Science:肠内生存不易,倒位子或是细菌适应肠道环境的利器

创作:李丹宜 审核:李丹宜 02月01日
倒位子(inverton)是能发生可逆性倒位的基因间区域,是细菌适应环境的一种遗传机制;
开发算法从5万多个细菌基因组中鉴定出4686个倒位子,在肠道菌中较普遍;
含有启动子的倒位子大多调节胞外产物,如荚膜多糖,提示细菌表面结构多样性对其在肠道内定殖的重要性;
抗生素抗性基因的启动子,其所处倒位子的方向可在抗生素处理后从“关闭”变为“打开”;
同一菌株的倒位子在粪菌移植后可改变方向,体现宿主施加的选择压力有个体差异。
延伸阅读
Science [IF:41.058]

Invertible promoters mediate bacterial phase variation, antibiotic resistance, and host adaptation in the gut

可逆启动子介导肠道中的细菌相变、抗生素耐药性和对宿主的适应性

01-11, Report, 10.1126/science.aau5238more

Abstract:
Phase variation, the reversible alternation between genetic states, enables infection by pathogens and colonization by commensals. However, the diversity of phase variation remains underexplored. We developed the PhaseFinder algorithm to quantify DNA inversion–mediated phase variation. A systematic search of 54,875 bacterial genomes identified 4686 intergenic invertible DNA regions (invertons), revealing an enrichment in host-associated bacteria. Invertons containing promoters often regulate extracellular products, underscoring the importance of surface diversity for gut colonization. We found invertons containing promoters regulating antibiotic resistance genes that shift to the ON orientation after antibiotic treatment in human metagenomic data and in vitro, thereby mitigating the cost of antibiotic resistance. We observed that the orientations of some invertons diverge after fecal microbiota transplant, potentially as a result of individual-specific selective forces.

First Authors:
Xiaofang Jiang,A Brantley Hall

Correspondence Authors:
Eric J Alm,Ramnik J Xavier

All Authors:
Xiaofang Jiang,A Brantley Hall,Timothy D Arthur,Damian R Plichta,Christian T Covington,Mathilde Poyet,Jessica Crothers,Peter L Moses,Andrew C Tolonen,Hera Vlamakis,Eric J Alm,Ramnik J Xavier