Comparative optimization of combinatorial CRISPR screens

Combinatorial CRISPR screens can be utilized to identify genetic interactions and functional redundancies of multiple genes. Here, the authors benchmark ten digenic CRISPR technologies and identify novel Cas9 tracrRNA combinations that show superior performance. Combinatorial CRISPR technologies have emerged as a transformative approach to systematically probe genetic interactions and dependencies of redundant gene pairs. However, the performance of different functional genomic tools for multiplexing sgRNAs vary widely. Here, we generate and benchmark ten distinct pooled combinatorial CRISPR libraries targeting paralog pairs to optimize digenic knockout screens. Libraries composed of dual Streptococcus pyogenes Cas9 (spCas9), orthogonal spCas9 and Staphylococcus aureus (saCas9), and enhanced Cas12a from Acidaminococcus were evaluated. We demonstrate a combination of alternative tracrRNA sequences from spCas9 consistently show superior effect size and positional balance between the sgRNAs as a robust combinatorial approach to profile genetic interactions of multiple genes.

Automated summary

Combinatorial CRISPR screens were used to study genetic interactions and functional redundancies of genes. The authors evaluated ten different CRISPR technologies and identified novel Cas9 tracrRNA combinations with superior performance. The study demonstrates the effectiveness of specific combinatorial approaches for analyzing genetic interactions of multiple genes.