Latest Gene Editing Techniques

Introduction:

Gene editing mediated by the CRISPR-Cas system has emerged as a powerful technology with the capability of precisely modifying the genome of a wide range of organisms.

Context:

Scientists at the Indian Agricultural Research Institute(IARI) are in the process of developing resilient and high-yield rice varieties using such gene-editing techniques, which have already been approved by many countries, and they hope to have such rice varieties in the hands of Indian farmers by 2024.

Background:

The IARI has previously worked on golden rice, a traditional GM variety that inserted genes from other organisms into the rice plant but ended trials over five years ago due to agronomic issues.

The Institute has now moved to newer technologies such as Site-Directed Nuclease (SDN) 1 and 2.

They aim to bring precision and efficiency into the breeding process using gene-editing tools such as CRISPR.

What are SDN-1 AND SDN2?

SDN-1 and SDN-2 do not use recombinant DNA, do not lead to the insertion of foreign DNA. As such, they do not produce new plant varieties that fall under the scope of the GMO legislation.

What are the benefits of SDN technology?

• It can be used to precisely remove undesirable traits in plants – such as anti-nutrients or allergens, in order to reduce environmental pollution or to enhance the nutritional value of a crop, for instance in maize.
• It can also modify certain existing characteristics in a plant to respond to consumer needs such as enhanced shelf-life and improved taste or texture, for instance in tomatoes.

What is the CRISPR technique?

• “CRISPR” (pronounced “crisper”) is shorthand for “CRISPR-Cas9.” CRISPRs are specialized stretches of DNA, and the protein Cas9 — where Cas stands for “CRISPR-associated” — is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA.
• CRISPR is a powerful tool for editing genomes, meaning it allows researchers to easily alter DNA sequences and modify gene function. It has many potential applications, including correcting genetic defects, treating and preventing the spread of diseases, and improving the growth and resilience of crops. However, despite its promise, the technology also raises ethical concerns.

How GEAC works?
The Genetic Engineering Appraisal Committee (GEAC) functions in the Ministry of Environment, Forest and Climate Change (MoEF&CC). As per Rules, 1989, it is responsible for the appraisal of activities involving large scale use of hazardous microorganisms and recombinants in research and industrial production from the environmental angle. The committee is also responsible for the appraisal of proposals relating to the release of genetically engineered (GE) organisms and products into the environment including experimental field trials.

Why CRISPR technique is comparatively safe?

• In this case, you are just tweaking a gene that is already there in the plant, without bringing in any gene from outside. When a protein comes from an outside organism, then you need to test for safety. But in this case, this protein is right there in the plant and is being changed a little bit, just as nature does through mutation. But it is much faster and far more precise than natural mutation or conventional breeding methods which involve trial and error and multiple breeding cycles.
• The technology is based on an existing bacterial immune system and is adopted worldwide as a simple, precise and efficient method to genetically improve living organisms including animal and plant species for agriculture, food and nutrition.
• The recent approvals of genome-edited mushroom, soybean, and petunia by the United States Department of Agriculture, and the CRISPR-edited nutritionally enhanced tomato by the Japanese Government are significant examples of translational progress in this area that would encourage other countries including India to use CRISPR for various plant breeding innovations.

Conclusion:

The simplicity of the CRISPR platform, compared with the earlier tools, has led to its rapid adoption and wide expansion of its applications. With these advancements, genome editing can positively impact sustainable development, environmental management, food security and find applications in the development of affordable diagnostics and therapeutics for various diseases.