Friday, January 30, 2015

GMO Mosquitoes will not turn you into MosquitoMan

My teenage years were spent in the small town of Jenks, Oklahoma, a suburb of Tulsa. I have memories of summer evenings marred by the passing trucks spewing poison gas out into the neighborhood. The noxious fog they released drove all the children indoors for hours. These trucks were there on the behalf of the city. The poison gas they released was an attempt to reduce mosquito populations. I don't know what murderous chemical was used to rid us of the disease-carrying mosquitoes, I don't know what terrible side effects these chemicals might cause,  but I remember how it stung the eyes and burned the nose and caused coughing and other respiratory distress. I remember being angry that a lovely evening playing outside in the yard was ruined.

As I went through school, study biology as an undergraduate, then Master's and finally a Ph.D. student, I would hear tell of different programs that were being developed to reduce mosquito populations without the use of chemicals - from mosquito nettings, to removing mosquito breeding grounds in the back yard, to releasing of sterile male mosquitoes....all of which I thought, and still think, are marvelous ideas. 

Today, a friend of mine asked me to comment on an article from NPR, about a program to release genetically modified male mosquitoes in an effort to reduce mosquito populations. Apparently, he has heard a lot of outrage against this program, outrage about GMO organisms being released into the wild. GMO, as it relates to food, has become such a scary word, that people are reacting to that portion of the story without really understanding what it means. 

GMO stands for Genetically Modified Organism. But what exactly does that mean? In the broadest terms, it means that humans have purposefully changed the genetics of an organism to suit their own purpose. From this perspective - humans have been genetically modifying organisms for millenia. Do you own a pure-breed dog? We could call that great dane or border collie or poodle a genetically modified organism, because, these breeds have come about through human intervention of which individuals get to mate. This type of genetic modification has influenced crops (corn, wheat, barley, tomatoes, peppers, apples, etc), garden flowers (roses, dahlias, petunias, etc), pets (dogs, cats, pigeons), and livestock (cattle, pigs, horses, llama, etc). We are comfortable with this type of genetic modification, this type of humans tampering with the genetics of other organisms, because it is familiar to us.

Recently, humans have been able to genetically modify organisms in a totally different manner. The discovery of DNA structure and the decoding of the genetic code (how sequences of DNA nucleotides are translated in the amino acids of proteins) that occurred in the 1950's and 1960's, laid the groundwork for the rapidly growing field of molecular genetics. Now, we are able to actually change the genes of organisms at the most fundamental level - that of the DNA. We are able to make precise and controlled changes in the genes. Because the genetic code is redundant (meaning bacteria, roses, mosquitoes, slime molds, puppies and humans, indeed all life on earth, share the same genetic code), we can even take a gene from one species and put it into another species. This is how Bt Corn was made - a gene from a bacteria that confers resistance to insects was placed into corn plants, making the corn also resistant to insect damage. It is this type of genetic modification, which I believe should specified by calling it Genetic Engineering, that people fear, especially when talking about moving genes between different species. (And I don't think they need to fear it, but rather, take the time to understand it

So..that leads us to the mosquitoes in Florida. What is it they have done? According to the article they have genetically modified male mosquitoes in such a way that when they breed with female mosquitoes, the offspring they produce won't live to adulthood. There is some genetic mutation that prevent the larval stage of these offspring from growing up to the adult stage. 

http://extension.entm.purdue.edu/publichealth/images/downloads/lifecycle-mosquito.jpg

Now, from the article posted above, I don't know how these genetically modified insects were made, nor do I know how exactly they effect the larval stages. What I do know, is that there is no risk to human health from this GMO male mosquitoes being released. Only female mosquitoes bite humans, so there is no risk of this gene somehow being transferred to humans. And frankly, even if the females carried the gene, there is no mechanism by which the genes of the mosquito can become incorporated into the human genome. Spiderman is made up - a mosquito bite by a GMO mosquito will not make you MosquitoMan. 

And the health benefits to the community are tremendous - no poisonous gasses being sprayed, the reduction on mosquito-born illnesses (in this case, Dengue Fever). 

In parting - I would suggest - don't get swept up by the hype about GMO's - and especially don't automatically assume that GMO = BAD.  Instead - educate yourself. This article, published by Nature Education is a good place to start.







1 comment:

  1. I've heard the argument made that if a person has had a viral disease (say, chicken pox), they are a GMO....because they have DNA from another species within their genome.

    I remember Ohio summers with the mosquito trucks. They usually came LATE in the evening and I remember my parents hollering at my brother and me to close our windows (so we wouldn't breathe the stuff). It made me mad because it seemed always to be hot nights, and we didn't have any air conditioning in the house, so it got stuffy fast.

    I'm guessing my dad (who was a geochemist) knew what the chemical they were spewing was, but he never told us.

    I've also seen the idea floated of artificially increasing populations of another insect predator that feeds on the larvae. Good idea, but very hard to get good distribution of that. I know some people with ponds have Gambusia fish because they eat mosquito larvae....

    ReplyDelete