More Information on Horizontal Gene Transfer and Biotech Crops

Since it was proved that DNA is the genetic material, molecular biologists have amassed incontrovertible evidence that DNA is chemically the same, regardless of its source. DNA is contained in the cells of virtually all organisms, and its chemistry is conserved across life forms. In addition, the DNA in all organisms is subject to mutation, recombination, restriction and replication.

The universality of DNA among diverse species provides the basis for recombinant DNA technology. Genes are composed of the same four nucleotides, so distinguishing transgenic DNA from non-transgenic DNA based on chemical makeup is not possible. In addition, all of the components used to create transgenes, such as promoter sequences, the desired trait and marker sequences, were originally discovered in living organisms.

Because of DNA’s universality, all organisms that are consumed or that decay in the environment, transgenic or not, contain DNA. DNA from all organisms and sources, including the component sequences that code for regulatory and housekeeping gene functions, is in the environment. Because of their identical chemical make-up, there is no reason to believe an organism is more likely to take-up a transgene than another gene.

While the overall chemistry of DNA is similar irrespective of its source, species uniqueness results from differences in the sequence of nucleotides that is then translated into a sequence of amino acids. Because the code for converting a chain of nucleotides into a chain of amino acids is universal, one organism, irrespective of the degree of their phylogenetic divergence, can translate a gene from another organism.