Genetic diseases have always posed problems for the medical societies. The problem is that the enemy is the gene, an important part of the body. Neither can a malfunctioned gene be loved nor can it be killed with a pill. Patients suffering with diseases such as sickle cell anemia and cystic fibrosis were hopeless until CRISPR emerged as their messiah.
History of CRISPR
CRISPR is short for Clustered Regularly Interspaced Short Palindromic Repeats. It was discovered in three different places.
In 2001 the acronym CRISPR, was composed
In 1987, an Osaka University researcher, Yoshizumi Ishino along with his colleagues stumbled upon CRISPR but its function was not known at the time. Then some researchers in the Netherlands observed some clustered direct repeats in Mycobacterium tuberculosis in 1993. They also noticed the diversity of these repeats in different strains of bacteria. In Spain, at the same time, Francisco Mojica at the University of Alicante pondered over the functions of these repeats in some archaeal organisms. Initially his hypothesis was rejected and he started a survey of scientific literature. In 2001, Mojica and Ruud Jansen together composed the acronym CRISPR.
How does CRISPR work?
CRISPR is actually a mechanism used by bacteria to fight viruses. Its workings are similar to the fashion of the adaptive immune system. Only in CRISPR, a unique DNA endonuclease enzyme named Cas9 is employed. Cas9 with the RNA-guide has the amazing ability to find, cut, and degrade the viral DNA.
CRISPR allows the cell to record the mechanisms of the viruses it has been exposed to and pass the information to the progeny— just like the adaptive immune system.
When CRISPR becomes applicable to humans, it will create history.
When a virus attacks a bacterium, CRISPR allows the cell to cut a part of the DNA and insert it into the chromosome of the bacterial cell. The cell then makes an exact copy of the DNA but in the form of RNA. This RNA copy then attaches itself to Cas9 and forms a complete molecule. This RNA is called guide RNA which guides the Cas9 towards the target which, in this case, is the virus. Cas9 attaches itself to the viral DNA and removes the threat.
What can CRISPR accomplish?
The genetic diseases occur because of the malfunctioned genes. CRISPR can be used to cut out the malfunctioned gene. But how would DNA work if a gene is eliminated?
When we cut and degrade a gene, there are two ways to repair it:
1) The both parts of the DNA are forced to merge together. This is considered as an ineffective method.
2) The effective method is to “fool” the DNA. The codings of the gene are composed with the adjoining letters in the sequence. We can create a false gene which is not sequenced in the middle but ends at the sequences letters. The DNA would treat it as a fully functioned gene as DNA cares only for the adjoining letters.
When CRISPR becomes applicable to humans, it will create history. Diseases that were lethal in the past would be cured effectively. Science will create yet another hope.
Some questions about CRISPR
Science paves the way for the developme of humans. However, almost always it gets into the hands of the ill-minded.
CRISPR will allow us to make changes in the genome of embryos. If a father wishes his child to be a blonde and uses CRISPR for it, it could be possible that the child grows up to resent the decision. Wouldn’t it create a dilemma about free will or at least some resentment towards his father?
What if the military started using CRISPR to create a naturally trained army?
What if? What if? What if?