Re-Making Mosquitoes

Malaria, a devastating parasitic disease, kills millions of children per day in many countries in Africa, South America, & South/Southeast Asia. It is caused by parasites in the Plasmodium genus. These parasites are transmitted via female Anopheles mosquitos thus spreading malaria from person to person.

For the past three decades, scientists have been looking for clues and for evidence as to how to device an "intervention method".

There are three major concerns:
1) Can we re-engineer mosquitoes so they canNOT become "carriers" for malaria parasites?
2)Will these mosquitoes survive, if their genomes are modified?
3)Will they procreate and make a new population outside of laboratory environment?

The first two of these concerns have been brought to our attention when scientists began to publish their findings in 2003. They found that they could re-engineer certain species of Anopheles with an altered genome. A special protein peptide called SM1 blocks mosquitoe's gut and thus prevents Plasmodium development. It can be genetically engineered into the mosquitoe genome such that mosquitoes can pass-on the SM1 gene to their progenies.

Will these progenies surivive when they come in contact with infected blood? The most recent research article addressed this question. SM1-Mosquitoes were tested for survival fitness, compared with regular wildtype mosquitoes of the same species, when they were exposed to infected blood in the laboratory. If mosquitoes had only one copy of the SM1 incorporated into their genome, rather than 2 copies, they could survive better but doesn't reduce mosquitoe's resistence to malaria. Their experiments have to be repeated, of course, for Plasmodium species specific to human infections. It can turn out to be a powerful new technology for the future.

However, I cannot stop to wonder: Will a re-engineered mosquito species replace what's already in existence in nature? How many "mosquito generations" will it take??



Marrelli M. T., Li C., Rasgon J. L. & Jacobs-Lorena M. Proc. Natl Acad. Sci. USA, 104 . 5580 - 5583 (2007).
Catteruccia F., Godray H. C. & Crisanti A. Science, 299 . 1225 - 1227 (2003).
Riehle M. M., et al. Science, 312. 577 - 579 (2006).