Random and targeted transgene insertion in Caenorhabditis elegans using a modified Mos1 transposon

Area of Science:

• Genetics and Genomics
• Molecular Biology
• Transposon Biology

Background:

• The Mos1 transposon system is a valuable tool for genetic manipulation in various organisms.
• Efficient and targeted insertion of large DNA fragments into the genome remains a challenge in model organisms like Caenorhabditis elegans.

Purpose of the Study:

• To engineer a minimal Mos1 transposon (miniMos) for high-frequency transgene insertion in Caenorhabditis elegans.
• To create a set of universal Mos1-mediated single-copy insertion (mosSCI) landing sites for targeted gene delivery.
• To generate specialized C. elegans strains for genetic balancers and genome position tracking.

Main Methods:

• Construction of a minimal Mos1 transposon (miniMos) capable of carrying up to 45-kb transgenes.
• High-frequency germline transformation via microinjection of the miniMos construct into C. elegans.
• Generation of mosSCI landing sites by integrating the miniMos transposon into specific genomic locations.
• Creation of fluorescent and lacO insertion strains for balancer and genome tracking applications.

Main Results:

• The miniMos transposon demonstrated high insertion frequency (~60%) into the C. elegans genome.
• The transposon is active in both C. elegans isolates and Caenorhabditis briggsae.
• Six universal mosSCI landing sites were successfully generated on all autosomes, enabling targeted transgene insertion.
• Two distinct collections of strains were created: fluorescent insertions for genetic balancers and lacO insertions for genome position analysis.

Conclusions:

• The developed miniMos transposon system provides an efficient and versatile method for targeted transgene insertion in nematodes.
• The mosSCI landing sites facilitate precise integration of large DNA constructs into permissive genomic locations.
• The generated specialized strains offer valuable resources for genetic studies, including dominant balancer lines and genome position tracking tools.