Widespread recombinase expression using FLPeR (flipper) mice

Area of Science:

• Genetics and Genomics
• Molecular Biology
• Developmental Biology

Background:

• Advancing conditional genetic strategies necessitates diverse site-specific recombinase systems.
• Existing tools may not fully address the need for broad-spectrum gene manipulation.
• The ROSA26 locus is a well-established site for constitutive gene expression in mice.

Purpose of the Study:

• To develop a novel mouse model for generalized expression of the enhanced FLP recombinase (FLPe).
• To establish a resource for extensive target gene recombination across multiple tissue types.
• To provide a tool for generating FLPe-expressing cell lines and serving as a deleter strain.

Main Methods:

• Targeting the constitutive ROSA26 locus to achieve generalized FLPe expression.
• Generation and characterization of the FLPeR mouse strain.
• Assessment of recombination efficiency in various tissue types, including germ line cells.

Main Results:

• Successful creation of the FLPeR mouse strain with constitutive FLPe expression.
• Demonstration of extensive target gene recombination in most tissue types, including the developing germ line.
• FLPeR mice serve as a valuable source for FLPe-expressing primary cell lines and as a deleter strain.

Conclusions:

• The FLPeR mouse strain provides a powerful tool for conditional genetic studies.
• Its utility spans primary cell line generation, gene deletion strategies, and germ line manipulation.
• Preservation of a 129 genetic background in crossed progeny aids in maintaining reproducible results and genetically defined controls.