Rewriting the code of life

This year's Nobel Prize in Chemistry has created history by honouring an all-women team. The Nobel prize in Chemistry for 2020 is bagged by Jennifer A. Doudna and Emmanuelle Charpentier, who pioneered the revolutionary CRISPR-Cas9 gene editing technology. This technology was first developed in the year 2012. CRISPR (short for Clustered Regularly Interspaced Short Palindromic Repeats) works like a genetic cut-and-paste tool that allows researchers to permanently modify genes in living cells. One of the best parts of CRISPR is its ease-of-use and is affordable.

What is genome? 

Genome is a language which describes how tall you should be, what color of hair you should have, what color of eyes you should have. They act as instruction manual for synthesis of proteins. There is a particular gene sequence for everything, which determines our traits.

How did researchers get to know about CRISPR-Cas9? Had someone dreamt about it? 

No. A particular form of bacteria, with an immune system known as CRISPR Cas, was closely studied and it was found that they were using this to protect themselves from the attack of viruses. This technology is basically replica of bacteria's natural defence mechanism. This bacterial defense system has been modified to expand its utility as a genome-editing tool.  

How does this work?

Imagine it like cutting a part of zipper and replacing it with another fresh segment. 

Steps involved:

• Initially, researchers created a guide Ribonucleic acid (RNA) template whose work was to take the genetic scissors, Cas9, to the genome which needs to be cut.
• Since broken Deoxyribonucleic acid (DNA) can auto repair itself but there are chances that regrowth of problematic sequence will take place.
• Therefore, the next step was to design a DNA template, which supplies the desired sequence of genetic codes and hence replacing the original sequence with the new one. 
• In simple language, RNA will find the bad guy and will order Cas9 to cut it into pieces. Then a good guy will enter taking the place of bad one. This mechanism can also be dictated as find-replace mechanism. 

This tool is most often used to make a cut or to make minor changes in the DNA. This gene-editing technology has opened up a vast window of opportunity. This tool will be used in treating few disorders like Cancer and cardiovascular diseases including inherited ones like Cystic Fibrosis, Hemophillia, Sickle Cell Anemia and many more. It has extensively being used in agriculture till now as it helps to increase plant yield, quality and to create large number of crop varieties with improved performance. It can even open up more possibilities of producing designer babies.

There is a huge need to develop international rules and guidelines for the use of CRISPR technology. 

Concerns?

The ethical implications of this technique has to be researched before implication on large scale. Genetic editing in humans with customized traits may empower racists. Therefore, it should be used very judicially.