Researchers from the Biologically Inspired Engineering, Harvard Wyss Institute have created a new gene-editing tool that will allow scientists to perform millions of genetic experiments simultaneously.
They call the innovation the Retron Library Recombineering (RLR) technique and use segments deoxyribonucleic acid (DNA) bacteria called retons which can produce single-stranded DNA fragments.
When it comes to gene editing, currently CRISPR-Cas9 is perhaps the most well-known technique. This method has made waves in the world of science in recent years, giving researchers the tools they need to be able to easily change the sequence of DNA.
This technique is more accurate than any previously used technique, and has a wide variety of potential applications, including life-saving treatments for a variety of ailments.
However, the tool has several major limitations. It may be difficult to ship large quantities of CRISPR-Cas9 material, which remains a problem for studies and experiments. In addition, the way this technique works can be toxic to cells because the molecular “scissors” Cas9 enzyme, which cuts DNA strands, often cuts non-target sites as well.
During the repair process, CRISPR-Cas9 physically cuts DNA to insert a mutant sequence into its genome. Meanwhile, retrons can insert mutant DNA strands into the replicating cells so that the strands can fuse with the DNA of the daughter cells.
Furthermore, retron sequences can serve as “barcodes” or “name tags”, allowing scientists to track individuals in bacterial assemblages. That means it can be used to edit the genome without destroying the original DNA, and it can be used to carry out multiple experiments in one large mix.
Wyss Institute scientists tested RLR on E coli bacteria and found that 90 percent of the population entered the retron sequence after they had made some changes. They were also able to prove how useful it was in a large-scale genetic experiment. During the tests, they were able to find antibiotic resistance mutations in E coli by sequencing barcode network rather than sequencing individual mutants, making the process a lot faster.
Study co-author Max Schubert explains:
“RLR allows us to do something that’s not possible with CRISPR: we randomly chop the bacterial genome, convert that genetic fragment into single-stranded DNA in situ, and use it to screen millions of sequences simultaneously.
RLR is a simpler, more flexible gene editing tool that can be used for highly multiplex experiments, which eliminates the toxicity often observed with CRISPR and improves the researchers’ ability to explore mutations at the genome level, “he said.
He added that for a long time, CRISPR was only seen as a strange thing that bacteria do, and looking for ways to use it to engineer genomes to change the world.
“Retron is another bacterial innovation that may also provide some important advances,” he said.
There is still work to be done before RLR can be widely used, including improving and standardizing its editing rates. However, the team believes that it can “lead to new, exciting and unexpected innovations.” n SB/yahoo/P-4
Editor : Khairil Huda