CRISPR to save us from hunger?

Dear Prof McCrindle,

Do we have gene-editing technology such as CRISPR in South Africa and can it solve the planet’s food crisis sometime in the near future, as predicted? Kind regards, Joshua

Dear Joshua,

Thermo Fisher Scientific has opened a CRISPR/Cas9 laboratory in South Africa. This genetic modification method is used to direct the Cas9 nuclease to create a sitedirected double-strand DNA break, using a small RNA molecule as a guide. It causes a permanent modification of the genomic target sequence and can produce genetically modified plants and livestock. This technique provides far quicker results than the many years previously needed for genetic improvement.

In 2020, the Food and Agriculture Organization of the UN estimated that there were about eight billion people in the world. Of these, one billion were undernourished, while about two billion showed deficiencies in essential vitamins and minerals. The UN’s Sustainable Development Goals include a ‘worldwide policy for reducing hunger and poverty’. Its aim is to end hunger, ensure food security, improve nutrition, and promote sustainable agriculture by the year 2030. It has been suggested that genetic modification of crops and livestock could help realise this goal. Genetically modified organisms (GMO) became a huge issue in the 1990s. Scientists started changing the DNA of crops to increase productivity and decrease susceptibility to diseases and pests. GM maize became a hot topic and certain countries, including Zambia, refused to plant or market GM maize. South African exports were jeopardised because our maize was genetically modified. However, a far higher level of production compensated for this boycott. It was also easier and cheaper to grow GM maize, partly because it was pest resistant.

By 2024, however, GM crops have become the norm, rather than the exception. This has helped to reduce the cost of crop production. In livestock, genetic engineering has not made much progress, although most stud animals are now genotyped. Genetic markers are used to eliminate breeding animals with unwanted heritable traits. Livestock can also be genetically modified, for instance, doublemuscling in cattle. Grasslands and deserts in Africa, the US and Australia are unsuitable for crop or livestock farming. However, if crops and livestock could be genetically modified to be more drought and heat resistant, this might offer better food security.

Is genetic engineering of plants and livestock the best answer to global food insecurity, global warming, methane, and disease prevention? This promise was made many years ago but it is not yet solving those problems, mainly because the human population is increasing too rapidly and by-products of human overpopulation are accumulating too fast. It has, however, made a difference to food quality, security and safety, and decreased food-related diseases. Kind regards, Prof Cheryl McCrindle ȊȲSource: Rodríguez DR. ‘Genome editing: A perspective on the application of CRISPR/Cas9 to study human diseases (Review)’. Int J Mol Med. 2019 Apr; 43(4): 1559–1574. Visit spandidos-publications. com/10.3892/ijmm.2019.4112.