A revolution in gene editing
Accelerated gene Editing with CRISPR: 25 genes at a time
Scientists from the Federal Institute of Technology in Zurich (ETH) have revolutionized the CRISPR-Cas gene editing technology. Now it is possible to modify 25 genes of a cell at the same time – instead of one. And this number can be increased to tens or even hundreds of genes, according to the website of ETH (Revolutionising the CRISPR method). An article with a detailed description of the development was published in the journal Nature Methods (Campa et al., Multiplexed genome engineering by Cas12a and CRISPR arrays encoded on single transcripts).
CRISPR-Cas is a biotechnological method that allows relatively quick and simple manipulation of individual genes in cells: genes can be deleted, replaced or changed. In addition, scientists have recently been actively using "genetic scissors" to increase or decrease the activity of individual genes. This method has become very popular in a very short time, both in fundamental biological research and in applied fields such as plant breeding. Typically, researchers could only modify one gene at a time. Sometimes they managed to do all the manipulations with two or three "targets" at the same time, and only in one case they were able to edit seven genes at the same time.
CRISPR-Cas requires an enzyme known as Cas and a small RNA molecule. Its sequence of nucleic bases serves as an "address label" that directs the enzyme exactly to the designated site of action on the chromosomes. ETH scientists have created a plasmid, or a ring DNA molecule, which stores the Cas enzyme scheme and numerous RNA molecules arranged in sequences: in other words, a whole "directory of addresses" (there can be 25 or more addresses). In their experiments, the researchers inserted this plasmid into human cells, thereby demonstrating that several genes can be modified and regulated simultaneously.
Another innovation: for the new technique, scientists took not the Cas9 enzyme, which has been used in most CRISPR-Cas methods so far, but the Cas12a enzyme associated with it. Not only can it edit genes, but it can also cut a long "list of RNA addresses" into separate "address labels". In addition, Cas12a can process molecules with a shorter RNA address than Cas9. The shorter these addressing sequences are, the more sequences can be placed on the plasmid, the scientists note.
The improved method allows you to edit entire gene networks at once – for example, networks that are responsible for the differentiation of cells into neuronal stem and immune cells. Moreover, it paves the way for complex, large-scale programming of the cell: with its help, it is possible to increase the activity of some genes at one time and reduce the activity of others.
The new "genetic scissors" are of particular interest for fundamental research: they can be used to study, for example, the behavior of various cell types or the nature of complex genetic disorders. They will also find application in cell replacement therapy, which includes the replacement of damaged cells with healthy ones. In this case, researchers can use the method to convert stem cells into differentiated cells, such as neuronal cells or beta cells that produce insulin, or vice versa, to obtain stem cells from differentiated skin cells.
Portal "Eternal youth" http://vechnayamolodost.ru