What is crispr
What is CRISPR

What is CRISPR: Definition, History, and Mechanism of Action

Have you ever wanted to have skills like idols?

It turns out that there has been a method that can be used to modify genes (DNA) in the body of living things, called CRISPR.

What is CRISPR?

CRISPR stands for Clusteres Regularly Interspaced Short Palindromic Repeats.

CRISPR is derived from the phenomenon of bacterial defense mechanisms when fighting viruses that try to breed in them or kill those bacteria.

CRISPR is part of the bacterial immune system, where if the bacteria is infected with a virus, it then stores part of the virus to be recognized if the virus attacks again at a later time, and also to defend itself against the virus.

In short, CRISPR works to change the genome. The genome itself is the sort of recipe that makes you who you are now, that determines the color of your hair, and that determines how tall you are. The genome carries genetic information that a person has. CRISPR finds a sp

ecific place in the DNA, cuts out a small portion of the DNA in that place, and edits that DNA. Thus, this technology can be used to correct genetic mutations, improve crops, and even cure diseases such as cancer.

These gene engineering tools are more precise, more affordable, more customizable, and more efficient than other genetic engineering tools. Other tools have to be paired with some cutting enzymes, whereas CRISPR is unnecessary because the system uses Cas9 which serves as molecular scissors that can cut DNA strands. Cas9 or CRISPR-associated protein 9 is a protein that has a large role in the bacterial defense system against DNA viruses.

CRISPR is more precise and more customizable because it works with RNA guides who tell Cas9 where to go and which genes to cut. CRISPR is very programmable because guide RNA can be created easily. Cas9 can also be programmed to target multiple genes at the same time.

CRISPR History

A group of Japanese researchers, Ishino et al., reported findings of unknown foreign sequences that infiltrated the DNA array of Escherichia coli bacteria, a genetic material that did not belong to E. coli in 1987. However, when it was Ishino et. al does not characterize the nature of the genetic makeup found. E. Coli bacteria are normally found in the colon of humans or animals that also play a role in maintaining digestive health.

In the other hemisphere, precisely on Spain’s Costa Blanca, in 1989, an unrecognizable DNA array in Haloferax mediterranei bacteria, bacteria living in high salt-content environments, was observed by Francisco Mojica, who led him to further research into the thought that the presence of this unidentified genetic material must indicate an important function in the prokaryotic organism (organism without cell membranes).

Similar replication structures were later found in other types of bacteria, but with different arrangements, including Mycobacterium tuberculosis, Clostridium difficile and a number of Yersinia pestis bacteria plague, of which the three bacteria are disease-causing bacteria in humans. The phenomenon of replication of foreign genetic material in the RNA array, which is found only in Archaea and this bacterium was later named Clustered Regularly Interspaced Palindromic Repeats (CRISPR). The term appears in research conducted by Jansen et al., 2002; Mojica & Garrett, 2012.

Further research conducted by Mojica in 2005 suggested that CRISPR must contain a number of biological codes that serve as a form of immune system adaptation that protects Archaea (prokaryotic organisms living in extreme habitats) and bacteria from virus attacks.

In 2007, CRISPR’s function as an immune system to fight viral infections was proven by Barrangou et al. In the years of publication of this paper on the function of CRISPR, research in other similar fields also complements CRISPR findings, such as research by Gilles Vergnaud in France in the field of forensic microbiology that developed a method for tracing the source of disease based on genetic differences among a number of pathogenic strains, and also Alexander Bolotin’s research in Russia which raised the issue of CRISPR speculation which is a form of immunity

Historically, study after study by researchers in various parts of the world in various fields of molecular biology has developed this bacterial adaptive immune system as a DNA editing tool. What exactly does CRISPR look like?. CRISPR itself is a term given to a piece of RNA containing information-carrying molecules.

The information stored in CRISPR is a copy of the genetic material of a virus that has previously infected a bacterium. RNA containing CRISPR can then direct the enzyme CaS9, which is also present in bacteria, to cut the part of RNA that wants to be changed (in mutation) with the aim that a DNA can be studied or used for a specific purpose by scientists, because CRISPR is inseparable from the role of the enzyme CaS9, so it is often referred to also by the term CRISPR-CaS9. Until now CRISPR is claimed by many researchers in the world as an easy, fast, and inexpensive DNA editing tool. Is that true?.

What is CRISPR CAS9 Mechanism of Action?

Mechanism of action of CRISPR CAS9 in Prokaryotes

The CRISPR-Cas9 system is two important synergistic components for destroying foreign genetic material. Naturally, when bacteria or archaea are infected with foreign genetic material such as bacteriophage, the CRISPR-Cas9 work process has three main mechanisms: DNA acquisition, crRNA processing, and interference.

When foreign DNA enters the cell, it will immediately be recorded as a genetic memory and stored in a spacer called the DNA acquisition stage. When there is a virus with DNA fragments that have already been recorded, the next step is crRNA processing. The CRISPR gene will transcribes to produce CRISPR RNA (crRNA) while the Cas9 gene will produce the Cas9 protein.


Last Updated on April 18, 2021 Reviewed by Market Health Beauty Team


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