文章基本信息

标题：Fluorescent CRISPR Adaptation Reporter for rapid quantification of spacer acquisition
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作者：Lina Amlinger ; Mirthe Hoekzema ; E. Gerhart H. Wagner 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2017
卷号：7
期号：1
DOI：10.1038/s41598-017-10876-z
语种：English
出版社：Springer Nature
摘要：CRISPR-Cas systems are adaptive prokaryotic immune systems protecting against horizontally transferred DNA or RNA such as viruses and other mobile genetic elements. Memory of past invaders is stored as spacers in CRISPR loci in a process called adaptation. Here we developed a novel assay where spacer integration results in fluorescence, enabling detection of memory formation in single cells and quantification of as few as 0.05% cells with expanded CRISPR arrays in a bacterial population. Using this fluorescent CRISPR Adaptation Reporter (f-CAR), we quantified adaptation of the two CRISPR arrays of the type I-E CRISPR-Cas system in Escherichia coli, and confirmed that more integration events are targeted to CRISPR-II than to CRISPR-I. The f-CAR conveniently analyzes and compares many samples, allowing new insights into adaptation. For instance, we show that in an E. coli culture the majority of acquisition events occur in late exponential phase.