根瘤菌引起线虫的肠道细胞DNA损伤
创作:aluba 审核:aluba 2019年02月17日
  • 根瘤菌可造成线虫的基因组不稳定性,表现为因异常核分裂造成的肠道细胞核的变长或片段化,以及有缺陷的有丝分裂;
  • 有丝分裂缺陷仅发生在肠道细胞中,并且需要根瘤菌与线虫的密切接触;
  • 筛选出造成同样的肠道细胞有丝分类缺陷的突变,发现携带该突变的线虫的DNA损伤修复通路受到破坏;
  • 根瘤菌可能通过产生活性氧而引起线虫的DNA损伤,清除游离自由基可抑制根瘤菌引起的线虫DNA损伤。
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aluba
线虫以腐烂的果子为食,腐烂果子的多种细菌可能影响线虫的生长。PNAS上发表的一项最新研究,发现根瘤菌可通过产生活性氧,而引起线虫的肠道细胞DNA损伤。
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PNAS [IF:12.779]

Rhizobium induces DNA damage in Caenorhabditis elegans intestinal cells

根瘤菌引起秀丽隐杆线虫肠道细胞的DNA损伤

10.1073/pnas.1815656116

2019-02-11, Article

Abstract & Authors:展开

Abstract:收起
In their natural habitat of rotting fruit, the nematode Caenorhabditis elegans feeds on the complex bacterial communities that thrive in this rich growth medium. Hundreds of diverse bacterial strains cultured from such rotting fruit allow C. elegans growth and reproduction when tested individually. In screens for C. elegans responses to single bacterial strains associated with nematodes in fruit, we found that Rhizobium causes a genome instability phenotype; we observed abnormally long or fragmented intestinal nuclei due to aberrant nuclear division, or defective karyokinesis. The karyokinesis defects were restricted to intestinal cells and required close proximity between bacteria and the worm. A genetic screen for C. elegans mutations that cause the same intestinal karyokinesis defect followed by genome sequencing of the isolated mutant strains identified mutations that disrupt DNA damage repair pathways, suggesting that Rhizobium may cause DNA damage in C. elegans intestinal cells. We hypothesized that such DNA damage is caused by reactive oxygen species produced by Rhizobium and found that hydrogen peroxide added to benign Escherichia coli can cause the same intestinal karyokinesis defects in WT C. elegans. Supporting this model, free radical scavengers suppressed the Rhizobium-induced C. elegans DNA damage. Thus, Rhizobium may signal to eukaryotic hosts via reactive oxygen species, and the host may respond with DNA damage repair pathways.

First Authors:
Marina Kniazeva

Correspondence Authors:
Gary Ruvkun

All Authors:
Marina Kniazeva,Gary Ruvkun

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