GM ( Genetically Modified) Food has been on the limelight for the past few weeks with the visit of the representative from Monsanto ( L’express, Mauritius 22/10/2000). This visit from one of the pioneers in Biotechnology would certainly ignite controversy and give Mauritians a lot on their plates to think about!

With changing climatic conditions, unforcastable weather conditions, pests infestations, growing food is becoming a real challenge to farmers locally and internationally. This situation is rendered worse by the exponential population growth in the world population. With a predicted population of 10 billion by the mid century, makes it imperative for farmers to find crops that are more productive, resistant to the changing weather conditions and to pests.

In this race, many Biotechnology companies are making use of Recombinant Gene Technology to produce genetically modified crops that would in theory be able to meet these conditions.

Different genes have been studied that would make plants more resistant to pests or grow in adverse weather conditions.

One such gene is from the organism Bacillus thuringiensis ( Bt). This Bt Gene produces a protein that is toxic to certain insects. The rationale for the introduction of this gene in the crops under culture genome is that it will unable the plants to be resistant to certain insects by producing natural insecticide, thus reducing or eliminating the use of pesticides. The quality of food thus produced will be better and also cheaper. Bt is currently used in corn and soybeans. Trials in rice fields are underway in China, while Kenya has been trying to develop the "Golden Maize". Probably Mauritius might be interested in introducing this gene in sugar cane and eliminating the use of pesticides!

Other interest has been in the gene that allows sorghum to grow in extremely dry conditions. Researchers at A&M University in Texas, has been studying this plant for the past 15 years. They are confident that this gene will allow plants to grow in arid conditions.

Other concepts to surface has been in the delivery of "edible Vaccines", where a certain gene with vaccine potential like e.g for flu is introduced in tomato or potato plants. The aim is to deliver vaccines to remote inaccessible places , like in parts of Africa.

Up to now, GM food has not been proven to be harmful, although there has been fears about allergies. An allergy is an immunological response to the presence of foreign proteins in the body. This problem has not been documented on large scale.

From Mendelian time till now, plant biologists have been cross breeding species to produce more resistant and productive traits. This type of cross breeding transfers uncontrolled and randomly assorted group of genes, while Recombinant DNA allows precise identification, characterisation, enhancement and transfer of the appropriate genes.

There is quite founded fear about the conferring of resistance during the process of selection of hybrid plants. Indeed, antibiotics like Kanamycin, Ampicillin or Chloramphenicol are used as selective markers to differentiate between organisms that have taken up the gene of interest. However, new concepts have been developed that do not require the use of antibiotics as a selectable marker for gene uptake.

Mannose, which is a simple sugar is used instead. Plants convert Mannose to Mannose - 6 phosphate using a Hexokinase. In susceptible plants that cannot shunt it into its metabolic pathway, Mannose-6-phosphate accumulates and inhibits growth. The plants are therefore transformed with the gene of interest and Phospho Mannose Isomerase (PMI). PMI converts Mannose-6 -Phosphate into easily metabolisable Fructose -6-Phosphate. The plants are screened for the uptake of the gene of interest, are grown on Mannose. Only those that have taken up the gene of interest and PMI will therefore grow, while those that have not been transformed will not.

Interestingly, Recombinant DNA Technology, has been used for decades in the health sector. Scientists at Genentech cloned human Insulin in 1978 and in 1982 recombinant insulin was marketed, while recombinant Hepatitis B vaccines are offered to all our health workers to prevent HBV infections. The FDA (Food and Drug Agency) stringently tested these products of the USA before they were made available for use.

People are still skeptical about GM products. But what is the real fear about?. If it is antibiotic resistance in the food chain, then we would certainly have to go to the drawing board again. The heavy user of antibiotics is the veterinary industry. Antibiotics are given prophylactically to animals to act as an enhancer to allow these animals to put on weight. These animals are then slaughtered for human consumption. The antibiotics eventually find their way to the human through the food chain. Since the pressure is there for the farmers to produce more, they will not stop the practice of using prophylactic antibiotics in animal husbandry.

The fear that GM plants may produce harmful proteins is worth worrying about. But since, genetic modification is carried in a controlled manner, production of any unusual protein can be detected and accounted for by the use of techniques like PCR.

This article may be leading to believe that GM food is safe, but my emphasis would be that people should be comfortable with what they eat. If we happen to join the GM bandwagon, it should be imperative that the public is made aware about the products that are genetically modified. The choice should be there.

However, as the farming industry is under duress to produce more food at a competitive price, it would not be very long to find GM food in our markets and supermarkets. The future of this industry will rely solely on the consumers’ expectations.