Raw Data from Variability in the durability of CRISPR-Cas immunity.

The durability of host resistance is challenged by the ability of pathogens to escape the defence of their hosts. Understanding the variability in the durability of host resistance is of paramount importance for designing more effective control strategies against infectious diseases. Here, we study the durability of various clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) alleles of the bacteria Streptococcus thermophilus against lytic phages. We found substantial variability in durability among different resistant bacteria. Since the escape of the phage is driven by a mutation in the phage sequence targeted by CRISPR-Cas, we explored the fitness costs associated with these escape mutations. We found that, on average, escape mutations decrease the fitness of the phage. Yet, the magnitude of this fitness cost does not predict the durability of CRISPR-Cas immunity. We contend that this variability in the durability of resistance may be because of variations in phage mutation rate or in the proportion of lethal mutations across the phage genome. These results have important implications on the coevolutionary dynamics between bacteria and phages and for the optimal deployment of resistance strategies against pathogens and pests. Understanding the durability of CRISPR-Cas immunity may also help develop more effective gene-drive strategies based on CRISPR-Cas9 technology.This article is part of the themed issue ‘The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems’.

宿主抗性的持久性会受到病原体逃逸宿主防御能力的挑战。解析宿主抗性持久性的变异规律，对于设计更有效的传染病防控策略至关重要。本研究针对嗜热链球菌（Streptococcus thermophilus）的多种成簇规律间隔短回文重复序列-Cas（clustered regularly interspaced short palindromic repeats-Cas, CRISPR-Cas）等位基因，探究其针对裂解性噬菌体的抗性持久性。研究发现不同抗性菌株的抗性持久性存在显著差异。由于噬菌体的逃逸由CRISPR-Cas靶向的噬菌体序列突变所驱动，本研究进一步探究了这些逃逸突变相关的适合度代价。结果显示，平均而言逃逸突变会降低噬菌体的适合度，但该适合度代价的强弱无法预测CRISPR-Cas免疫的持久性。我们推测，抗性持久性的这种变异可能源于噬菌体突变率的差异，或是噬菌体基因组内致死突变占比的不同。本研究结果对于解析细菌与噬菌体的协同进化动态，以及优化针对病原物与害虫的抗性策略部署具有重要意义。解析CRISPR-Cas免疫的持久性，还有助于开发基于CRISPR-Cas9技术的更高效基因驱动策略。本文隶属于“原核生物CRISPR-Cas适应性免疫系统的生态与进化”专题栏目。