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大肠杆菌中CRISPR-Cas适应的单个殖民地分辨率揭示了固相生长过程中改变的间隔源偏差

Jack Braithwaite¹, Christopher Cannon¹, Ronald Chalmers¹

¹School of Life Sciences, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UK, United Kingdom.

Nucleic acids research

|October 21, 2025

概括

一种新的视觉测试检测了在大肠杆菌殖民地中的CRISPR-Cas适应. 殖民地生长条件,而不仅仅是DNA的可用性,显著改变哪些DNA片段 (间隔器) 被CRISPR系统获得.

科学领域:

微生物学微生物学
分子生物学分子生物学
遗传学是一个遗传学.

背景情况:

克里斯普尔-卡斯系统通过将外来DNA片段 (间隙) 纳入宿主基因组,在细菌中赋予适应性免疫力.
影响CRISPR-Cas适应过程的生理因素,特别是间距获取,仍然不完全理解.

研究的目的:

开发和验证一种用于检测和分析单个细菌殖民地CRISPR-Cas适应事件的新型视觉试验.
研究不同的生长环境,特别是液体与固体介质,如何影响获得的CRISPR间隔器的源偏差.

主要方法:

在使用破坏的lacZ基因记者系统的Escherichia coli中开发视觉 papillation测定.
通过观察X-gal板块上的蓝色乳头形成来检测CRISPR-Cas适应的检测,表明了间隔器的获取.
通过测序和在液体培养基与固体培养基中培养的细胞之间的比较进行间隔器起源分析.

主要成果:

视觉乳头测试具有敏感性,半定量性,并且能够检测单个适应事件.
观察到间隔器获取源偏差的显著转变:等离子体衍生间隔器从液体培养中的64%下降到固体培养中的约9%.
这种转变归因于殖民地生长的空间和代谢条件,而不仅仅是DNA的可用性.

结论:

细菌群体的物理和代谢结构深深地影响了CRISPR-Cas适应格局和间隔器的获取.
开发的试验提供了一个可扩展的平台,用于研究特定条件的CRISPR-Cas适应机制,包括间隔器起源和序列特征.

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