Multiplex conditional mutagenesis in zebrafish using the CRISPR/Cas system.

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) system is a versatile genome editing tool.
• Current applications often result in global gene editing, limiting the study of gene function in specific contexts.
• Tissue and temporal specific mutagenesis is crucial for understanding gene function during development and avoiding systemic side effects.

Purpose of the Study:

• To develop a conditional CRISPR/Cas system for targeted mutagenesis in transgenic zebrafish.
• To enable precise control over gene editing in specific tissues and at inducible time points.
• To facilitate multiplex mutagenesis for studying multiple gene functions simultaneously.

Main Methods:

• Development of a CRISPR/Cas system utilizing tissue-specific and/or inducible expression of Cas9.
• Implementation of U6-driven expression of single guide RNA (sgRNA) for targeted mutagenesis.
• Isolation of four distinct U6 promoters and design of Golden Gate vectors for assembling multiple sgRNAs for multiplexing.

Main Results:

• Successful establishment of a conditional CRISPR/Cas system in transgenic zebrafish.
• Demonstration of tissue-specific and inducible control over gene editing.
• Efficient assembly of transgenes for multiplex conditional mutagenesis using Golden Gate vectors.

Conclusions:

• The developed CRISPR/Cas system provides a powerful tool for conditional and multiplex mutagenesis in zebrafish.
• This approach allows for precise investigation of gene function in specific tissues and developmental stages.
• The methodology offers significant advantages for functional genomics and developmental studies in zebrafish.