Djuranovic himself is interested in modulating gene expression to study disease-related genes, such as ones implicated in cancer. Now we can look at everything in between. The technique takes advantage of a feature in the cellular process known as mRNA translation that is a key step in producing proteins from DNA.
To make a protein, a gene first is copied into a related molecule known as messenger RNA, which is then translated into proteins. In general, these links are mixed together, like letters in words, but sometimes many A's occur in a row. Such sequences are slippery; the molecular machinery that translates the RNA into proteins has a tendency to stop and slip on a long track of A's before it reaches the end, thereby reducing the amount of protein that is produced.
Djuranovic, graduate student Laura Arthur and colleagues showed that the slipperiness of strings of A's could be used to regulate the amount of protein produced from a gene. The more A's they added to the beginning or middle of a piece of messenger RNA, the less protein that was produced from it.
By carefully controlling the length of the string of A's, or introducing different molecular links in certain position along the string they could produce exactly as much protein as they wanted. Djuranovic and colleagues tested the technique in bacteria, protozoa, yeast, plants, fruit flies, and mouse and human cells. It worked in all these organisms because RNA translation is an evolutionarily ancient process that occurs the same way across all lifeforms.
Now we can do it in a few days. Materials provided by Washington University School of Medicine. Original written by Tamara Bhandari. Open survey. In: Facts Methods and Technology. What is genetic engineering? Genetic engineering is used by scientists to enhance or modify the characteristics of an individual organism. Genetic engineering can be applied to any organism, from a virus to a sheep.
For example, genetic engineering can be used to produce plants that have a higher nutritional value or can tolerate exposure to herbicides.
How does genetic engineering work? Normally insulin is produced in the pancreas , but in people with type 1 diabetes there is a problem with insulin production. People with diabetes therefore have to inject insulin to control their blood sugar levels.
Genetic engineering has been used to produce a type of insulin, very similar to our own, from yeast and bacteria like E. The genetic engineering process A small piece of circular DNA called a plasmid is extracted from the bacteria or yeast cell. The gene for human insulin is inserted into the gap in the plasmid. This plasmid is now genetically modified. The genetically modified plasmid is introduced into a new bacteria or yeast cell.
This cell then divides rapidly and starts making insulin. To create large amounts of the cells, the genetically modified bacteria or yeast are grown in large fermentation vessels that contain all the nutrients they need. And then taking what you have engineered and propagating that in any number of different organisms that range from bacterial cells to yeast cells, to plants and animals. So while there isn't a precise definition of genetic engineering, I think it more defines an entire field of recombinant DNA technology, genomics, and genetics in the s.
David M. Bodine, Ph.
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