In a significant breakthrough for Indian agriculture, scientists have developed a homegrown genome-editing technology that promises to be a cheaper and more accessible alternative to the patented CRISPR-Cas9 system. This innovation comes at a critical time when restrictive intellectual property (IP) rights over advanced gene-editing tools pose a serious challenge for countries like India, which urgently need such technologies to ensure food security and enhance crop resilience.
The Patent Bottleneck and India's Agricultural Imperative
The revolutionary CRISPR-Cas9 technology, derived from a bacterial immune system, has become a fiercely contested intellectual property battleground. The primary stakeholders are the University of California, Berkeley (UCB) and the Broad Institute of MIT and Harvard. While Broad holds dominant rights for applications in human and animal cells, UCB's foundational patents cover uses in plants and bacteria.
This complex web of patents, further entangled by commercial exclusivities held by start-ups founded by CRISPR pioneers, has severely restricted access for low- and middle-income nations. For India, with its vast population and pressing agricultural needs, developing an indigenous, cost-effective solution is not just an innovation—it's a necessity.
Harnessing 'Jumping Genes': The Indian Innovation
Led by Kutubuddin Ali Molla at the Indian Council of Agricultural Research’s Central Rice Research Institute (ICAR-CRRI) in Cuttack, a team has successfully demonstrated a novel genome-editing system. They utilized a compact protein called RNA-guided transposon-associated protein (TnpB), which originates from mobile genetic elements known as transposons or "jumping genes."
Discovered by Nobel laureate Barbara McClintock, transposons are DNA sequences that can change their position within a genome. Far from being rare, they constitute over 50% of the human genome and a similar proportion in maize. While their movement can sometimes cause harmful mutations, they are also powerful engines of evolutionary change.
The ICAR team's work builds on the evolutionary link between CRISPR systems and transposons. Research indicates that the Cas9 protein itself likely evolved from a transposon-encoded nuclease called IscB. The team's chosen editor, TnpB, is even more compact than Cas proteins, making it easier to deliver into plant cells.
From Lab to Field: Editing Rice for a Secure Future
The researchers demonstrated the practical application of the TnpB system in rice plants. They designed specific guide RNAs to target six genomic locations, successfully introducing deletions of 7 to 53 base pairs. The editing efficiency in rice protoplasts reached 34%, a promising rate for a new technology.
In a key experiment, they targeted genes responsible for chloroplast development, generating albino rice plants through editing. The monoallelic editing efficiency in regenerated plants was observed to be 38% (20 out of 53 plants). The team also tested the system on the model plant Arabidopsis and performed multiplexed editing, targeting two genes simultaneously.
Like CRISPR-Cas9, which requires a specific PAM sequence (NGG) near its target, the TnpB system requires a TTGAT sequence, known as a TAM. This requirement currently limits the proportion of genomic sites that can be targeted, but the system's simplicity and low cost offer a substantial advantage.
A Path to Self-Reliance in Agricultural Biotechnology
This indigenous technology represents a paradigm shift. By developing a genome-editing platform that circumvents expensive international patents, Indian scientists have opened a door to affordable, scalable crop improvement. This is crucial for developing climate-resilient, high-yielding, and nutritious crop varieties tailored to local conditions.
The innovation aligns with the global distinction between Genetically Modified (GM) crops, which involve inserting foreign DNA, and Genome-Edited (GE) crops, which introduce precise changes within the plant's own genome, often resulting in products indistinguishable from those developed through conventional breeding.
The work at ICAR-CRRI establishes the clear feasibility of transposon-mediated genome editing as a viable alternative to the CRISPR-Cas system. It offers renewed hope for achieving food security through scientific self-reliance, empowering Indian agriculture to meet the challenges of the future with homegrown solutions.
