cysD含有一个SCP1端粒和一个染色体端粒，因此没有末端反向重复序列。此外，各种诱变处理都不能将SCP1‘-cysD从2106菌株中消除。因此，我们得出结论，7.2-Mb染色体和SCP1‘-cysD都是由野生型染色体和SCP1的单个交换产生的嵌合染色体。这可能被视为基因组进化中的一种染色体复制模式。
Streptomyces coelicolor A3(2) strain 2106 carries a 1.85-Mb linear plasmid, SCP1'-cysD, in addition to a 7.2-Mb linear chromosome. Macrorestriction analysis indicated that both linear DNAs are hybrids of the wild-type chromosome and the linear plasmid SCP1 on each side. Nucleotide sequencing of the fusion junctions revealed no homology between the recombination regions. SCP1'-cysD contains an SCP1 telomere and a chromosomal telomere at each end and therefore does not have terminal inverted repeats. In addition, SCP1'-cysD could not be eliminated from strain 2106 by various mutagenic treatments. Thus, we concluded that both the 7.2-Mb chromosome and SCP1'-cysD are chimeric chromosomes generated by a single crossover of the wild-type chromosome and SCP1. This may be regarded as a model of chromosomal duplication in genome evolution.