Achigar Rodrigo, Scarrone Martina, Rousseau Geneviève M, Philippe Cécile, Machado Felipe, Duvós Valentina, Campot María Pía, Dion Moïra B, Shao Yuyu, Pianzzola María Julia, Moineau Sylvain
Laboratorio de Biotecnología, Facultad de Ingeniería, Universidad ORT Uruguay, Montevideo 11100, Uruguay.
Département de Biochimie, De Microbiologie et de Bio-Informatique, Faculté des Sciences et de Génie, Université Laval, Québec, QC G1V 0A6, Canada.
Microorganisms. 2021 Mar 1;9(3):512. doi: 10.3390/microorganisms9030512.
relies heavily on two type II-A CRISPR-Cas systems, CRISPR1 and CRISPR3, to resist siphophage infections. One hallmark of these systems is the integration of a new spacer at the 5' end of the CRISPR arrays following phage infection. However, we have previously shown that ectopic acquisition of spacers can occur within the CRISPR1 array. Here, we present evidence of the acquisition of new spacers within the array of CRISPR3 of . The analysis of randomly selected bacteriophage-insensitive mutants of the strain Uy01 obtained after phage infection, as well as the comparison with other strains with similar CRISPR3 content, showed that a specific spacer within the array could be responsible for misguiding the adaptation complex. These results also indicate that while the vast majority of new spacers are added at the 5' end of the CRISPR array, ectopic spacer acquisition is a common feature of both CRISPR1 and CRISPR3 systems in , and it can still provide phage resistance. Ectopic spacer acquisition also appears to have occurred naturally in some strains of , suggesting that it is a general phenomenon, at least in type II-A systems.
严重依赖两种II-A型CRISPR-Cas系统，即CRISPR1和CRISPR3，来抵抗噬菌蛭弧菌感染。这些系统的一个特点是在噬菌体感染后，新的间隔序列会整合到CRISPR阵列的5'端。然而，我们之前已经表明，间隔序列的异位获取可以发生在CRISPR1阵列内。在此，我们展示了在[具体菌株]的CRISPR3阵列内获取新间隔序列的证据。对噬菌体感染后获得的Uy01菌株的随机选择的噬菌体不敏感突变体进行分析，以及与其他具有相似CRISPR3含量的菌株进行比较，结果表明阵列内的一个特定间隔序列可能导致适应复合体的错误引导。这些结果还表明，虽然绝大多数新间隔序列是添加到CRISPR阵列的5'端，但异位间隔序列获取是[具体菌株]中CRISPR1和CRISPR3系统的共同特征，并且它仍然可以提供噬菌体抗性。异位间隔序列获取似乎也在[具体菌株]的一些菌株中自然发生，这表明至少在II-A型系统中，这是一种普遍现象。
