Improving precise gene editing by blocking DNA repair in a spider relative

Loss of DNA polymerase theta (Polθ) in the two-spotted spider mite enhances homology-directed repair efficiency.

• SYNCAS-mediated genome editing in Tetranychus urticae may vary in efficiency due to competition between DNA repair pathways.
• The absence of DNA polymerase theta redirects repair mechanisms almost entirely toward homology-directed repair.
• No detectable impact on DNA repair was observed with the loss of Ligase IV.
• Polθ-deficient strains show increased incorporation of repair templates, even with distant mutations.
• Inserting larger DNA fragments is more successful in Polθ-deficient strains.
• Disruption of Polθ results in only a modest fitness cost, suggesting potential for future genome engineering.

Simplified