These sequences, which proved to be part of a sophisticated immune system used by bacteria to fight viruses, give scientists an unprecedented opportunity to rewrite the code of life. Just a year ago, it was discovered that bacteria can be used to perform specific changes in the DNA of plants, animals, and people.
The molecular system known as Crispr has already made the production of genetically modified animals a much easier process. The first experimental results of the Dutch Institute Humbrecht show that this system can be used to restore a mutation that causes the cystic fibrosis disease.
Although Crispr is accompanied by much enthusiasm, at the same time it raises important concerns, such as safety and ethics, since the technical modification of genes in mammals and their embryos are not unlikely to be used in human embryos, raising the concern of creating ‘bespoke’ babies.
As confirmed in 2007, these unusual repeats in the DNA sequences are part of the adaptive immune system and have taken the important role of remembering pathogenic invaders that challenged the organism in the past.
The function of the genome of the bacteria is as follows: The DNA repeated sequences are separated by other sequences. These “spacers” are pieces of the DNA of the viruses that attacked the organism in the past.
Nevertheless, the real frenzy in the scientific community began in 2012 when a team led by Emmanuelle Charpentier from Umea University in Sweden and Jennifer Doudna from the University of California at Berkeley, showed a method of using the Crispr system that allowed them to cleave any DNA sequence they want.
The cell, while making efforts to undo the damage, usually does not succeed completely. To mutate a gene, scientists typically introduce a “patch” DNA, similar to the one that existed at the point where the sequence was cut, but which contains the desired change.
However, could this apply to other organisms except for bacteria? Doudna says: “Today researchers can create genetically modified mice in their laboratory,” while scientists consider it to be very likely that in a few years Crispr will be tested in humans.
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