Why in news?

• Indian Council of Agricultural Research (ICAR) has developed and patented a new indigenous gene editing technology based on TnpB (transposon-associated proteins) as a "miniature alternative" to CRISPR-Cas.
• This allows precise, cheaper genome editing in crops, reducing dependency on patented CRISPR-Cas technology.

About TnpB (transposon-associated proteins)

• It is a tiny protein that helps transposons (bits of DNA that can move around in the genome) to cut and insert DNA at specific places.​
• It is  found in certain mobile genetic elements called transposons.
• TnpB uses a small RNA guide (called ωRNA) to find and cut specific DNA sequences, similar to how CRISPR systems work, but TnpB is much smaller.​
• TnpB called a "miniature" tool because it is much smaller in size(~400 amino acids) compared to other gene-editing tools like CRISPR-Cas9(~1000–1400 aa), making it easier to deliver into cells and use in therapies or experiments.​
• TnpB can be programmed to cut DNA at specific sites, which could make it useful for editing genes in humans, plants, or animals, similar to CRISPR but with simpler delivery and possibly fewer side effects.​
• TnpB has the potential to be a cheaper, easier, and smaller alternative to current gene-editing tools, opening new possibilities for medicine and agriculture.​

Comparison with CRISPR-Cas9/Cas12

• Advantages vs Cas9/Cas12: far smaller size, easier viral delivery, potential to target genomic regions not accessible to standard PAM-dependent systems, and fully indigenous toolchains in some countries (e.g., India).​
• Limitations: editing efficiencies and TAM compatibility are still being optimized, off-target and collateral activities need systematic characterization, and the tool is less mature than widely used Cas9/Cas12 platforms.​

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