Malaria-Proof Mosquito Research by UC Davis-University of Arizona Team Makes Time Magazine's '50 Best Inventions of 2010'
Jan. 7, 2011
The UC Davis malaria-proof mosquito team that co-authored research that made Time Magazine's "Top 50 Inventions of 2010." In front, at the microscope, is entomology doctoral student Anna Drexler. In back (from left) are professor Edwin Lewis, postdoctoral scholar Nazzy Pakpour, and professor Shirley Luckhart. In the foreground: anopheline mosquitoes. (Photo by Kathy Keatley Garvey)
DAVIS--A malaria-proof mosquito, the work of scientists at the University of California, Davis and the University of Arizona, has made Time Magazine’s “50 Best Inventions of 2010.”
It's listed as No. 1 in Time Magazine’s Health and Medicine Category.
The genetically engineered mosquito drew international attention July 15, 2010 when an 11-member team from the University of Arizona Department of Entomology and the UC Davis Department of Medical Microbiology and Immunology and the Department of Entomology published its research in the journal Public Library of Science Pathogens (PLOS).
“The transgenic mosquitoes were developed at the University of Arizona and we performed the malaria parasite infection studies here at UC Davis,” said malaria researcher and professor Shirley Luckhart of the Department of Medical Microbiology and Immunology and an advisor in the Entomology Graduate Program.
Among the 11 scientists co-authoring the paper were four UC Davis researchers: Luckhart; professor Edwin Lewis, who has a joint appointment in the Entomology and Nematology departments; Entomology doctoral student Anna Drexler who studies with major professor Luckhart; and postdoctoral scholar Nazzy Pakpour of the Department of Medical Microbiology and Immunology. Pakpour did her undergraduate work in entomology at UC Davis.
“This is the first time anyone has created a transgenic mosquito line that has two important features for malaria transmission control: (1) reduced lifespan, and (2) complete resistance to infection with the human malaria parasite Plasmodium falciparum,” Luckhart said. Globally, malaria infects some 250 million people annually and kills more than a million a year, primarily in Africa.
“We know that one mosquito phenotype,” Luckhart said, “might not be enough to block transmission – that is, selection could result in parasites that develop more quickly or are more virulent to overcome one or the other phenotype, but the chance that parasites could evolve to evade both would be very small. We’re working on the mechanism of anti-parasite resistance right now and we have some tantalizing results that suggest that the effect on lifespan and immunity are linked through some major metabolic changes in the transgenic mosquitoes.”
Scientists from UC Davis and University of Arizona began collaborating on the malaria-proof mosquito research in 2008. Their grant, from the National Institutes of Health, is funded through 2013.
Malaria mosquito, Anopheles gambiae, feeding. (Photo by Anthony Cornel)
As of Jan. 7, their scientific paper, “Activation of Akt Signaling Reduces the Prevalence and Intensity of Malaria Parasite Infection and Lifespan in Anopheles stephensi Mosquitoes, has generated nearly 7000 article views and has drawn extensive news coverage. ABC and BBC spotlighted the work. In a July 17 news article headlined “Malaria-Proof Mosquito Created,” science writer Eric Bland of ABC News wrote that scientists created “a malaria-proof" mosquito, that scientists “engineered a genetic ‘on switch' that permanently activates a malaria-destroying response.”
“If these mosquitoes,” Bland wrote, “are successfully introduced into the wild, they could prevent millions of people from becoming infected with life-threatening Plasmodium -- the parasite that causes malaria.”
BBC science reporter Victoria Gill, in a July 16th article headlined “Malaria-Proof Mosquito Engineered,” wrote that scientists in the United States “have succeeded in genetically engineering a malaria-resistant mosquito.”
Of the mosquito, Time Magazine reporter Jeffrey Kluger wrote: “It's been a bad year to be a mosquito. The world's most annoying insect is responsible for 250 million cases of malaria per year — and 1 million deaths. But scientists...have genetically engineered a mosquito that's immune to the Plasmodium parasite, the malaria-causing agent it transmits with its bite. The next step is to make the new mosquito hardier than the ordinary kind, then release it into the wild (perhaps within 10 years), where it will displace the deadly variety. Meanwhile, former Microsoft exec Nathan Myhrvold, working with the Intellectual Ventures Laboratory, is developing a laser that can zap mosquitoes without harming other insects or humans. The laser targets the mosquitoes' size and signature wing beat and sends the bugs down in a burst of flame, making their deaths good for public health and, well, kind of cool.”
The scientific paper abstract:
“Malaria (Plasmodium spp.) kills nearly one million people annually and this number will likely increase as drug and insecticide resistance reduces the effectiveness of current control strategies. The most important human malaria parasite, Plasmodium falciparum, undergoes a complex developmental cycle in the mosquito that takes approximately two weeks and begins with the invasion of the mosquito midgut. Here, we demonstrate that increased Akt signaling in the mosquito midgut disrupts parasite development and concurrently reduces the duration that mosquitoes are infective to humans. Specifically, we found that increased Akt signaling in the midgut of heterozygous Anopheles stephensi reduced the number of infected mosquitoes by 60–99%. Of those mosquitoes that were infected, we observed a 75–99% reduction in parasite load. In homozygous mosquitoes with increased Akt signaling parasite infection was completely blocked. The increase in midgut-specific Akt signaling also led to an 18–20% reduction in the average mosquito lifespan. Thus, activation of Akt signaling reduced the number of infected mosquitoes, the number of malaria parasites per infected mosquito, and the duration of mosquito infectivity.”
Download PLOs Paper on Malaria-Proof Mosquito (Open Access)
--Kathy Keatley Garvey
UC Davis Department of Entomology