Better than CRISPR: New tool can the genome change precise

Since the development of the Genschere CRISPR/Cas9, researchers can modify the genome at specific locations. However, the method is not absolutely precise and can develop unwanted effects. Now, scientists provide an improved process for genetic Manipulation.

With a novel method genetic material can even better change than before. On the Genschere CRISPR/Cas9 construction method allows the individual building blocks of the genetic molecule DNA exchange and to remove small sections or add, report US researchers in the journal "Nature".

Theoretically, almost 90 percent of the approximately 75,000 to diseases, leading to genetic changes so that they can correct it. In Cell experiments, the researchers showed this, among other things, for the sickle-cell anemia, a disease of the red blood cells, and for the Tay-Sachs disease, an incurable and fatal disorder of the fat metabolism.

The method expand the possibilities of genome editing greatly, judging from specialist colleagues in Germany. However, further optimizations are necessary before an application could be moved to the people consideration.

"Important contribution to the improvement of the genome-Editierung"

"As a basic researcher, I am mostly of the intellectual brilliance with which the technology was developed, very impressed. Based on the CRISPR/Cas System here are several different types of DNA were combined-change in a very clever way to targeted mutations einzubringen&quot into the genome;, Holger Puchta, Karlsruhe Institute of technology says.

Now article for later “Pocket” to save

So you use the practical Tool “Pocket”

"Of course, remains to be seen how broadly the technology can be applied, but it is certainly an important contribution to the improvement of the existing techniques for genome-editing."

Faulty genes can be muted

With only a few years ago featured Genschere CRISPR/Cas9, scientists have a laboratory tool, with which genetic material can be a simple way to precisely change. The Genschere controls a defined area in the genome and cuts with the help of the enzyme Cas9 to the DNA double strand. In the case of the repair of the genetic Information is changed at the interface – faulty genes can be, for example, muted.

It is also possible to individual building blocks of DNA and exchange of new genetic Information at the interface to insert it. However, the efficiency of the process is not very high and it can also quarries outside the areas contributed to the double strand and thus unwanted changes in the DNA, so-called Off-Target effects.

Reports, Videos, backgrounds: From Monday to Friday, provided you FOCUS Online with the most important messages from the health Department. Here you can subscribe to the Newsletter easily and free of charge.

Tools for genome editing, the get along without a problematic double-strand break, are called the bases editors. Only certain genetic changes, however, can be achieved. Sections with a plurality of letter – bases of the genetic alphabet can not be removed, for example, or added.

"Targeted correction of errors in the genome is key to the treatment of Erbkrankheiten"

In the case of the newly presented method of the team to Andrew Anzalone of Harvard University in Cambridge (USA), the DNA double strand are also not cut, but only one of the two strands. New genetic information will then be supplied not in the Form of DNA, but in the Form of RNA in the cells.

This related the genetic make-up molecule is transcribed on the spot from a supplied enzyme in DNA and cut the DNA strand to be inserted. The researchers call their method "Prime Editing", PE for short. In tests on human cells, they showed that individual bases can be exchanged and smaller sections can be removed or added.

"The new method allows precise Modifications of the genome with high efficiency, many of which are not waren&quot so far as possible;, Jens Boch commented by the Institute of plant genetics, Gottfried Wilhelm Leibniz University of Hannover, Germany the study. "The targeted correction of errors in the genome is the key to the therapy of hereditary diseases in humans."

Less unwanted side effects and higher efficiency than CRISPR

The researchers corrected about the Mutation in the Gene HBB (hemoglobin beta), which is the basis of sickle cell anemia. The genetic mutation that leads to Tay-Sachs syndrome, were you able to fix it. A little DNA is inserted-section in a Gene. In the case of the manipulation of unwanted side effects occurred in less than Genschere CRISPR/Cas9, the efficiency was higher, the scientists report.

"As already known CRISPR/Cas9 technology also the Prime Editing is not free of risks – that is, it produces unwanted mutations as by-products of genome editing. This includes mutations that are currently common methods difficult to measure, such as, for example, larger rearrangements of Chromosomen", limits Jan Korbel of the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany. "Such by-products should be excluded in the future, before the technology can be safely applied in medicine. As far as we are currently but still."

In the view of colleagues, the technique can, in principle, also be applied to alter the genome of plants and to develop varieties that are resistant against certain diseases, capable of or other wish to have values of the properties.

"For plants, the technology appears to be particularly interesting. We have been working on it, carefully planned changes into the genome einzubringen", about Puchta says. "This is in contrast to the simple deactivation of genes is still very inefficient. The technique could help in fact, easier to obtain disease-resistant plants, or gluten-free plant products. But this must of course be tested first."

Omega-3 Boost by salmon, mackerel and Arctic char: Why we should, each week, eat fish

FOCUS Online/Wochit Omega-3 Boost by salmon, mackerel and Arctic char: Why we fish every week should eat