New "scissors"

Few developments have shaken the world of biotechnology or caused as much noise as the discovery of CRISPR-Cas systems – a breakthrough in gene editing, awarded the Nobel Prize in 2020. But these systems, which work naturally in bacteria, are limited, and researchers can use them to make only small changes to genes.

In recent years, scientists have discovered another system in bacteria that will help create more powerful gene editing methods to insert genes or large fragments of DNA into the genome. A new study conducted by the University of Texas at Austin significantly expands the number of natural versions of this system, providing researchers with potential new tools for large-scale gene editing.

There are clusters of genes that are inserted using CRISPR into different sites in the genome of an organism – the so-called CRISPR-associated transposons (CRISPR-associated transposons, CASTs). Earlier work has shown that they can be used to add an entire gene encoding many complex functions, or a large fragment of DNA to the genome of bacteria. This opens up the possibility of treating complex diseases associated with more than one gene, and CASTs within a decade can become an important tool for genetic engineers, allowing them to make any changes in any part of the genome of any organism.

Now the researchers have been able to increase the number of probable CASTs from about ten to almost one and a half thousand. Using the Stampede2 supercomputer, they analyzed the world's largest database of fragments of bacterial genomes that have not yet been cultured in the laboratory or fully sequenced.

As a result, 1,476 new suspected CASTs were discovered, including three new families. The authors have already tested some of them and plan to continue experiments to discover real CASTs.

The presence of more than a thousand different CASTs in the arsenal of scientists will help you choose the most convenient, effective and accurate of them to create an optimal gene editing system. In the short term, many of these new systems can be adapted for genetically engineered bacteria. The long-term challenge is to make the systems work in mammalian cells.

Article by J.R.Rybarski et al. The metagenomic discovery of CRISPR-associated transposons is published in the journal PNAS.

Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of The University of Texas at Austin: Potential New Gene Editing Tools Uncovered.