Risks inherent to r-DNA technology

The Hindu 17may01

In reply to Monsanto's letter on his article, Mr. Debashis Banerji writes:

Ms. Meera Vaidyanathan, Manager, Public Affairs, Asia Region, Monsanto (The Hindu, May 14), makes a number of points in response to my article 'Risks of Genetic Engineering' (The Hindu, May 3). The thrust of her points is to question the references I have cited in support of my basic argument. To these I shall come in a moment. I must first draw attention to her inability to question the central thesis of my article. That the very mechanisms used by r-DNA technology to facilitate horizontal gene transfer could have potentially dangerous consequences for the health of all living beings through a proliferation of dangerous bacteria and viruses. This is a danger inherent to the technology and will invariably arise whenever it is used, quite irrespective of the evidence of its manifestation that may have accumulated to date. Ms.

Vaidyanathan suggests that r-DNA technology is being used to develop "high-yielding, high-quality crop varieties". On the contrary, a global survey (C. James, 1997), suggests that herbicide tolerance and insect resistance were the two most common genetically-engineered traits, accounting for more than 90 per cent of the global area planted with transgenic crops. Ms. Vaidyanathan's company, Monsanto, has engineered a wide range of crops resistant to its own top selling herbicide, the glyphosate- based 'Roundup', which is toxic to animals and human beings as well as plants. So you first make farmers dependent on your herbicide and when the herbicide starts killing not just weeds but the crops themselves, you come up with genetically-engineered herbicide-resistant crops. Farmers are compelled to buy these in the next round, but these crops in turn create new problems, for which Monsanto will obviously devise another ingenious solution! Endless rounds of profits, rather than global food security, is clearly the goal of the MNCs. What is worse, studies conducted at the U.S. universities of Nebraska, Wisconsin (Madison) and Georgia (Athens) have shown that Monsanto's glyphosate herbicide resistant 'Roundup Ready soybean' gives lower yields than non-GE varieties. Dr. Roger Elmore, Professor of Agronomy, University of Nebraska, has described the transgene-induced lower yield as a "yield drag", likening it to the effect of turning on an air- conditioner on the pickup of a car. Ms.

Vaidyanathan suggests that "scientists deliberately choose those antibiotic-resistant marker genes for antibiotics which do not have significant clinical use". An example of this was the selection of the Kanamycin resistance gene as it was considered harmless, being not much in use. However, there are reports of even this gene conferring cross resistance in bacteria against clinically important Kanamycin- related antibiotics (V.V. Smirnov and others in Antibiot- Khimiorec, 1994; J. Onaolapo in African Journal of Medical Science, 1994). As for her questioning my reference to the work of Mercer and others, I would like to make it clear that they have not precluded possibilities of such transformation, considering that human saliva contains factors which promote transformation competence of resident bacteria by "free" or "naked" DNA. For Ms. Vaidyanathan's information, it may also be mentioned that some of the extrachromosomal (and not extracircular as stated by her) plasmid DNA replicate independently within bacteria and not outside. The vector-transgene DNA construct is designed to resist degradation and therefore the GMO DNA residues survive harsh conditions such as digestion and even exposure to soil. Evidence of the kind I had mentioned in my article multiplies by the day. The New Scientist (2001) reports that researchers in Australia who were trying to genetically engineer a contraceptive vaccine for mice have accidentally created a deadly virus. The Yugoslav virologist, Mr. Veljkovic, has warned that dangerous recombinant viruses and bacteria may also be inadvertently created while making vaccines against AIDS. In a paper presented before the U.S. National Academy of Science, Ms.

Mae-Wan Ho (2001) reviews possible links between genetic engineering and the recent resurgence of antibiotic-resistant infectious diseases. She reports two most important findings: "persistence of nucleic acids in all environments, including the gut of animals, and the ease with which nucleic acids can get into all cells, especially those of human beings". While Ms. Vaidyanathan seeks to underplay problems created by the use of antibiotic resistance markers, I would like to inform readers that scientific opposition to these markers has mounted to such an extent that "positive selection" markers, such as dependence of cells on a specific nutrient, are being devised. These, of course, have their own problems. As for her reference to the work of Suzuki and others, let me directly quote their conclusions which are even more serious than what I had mentioned in my article: "This phenomenon may contribute to the development of auto-immunity when plasmid DNA is introduced during gene therapy and may be important when double stranded DNA is used in plasmid vaccines."

If media reports are to be believed (New York Times, January 25), for GM giants such as Aventis, Monsanto and Syngenta, "Food biotech is dead." They have all announced that they would henceforth concentrate on genomics and marker-assisted conventional breeding. Meanwhile though they are still forcing the Third World to accept GM crops.