Editing DNA: the « molecular scissors» CRISPR-Cas9
The genome editing technique CRISPR-Cas9, sometimes called the "molecular scissors", allows the modification of the genome of living beings, in a similar fashion to cutting and pasting on computers. VIDEOGRAPHIC
Category
🗞
NewsTranscript
00:00The genome editing technique CRISPR-Cas9, sometimes called the molecular scissors, allows
00:13the modification of the genome of living beings in a similar fashion to cutting and pasting
00:18on computers.
00:20The molecular scissors imitate what certain bacteria do in nature.
00:25When they attack a virus, these types of bacteria defend themselves by capturing DNA fragments
00:31of their attacker.
00:33The bacteria integrates the foreign DNA into its own genome to create an RNA molecule.
00:40This type of RNA, produced from the DNA of the bacteria named CRISPR, has the ability
00:46to remember an attack by a virus, a little like a vaccine, and allows the bacteria to
00:53defend itself against new attacks.
00:56Combined with the protein Cas9, the CRISPR RNA functions like molecular scissors, recognizing
01:02the virus DNA and cutting it at the right place to neutralize the intruder.
01:08To reproduce this behavior in cells in the laboratory, the researchers use an RNA strand,
01:14the RNA guide, which will play the same role as the CRISPR molecule.
01:18For this, they combine the Cas9 protein with the RNA guide, which can be chemically synthesized,
01:24then introduce this aqueous solution into the targeted cells.
01:30The researchers can then remove or replace a DNA sequence by another.
01:36The CRISPR-Cas9 technique allows the treatment of hereditary diseases like sickle cell anemia
01:42or to create new varieties of genetically modified plants.