旗定位基因控制了从强制性掠食到自主性掠食和细菌捕食者的生物膜形成的热量转移
Abhirup Mookherjee1, Mohor Mitra1, Gal Sason1
1Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
mBio
|July 22, 2024
概括
捕食性细菌Bdellovibrio bacteriovorus可以变得独立于宿主,通过遗传突变形成生物膜. 这些变化允许选择性捕食,挑战其强制性捕食者地位.
科学领域:
- 微生物学 微生物学
- 细菌的掠食行为
- 生物膜形成的形成
背景情况:
- Bdellovibrio bacteriovorus是一种强制性宿主依赖 (H-D) 的细菌捕食者,无法在没有猎物的情况下复制或形成生物膜.
- 独立于宿主 (H-I) 的B. bacteriovorus的自发变种可以在轴突上生长并形成生物膜.
- 生物膜形成是一个关键的表型,在生物学,医学和环境科学中具有重要意义.
研究的目的:
- 调查使宿主独立和B. bacteriovorus.生物膜形成的遗传途径.
- 了解鞭状定位基因和柱状相关蛋白在H-I变异表型中的作用.
- 探索这些遗传转变对掠夺性行为和社区动态的影响.
主要方法:
- 对B. bacteriovorus的350个H-I突变体进行查.
- 基因分析涉及鞭毛状态基因 (fliL, motA) 和柱状相关蛋白质 (Bd0108) 的突变.
- 转录概况,循环-di-GMP (cdG) 测量和全人口的等位基因测序.
- 评估运动性,表面粘附性,生物膜发育和捕食效率.
主要成果:
- 在fliL或motA中发生的单一突变产生了缺陷鞭毛运动性的H-I菌株,这些H-I菌株附着在表面上,但没有形成生物膜.
- 这些突变者在鞭毛,猎物入侵和cdG相关基因中表现出显著的转录转移,cdG水平发生了变化.
- 一种与pilus相关的蛋白质 (Bd0108) 的突变对于生物膜形成是必要的,包括细胞外基质分泌;然而,FLL的破坏减少了生物膜的发展.
- H-I变种在悬浮中显示了降低的捕食效率,但在猎物生物膜中保持了高效率,表明转向自主捕食.
结论:
- 定位器和入侵极依赖信号通路在B. bacteriovorus中关键控制H-D和H-I生物膜形成表型.
- 特定的基因突变可以取代猎物的需求,使得从强制性捕食转变为自愿性捕食.
- B. bacteriovorus的适应能力挑战了这些生物作为独家义务捕食者的长期概念.
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