GUIDEseq

GUIDEseq analyzes GUIDE-seq sequencing data to identify and characterize CRISPR-Cas9–induced DNA double-strand breaks (DSBs) genome-wide.

Key Features:

• Flexible Analysis Platform: Provides over 60 adjustable parameters to customize analysis for different nuclease platforms, accommodating variation in guide RNA and PAM recognition sequence length and complexity and DNA cleavage positions.
• Identification of Cleavage Sites: Detects unique insertion sites as proxies for cleavage events and estimates their genomic positions as peaks.
• Off-Target Site Analysis: Performs off-target searches in extended regions around identified insertion sites and annotates potential off-target sites that overlap genes.
• Customization and Visualization: Allows tailoring of sequence aggregation criteria and adjustment of peak-calling thresholds and supports comparison and visualization of off-target site overlaps between datasets.
• Cleavage Score Prediction: Outputs mapped read counts and cleavage scores for each identified off-target site using user-specified prediction algorithms.
• Cross-Species Application: Analyzes GUIDE-seq data for any species with a defined genomic sequence.
• Implementation: Implemented as a Bioconductor package in R.

Scientific Applications:

• Genome-editing specificity assessment: Identifies and characterizes on-target and off-target CRISPR-Cas9 cleavage events to assess nuclease specificity and efficiency.
• Therapeutic safety evaluation: Supports assessment of off-target effects relevant to the safety and efficacy of therapeutic gene-editing applications.
• Development of precise editing strategies: Informs the development and optimization of guide RNA and nuclease configurations based on empirical cleavage patterns.
• Cross-species research: Enables GUIDE-seq analysis across diverse organisms provided a defined reference genome.

Methodology:

Implemented in R as a Bioconductor package, GUIDEseq maps reads to identify unique insertion sites, calls peaks to estimate cleavage locations, performs off-target searches in extended regions around insertion sites, annotates overlaps with genes, aggregates sequences with adjustable criteria and peak-calling thresholds, and outputs mapped read counts and cleavage scores derived from user-specified prediction algorithms.