GMOs (genetically modified organisms)

[science_spot]

Here is one of those topics I didn't realize there was alot of fuss about until just this year.  Having worked with alot of GMO in the research laboratory, it seemed like such a normal thing, until two things happened.  First, interacting with European companies as part of my job, and second, joining Cafemom.  The Europeans have a very strong dislike for anything GMO, and so as part of my job, they ask very detailed questions about the possibility of GMOs in my company's product line.  The Cafemom community has many individuals with an equally strong dislike for GMO, and I have learned alot about their concerns during my time here, particularly as part of the food supply, including those with kosher and halal requirements.  I still see that many people do not understand what GMOs really are, and how they got that way.

GMOs (genetically modified organisms) range from plants to bacteria and yeast species to vertabrates.  GMOs have had their DNA modified in order to give them additional desireable traits.  Examples include research animals that have new genes that allow us to study the causes of cancer, plants such as corn or rice that make their own pesticides or require less water, and bacteria that generate human insulin for use by diabetics.  There is alot of controvery around the safety of some of these products, particularly those that enter the food supply.  The purpose of this post is to explain GMOs, not to debate their safety.

The generation of GMOs is through the process called Recombinant DNA Technology, AKA Genetic Engineering.  This is a molecular biology technique that is very powerful, albeit very new, and not without its challenges and risks.  Even so, it has been incredibly successful in a wide range of applications, from food development to research use.  In order to really understand how this technique works, you will need to understand the concepts I brought out in my earlier DNA posts The Basics of DNA and How DNA Does its Thing.  If you prefer a more general understanding, skip the next three paragraphs.  I really love how one post can become a series of posts on a topic, and eventually shows the reader how the topic matters in real life.  Science is Everywhere!

While there are many different variables that go into making a GMO, the basic concept remains the same. The point is to introduce a specific new gene into an organism so it acquires the new trait that gene controls.  For example, if you would like to make a new rice plant that has a lower water requirement or is drought resistant, the traditional method of generating this new plant would be to performa a series of crosses, selecting the most drought-tolerable plants from each generation and continue to cross them until you are happy with the drought resistance qualities you achieve.  The limit of this the time it takes to raise plants over multiple generations, and you may also select for other traits that are not as desireable, such as tough rice or incredibly short plants with low rice yield.

Recombinant DNA Technology has a limit (among others) that you must have identified the gene controlling the trait you want to modify, in this case, a gene controlling drought resistance.  Many plant genes have known functions, so this may not be a huge problem, depending on the trait you would like to add. Once the gene identity is known, you will need to know the sequence of that gene, so you can make many copies of it, through a process known as PCR (I'll do a separate post on this in the future).  Once a fair amount of the gene is generated, it is built into a "vector" that can some additional genetic elemets in it, among them being a gene for antibiotic resistance, such as ampicillin.  This vector, containing the gene of interest (drought resistance) and ampicillin resistance is inserted into special bacteria.  These special bacterial are called competent cells (AKA competent bugs); their competence refers to their ability to take up the vector.  Once the vector is taken into the bacteria (a process called transformation), a large quantity of bacteria are grown, in order to isolate the vector DNA they are keeping inside.  These bacteria are being used just to make large quantities of the vectors, since they grow so fast and very cheap!  The ampicillin resistance gene that was added is being used to make sure the only bacteria grown and used are those resistant to ampicillin, which implies they are carrying the special DNA vector, including the gene for drought resistance. 

Once the vector DNA is acquired, it is transfected into the plant cells.  The point here to get the vector to not only get inside the plant cells, but to insert into one of the chromosomes.  This part of the technique is not very efficient, since few vectors will make it into the cells, even fewer will make it into the nucleus, even fewer will integrate into a chromosome, and even fewer will have an integration site that doesn't disrupt another important gene.  But for the one cell that has a good integration, the work is not yet complete.  The cell needs to be grown into a new plant that has the gene as a permanent part of its DNA (genome), and can pass this on to its reproductive cells so all new generations will have the same new trait.  Once this has happened, there will be a new plant established that is now a GMO.

If you are interested in how this relates to halal, see my post in The Science Spot explaining this previously.  There are alot of great videos out there about this, so I won't link to any one in particular.  As always, please let me know if you have any questions.

 

Tonya

AKA sunmoonstars

The Science Spot

 

 

[cleanaturalady]

Aug. 21, 2009 at 4:07 PM

Say NO to GMO.  That is my motto, anyway.  Thanks for posting.  Your posts are always so informative and we can always rest assured that you did your research.

[evwsquared]

Aug. 21, 2009 at 5:44 PM

Thanks for the link the the halal/kosher discussion in The Science Spot. It was really interesting, and not a topic I would have thought of.

[missiongirl]

Aug. 21, 2009 at 9:49 PM

Thanks for the education!  I was just thinking about this since I have recently started a major health change and see it on some of the labels. 

[jramsaran]

Aug. 22, 2009 at 4:54 AM

i did this for my undergrad research.  i created an E.Coli bacterial strain that produced Cholesterol 7-alpha hydroxylase, the rate limitng enzyme in cholesterol metabolism.  producing this enzyme allowed us to break it down and derive the active sequences. 

http://www.ncbi.nlm.nih.gov/pubmed/15752749

if you ever get bored....

 

[bibdybobdyboob]

Aug. 22, 2009 at 12:29 PM

Thanks.  Great information.

[sati769leigh]

Aug. 22, 2009 at 2:04 PM

wow never even thought about how this could be a controversial topic!

[ivansmom07]

Aug. 22, 2009 at 5:41 PM

I'm with cleanaturalady...no to GMO!

I absolutely LOVE reading your posts!  They are always so informative.  Thanks!