Hill C W, Harnish B W
Proc Natl Acad Sci U S A. 1981 Nov;78(11):7069-72. doi: 10.1073/pnas.78.11.7069.
It might be anticipated that the presence of redundant but oppositely oriented sequences in a chromosome could allow inversion of the intervening material through homologous recombination. For example, the ribosomal RNA gene rrnD of Escherichia coli has the opposite orientation fro rrnB and rrnE and is separated from these genes by roughly 20% of the chromosome. Starting with a derivative of Cavalli Hfr, we have constructed mutants that have an inversion of the segment between rrnD and either rrnB or rrnE. These mutants are generally quite viable but do exhibit a slight reduction in growth rate relative to the parental strain. A major line of laboratory E. coli, W3110 and its derivatives, also has an inversion between rrnD and rrnE, probably created directly by a recombinational event between these highly homologous genes.
可以预期，染色体中存在冗余但方向相反的序列可能会通过同源重组使中间物质发生倒位。例如，大肠杆菌的核糖体RNA基因rrnD与rrnB和rrnE的方向相反，并且与这些基因被大约20%的染色体隔开。从卡瓦利Hfr的一个衍生物开始，我们构建了一些突变体，这些突变体在rrnD与rrnB或rrnE之间的片段发生了倒位。这些突变体通常相当有活力，但相对于亲本菌株，其生长速率确实略有降低。实验室常用的大肠杆菌品系W3110及其衍生物在rrnD和rrnE之间也存在倒位，可能是由这些高度同源的基因之间的重组事件直接产生的。
