A versatile reporter system for CRISPR-mediated chromosomal rearrangements

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• Chromosomal deletions and inversions are significant in cancer development.
• Traditional methods for detecting DNA rearrangements are time-consuming and indirect.

Purpose of the Study:

• To develop rapid fluorescent reporters for quantifying CRISPR/Cas9-mediated DNA deletions and inversions.
• To investigate the mechanisms underlying these chromosomal rearrangements.

Main Methods:

• Development of fluorescent reporters for CRISPR/Cas9.
• Quantification of deletions and inversions in mouse liver using engineered reporters.
• Analysis of DNA repair pathways, specifically non-homologous end-joining (NHEJ).
• Characterization of Cas9 cleavage patterns and resulting DNA breaks.

Main Results:

• CRISPR/Cas9-mediated inversions were found to depend on the LIG4 enzyme.
• Deletions and inversions were successfully engineered in a 50 kb Pten genomic region.
• Sequence-specific insertions/deletions (indels) were observed at rearrangement fusion sites.
• Cas9 cleavage was detected at the fourth nucleotide, causing staggered DNA breaks.

Conclusions:

• The developed fluorescent reporters enable rapid quantification of CRISPR/Cas9-induced chromosomal rearrangements.
• The study elucidates the role of LIG4 in inversion formation and provides insights into Cas9 cleavage mechanisms.
• This technology facilitates further investigation into the mechanisms of chromosomal rearrangements.