A New Look At CRISPR

    Recently there have been significant advances in CRISPR gene-editing technology. The CRISPER stands for "Clustered Regularly Interspaced Short Palindromic Repeats" which refers to a family of DNA sequences that are found in genomes of bacteria and other microorganisms. 

   

 In recent news, researchers apart of Harvard University, Broad Institute, and the Howard Hughes Medical Institute have found advances in the CRISPR gene. Two papers were published with the work and the finding. The first paper deals with the introduction of cytosine base editors. These cytosine base editors reduce off targeting and edit by a 10 to 100-fold, and this is showing for treatment in human diseases. 

    The second paper deals with the new finding of CRISPR-Cas9 proteins and how they are capable of targeting larger fractions of pathogenic mutations like the ones that are responsible for diseases related to sickle cell anemia. With these findings are also advancements which are trying to minimize risks of adverse effects and start to expand the components of CRISPR in genome editing. In the research it showed how CRISPR has limited ability to access the entire human genome and introducing us to proteins which are able to recognize DNA sequences without a common pattern. This allows us to target half of DNA sites, even those that were challenged mutations. Because of these findings we have been introduced to more ways to edit genomes and find treatments for genetic diseases.

Source:

How CRISPR technology is advancing — Harvard Gazette

Other:

What is CRISPR/Cas9? - PMC (nih.gov)

The First Mitochondrial Gene Editor

 

It has never been possible to fix mutations in mitochondria... until now. Recently, a protein from bacteria has been re-engineered to change DNA in mitochondria, which has not been possible before.  Tools such as Crispr-Cas9 have attempted to be used in mitochondrial DNA, but they have not worked. But, the bacteria Burkholderia cenocepacia has been found to secrete a toxin that is capable of assisting in the creation of a mitochondria-friendly base editor. This toxin is a cytosine-converting protein, which means that it binds to DNA and converts cytosine to thymine. However, unlike all other cytosine-converting proteins, this toxin makes changes to double-stranded DNA, rather than single-stranded DNA. Most gene editors must edit DNA in single strand form, so this toxin is a huge step in the right direction for mitochondrial gene editing. In my opinion, mitochondrial gene editing would be an amazing capability of human gene editing. "Mutations in mitochondrial DNA cause over 150 distinct syndromes and affect 1,000 to 4,000 children born in the United States every year," (Lee, 2020). It could help prevent mitochondrial mutations, as well as so many types of diseases. It could also aid in the process of finding cures for these diseases. Mutations in mitochondrial DNA often involve multiple organ systems and can affect the body as a whole in so many different ways. It would be a miracle to find a way to cure these diseases, and even better, prevent them. I think this work is something that needs to be rapidly pursued, but it seems like scientists are on their way to fixing mitochondrial mutations!

https://www.sciencenews.org/article/mitochondria-gene-editing-bacterial-toxin-crispr

https://www.the-scientist.com/news-opinion/new-gene-editing-tool-corrects-mutations-in-mitochondrial-dna-67726

https://medlineplus.gov/genetics/understanding/mutationsanddisorders/mitochondrialconditions/#:~:text=In%20some%20cases%2C%20inherited%20changes,often%20involve%20multiple%20organ%20systems.