一些插入序列(IS)元件使用氧化应激条件主动转位,包括γ辐照和过氧化氢处理,在地热球菌中,一种抗辐射细菌.D.地热哺乳动物野生型(WT),西格玛因子基因破坏(Δdgeo_0606),并检查了LysR基因破坏的(Δdgeo_1692)突变体的IS诱导,该诱导在γ辐照(5kGy)暴露后导致非色素菌落。色素沉着的丧失是因为dgeo_0524,它在类胡萝卜素途径中编码一种八烯去饱和酶,被IS元素的转座打断。IS元件的类型和基因座被鉴定为ISDge2和ISDge6在Δdgeo_0606突变体和ISDge5和ISDge7在Δdgeo_1692突变体,但未在WT菌株中鉴定。此外,80和100mMH2O2处理诱导了Δdgeo_0606(ISDge5,ISDge6和ISDge7)和WT(ISDge6)中IS元素的不同移位。然而,在Δdgeo_1692突变体中未观察到IS转座。Δdgeo_0606突变的互补菌株在活力测定中显示出恢复效应;然而,生长延迟曲线没有返回,因为相邻基因dgeo_0607过度表达,可能是反西格玛因子。某些转座酶的表达水平,被认为是IS换位的关键贡献者,在不同的氧化环境中与活性转座没有精确的相关性。然而,这些发现表明,特定的IS元件以靶基因缺陷和氧化源依赖的方式整合到dgeo_0524中。
Some insertion sequence (IS) elements were actively transposed using oxidative stress conditions, including gamma irradiation and hydrogen peroxide treatment, in Deinococcus geothermalis, a radiation-resistant bacterium. D. geothermalis wild-type (WT), sigma factor gene-disrupted (∆dgeo_0606), and LysR gene-disrupted (∆dgeo_1692) mutants were examined for IS induction that resulted in non-pigmented colonies after gamma irradiation (5 kGy) exposure. The loss of pigmentation occurred because dgeo_0524, which encodes a phytoene desaturase in the carotenoid pathway, was disrupted by the transposition of IS elements. The types and loci of the IS elements were identified as ISDge2 and ISDge6 in the ∆dgeo_0606 mutant and ISDge5 and ISDge7 in the ∆dgeo_1692 mutant, but were not identified in the WT strain. Furthermore, 80 and 100 mM H2O2 treatments induced different transpositions of IS elements in ∆dgeo_0606 (ISDge5, ISDge6, and ISDge7) and WT (ISDge6). However, no IS transposition was observed in the ∆dgeo_1692 mutant. The complementary strain of the ∆dgeo_0606 mutation showed recovery effects in the viability assay; however, the growth-delayed curve did not return because the neighboring gene dgeo_0607 was overexpressed, probably acting as an anti-sigma factor. The expression levels of certain transposases, recognized as pivotal contributors to IS transposition, did not precisely correlate with active transposition in varying oxidation environments. Nevertheless, these findings suggest that specific IS elements integrated into dgeo_0524 in a target-gene-deficient and oxidation-source-dependent manner.