Mains Paper 3: Science & Technology | Science and Technology- developments and their applications and effects in everyday life
From UPSC perspective, the following things are important:
Prelims level: CRISPR-Cas9, Gene editing
Mains level: Gene editing, its advantages and issues involved.
- Recently a Chinese researcher created an international sensation with his claim that he had altered the genes of a human embryo that eventually resulted in the birth of twin girls.
- If proven, it would be the first instance of human offspring having been produced with specific desired attributes, using newly-developed tools of gene “editing”.
- In the case of the new-born Chinese babies, the genes were claimed to be “edited” to ensure that they do not get infected with HIV, the virus that causes AIDS.
- Genes contain the bio-information that defines any individual.
- Physical attributes like height, skin or hair colour, more subtle features and even behavioral traits can be attributed to information encoded in the genetic material.
- An ability to alter this information gives scientists the power to control some of these features.
- Gene “editing” — sometimes expressed in related, but not always equivalent, terms like genetic modification, genetic manipulation or genetic engineering — is not new.
- It is widely practised in agriculture, to increase productivity or resistance to diseases, etc.
- But even in agriculture, genetic modification is a subject of major debate, especially in developing countries, including India.
- CRISPR (short for Clustered Regularly Interspaced Short Palindromic Repeats) technology is a new and the most efficient, tool for gene “editing” developed in the last one decade.
- The technology replicates a natural defence mechanism in bacteria to fight virus attacks, using a special protein called Cas9.
- CRISPR-Cas9 is a simple, effective, and incredibly precise technology.
How it works?
- CRISPR-Cas9 technology behaves like a cut-and-paste mechanism on DNA strands that contain genetic information.
- The specific location of the genetic codes that need to be changed, or “edited”, is identified on the DNA strand, and then, using the Cas9 protein, which acts like a pair of scissors, that location is cut off from the strand.
- A DNA strand, when broken, has a natural tendency to repair itself.
- Scientists intervene during this auto-repair process, supplying the desired sequence of genetic codes that binds itself with the broken DNA strand.
Loopholes in Gene Editing
- The technology was used to solve a problem potential infection to HIV that already has alternative solutions and treatments.
- It was not necessary to tamper with the genetic material, which can have unintended, and as yet unknown, consequences.
- There is no way to verify the claims or whether the “editing” was carried out in the proper manner.
- The technology is extremely precise, but not 100% precise every time.
- There is a possibility that some other genes also get targeted. In such scenarios, unintended impacts cannot be ruled out.
- If regulatory approvals were obtained, then there will be data and information gaps about the experiment.
- The most promising use of the CRISPR technology is in treatment of diseases.
- For example, in sickle cell anaemia, a single gene mutation makes the blood sickle-shaped.
- This mutation can be reversed using gene editing technology.
- In such cases, the genetic codes of just one individual are being changed to cure a disease.
Ethics at Stake
- Gene “editing” capabilities now exist with hundreds of researchers and laboratories across the world.
- Tampering with the genetic code in human beings is more contentious.
- Leading scientists in the field have for long been calling for a “global pause” on clinical applications of the technology in human beings, until internationally accepted protocols are developed.
Core of the Issue
- The Chinese researcher has done is to edit the genes of an embryo. Such a change would be passed on to the offspring.
- The aforesaid experiment has been basically making changes in the genome of the next generation.
- If we allow this, nothing stops people with access to CRISPR technology to produce babies with very specific traits.
- There is this highly problematic issue of trying to produce “designer” babies or human beings.