韩国延世大学医学院Hyongbum Henry Kim团队近期取得重要工作进展，他们对17个小型Cas9的活性和特异性的大规模并行评估和计算预测。相关研究成果2023年5月15日在线发表于《自然—方法学》杂志上。

据介绍，近期已经报道了用于体内递送应用的各种小Cas9的同源物和变体。尽管小型Cas9特别适合这一目的，但选择最优化的小型Cas9用于特定靶序列仍然是一项挑战。

为此，研究人员系统地比较了17个小Cas9在数千个靶序列中的活性。对于每个小的Cas9，研究人员已经表征了原间隔区相邻基序，并确定了最佳的单引导RNA（sgRNA）表达形式和支架序列。高通量比较分析揭示了小Cas9的不同高活性组和低活性组。研究人员还开发了DeepSmallCas9，这是一组预测小Cas9在匹配和不匹配靶序列上活性的计算模型。

总之，这些分析和计算模型共同为研究人员选择最适合特定应用的小型Cas9提供了有用的指导。

附：英文原文

Title: Massively parallel evaluation and computational prediction of the activities and specificities of 17 small Cas9s

Author: Seo, Sang-Yeon, Min, Seonwoo, Lee, Sungtae, Seo, Jung Hwa, Park, Jinman, Kim, Hui Kwon, Song, Myungjae, Baek, Dawoon, Cho, Sung-Rae, Kim, Hyongbum Henry

Issue&Volume: 2023-05-15

Abstract: Recently, various small Cas9 orthologs and variants have been reported for use in in vivo delivery applications. Although small Cas9s are particularly suited for this purpose, selecting the most optimal small Cas9 for use at a specific target sequence continues to be challenging. Here, to this end, we have systematically compared the activities of 17 small Cas9s for thousands of target sequences. For each small Cas9, we have characterized the protospacer adjacent motif and determined optimal single guide RNA expression formats and scaffold sequence. High-throughput comparative analyses revealed distinct high- and low-activity groups of small Cas9s. We also developed DeepSmallCas9, a set of computational models predicting the activities of the small Cas9s at matched and mismatched target sequences. Together, this analysis and these computational models provide a useful guide for researchers to select the most suitable small Cas9 for specific applications.

DOI: 10.1038/s41592-023-01875-2

Source: https://www.nature.com/articles/s41592-023-01875-2