Overview
The ability to alter the genetic material of mammalian cells in a precise and time-effective manner will enhance our ability to understand the molecular basis of disease and facilitate treatment options. Altering the genetic makeup relies on the development of biochemical reagents that interact with DNA in a site-specific manner, with minimal interactions at unwanted sites. Developing these reagents is not trivial given the size of the human genome. The biochemical reagents in question are “molecular scissors”, site-specific DNA endonucleases that make a break in DNA at defined sites. The lab under Dr. David Edgell and Dr. Gregory Gloor at The University of Western Ontario has recently developed a new type of molecular scissor based on the nuclease (or cutting domain) from the phage T4 protein I-TevI that is fused to the TAL effector targeting domain which encodes DNA sequence specificity. The Tev-TAL fusions promise to be more specific and smaller than existing reagents. To realize the potential of the Tev-TAL nucleases, the DNA recognition “code” of the Tev-TAL scissors must be fully understood. That is, we must know what DNA sequences we can and cannot target with the Tev-TAL scissors. Knowing this code will allow us to design Tev-TAL scissors that will facilitate both basic and applied research. For instance, it will allow researchers to use Tev-TALs to knockout candidate genes in mouse models of human diseases, accelerating our basic understanding of complex human diseases.