The Future of Genetic Engineering: Mini-chromosomes

Genetic engineering is the process of directly manipulating the genes of an organism. In order to alter the genes, cloning techniques as well as transformation techniques are used. The field of agriculture and medicine have most benefited from genetic engineering. Genetically modified crops promise higher yield in harsh weather conditions, greater resistance to pests, insects and diseases and increased nutritional value. Gene therapy holds great promise for medicine. In gene therapy, mutated or diseased genes are repaired or modified or replaced by therapeutic genes in order to fight diseases.

Genetic modification of crops has had its share of problems, both technical and ethical. Some of the highlighted potential problems are unintended harm to organisms, reduced effectiveness of herbicides and pesticides, horizontal gene transfer to unintended species, allergic reactions and fear of other health hazards in humans.

One of the areas where genetic engineering has an interesting future is that of the construction of artificial mini-chromosomes and transformed organelles. These provide a means of circumventing the conventional problems of genetic engineering. A mini-chromosome is a eukaryotic chromosome that has been reduced in size by deleting segments of DNA. Many mini-chromosomes have been generated that contain only centromeres and telomeres. Transgenes can be easily attached to these mini-chromosomes through site-specific recombination.

A group of scientists working at the University of Missouri-Colombia discovered a method to engineer mini-chromosomes in maize and to attach transgenes to them. Genes were stacked onto these mini-chromosomes which is an advantage over traditional gene manipulation techniques.

Unlike in normal chromosomes, genes can be arrayed in a specific manner around the centromere of mini-chromosomes and specific regulatory regions can flank them. Numerous genes can be added and manipulated easily because they are all in the one place.

This genetic engineering technique should create crops with many beneficial traits such as multiple resistance, that is, crops that are simultaneously resistant to insects, bacteria, viruses, fungi, and herbicides. These crops could also artificially produce metabolites and proteins that could be used in the treatment of human diseases, and according to scientists they might also be used to increase the production of biofuels.