Part 1 CRISPR/Cas9- Targeted Gene Editing

During my graduate research, a particular technique was by no exaggeration, used everywhere and spoken about all the time. My committee members, colleagues, supervisors, classmates, papers, everyone was and still is excited about CRISPR/Cas9.  It became necessary to understand the technique and its profound implications in molecular biology; the ability to make targeted and precise changes to the genome of living cells and in turn alter the outcome.

To understand CRISPR/Cas9, we break it down into two main components:

  1. CRISPR– clustered regularly interspaced short palindromic repeats, is a defense technique against viral infections, found in bacterial organisms. These organisms contained unique and random DNA sequences/code that repeated. It turned out that these sequences matched with the DNA of infectious viruses. As a result, the CRISPR sequences were identified as a signal of sorts that would then signal for enzymes-
  2. Such as Cas9, that specifically target the DNA of these invading viruses through the matching sequences. As a result, the virus is prevented from replicating and spreading.

What we have is a precision targeted mechanism that is able to terminate a specific sequence and in turn alter the genetic make-up of an organism. The potential appears to be endless, with CRISPR we are able to develop targeted gene editing mechanisms; silencing genes responsible for diseases, ecosystem conservation (ex.developing pesticides through gene editing in weeds), altering specific food traits, controlling organisms that carry infectious diseases and most recently gene editing within embryos.

According to researchers from the Guangzhou Medical University (China), mediated gene editing within human embryos is possible. The objectives currently are to correct mutations related to genetic diseases within the embryo, eliminating the disease upon birth. For example, a fetus with down syndrome (containing an additional chromosome) could theoretically be treated with CRISPR/Cas9, removing the extra chromosome and in turn removing the disease. What the side effects or potential impacts of such a technique would have on the fetus, remains largely unknown, there is no way of knowing exactly what would happen if the genetic makeup of the fetus was altered. Additionally, there is currently no guarantee that all the cells would be corrected or if the technique would be successful in all cells. There is also the ethical question associated with gene editing in embryos, and whether regulations to monitor and supervise the use of such a technique would be required in the future. Defining the boundaries and imposing specific regulations have proven difficult as the science continues to evolve and promise innovation. Is science to be regulated during its early stages? An integral component of science is curiosity and a drive to solve complex problems coupled with a rigorous scientific methodology, so is regulation necessary prior to discovery and would this not in turn hamper the creative force that drives scientists to discover?




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