PT  - JOURNAL ARTICLE
AU  - Yan You
AU  - Sharmila G. Ramachandra
AU  - Tian Jin
TI  - A CRISPR-based method for measuring the essentiality of a gene
AID  - 10.1101/736512
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 736512
4099  - http://biorxiv.org/content/early/2019/08/15/736512.short
4100  - http://biorxiv.org/content/early/2019/08/15/736512.full
AB  - The CRISPR/Cas9 system is a powerful method of editing genes by randomly introducing errors into the target sites. Here, we describe a CRISPR-based test for gene essentiality (CRISPR-E test) that allows the identification of essential genes. Specifically, we use sgRNA-mediated CRISPR/Cas9 to target the open reading frame of a gene in the genome and analyze the in-frame (3n) and frameshift (3n+1 and 3n+2) mutations on the target region of the gene in surviving cells. If the gene is non-essential, the cells would carry both in-frame (3n) and frameshift (3n+1 and 3n+2) mutations. In contrast, the cells would carry only in-frame (3n) mutations if the targeted gene is essential, and this selective elimination of frameshift (3n+1 and 3n+2) mutations of the gene indicate its essentiality. As a proof of concept, we have used this CRISPR-E test in the model organism Dictyostelium discoideum to demonstrate that Dync1li1 is an essential gene while KIF1A and fAR1 are not. We further propose a simple method for quantifying the essentiality of a gene using the CRISPR-E test.One Sentence Summary CRISPR-E measures a gene’s essentiality