Why is the Cre loxP system used in conditional knockout mice?

Techniques for Obtaining a Conditional Knockout Mouse The Cre-lox system thus enables conditional gene knockout by the introduction of loxP sites into or surrounding the gene of interest and subsequent deletion of the loxP-flanked gene by tissue-specific Cre.

What is loxP sequence?

The Cre protein is a site-specific DNA recombinase that can catalyse the recombination of DNA between specific sites in a DNA molecule. These sites, known as loxP sequences, contain specific binding sites for Cre that surround a directional core sequence where recombination can occur.

What is conditional knockout mice?

A conditional Knockout mouse defines an animal model in which a gene of interest can be: Inactivated in specific cell types in a certain tissue; other cell types and tissues exhibit an unmodified, functional gene expression.

How does Cre lox recombination work?

How does it work? As alluded to above, the Cre recombinase catalyzes the site specific recombination event between two loxP sites, which can be located either on the same or on separate pieces of DNA. Both 13bp repeat sequences on a single loxP site are recognized and bound by a Cre protein, forming a dimer.

How are conditional knockout mice generated in Cre-loxP?

Conditional knockout mice are then generated by breeding the Cre-driver strain with a floxed mouse strain (Figure 1B). The specificity and timing of recombination are controlled by used promoter and/or enhancer. Inducible Cre-loxPsystem; CreERT

How does the Cre-Lox recombination system work?

The Cre-Lox recombination system enables the generation of tissue-specific or inducible knockouts with a high level of control over the spatial and temporal expression of genes. Figure 1. Mechanism of Cre-LoxP System

How can I generate a conditional knockout mouse?

Diagram showing how to generate a conditional knockout mouse. A mouse containing the Cre gene and a mouse containing the lox gene were bred to generate a conditional knockout for a particular gene of interest.

When to use Cre-loxP or floxed alleles?

Tissue-specific Cre-driver crossing with Floxed alleles of gene Y leads to inactivation of Gene Y in tissues associated with Promoter X. As outlined in Figure 1, the basic Cre-loxP recombination event is most often used for controlled excision of genetic sequences.