Last week’s column described conventional breeding techniques for the production of varieties and hybrids. Today’s column delves into genetic engineering. Before tackling that it’s important to remember that much of today’s crop and livestock in large part remain tied entirely or partially to these “conventional” techniques. And no matter how sophisticated genetic manipulation becomes, we still take the materials into the field.
How does genetic engineering differ from conventional breeding? Genetic engineering directly manipulates an organism’s genome using biotechnology. New DNA might be inserted in the host genome through isolating and copying genetic material of interest using molecular cloning methods to generate a particular DNA sequence. You can also synthesize the DNA, and insert the sequence into the host organism. Genes may be removed using a nuclease enzyme. Mutations of an organisms DNA may also be induced. The resulting organism is then termed “genetically modified” or a GMO. We will delve into the agricultural side of this but keep in mind that GMOs are all around you from you laundry detergent to insulin to treat diabetes.
You will hear the term “transgenic” in discussions of GMO crops which simply means genetic material from another species is added to the host’s. Sometimes genetic material from the same species is used. A “gene knockout” organism is one where genetic material has been removed for the species. The difference between a GMO and a conventionally produced difference in genetics is the GMOs genetics are directly modified. There simply isn’t space for a detailed history of genetic engineering or the techniques which is fascinating. Instead, let’s briefly examine where GMO’s are found inside and outside of agriculture. Keep in mind that the vast majority of GMOs in our lives are agriculturally related.
• A variety of medicines including mass produced insulin, growth hormones, and a number of safer more effective vaccines.
• Gene therapies have and are being developed for diseases like chronic lymphocytic leukemia and Parkinson’s disease.
• Genetically engineered bacteria able to make bio-fuels, clean up oil spills and eliminate toxic wastes.
• We will explore it in greater detail next week but in agriculture the primary areas where GMOs are found in crops is herbicide tolerance and insect/disease resistance.
• Other areas of crop modification include more heat and drought tolerant crops, crops of differing compositions of oils and starches, and to produce crops with particular nutrients to prevent illnesses such as blindness by producing “golden rice” that helps with Vitamin A production.
• Work is ongoing in the meat and milk industry to provide products with particular traits including pigs, dairy cows, dairy goats, and fish.
Next week will discuss two major GMO traits – glyphosate resistant crops and Bt technology.