Orpheus recombination : a comprehensive bacteriophage system for murine targeting vector construction by...

Area of Science:

• Molecular Biology
• Genomics
• Genetic Engineering

Background:

• Traditional targeting vector (TV) construction can be complex and time-consuming.
• In vivo recombination methods in Escherichia coli offer a simplified alternative, reducing reliance on restriction enzymes.
• Existing protocols facilitate the fabrication of intricate TV constructs with greater ease.

Purpose of the Study:

• To develop a comprehensive and streamlined protocol for targeting vector construction.
• To introduce the Orpheus recombination (ORE) system for efficient gene targeting and modification.
• To demonstrate the versatility of ORE in isolating specific genomic clones and introducing desired genetic alterations.

Main Methods:

• The Orpheus recombination (ORE) system utilizes a phage-plasmid recombination methodology.
• A small recombination plasmid with selection markers and a homologous probe region is employed.
• Two rounds of single crossover recombination facilitate the introduction and excision of the probe plasmid into/from phage-borne genomic clones.

Main Results:

• ORE enables the specific isolation of desired clones from heterogeneous phage libraries.
• The system allows for the seamless deposition of designed mutations into genomic clones.
• Successful demonstrations include gene-specific clone isolation, point mutations, large deletions, and cassette insertions.

Conclusions:

• The Orpheus recombination (ORE) system provides a robust and efficient method for targeting vector construction.
• ORE simplifies complex genetic modifications, including mutagenesis and clone isolation.
• This protocol allows for customizable and finalized targeting vectors within weeks, enabling repeated procedural use.