Mathematics Explains Why Crispr-Cas9 Sometimes Cuts the Wrong DNA

Mathematics Explains Why Crispr-Cas9 Sometimes Cuts the Wrong DNA:

The discovery of the Cas9 protein has simplified gene editing, and may even make it possible to eliminate many hereditary diseases in the near future. Using Cas9, researchers have the ability to cut DNA in a cell to correct mutated genes, or paste new pieces of genetic material into the newly opened spot. Initially, the Crispr-Cas9 system seemed to be extremely accurate. However, it is now apparent that Cas9 sometimes also cuts other DNA sequences similar to the sequences it was programmed to target. Scientists at Delft University of Technology have developed a mathematical model that explains why Cas9 cuts some DNA sequences while leaving others alone.


The Crispr-Cas9 system is a defence mechanism that protects bacteria from viruses. If a virus enters a bacterium but does not take over the cell, the defence system cuts out some  from the virus and stores it in the bacterium’s own genome. The built-in viral DNA acts as a genetic memory. If the same virus attacks the bacterium (or its descendants), it quickly recognises the attacker and can send out Cas9 proteins to track it down. Using viral RNA as a sort of “cheat sheet,” the protein hunts for hostile DNA in the cell. If it finds a match, the Crispr-Cas9 system then cuts the viral DNA, incapacitating the threat.

Harmful effects

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High Stakes for CRISPR and GMO Regulation in Europe

And what could possibly go wrong?

High Stakes for CRISPR and GMO Regulation in Europe:

The European Court of Justice has been considering whether organisms obtained by mutagenesis are exempt from the EU’s Genetically Modified Organisms Directive.

Source: By Lawrence Woodward

That might sound esoteric or gobbledygook but both pro- and anti-GMO camps are keenly awaiting the outcome as many believe it will determine the legal status in the EU of the “new genetic engineering techniques”.

It almost certainly won’t but it might set the stage – or one of them.

These techniques are usually and erroneously lumped together and called gene (more properly genome) editing; chief of which is the much vaunted – some might say irresponsibly over hyped and promoted – CRISPR-Cas. Together with “synthetic biology” they make up what has been called GMO 2.0 and are seen by proponents and opponents as the future – direction and/or battleground – of genetic engineering in food and farming.

High stakes on all sides

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