Improved analysis of CRISPR fitness screens and reduced off-target effects with the BAGEL2 gene essentiality classifier

• Published in: Genome medicine Vol. 13; no. 1; pp. 2 - 11
• Main Authors: Kim, Eiru, Hart, Traver
• Format: Journal Article
• Language: English
• Published: London BioMed Central 06.01.2021; BioMed Central Ltd; Springer Nature B.V; BMC
• Subjects: Algorithms; Analysis; Bayes Theorem; Bayesian analysis; Bioinformatics; Biomedical and Life Sciences; Biomedicine; Cancer; Cancer Research; Cell Line, Tumor; CRISPR; CRISPR-Cas Systems - genetics; Data Accuracy; Datasets; Deoxyribonucleic acid; DNA; Gene expression; Gene loci; Genes; Genes, Essential; Genetic aspects; Genetic screening; Genetic Testing; Genomes; Genomics; Human Genetics; Humans; Likelihood Functions; Medicine/Public Health; Metabolomics; Pipelines; Proteins; Regression Analysis; Reproductive fitness; Ribonucleic acid; RNA; Software; Systems Biology; Tumor suppressor genes
• ISSN: 1756-994X; 1756-994X
• DOI: 10.1186/s13073-020-00809-3

Background Identifying essential genes in genome-wide loss-of-function screens is a critical step in functional genomics and cancer target finding. We previously described the Bayesian Analysis of Gene Essentiality (BAGEL) algorithm for accurate classification of gene essentiality from short hairpin RNA and CRISPR/Cas9 genome-wide genetic screens. Results We introduce an updated version, BAGEL2, which employs an improved model that offers a greater dynamic range of Bayes Factors, enabling detection of tumor suppressor genes; a multi-target correction that reduces false positives from off-target CRISPR guide RNA; and the implementation of a cross-validation strategy that improves performance ~ 10× over the prior bootstrap resampling approach. We also describe a metric for screen quality at the replicate level and demonstrate how different algorithms handle lower quality data in substantially different ways. Conclusions BAGEL2 substantially improves the sensitivity, specificity, and performance over BAGEL and establishes the new state of the art in the analysis of CRISPR knockout fitness screens. BAGEL2 is written in Python 3 and source code, along with all supporting files, are available on github ( https://github.com/hart-lab/bagel ).