Fluorescence-based CRISPR interference system for controlled genetic repression and live single-cell imaging in...

Area of Science:

• Molecular Biology
• Microbiology
• Genetic Engineering

Background:

• CRISPR interference (CRISPRi) is a powerful tool for gene regulation.
• Existing CRISPRi vectors may require optimization for specific applications, such as in mycobacterial species.
• Efficient genetic tools are crucial for advancing research in challenging microbial systems.

Purpose of the Study:

• To develop and validate a new series of fluorescence-based CRISPRi tools (pJL series) for mycobacterial research.
• To provide researchers with improved vectors for inducible targeted gene repression.
• To establish an efficient method for co-transforming mycobacteria with integrative and episomal vectors.

Main Methods:

• Development of pJL series CRISPRi vectors derived from pIRL vectors.
• Incorporation of two distinct fluorescent markers under the constitutive psmyc promoter.
• Demonstration of vector functionality by targeting mmpL4b, rpoB, and mmpL3 gene expression.
• Establishment of a single-step co-transformation procedure for mycobacterial species.

Main Results:

• Successful development and validation of the pJL series of CRISPRi vectors.
• Demonstrated efficient inducible gene repression of target genes (mmpL4b, rpoB, mmpL3).
• Showcased simplified selection of recombinant clones using fluorescent markers.
• Established an efficient single-step co-transformation protocol for mycobacteria.

Conclusions:

• The pJL series provides robust and user-friendly CRISPRi tools for mycobacterial gene repression.
• These tools and the described co-transformation method will facilitate new discoveries in mycobacterial research.
• The fluorescence-based selection simplifies experimental workflows, enhancing reproducibility and efficiency.