We were introduced to CRISPR-Cas9 as a tool for targeting cellular mRNA translation through Dr. Peter Ellis, a lecturer in Molecular Biology and Reproduction. However, through research, we discovered that Cas9 is a DNA endonuclease, meaning it recognizes DNA targets and cuts them. It would need to be ‘tricked’ by molecular means. C2C2, however, or Cas13a is an RNA endonuclease, meaning it cuts the RNA rather than the DNA. There are two key differences when comparing Cas13 to CAS9: Firstly, Cas13 recognizes RNA rather than DNA. Secondly, once the target is recognized, it acts promiscuously and starts to ‘chew up’ all of the RNA around it, not only the intended target sequence.
We wanted to utilize this knowledge and build upon the CRISPR-Cas9 and produce a tool that would just track the mRNA, not cut it. We did not want to overcomplicate our methodology and deemed tagging the mRNA with GFP would be sufficient as we would be able to essentially track the mRNA movement to ensure its localization without damaging its integrity through cutting it.
