Crispr describes a series of DNA sequences discovered in microbes, part of a system to defend against attacking viruses. Microbes make thousands of forms of Crispr, most of which are just starting to be investigated by scientists. If they can be harnessed, some may bring changes to medicine that we can barely imagine.But that's just another variant of the CRISPR gene editing process that is becoming familiar. Another group of scientists have discovered a completely different bacterial gene editing mechanism, based on proteins called Argonautes.
On Thursday, in the journal Science, researchers demonstrated just how much is left to discover. They found that an ordinary mouth bacterium makes a form of Crispr that breaks apart not DNA, but RNA — the molecular messenger used by cells to turn genes into proteins.
If scientists can get this process to work in human cells, they may open up a new front in gene engineering. . . .
Previously discovered Crispr molecules are very good at whacking apart DNA but don’t protect bacteria from an RNA virus. Dr. Zhang and his colleagues discovered that bacteria with C2c2 make molecules that can attack RNA and chop it up, destroying the invaders.
The researchers also found that they could tailor these genes to cut any RNA molecule they wanted. Now they are tinkering with the process to try to get it to work in human cells.
Given that there are probably thousands of such mechanisms in the bacterial world, it seems highly unlikely that CRISPR-CAS9, the system currently being used to edit human genes, is that best one for our species, and it already works spectacularly well compared to everything else that has been tried. Our skill at gene editing is getting better by leaps and bounds and it won't be long before it revolutionizes our world.