What is a Flox mouse?

A Flox mouse is a genetically modified mouse crucial in neuroscience research, possessing specific DNA sequences flanked by loxP sites.

Understanding Flox Mice and the Cre/loxP System

Researchers often need to study the effects of turning off (inactivating) a specific gene in a particular tissue or at a specific time during an organism's life. This is where Flox mice and the Cre/loxP system come into play.

Key Components

• loxP sites: These are short DNA sequences that act like molecular "bookmarks." They flank the gene of interest.
• Cre recombinase: This is an enzyme that recognizes loxP sites. When Cre recombinase is present, it cuts the DNA at the loxP sites and removes the DNA sequence between them (the "floxed" gene).

How it Works

1. Creating a Floxed Mouse: Scientists create mice with a gene of interest surrounded by loxP sites. These are the "Floxed" mice.
2. Introducing Cre Recombinase: These Floxed mice are then bred with mice that express Cre recombinase in specific tissues or at specific times.
3. Conditional Gene Inactivation: In cells where Cre recombinase is present, it removes the floxed gene, effectively turning it off only in those cells.

Significance in Neuroscience

According to research (Alcohol, 2019), the Cre/loxP system using Flox mice allows for conditional gene inactivation. This is particularly useful in neuroscience because:

• Targeted Gene Studies: Researchers can inactivate genes in specific brain regions to study their function.
• Temporal Control: Genes can be turned off at specific developmental stages or in response to certain stimuli.

Example

Imagine researchers want to study the role of a specific gene, let's call it "Gene X," in memory formation in the hippocampus.

1. They create a Floxed mouse with Gene X flanked by loxP sites.
2. They breed this mouse with a mouse that expresses Cre recombinase specifically in the hippocampus.
3. In the offspring, Gene X will be inactivated only in the cells of the hippocampus. This allows the scientists to observe how the lack of Gene X in the hippocampus affects memory formation.