CRISPR, a family of DNA sequences taking over the biology field lately, may have become even more astonishing.
DNA pieces could be inserted into genomes in a new version of the method known as "jumping genes."
Geneticist Helen O’Neill of University College London says, “It’s still in the experimental phase, but it’s quite exciting.”
What does CRISPR do?
CRISPR is one of the current ways genome editing is conducted. It is faster, cheaper and more accurate way of editing genes. Currently, CRISPR is on a mission to "find and delete" genetic materials, whereas biologists would prefer to "find and replace".
The way it functions is through cutting specific sections of DNA, creating RNA, using enzymes such as Cas9 to bind the RNA, which can then lead to deletions or cuts in the DNA in a specific location and that usually disables the targeted genes.
This way of operating is extremely useful as a number of diseases could be treated through this manner. For example, when lowering cholesterol levels or for single-gene disorders.
However, there are other instances when it would be more beneficial to fix the faulty genes instead of deleting them entirely. At the moment, this is mostly possible by adding a corrected gene in with the CRISPR.
That said, this still doesn't work for many cell types, and only has a 20 percent rate of success.
"Find and Replace"
Feng Zhang of the Massachusetts Institute of Technology (MIT) is one of many who is working on improving the "find and replace" system. Feng has developed a novel approach based on trasposons, another name for jumping genes.
These genes copy and replicate themselves from one section of the genome to another by using transposase enzymes.
More than half of our genome, in fact, consists of now defunct jumping genes. These transposase enzymes insert jumping genes into specific sequences.
What Feng's team has demonstrated, with an impressive 80 percent success rate, is that DNA several thousand letters long can now be inserted, with the use of Cas12k protein and Tn-7 jumping genes, into specific areas in the genome of the E. coli bacterium.
“Overall, the results shown in the paper are remarkable,” says Gaeten Burgio of the Australian National University, who studies CRISPR systems. However, this method has yet to be used successfully on animal and plant cells.
If this CRISPR system functions correctly in complex cells, it'll be more of a "find and add" function, rather than a "find and replace" one.
It would be a powerful addition for everything ranging from regular research to treating diseases.