Qhow can an organism be genetically modified for a particular use?

how can an organism be genetically modified for a particular use?

AExpert Answer

Each GM crop is modified for a particular use—for a specific trait or combination of traits. These traits provide different types of benefits. One type of benefit is enhanced nutrition. For example, GM pineapple with lycopene (not currently available in the U.S.) may help prevent lung and prostate cancer. Another benefit is a decrease in production inputs, such as irrigation. GM drought-tolerant corn (fully approved in the U.S. and currently beginning limited commercial testing) can help farmers improve environmental stewardship by conserving water resources.

 

Alan McHughen, biotechnology specialist and geneticist, discusses how scientists can ensure that an inserted gene will perform as expected in another response, which is included below:

 

“Genes are like recipes: they tell the cell how to make a particular protein. It is the presence (or absence) of the particular protein (often an enzyme) that gives the plant, animal or microbe a trait. Insulin, for example, is a protein that helps control blood sugar in mammals. The insulin gene recipe is carried in the genome of mammals but is not present in the genomes of animals lacking blood, nor in plants or microbes, for that matter, as they have no blood to regulate. Since the 1980s, insulin used by diabetics is made by genetically modified bacteria into which the human insulin gene recipe was inserted. Although the bacteria have no insulin gene themselves, they were able to read and follow the human gene recipe to make insulin identical to the insulin made by human cells. This bacterial source GM insulin is extracted from the bacterial culture medium and provided to diabetics.

 

“Genetic modification works only because all living things use the same genetic language, so a human gene—such as the insulin gene—transferred to bacteria will work the same way in the bacteria as it does in humans.

 

“Genes are composed of long stretches of DNA, which is composed of the chemical building blocks we abbreviate as a, t, c and g (adenine, thymine, cytosine and guanine, respectively). Just as in the human language English, in which thousands of words are composed of specific sequences of 26 letters, in biology all genes in all species are made of specific sequences of the four DNA bases, a, t, c and g. The human insulin gene consists of 4,044 of these bases, beginning with atggccctgtggatgcg at the start of the insulin recipe.

 

“When the plant, animal or microbe is ‘expressing’ a gene to make the requisite protein, it reads the DNA three letters at a time. Each three-letter ‘word’ in DNA specifies a particular amino acid—of which there are 20 different kinds floating around in the cell—and these amino acids serve as building block ingredients for proteins. As the gene sequence is read by the cell’s kitchen machinery, amino acids are strung together like beads on a string, called a polypeptide chain. Thus, the first part of the DNA recipe, atg gcc ctg tgg atg cgc, translates to the amino acids (in order) methionine, alanine, leucine, tryptophan, methionine, arginine and so on, until the entire sequence of 102 amino acids is completed. The string of amino acids is processed in the cell to release functional insulin.

 

“Therefore, when engineers insert a known DNA sequence into a plant animal or microbe, the resulting ‘expressed’ string of amino acids in the protein will correspond to the recipe as provided in the DNA base sequence. This is true regardless of the species source or the species recipient, as all living things use the same DNA language.

 

“To ensure the inserted gene does what it is supposed to, various molecular, chemical and biological tests are conducted on the GM plant, animal or microbe to check that the inserted DNA sequence is intact and the expressed protein functional before the GMO is commercialized. They are also extensively tested for safety and efficacy for several years prior to commercial release, to ensure there are no unexpected or unusual results.

 

“There are no known examples where a specific gene recipe (DNA sequence) was inserted into a cell and produced something other than the predicted protein. What can—and does—go wrong is that the inserted gene goes unexpressed, or is only partially expressed, such that the amount of protein is insufficient to prove commercial levels of the desired trait. In those cases, the GMO is destroyed as soon as it is detected, usually in very early testing, and in any case long before commercialization.

 

“Finally, the ‘proof of the pudding’ is in the final product. If a culture batch of bacteria genetically modified with the human insulin gene does not produce insulin, it cannot be commercialized. Similarly, if a corn plant is genetically modified to produce a protein allowing the plant to survive an herbicide treatment, and the gene does something other than what is it designed to do, the GM corn plant will die upon application of that herbicide.”

 

The Explore section of this website includes additional information that might be helpful to you.

Posted on August 15, 2017
GMO crops are not "banned" in any countries around the world in the normal sense of that word. Usually when something is banned for consumption, etc., it is because some problem emerged that needed a response. The history of regulation for biotech crops is quite different in that there were regulatory approval processes developed long before any such crops were commercialized. The goal was to try to anticipate any potential health or environmental issues and to make... Read More
Answer:
Posted on August 15, 2017
  On average, the recent research that has been conducted on GMOs, on a per product basis is calculated to be an average of $130 Million (and 13 years). This is a per product average, so each product that reaches commercialization in a given year would also cost something similar to this value.   Please see below for additional helpful resources: The Cost and time involved in the discovery, development and authorization of a new plant biotechnology derived trait by Phillips... Read More
Posted on August 15, 2017
The first use of recombinant DNA technology, was created by Cohen and Boyer in 1972 with E.coli in 1972 and this article explains this advancement in biotechnology in greater detail. Here is an excerpt: “Their experiments dramatically demonstrated the potential impact of DNA recombinant engineering on medicine and pharmacology, industry and agriculture.”   Recombinant insulin was the first commercial product derived from genetic engineering techniques created in 1976 by the... Read More

Explore More Topics