Genetic Update Report GMO MOSQUITOPresented before class by: Avila, Ernie C. BSE 4B
GMO mosquito that can save the world from Malaria?• Researchers have been experimenting with genetically modifying a variety of insects, including mosquitoes, fruit flies, moths and bollworms.• In an effort to help eradicate dengue fever and the mosquitoes that spread it, scientist is seeking approval to release hundreds of thousands of genetically-modified (GM) mosquitoes designed to kill off the natural Aedes aegypti variety of the fly in different countries.
TRIVIA• Mosquitoes don’t cause malaria—the disease comes courtesy of the Plasmodium falciparum parasite. Yet mosquitoes do a fine job of spreading Plasmodium to about half a billion people every year.• The parasite depends on mosquitoes for more than just transport, however. Plasmodium goes through much of its complex life cycle inside the mosquito, passing through the gut as it goes.
• While mosquitoes may ingest anywhere from 100 to 1,000 immature cells during a blood meal, by the time the parasite ends up in the mosquito’s gut, only five or fewer spores, known as oocysts, remain.• This is where researchers targeted their attack. The gut is a complicated place, full of bacteria that help break down nutrients and digest food. Perhaps some of these bacteria could be enlisted to break down the Plasmodium spores as well.
• Researchers at the Johns Hopkins Malaria Research Institute devised a genetically modified version of the Pantoes agglomerans bacteria that naturally lives in the mosquito gut. The new P. agglomerans acts much the same as ordinary P. agglomerans, and should be able to spread through wild mosquito populations. Except the engineered bacteria has one unique and deadly trait: It produces proteins that destroy Plasmodium oocysts.
• This isn’t the first use of genetic modification strategies to quell mosquito-spread disease. In November we reported on a project that has introduced genetically modified mosquitoes into the wild. The new mosquitoes carry genes that kill their young—when they mate with native mosquito populations, the offspring die before they can fly.
• This new approach doesn’t require modifying the mosquitoes directly, just their gut bacteria, which makes the technique more portable. More than 100 species of mosquito transmit malaria, and although the researchers only tested two, reported that in the Proceedings of the National Academy of Sciences that the strategy “may well be ‘universal’ as effectiveness does not appear to be influenced by mosquito species.” And effective it was: the genetically enhanced bacteria suppressed populations of both the human malaria parasite Plasmodium falciparum and the rodent malaria parasite Plasmodium berghei by 98 percent.
• In Florida Rather than spend $400,000 or more a year to conduct the aerial sprayings, FKMCD says it would instead only have to spend $200,000 to $300,000 a year on the GM mosquitoes.
• Created by U.K.-based insect eradication company Oxitec, the GM mosquitoes have been created with an added gene that, unless they are given the antibiotic tetracycline, will automatically kill them. When they mate with wild mosquitoes, these GM mosquitoes also pass on this gene to the offspring, which is intended to gradually decrease the population of wild mosquitoes over time.
• Though the vast majority of the GM mosquitoes being released are male, which do not bite humans, a small percentage of them are female. So looking at the situation just from a human health perspective, what are the risks involved with a human getting bitten by a GM mosquito? Nobody really knows, as Oxitec has not conducted any long-term research on the safety of GM mosquitoes interacting with other creatures or with humans.