Precision-guided Sterile Insect Technique (pgSIT)

Why in News?

• Leveraging advancements in CRISPR-based genetic engineering, researchers at the University of California San Diego have created a new system that restrains populations of mosquitoes that infect millions each year with debilitating diseases.

More about the news:

• The new precision-guided sterile insect technique, or pgSIT, alters genes linked to male fertility--creating sterile offspring--and female flight in Aedes aegypti, the mosquito species responsible for spreading wide-ranging diseases including dengue fever, chikungunya and Zika.

About Precision-guided sterile insect technique (pgSIT):

• pgSIT is a new scalable genetic control system that uses a CRISPR-based approach to engineer deployable mosquitoes that can suppress populations.
• Males don't transmit diseases so the idea is that as you release more and more sterile males, you can suppress the population without relying on harmful chemicals and insecticides.
• pgSIT differs from "gene drive" systems that could suppress disease vectors by passing desired genetic alterations indefinitely from one generation to the next. Instead, pgSIT uses CRISPR to sterilize male mosquitoes and render female mosquitoes, which spread disease, as flightless.
• The system is self-limiting and is not predicted to persist or spread in the environment, two important safety features that should enable acceptance for this technology.
• pgSIT system could be implemented by deploying eggs of sterile males and flightless females at target locations where mosquito-borne disease spread is occurring.

What is CRISPR?

• It is a gene editing technology, which replicates natural defence mechanisms in bacteria to fight virus attacks, using a special protein called Cas9.

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.
• CRISPR-Cas9 is a simple, effective, and incredibly precise technology with potential to revolutionise human existence in future.
• Emmanuelle Charpentier of France and Jennifer A Doudna of the USA were awarded the 2020 Nobel Prize in Chemistry for developing CRISPR/Cas9 genetic scissors.

PRACTICE QUESTION:

Consider the following pairs:

Terms sometimes seen in news  : Context / Topic

1. CRISPR – Cas9                           : Particle Physics

2.Block chain technology              : Digital Crypto currency

3. Belle 2 experiment                     : Artificial Intelligence

Which of the pairs given above is/are correctly matched?

(a) 1 and 3 only

(b) 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Answer