Quantifying Off-Target Effects in Plant CRISPR/Cas9 Studies : A Systematic Review with Exploratory Quantitative Synthesis
Year: 2026
Type: dissertation
Study design: Systematic Review
Abstract: CRISPR/Cas9 is widely used in plant biology because it enables targeted modification of genomic DNA in both model plants and crop species. Despite its precision, unintended off-target mutations remain an important concern because they can complicate the interpretation of edited phenotypes and influence how genome-edited plants are evaluated. This thesis examined how often experimentally tested candidate off-target sites were confirmed as mutated in published plant CRISPR/Cas9 studies. The work was designed as a systematic literature review and exploratory quantitative synthesis of primary research articles published from 2013 onward. No laboratory work was performed. Six study records provided directly extractable numerical data for quantitative synthesis. Across these studies, 7,921 candidate off-target sites were tested and 18 were confirmed as mutated, corresponding to a crude aggregate proportion of 0.23% with an exact 95% confidence interval of 0.13% to 0.36%. An exploratory random-effects meta-analysis produced a higher pooled estimate of 1.58%, but heterogeneity was very high. Off-target mutations were uncommon in routine specificity screens and in broad whole-genome studies using carefully designed guide RNAs, but they were clearly detectable in high-risk sequence contexts with highly similar genomic near-matches. The results indicate that plant CRISPR/Cas9 editing is often highly specific, but that specificity is conditional rather than absolute and must be interpreted together with guide design, genomic context, detection method, and background variation introduced during plant transformation and regeneration.
Author: Surkova, Glafira
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7221268041