Liu Guoqiang, Kong Yingying, Liu Hualin, Peng Donghai, Ruan Lifang, Wu Yiming, Sun Ming
FEMS Microbiol Lett. 2017 Feb 1;364(3). doi: 10.1093/femsle/fnw293.
Transposon mutagenesis and subsequent phenotype-driven screening have been extensively used to annotate gene function and uncover the mechanisms of biological phenomena. During this process, the resulting phenotypic differences are specifically attributable to the disrupted genes. In this study, the complementation of the mini-Tn10 transposon-disrupted gene gntP did not restore the germination ability of the Bacillus thuringiensis MT1518-1 mutant to the wild-type level. Genome sequencing identified 186 unlinked mutations on the chromosome of the mutant MT1518-1, including one frameshift mutation in the germination-related gene exsA. We randomly selected 19 mini-Tn10 mutants for high throughput genome sequencing. The sequencing data revealed that incidental mutations occurred frequently on their chromosomes, including 2343 single-nucleotide polymorphisms, three insertions and one deletion. We also found that stressful conditions are the underlying cause for the appearance of incidental mutations. Caution is warranted when attributing the observed phenotypic changes to the transposon-disrupted genes.
转座子诱变及随后基于表型的筛选已被广泛用于注释基因功能和揭示生物学现象的机制。在此过程中，所产生的表型差异具体归因于被破坏的基因。在本研究中，mini-Tn10转座子破坏的基因gntP的互补并未将苏云金芽孢杆菌MT1518-1突变体的萌发能力恢复到野生型水平。基因组测序在突变体MT1518-1的染色体上鉴定出186个非连锁突变，包括萌发相关基因exsA中的一个移码突变。我们随机选择了19个mini-Tn10突变体进行高通量基因组测序。测序数据显示，其染色体上频繁发生偶然突变，包括2343个单核苷酸多态性、三个插入和一个缺失。我们还发现应激条件是偶然突变出现的根本原因。在将观察到的表型变化归因于转座子破坏的基因时应谨慎。
