Genome editing refers to procedures that use special enzyme complexes toalter DNA. The discovery of CRISPR/Cas 9 in 2012 significantly simplified and accelerated the process. Since then, genome editing has become a standard procedure in molecular biology. The most important component of CRISPR/Cas is an RNA sequence that recognizes and binds DNA segments. In the area of the binding site, the DNA can be cut or rebuilt.
Genome editing can be used in several ways:
- A DNA section is shut down (knock out)
- A defective DNA section is replaced by a functioning one from the same animal or plant species
- Genes are exchanged between variants of the same species. The result is the same as with classical breeding, but it is much faster and no unwanted genes are included
- Genes from a different species are incorporated into the DNA of an organism.
- Gene drive is incorporated into the CRISPR/Cas system. The resulting organism inherits the ability to pass the modified gene to all its offspring.
In the first three cases, the resulting organism can not be distinguished from an organism obtained by classical breeding.
The industrial application of genome editing is hampered by a patent dispute between two research groups, both of whom claim copyright for CRISPR/Cas. Ethical concerns arise when genome editing involves the incorporation of foreign genes into organisms. The concerns are compounded by the fact that CRISPR/Cas9 is relatively easy to implement and could make "bio-hacking" possible.
In 2018, the European Court of Justice ruled that genome-edited plants are genetically modified, whether or not they contain foreign DNA. Because many EU countries, e.g. Germany, prohibit the release of genetically modified organisms (GMOs), the use of genome editing in agriculture in the EU is severely limited until further notice. On the other hand, worldwide it is predicted to have a sudden spread.
Bilal Altun, Wolfgang Kehren, Tobias Remmen
Tannenbusch-Gymnasium, Hirschberger Straße 3, D-53119 Bonn