Genetic Scissors | Noble Prize in Chemistry 2020 | UPSC

Spread the love

Genetic Scissors | Noble Prize in Chemistry 2020 | UPSC

Genetic Scissors | Noble Prize in Chemistry 2020

      HEADLINES:

‘Genetic scissors’ and rewriting the code of life

      WHY IN NEWS:

How does a method for genome editing developed by two women scientists help in tackling diseases?

The discovery of “one of gene technology’s sharpest tools:the CRISPR/Cas9 genetic scissors” will lead to the emergence of novel biological applications by making it easier to edit genes.

SYLLABUS COVERED: GS 1 : 3 : Awards : Science and Technology

      LEARNING: 

For PRELIMS we have briefly explained CAS9 technology here . Take out your Prelims book and note this down ! It is important .

For MAINS ; this question has already been asked in Mains ! But still go through Benefits and the Misuses . Let us dive in !

      ISSUE: 

Scientists Jennifer Doudna and Emmanuelle Charpentier bagged the Nobel Prize for Chemistry “for the development of a method for genome editing”.

Genetic Scissors | Noble Prize in Chemistry 2020 | UPSC
American biochemist Jennifer Doudna, left, and French microbiologist Emmanuelle Charpentier. 

WHAT IS CRISPR/CAS9?

  • Much like Microsoft (MS) Word , the CRISPR/Cas9 system allows for adding, altering and deleting the genomic code in living beings.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) are pieces of DNA that bacteria snip off from viruses that once attacked them.

  • This is much like file names used to store various documents we write in MS Word.
  • The COVID-19 pandemic has brought to the fore the importance of ‘memory cells’.
  • Memory cells can quickly produce relevant antibodies to neutralise a repeat infection by a virus.
  • Similarly, the CRISPR are a part of bacteria’s immunological systems that help them in recognising threatening viruses.
  • When they sense a lurking virus, the bacteria produce customised RNA, which is necessary to translate DNA into protein, gleaned from the CRISPR libraries.
  • This also contains Cas (CRISPR-associated) genes that are used to produce enzymes such as Cas-9.
  • These enzymes — the Cas-9 being a particularly popular one — can be used to chop the DNA of the virus and destroy them.

HOW CAN THIS BE USED TO EDIT GENOMES?

  • Using the tool, researchers can change the DNA of animals, plants and microorganisms with precision.
  • While studying this, she discovered a previously unknown molecule, tracrRNA.

Her work showed that tracrRNA is part of bacteria’s ancient immune system, CRISPR/Cas, that disarms viruses by cleaving their DNA.

  • The same year, she initiated a collaboration with biochemist Jennifer Doudna, now a professor at the University of California, Berkeley.
  • Together, they succeeded in recreating the bacteria’s genetic scissors in a test tube .
  • They also simplified the scissors molecular components so they were easier to use.
  • In a significant experiment, they reprogrammed the genetic scissors.
  • In their natural form, the scissors recognise DNA from viruses.

Genetic Scissors

SOURCES : GOOGLE SITES

PRINCIPLE

  • Other genome editing systems like TALENs and Zinc-Finger Nucleases can do similar jobs.
  • But several users consider the Charpentier-Doudna tool more adaptable and easier to use.
  • It is less than a decade since this system gained wide research and commercial interest.

Scientists have been able to make precise single-base-pair changes or larger insertions.

  • Coupled with the availability of genome sequences for a growing number of organisms.

ADVANTAGES

  • The technology allows researchers to find out what genes do, characteristics , special attributes etc.

Move mutations that are identified and associated with disease into systems where they can be studied and tested for treatment.

  • Then they can be tested in combinations with other mutations too.
  • The commercial potential of the system is so compelling that within years of its development.
  • There was a battle over the ownership of the intellectual property rights of the CRISPR/Cas9 .
  • This involved the University of California and the Massachusetts Institute of Technology’s Broad Institute.

APPLICATIONS

  • A person with hereditary blindness became the first to have a CRISPR/Cas-9-based therapy directly injected into her body.
  • Gene-editing with beta thalassemia and  sickle cell disease would no longer require blood transfusions .
  • CRISPR is in the battle against the COVID-19 and has tied up with GlaxoSmithKline to develop a test to detect infections.

CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) in Delhi developed a COVID-19 testing kit, nicknamed ‘Feluda’.

  • The name has been chosen after the fictional Bengali detective, based on the CRISPR/Cas9 system.
  • There are commercial CRISPR-based home kits that allow amateur researchers to develop their own biotechnology applications, triggering a sub-culture called ‘bio-hacking’.

MISUSE

  • The most controversial application of CRISPR/Cas9 was in 2018.
  • Chinese researcher He Jiankui announced that he had used it to create ‘gene-edited twins’ Lula and Nana via in-vitro fertilisation.

He used the gene scissors on the children when they were embryos to edit a gene, CCR5, that in its modified form would protect the babies from HIV.

  • The HIV uses the CCR5 to infect cells and the modified gene would shut the door against such an entry.
  • He was widely condemned and sentenced to three years in jail, and stripped of his position too.
  • It is not known how these mutations are going to play out over the children’s lifetimes .
  • The CRISPR/Cas-9 system allows a democratic usage in labs across the world to tinker with genomes.
  • It still has not reached the level of precision required to be sure that it does not cause unintentional side effects.

      IASbhai WINDUP: 

  • Research is already underway for using proteins that are smaller and more efficient than Cas-9.

The system purportedly holds promise for treating more complex diseases, such as cancer, heart diseases etc.
 

  • This “may make the dream of curing inherited diseases come true”.
     SOURCES:THE HINDU  | Genetic Scissors | Noble Prize in Chemistry 2020 | UPSC

 

DISCOVER MORE : SCIENCE AND TECHNOLOGY

If you liked this article, then please subscribe to our YouTube Channel for Daily Current Affairs , Editorial Analysis & Answer writing video tutorials. You can also find us on Twitter and Facebook.


Spread the love

Leave a Comment

You have successfully subscribed to the newsletter

There was an error while trying to send your request. Please try again.

IASbhai will use the information you provide on this form to be in touch with you and to provide updates and marketing.