Growth and sporulation defects in Bacillus subtilis mutants with a single rrn operon can be suppressed by amplification of the rrn operon.
Growth and sporulation defects in Bacillus subtilis mutants with a single rrn operon can be suppressed by amplification of the rrn operon.
复制标题
具有单个 rrn 操纵子的枯草芽孢杆菌突变体的生长和孢子形成缺陷可以通过 rrn 操纵子的扩增来抑制。
DOI：
10.1099/mic.0.000207
复制
发表时间：
2016
期刊：
影响因子：
1.5
通讯作者：
F. Kawamura
中科院分区：
文献类型：
--
作者：
Koichi Yano;K. Masuda;Genki Akanuma;T. Wada;T. Matsumoto;Yuh Shiwa;Taichiro Ishige;H. Yoshikawa;H. Niki;Takashi Inaoka;F. Kawamura
枯草芽孢杆菌菌株 168 的基因组编码 10 个 rRNA (rrn) 操纵子。我们之前报道过仅具有单个 rrn 操纵子的菌株的生长和孢子形成频率降低。我们在这里报告了来自七个菌株的抑制突变体的分离和表征，每个菌株都有一个 rrn 操纵子（rrnO、A、J、I、E、D 或 B）。具有单个 rrnO 操纵子的菌株 RIK656 的抑制突变体具有较高的较大菌落频率。与亲本突变株 RIK656 相比，这些抑制突变体不仅生长速率增加，而且孢子形成频率和核糖体水平也增加。定量 PCR 分析表明，所有这些抑制突变体的 rrnO 操纵子拷贝数均有所增加。还从其他六种具有单 rrn 操纵子（rrnA、J、I、E、D 或 B）的菌株中分离出抑制突变体。下一代和毛细管测序表明，所有抑制突变体都具有包含剩余 rrn 操纵子（扩增子）的染色体位点的串联重复。这些扩增子的大小从大约 9 到 179 kb 不等。扩增很可能是由非同源序列或微同源序列之间的非法重组引发的，随后是 DNA 复制过程中的不等交换。这些结果与我们之前的报告一致，即 rrn 操纵子拷贝数在细胞生长和孢子形成等细胞过程中起着重要作用。
The genome of Bacillus subtilis strain 168 encodes ten rRNA (rrn) operons. We previously reported that strains with only a single rrn operon had a decreased growth and sporulation frequency. We report here the isolation and characterization of suppressor mutants from seven strains that each have a single rrn operon (rrnO, A, J, I, E, D or B). The suppressor mutants for strain RIK656 with a single rrnO operon had a higher frequency of larger colonies. These suppressor mutants had not only increased growth rates, but also increased sporulation frequencies and ribosome levels compared to the parental mutant strain RIK656. Quantitative PCR analyses showed that all these suppressor mutants had an increased number of copies of the rrnO operon. Suppressor mutants were also isolated from the six other strains with single rrn operons (rrnA, J, I, E, D or B). Next generation and capillary sequencing showed that all of the suppressor mutants had tandem repeats of the chromosomal locus containing the remaining rrn operon (amplicon). These amplicons varied in size from approximately 9 to 179 kb. The amplifications were likely to be initiated by illegitimate recombination between non- or micro-homologous sequences, followed by unequal crossing-over during DNA replication. These results are consistent with our previous report that rrn operon copy number has a major role in cellular processes such as cell growth and sporulation.
大肠杆菌染色体 lac 区域的串联重复。
影响因子：
3.9
作者：
Heath,JD;Weinstock,GM
通讯作者：
Weinstock,GM
光养菌群的异养共生体：以串联 rrn 操纵子结构为特征的新型多样化 Betaproteobacteria 簇的成员
影响因子：
5.1
作者：
Pfannes;Overmann
通讯作者：
Overmann