CRISPR gene editing

CRISPR

The history of CRISPR began in 1987, when Japanese scientists studying bacteria Escherichia coli discovered unusual repeating sequences in its DNA. It was not possible to find out their biological significance, but soon similar fragments were found in the genome of other bacteria and archaea. The sequences are called CRISPR — clustered regularly interspaced short palindromic repeats.

Discovery

Their function remained a mystery until 2007, when experts on the bacteria Streptococcus, which is used to make fermented milk products, determined that these fragments are part of the bacteria's immune system.

History

For some time this discovery was interesting only for microbiologists. However, that all changed in 2011, when biologists Jennifer Doudna and Emmanuelle Charpentier decided to study the CRISPR mechanism more closely. They found that a protein could be tricked into giving it RNA. A protein carrying this RNA will look for genetic fragments that match what it carries. Having found a correspondence with unfamiliar DNA, he will begin to grind it, regardless of who it belongs to - a virus, a plant or an animal. As noted in a 2012 paper by Doudna and Charpentier, this mechanism can be used to cut any genome in the right place.

In February 2013, it was shown that CRISPR/Cas9 can be used to edit DNA in cell culture in mice and humans. Furthermore, it turned out that the technology allows not only to remove unnecessary genes, but also to insert others in their place. To do this, it is enough to add enzymes that restore DNA.

Scientists quickly realized the tremendous promise of CRISPR. If in 2011 only 100 works about it were published, then by 2017 this figure reached more than 14,000.

Functions of CRISPR

Practical application can be divided into several points:

Changes in agriculture
CRISPR makes agricultural crops more nutritious, tastier and more resistant to heat and stress. You can add other properties to plants: for example, cut out the allergen gene from peanuts, and introduce resistance to a deadly fungus into bananas.
Fighting hereditary diseases
Scientists intend to use CRISPR to cut mutations from the human genome that are responsible for a range of diseases, such as sickle cell disease. The technology will also cut genes associated with breast cancer. In theory, a CRISPR attack could even stop the development of HIV.
New antibiotics and antiviral drugs
Bacteria develop resistance to antibiotics, and developing new ones is expensive and difficult. CRISPR technology makes it possible to kill certain types of bacteria with high accuracy, although a specific method has yet to be developed. Several researchers are also working on CRISPR systems that target viruses.

The idea of gene modification is not new, and its various techniques are in use for many years. However, CRISPR surpasses all technologies known so far due to its availability and accuracy. Editing a single gene will cost only $ 75 and take several hours. Importantly, the technology works with any organism on Earth.

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