Simply put, the Cre/lox system rocks. Research mouse models that incorporate the Cre/lox system typically involve generating double, triple, quadruple, or even n-tuple (is that really a word?) mutant/transgenic mice. Here is the most efficient breeding scheme for generating Cre/lox. The Cre/lox system is a site-specific recombination system widely used in mice. The enzyme Cre recombinase, originally derived from the P1 bacteriophage. The Cre-loxP recombination system is routinely used for the generation of mouse knockouts. In part 1 of this mini-series, I introduced the concept and.


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As with any other technology or research tool, it has limitations and pitfalls that need to be considered while planning experiments or interpreting results. This article will take you through some of these pitfalls along with potential cre lox recombination to solve your Cre-loxP challenges.

Cre-loxP-Mediated Recombination: General Principles and Experimental Considerations.

Cre Toxicity We often hear that too much of anything is cre lox recombination, and this is true for the Cre protein. Several researchers have found that excessive cellular accumulation of Cre recombinase can lead to DNA damage and cell death. This pitfall is a serious problem in certain cell types Cag-cre, CD2-cre but not cre lox recombination others.

Cre Mis-Recombination Cre recombinase may target sites in the genome that are similar to loxP sites cryptic loxP sitesthus inducing recombination or deletion events at non-specific sites.

Cre/lox breeding for dummies

Delete a Gene at a Particular Time Point With an Induction Stimulus Sometimes a complete gene knockout mouse could be cre lox recombination if the gene deleted cre lox recombination essential for embryonic development or other crucial cell functions.

The cre-recombinase is again under the control of a required promoter global or cell-specificbut is also attached to a mutated ligand-binding domain of the estrogen receptor that prevents the cre protein from translocating to the nucleus.

  • Cre-Lox recombination - Wikipedia
  • Cre/loxP recombination system and gene targeting.
  • Cre-loxP Recombination Essentials Part 2 - Bitesize Bio
  • Cre-loxP Recombination Essentials Part 2
  • Cre-loxP Recombination Essentials Part 1
  • Cre/loxP recombination system and gene targeting.

It binds to the mutated estrogen receptor causing it to translocate cre lox recombination the nucleus, thus helping the cre protein to recombine DNA between loxP sites.

Another variant to the Tamoxifen system is the Tet-ON system that uses Doxycycline a Tetracycline analog to induce cre expression. The inducible system is an invaluable way to study gene deletions at particular stages of development cre lox recombination the cell cycle.

Imagine that you place a STOP codon before a gene of interest thus preventing its transcription and translation in cells.


This has been largely due to the simplicity of its use and its adaptability to address diverse biological questions.

The points where the integration and excision reactions occur are called the attachment att sites. Thus, these are site-specific, occurring only at the respective att sites. The integrase class of enzymes catalyse this cre lox recombination reaction.

Efficiency cre lox recombination action Two factors have been shown to affect the efficiency of Cre's excision on the lox pair.

Cre/lox breeding for dummies | JAX Mice and Clinical Research Services

First, the nucleotide sequence identity in the spacer region of lox site. Engineered lox variants which differ on the spacer region tend to cre lox recombination varied but generally lower recombination efficiency compared to wildtype loxP, presumably through affecting the formation and resolution of recombination intermediate.

The choice of Cre driver is cre lox recombination important as low expression of Cre recombinase tends to result in non-parallel recombination. Non-parallel recombination is especially problematic in a fate mapping scenario where one recombination event is designed to manipulate the gene under study and the other recombination event is necessary for activating a reporter gene usually encoding a fluorescent protein for cell lineage tracing [24].

Failure to activate both recombination events simultaneously confounds the interpretation of cell fate cre lox recombination results.

Cre lox recombination control Another variant that aids in the control of the expression of the gene in terms of its timing is the tamoxifen-inducible system. I will also explain how to use Cre reporters.

Cre-loxP Recombination Essentials Part 1 - Bitesize Bio

These will be your experimental mice. Depending on your experimental parameters, you can use these as controls see Figure 3A below. I highly recommend that you check out his blog.