CRISPR/Cas9 System for Efficient Genome Editing and Targeting in the Mouse NIH/3T3 Cells

Area of Science:

• Molecular Biology
• Genome Engineering
• Gene Editing

Background:

• The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein (Cas) system is a key tool for genome engineering.
• The Rag1 and Rag2 genes are crucial for B and T lymphocyte development; their disruption leads to Severe Combined Immunodeficiency syndrome (SCID).
• This study investigates CRISPR/Cas9 system application for targeting Rag genes in NIH/3T3 mouse cells.

Purpose of the Study:

• To assess the efficiency and specificity of the CRISPR/Cas9 system for generating mutations in Rag genes.
• To create a mutant mouse NIH/3T3 cell line using CRISPR/Cas9 targeting of Rag1 and Rag2.
• To evaluate the effectiveness of rationally designed single guide RNAs (sgRNAs) for precise genome editing.

Main Methods:

• Four single guide RNAs (sgRNAs) were designed to target specific sequences within the coding regions of the Rag1 and Rag2 genes.
• CRISPR/Cas9 plasmids encoding sgRNAs were utilized to introduce targeted mutations in the NIH/3T3 mouse cell line.
• T7 endonuclease assay and sequencing analysis were performed to detect and confirm induced mutations.

Main Results:

• sgRNAs targeting Rag1 resulted in the deletion of the intervening DNA fragment in approximately 50% of transfected cells.
• sgRNAs targeting Rag2 with Cas9 induced indel mutations at both targeted sites.
• The T7 endonuclease assay and sequencing confirmed the generation of novel mutations in the targeted Rag genes.

Conclusions:

• The CRISPR/Cas9 system demonstrates high efficiency and specificity for genome engineering when sgRNAs are rationally designed.
• This approach provides a powerful method for generating mutations in cells and creating genetic models in animals.
• The study successfully produced a mutant NIH/3T3 cell line with targeted Rag gene disruptions.