Ward M J, Duggleby C J, Parton R, Coote J G
Microbiology Department, University of Glasgow.
Lett Appl Microbiol. 1992 Oct;15(4):137-41. doi: 10.1111/j.1472-765x.1992.tb00747.x.
Transposon Tn5-generated mutants of Bordetella pertussis were selected on the basis of their inability to bind the dye Congo red (Crb-). No mutants which were solely Crb- were found. Ten mutants were phenotypically equivalent to previously described strains with mutations in the virulence regulatory (bvg) locus and failed to express a range of virulence-associated factors. Two of these mutants were shown to have Tn5 insertions within the bvg locus, while another two mutants showed deletions in this regulatory region. Complementation studies indicated that the other six mutants had spontaneous mutations in the bvg locus, but with Tn5 inserted elsewhere in the chromosome. Several of the mutants, besides having a single Tn5 insertion, also showed additional IS50 insertions, indicating that the IS50 element contained within Tn5 had transposed independently. Such additional insertion events, which themselves would have the potential to cause mutation, could complicate the interpretation of mutant phenotypes which could thus arise from the insertional inactivation of more than one gene.
基于无法结合染料刚果红（Crb-）筛选出百日咳博德特氏菌的转座子Tn5诱导突变体。未发现仅为Crb-的突变体。有10个突变体在表型上与先前描述的毒力调节（bvg）位点发生突变的菌株相当，并且无法表达一系列毒力相关因子。其中两个突变体显示在bvg位点内有Tn5插入，而另外两个突变体在此调节区域有缺失。互补研究表明，其他六个突变体在bvg位点有自发突变，但Tn5插入在染色体的其他位置。除了有单个Tn5插入外，一些突变体还显示有额外的IS50插入，这表明Tn5中含有的IS50元件已独立转座。这种额外的插入事件本身有可能导致突变，可能会使对突变体表型的解释复杂化，而这些表型可能是由一个以上基因的插入失活引起的。
