Cre-lox

The IP's I spoke about in my last post are still ongoing. I have had some success with them but the results are too ambiguous to make any real conclusions yet. However, in our ongoing attempt to understand how Merlin is involved in cell signaling, we have obtained an new strain of mouse. Actually two new strains of mice. These mice utilize the cre-lox system to knock out my gene of interest. I'll try to describe it in general terms. First, one mouse is genetically modified so that my gene of interest (nf2 or merlin) is bordered on both sides by a sequence of DNA called loxP. A second mouse is engineered to contain the DNA for an enzyme called Cre recombinase. When Cre recombinase finds a loxP site, it snips it and recombines the remaining DNA (see below).

In our case, we are interested in making a deletion. Now the coolest thing about the particular Cre mouse we have is that we can control where and when the enzyme is expressed. The where is controlled by a sequence of DNA found upstream of the enzyme called a promoter. In this case, the promoter is specific for schwann cells. The when is controlled by an estrogen receptor that is sensitive to tamoxifen. When I breed a cre mouse (a hemizygote) with a mouse containing loxP sites (a homozygote), I get offspring that are able to knockout Merlin expression when I treat them with tamoxifen. How cool is that?

I just got my first round of mice treated and performed my first Merlin IP in order to determine if the system worked. I have yet to run the gel but when I do, I will post the gel.

Science rules.