CBC Members Receive NSF Career Award

Crop Bioengineering Consortium member Dipali Sashital (Assistant Professor of Biochemistry, Biophysics & Molecular Biology) has received a 5-y career award from the National Science Foundation for her proposal entitled “CAREER: Defining and improving Class 2 CRISPR-Cas endonuclease sequence specificity”. This 5-year grant studies the bacterial CRISPR-Cas immune systems.  All organisms require immune systems to stave off infection from viruses and other pathogens. Bacterial CRISPR–Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated) immune systems seek and destroy viral DNA, enabling rapid neutralization of infection. The minimal CRISPR–Cas system comprises a Cas endonuclease programmed with a guide RNA (gRNA) to bind and cleave matching DNA sequences. The programmability and simplicity of these systems have allowed them to be readily repurposed for myriad biotechnological applications, including genome editing, genetic circuitry, and gene drive. However, Cas endonucleases display “relaxed specificity”, allowing them to target DNA sequences with only partial matches to the gRNA. This inherent feature may provide more effective immunity against rapidly evolving viruses, but can also be highly detrimental to most biotechnological applications. This project will define and compare the extent of relaxed specificity for several Cas endonucleases, with the overall goals of understanding how this feature benefits bacteria during immunity and improving the specificity of CRISPR–Cas tools. In conjunction with this research, the project will develop a new course aimed at educating Iowa State students in both science and non-science majors on the science and ethics of CRISPR–Cas technologies. A major focus of this course will be training in science communication, and students will be given opportunities to extend these lessons beyond the classroom through engagement in informal scientific discussions with the general public.