Imagine a world where we are able to manipulate DNA to create hybrid organisms, clones, cure disease at the nucleotide level and personalize medicine, just as we see in the movies. In many ways, that world is already at our doorstep with advancing DNA technology.
What Is DNA Technology?
Biotechnology is defined as the making of useful products by using living systems and organisms. These products are part of medicine, agriculture, food production, to name a few. Biotechnology permeates all parts of our lives, and asks us to make important ethical decisions at times. DNA Technology is one of the areas of biotechnology that is centered around the use of DNA.
We will discuss some of the most important DNA Technologies below. You are not expected to understand every one of these in great depth, but you should have a general idea (based on the explanations below) how each DNA Technology serves humans and challenges us to ask important questions.
The Human Genome Project
The Human Genome Project, or HGP, was an international effort to determine all the base pairs of the human genome. It is the world’s largest collaborative biological project to date, beginning in 1990 and having completed in 2003. It also aimed to map all the genes discovered onto their respective chromosomes. Among other applications and benefits, knowing the human genome’s code allows us to discover the source of diseases and design effective treatments. The HGP’s public database is used by scientists exploring other DNA Technologies.
Scientists utilize the genetic “fingerprints” or profiles of humans to analyze DNA evidence. DNA profiles are the sets of unique letters that make up a person’s genome. To create someone’s fingerprint, their genome is broken into pieces that target parts of DNA that vary greatly among humans, since humans are 99.9% identical otherwise. The pieces are separated on a gel (seen below). The pattern of bands is unique to individuals, and related persons share common bands.
Forensic scientists use DNA profiles in criminal investigation. DNA profiles can also be used to determine paternity. You can see the banding patterns for 6 individuals in the following picture:
Genetic Engineering: Recombinant DNA, Molecular Cloning and GMOs
Genetic engineering, in a general sense, is any modification of an organism’s DNA by using biotechnology. It may involve knocking out genes, inserting genes or even targeting specific genes with an intended mutation within an organism.
There are a variety of ways in which genetic engineering may be used. One of it’s uses is for molecular cloning. This involves using an organism, such as bacteria, as a protein factory. This is how we are able to manufacture enzymes for use in detergents, as well as produce large amounts of insulin or human growth hormone for human medical uses.
Watch the short movie clip below (from WGBH and Digizyme, Inc.) to learn more about how genes are recombined (to create recombinant DNA) to make products, such as insulin:
Any organism whose DNA has been modified by these methods is called a genetically modified organism (GMO) or transgenic organism. The first GMOs were bacteria. Plants have been modified as GMOs in a number of ways, including resistance to pests, herbicides, extreme temperature and viruses, as well as modified for enhanced nutrition.
Gene therapy is way to combat disease by using a vector (often a virus) to deliver a lab-made nucleic acid (genes) as a drug into patients’ cells. The genes injected into the patient may produce proteins that help to fight disease, or they may aim to replace the original mutation.
In the picture below, you can see how an adenovirus is used to enter a cell and deposit a gene that will make a protein that the patient lacks, or that combats a disease.
The term cloning can refer to any of a number of biotechnologies that aim to reproduce a genetic copy of an entire organism. Take care not confuse this with DNA cloning, which we discussed above.
Learn more about cloning in this interactive activity from the Dolan DNA Learning Center. Ask yourself the following questions while progressing through this activity:
- What types of clones exist?
- What technique makes cloning of organisms possible?
- Which animals have scientists successfully cloned?
Watch the following video clip from Frontline/NOVA’s “Harvest of Fear,” and answer the questions that follow.
- How were the salmon genetically modified? Why?
- What are the benefits and drawbacks in making GMO salmon?
- Which uses of GMOs (other than salmon) are worth any risk they pose? Use a specific example and include a reputable source.