There are currently four different Gene Editing Techniques, including CRISPR-based technologies, which are designed to cure human disease by repairing the genetic code of their DNA.
Researchers from the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, have found that squid can edit its genetic code. The discovery could potentially help scientists who are working on gene editing-based vaccines, drugs, and treatments.
For most animals, any alterations made to the DNA are transmitted from the cell nucleus via messenger RNA to the cytoplasm. The team reported in the journal Nucleic Acids Research that the longfin inshore squid is the first known animal that can alter messenger RNA from outside the cell nucleus.
Joshua Rosenthal, MBL senior scientist and an author on the paper, said:
This unusual method of editing messenger RNA likely has something to do with the squid’s behavior in the ocean. It works by this massive tweaking of its nervous system. Which is a really novel way of going through life.
Squids’ RNA Editing
All organisms do some kind of RNA editing, but the squid does it on a massive scale, with over 60,000 brain cells that undertake the recoding process, compared with a few hundred in humans.
Together with collogues from Denver’s University of Colorado and the Tel Aviv University of Israel, Rosenthal found that RNA editing occurs in the squid’s axon. The axon is the region of the brain cell that transmits electrical signals to neighboring neurons. Squids’ nerve cells are enormous, with axons sometimes stretching several feet long, making this find a significant one. Since the squid can edit its RNA outside the nucleus, it can potentially change protein function closer to the area that needs alteration.
Rosenthal’s next steps are to understand why the squid has this cellular machinery that does RNA editing. He thinks it may have to do with adapting to changing environmental conditions, including water temperature.
RNA Editing Over DNA Editing
Scientists who are involved with human gene editing are very interested in how the squid accomplishes gene editing with messenger RNA, rather than DNA. Why? Coding modifications made to DNA are irreversible, whereas unused messenger RNA degrades quickly. The benefits of the RNA rapidly deteriorating is that any errors could be washed out, rather than staying with a human forever.
Rosenthal said:
RNA editing is a hell of a lot safer than DNA editing. If you make a mistake, the RNA just turns over and goes away.
Rosenthal is confident that this ability to alter damaged information in the cell without making permanent changes to the DNA in the nucleus could be a massive benefit for medical researchers. “If you have some faulty information inside of your genome—say, you inherited a nucleotide base from your parents, and normally it’s a ‘G,’ and it’s an ‘A’ in you—then you could potentially change it back by editing the RNA,” explained Rosenthal.
RNA Editing Field Of Research
RNA editing was first discovered in 1986, and since then, it has become a fast-moving field of research. The FDA approved the first therapy using RNA interference in 2018. The treatment involves inserting a small piece of RNA into a cell, which binds to its native messenger RNA and quickens their degradation. The procedure disrupts a protein that causes nerve damage in individuals who suffer a rare genetic disorder known as hereditary transthyretin amyloidosis, a condition that leads to organ failure and death.
Over 400 papers on RNA editing were published by researchers in 2019. Also, several biotech start-up companies are starting to use RNA-editing systems to create potential treatments for genetic diseases, including muscular dystrophy.
Rosenthal believes the squid is an incredible creature that will reveal many more biological secrets in the future.
