In the past few years, great excitement has built up over new technologies that enable us to edit DNA sequences and impact the genetic traits of organisms in ways never imagined before. Terms like “new breeding techniques”, “genome editing”, “CRISPR-Cas”, “gene drives” and many others have flooded news’ headlines, offering much promise, but also creating fear, confusion and uncertainty. This has re-kindled my excitement, of thirty years ago, when I first extracted genomic DNA. The stringy, jelly-like mass slowly becoming visible and capturing little air bubbles as it precipitated on the interphase while you carefully layer ice-cold alcohol on the watery extraction buffer. I still remember it vividly, because it filled me with a sense of awe – I could actually ‘see’ the molecules that encode life! Soon followed the knowledge and skills that enabled me to identify and clone genes, characterise their protein products and investigate their roles in living organisms. I am still smitten by genetics, molecular biology and genetic engineering.
After the primary structure of DNA was elucidated and breeders understood how DNA sequences serve as a template for the synthesis of proteins (referred to as the genetic code) in the 1950s, they were also able to induce additional genetic variation through mutation breeding. Finally, the advent of recombinant DNA technology in the 1970s, resulted in production of the first genetically modified (GM) crop plant in the early 1980s. The greatest advantage of GM-technology is the fact that it allowed, for the first time, the exchange of genetic traits between sexually incompatible species. Breeding is thus no longer completely dependent, or limited, by sexual reproduction and because most living organisms use DNA as their genetic blueprint, it is now theoretically possible to transfer any genetic trait to any organism.
The concept of “genome editing” refers to the precise alteration of the nucleotide sequence (the primary structure) of DNA. Naturally-occurring DNA repair mechanisms were purposefully redesigned to develop molecular tools such as CRISPR-Cas, which can accurately identify, cut and repair a specific target DNA sequence. Genome editing techniques can be used to make small changes, similar to mutations that may also occur naturally, but do so more precisely, to disrupt, correct or modify gene activity. Alternatively, whole genes may be deleted or inserted in specific positions within the genome. These inserted genes may originate from a sexually compatible organism (called cisgenesis) or from a non-compatible one (called transgenesis or genetic modification).
Genome editing applications are as wide-ranging as genetic diversity itself. They can be used to treat or eradicate diseases, develop pest resistant, high-yielding, environmentally adapted crops and livestock, nutritionally enhanced foods and much, much more. Genome editing is also a powerful research tool that can help elucidate gene function. The ability of DNA to change, or to be edited, over time has always been an important part of life itself and is also one of the most important assets available to plant and animal breeders to introduce beneficial traits into crops and livestock.
Comparatively, genome editing techniques, such as CRISPR-Cas, are more accurate, efficient, less technically challenging and therefore much cheaper and faster than older DNA modifying techniques. They therefore hold great potential for biotech innovation, especially in resource-limited environments. Developing locally relevant crops and livestock or cures to rare diseases, is now within reach of everyone. Moreover, we can apply it within already established frameworks that will ensure the sustainability (safety and viability) of the resulting products. We should not underestimate the potential of these techniques to democratise biotech innovation and to act as catalysts for the establishment of an ecosystem of sustainable bio-economies across the world and especially in Africa. But… to do so, society at large has to embrace the promise of DNA.
Unfortunately, genome editing has to establish itself in a world where perceptions about any form of induced genetic variation are still influenced by the continuing, emotion-based GMO-food debate. For it to become a transformative technology and deliver on its potential, technology developers have to see societal conditions as an integral part of the innovation process. Building trust between society, technology developers and regulators/government is essential to ensure success. Good governance of product development and deployment, better communication to address risk/benefit perceptions and, most importantly, developing products that clearly benefit the end-consumer will be key. Finally, those of us who understand the technology, its basis, potential and concerns, have the vital responsibility to communicate these transparently and understandably to society and its decision makers, not only in words, but also via safe, sustainable products that improve people’s lives.