Modular gene tagging in C. elegans.

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Endogenous gene tagging is crucial for understanding gene expression and protein localization.
• CRISPR technology, while widely used, presents challenges due to errors and the need for specific reagents for each gene and tag.
• Recombinase-based systems offer a potential solution for error-free and modular DNA insertion.

Purpose of the Study:

• To evaluate the germline function of eight recombinases in Caenorhabditis elegans.
• To introduce PhIT, a novel recombinase-based platform for endogenous protein tagging.
• To establish a versatile resource for inserting various modular tags into specific gene loci.

Main Methods:

• CRISPR-mediated insertion of a PhiC31 attB landing pad into the target gene locus.
• Utilizing PhiC31 integrase for site-specific insertion of desired DNA tags.
• Employing a tyrosine recombinase to remove extraneous backbone sequences post-insertion.
• Testing and validating eight different recombinases for germline activity in C. elegans.

Main Results:

• Successful testing of eight recombinases for germline function in C. elegans.
• Demonstration of PhIT's capability to insert diverse modular tags, including fluorescent proteins, cell-specific expression constructs, and degron tags.
• Establishment of a C. elegans strain resource for simplified, modular tag insertion.
• Validation that tag insertion can be achieved through genetic crosses, bypassing the need for microinjection.

Conclusions:

• PhIT provides an efficient, error-free, and modular approach for endogenous protein tagging in C. elegans.
• The recombinase-based strategy simplifies the generation of tagged organisms and expands the toolkit for genetic studies.
• The ability to insert tags via genetic crosses significantly enhances the accessibility and usability of this method for the research community.