India’s First Gene-Edited Sheep Developed by SKUAST Using CRISPR-Cas9 Technology

A team of researchers from the Sher-e-Kashmir University of Agricultural Sciences (SKUAST) in Srinagar has produced India’s first gene-edited sheep.

• India’s first Cloned Pashmina goat, ‘Noori’ was cloned by the same team in 2012 and played a key role in producing the world’s first cloned buffalo at NDRI, Karnal.

Key Highlights of The Research

• The project was sponsored by the Indian Council of Agricultural Research (ICAR).
• Technology: The gene editing was performed using CRISPR-Cas9 technology adhering to international biosafety protocols
• Experiment: The myostatin gene of the lamb was edited which is responsible for regulating the growth of muscle in the sheep.
• Result: A mutation disrupted the said gene in the sheep resulting in an increase in the muscle mass of the sheep by 30%.
• Significance:
• • Multiple Applications: The research will now pave the way to produce disease-resistant animals by editing the genes responsible for diseases. It can also help in the twinning of animals at birth.
  • No Foreign DNA: The edited sheep doesn’t contain any foreign DNA, thus distinguishing it from transgenic organisms.
  • Acceptance: The process brings precise, beneficial changes in genes of an organism without introducing foreign DNA making it efficient, safe, and acceptable to both regulators and consumers.

About Gene Editing

• Genome editing or gene editing is a group of genetic engineering technologies which enables changes in an organism’s DNA. 
  • These technologies allow genetic material to be added, removed, altered or modified at particular locations in the genome.
• Key Gene Editing Techniques:
  • CRISPR-Cas9: The technique was adapted from a naturally occurring genome editing system that bacteria use as an immune defense.
    • This technique relies on a protein called Cas9 and a guide RNA molecule to cut DNA at a specific location. 
      • CRISPR, won the 2020 Nobel Prize in Chemistry.
    • The cell’s repair mechanisms are then used to make desired changes, such as knocking out a gene or inserting a new sequence.

• • Zinc Finger Nucleases (ZFNs): ZFNs are engineered enzymes that bind to specific DNA sequences and cut them. They are used to modify DNA by introducing double-strand breaks. 
  • Transcription Activator-Like Effector Nucleases (TALENs): TALENs, like ZFNs, are engineered enzymes that target specific DNA sequences and cut them. They rely on TALE domains for DNA recognition.

Applications of Genetic Editing

• Disease Modeling: Gene editing tools allow for studying disease mechanisms and test potential therapies by creating animal models for human diseases.
• Crop Improvement: Gene editing can be used to enhance crop yield, improve nutritional content, and increase resistance to pests, diseases, and environmental stress. 
  • It can also develop new crop varieties with desirable traits. Example: India’s first gene-edited rice variety was released recently.
• Genetic Disease Treatment: CRISPR-Cas9 gene editing technique is practically in use in treating inherited diseases by correcting genetic defects and in treating cancers by modifying immune cells or tumor cells. 
• Personalized Treatment: Gene editing can help tailor treatments to individual patients based on their genetic makeup, leading to more effective and targeted therapies.
• Animal Health: Gene editing can be used to develop vaccines and therapies for animal diseases, improving animal health and productivity.
• Biomaterials and Biofuels : Gene editing can be used to create new biomaterials with specific properties and improve the efficiency of biofuel production.
• Research: Gene editing is a powerful tool for studying gene function, cell development, and other biological processes.

Regulation of Gene Editing In India

• Law: Genetically modified organisms (GMOs) and the related products are regulated under the “Rules for the manufacture, use, import, export & storage of hazardous microorganisms, genetically engineered organisms or cells, 1989” notified under the Environment (Protection) Act, 1986.
• Categories of Genome Editing: Genome editing are classified into three categories based on the degree of change and introduction of exogenous DNA. 
• • SDN-1 and SDN-2: It involves small changes without adding foreign DNA, are exempted from some regulations.
  • SDN-3:  It includes transgenic editing, is subject to more stringent scrutiny.
• Regulatory Authorities: 
  • The Genetic Engineering Appraisal Committee (GEAC): It is responsible for the approval of genetically engineered organisms for research, development and cultivation
  • Review Committee on Genetic Manipulation (RCGM): The RCGM, under the DBT, regulates upstream research. 
  • Institutional Biosafety Committees (IBSCs): IBSCs, also under the DBT, oversee research and educational experiments involving GMOs.

Concerns regarding Gene Editing Technologies

• Safety and Technical Challenges: If not handled precisely, DNAs can be edited in unintended locations, potentially leading to new, unwanted mutations.
• Effects on Future Generations: Germline editing (altering genes in sperm, eggs, or embryos) can pass on changes to future generations, making it difficult to foresee all potential consequences. 
• Designer Humans: The potential use using gene editing for non-medical purposes, such as enhancing traits like height or intelligence, which could lead to social inequality.
• Lack of regulations: There is a need for clear regulations and guidelines to ensure the safe and ethical use of gene editing technologies.

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