The creation of a GM crop involves the transfer of a gene coding of an organism, such as a bacterium, into the genome of the recipient species, such as corn. When the donor and the recipient are distant species, the engineered product is called transgenic.
These possibilities emerged with the marriage between molecular biology and genetics, which gave rise to the high-tech method of genetic engineering. Scientists established that the chemical deoxyribonucleic acid (DNA) forms the basis for inheritance in plants, animals, and some organisms.
They identified replication and protein synthesis as the two major processes that are directed by the molecules that form DNA. Replication makes it possible for each daughter cell to receive a complete copy of the original cell’s genetic information when a cell divides.
The structure and functioning of an organism is directed by proteins resulting from the protein synthesis process. A gene, on the other hand, is a segment within the DNA which directs the synthesis of amino acid to form proteins. Genes are packaged in chromosomes.
Armed with this knowledge, scientists use genetic engineering to improve medicine and agricultural products, and enhance nutrition. To overcome insect pests and to make GM crops resistant to herbicides that kill weeds, geneticists do a transgenic DNA transfer of powerful toxins from, for instance, bacteria to the genome of a crop plant. Examples of the high-yielding and pest-resistant GM crops are the Bt-corn, GM soya, GM cotton, and GM canola.
The most quoted story in agriculture regarding transgenic products is the insertion into the genome of crops, the gene coding responsible for creating toxic material in the bacterium Bacillus Thuringiensis. The insects that nibble on the plant die.
On a high, the problem of insect pests is resolved; but on a low, the transgenic plant has itself become a ‘pesticide’. The long-term effects on the health of humans and livestock that feed on these GM foods or plants is not clear.
Herbicides resolve the problem of weeds but may be hazardous to human health, animals and the environment. A report released on March 20, 2015, by a panel of scientists from the World Health Organization’s International Agency for Research on Cancer (IARC) deemed glyphosate to be “probably carcinogenic [cancer-causing material] to humans.’ Glyphosate is the active ingredient in the most commonly used herbicide, Roundup.
The claim by the IARC is, however, disputed by Monsato, the multinational agrochemicals and agricultural biotechnology company that manufactures Roundup. What is clear, however, is that carcinogenic agents or materials may cause cell cycle dysregulation to occur or inhibit DNA synthesis, which may result in cancer.
Allergy is another possible health problem. Concern arose regarding the allergenic properties of transgenic soya bean which was meant to be introduced to West African farmers.
To solve the problem of deficiency of the essential methionine in West African diet, researchers sought to genetically modify the West African soya bean by inserting into its genome the Brazil nut protein rich in methionine. The project was never implemented because the allergenic Brazil nut introduced allergenic properties in the transgenic soya bean.
For the transgenic soya bean project, the safeguards were in place to check on safety. But it is generally accepted that the process of genetic engineering itself has an aspect that may end in unpredictable results. For transgenic technologies to be effective, the two functional structural and regulatory stretches of DNA have to be read in the recipient genome.
The cell of the recipient species reads and manufactures the type of protein as directed by the chemical composition contained in the donor structural gene. The signaling system in the regulatory stretch determines where, when, and how much protein will be produced.
However, since genetic engineering uses vectors such as harmless bacteria, virus, or coated metal to deliver donor gene coding into the recipients’ DNA, structural or regulatory stretch may pop up anywhere else. This setback may make the results either ineffective or deleterious when the regulatory stretch interferes with another gene’s regulatory element.
Environmentalists are also concerned about ecological disruption. Unwanted supper weeds may emerge when the indigenous weeds develop resistance to herbicides. Another concern is the alteration and elimination of natural species. The seed head of the GMO plants does not self-propagate like the natural indigenous seed.
The implication is that every planting season, the farmers will have to depend on foreign manufactures with patents, and on local agents who rely on market forces to determine prices.
Given also that genetics is at its infancy in Uganda, the agricultural sector will have to depend on foreign scientists to generate GM seeds, herbicides, and pesticides. The small farmer with limited capital will most likely abandon farming.
But the most immediate impact of GMO introduction in Uganda will be more felt in the agricultural export sector. While Uganda can ably compete with big economies in organic agricultural produce, it is likely that the introduction of GM crops will diminish trade opportunities. Why should developed countries buy GM food from Uganda when they can produce it in quantities in their own countries?
However, this said, genetic engineering in agriculture is work in progress. We can approach it with caution, but it is unwise to reject it wholly.
The author is a bioethicist and lecturer at Uganda Martyrs University.