Date on Honors Thesis

Spring 5-13-2017


**Jesse D. Jones College of Science, Engineering and Technology**

Examining Committee Member

Dr. Howard Whitman, Advisor

Examining Committee Member

Dr. Alexey Arkov, Committee Member

Examining Committee Member

Dr. Timothy Johnston, Committee Member


CRISPR/Cas, a gene editing tool modified from an antiviral response in bacteria, has been demonstrated to faithfully and precisely introduce double strand breaks (DSB’s) in DNA at sites designated by guide RNA’s (gRNA’s). The system is applicable to many model organisms and shows promise in the study of gene function, creation of model organisms, and, importantly, treatment of heritable disease. However, the specificity of the Cas endonuclease is such that DSB’s are often introduced at sites similar to the target sequence, called off-target sites. Minimization of off-target DNA cleavage is important to prevent unknown and unwanted mutation, which can raise significant safety concerns. Thus, it is important for researchers using the tool to predict, prevent, and screen for these off-target DSB’s. Luckily, many methods have been developed to meet these needs. In the present analysis, the risk assessment efforts of several representative studies using various model organisms are investigated and summarized. Most often, researchers focus on predictive risk assessment strategies, leaving preventative and screening measures rarely or never used. CRISPR/Cas is a very potent gene editing tool whose greatest potential will likely be achieved in human germline cell editing. However, implementation in human embryos will likely only occur on a large scale after the tool is more fully understood. The use of all applicable risk assessment strategies could help further our understanding of CRISPR/Cas, lessening the time before it can be applied to human embryos in the way of heritable disease treatment.