FRIDAY, Oct. 22 (HealthDay News) -- Complicating efforts to
combat malaria, new research indicates that two physically
identical strains of a single mosquito responsible for most disease
transmissions appear to be evolving into two genetically distinct
Two studies reported in the Oct. 21 issue of
Science suggest that the evolution process is occurring
faster than previously thought, and note that substantial genetic
differences are already apparent. This development could undermine
efforts to control mosquito population growth with strategies that
may not be effective against both strains, the researchers
"Malaria is a deadly disease that affects millions of people across the world, and amongst children in Africa, it causes one in every five deaths," George Christophides, a professor in the division of cell and molecular biology at Imperial College London in England, said in a news release from the college. Christophides is one of the lead researchers.
"We know that the best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease," he continued. "Our studies help us to understand the makeup of the mosquitoes that transmit malaria, so that we can find new ways of preventing them from infecting people."
Malaria kills one child every 30 seconds worldwide, according to
World Health Organization figures cited in the studies.
The new studies focused on the so-called "M" and "S" strains of
the "Anopheles gambiae mosquito," which is involved in most
malarial transmissions in sub-Saharan Africa.
After conducting detailed genetic analyses, the authors of one
study concluded that significant genetic differences are dispersed
all across each strain's genome, potentially altering development,
eating habits, and reproductive patterns.
The other study examined 400,000 different spots on each
strain's genome and those on a third strain called "Bamako" to hone
in on genetic variations.
The research team theorized that the strains seem to be evolving
in different directions, perhaps in reaction to environmental
differences or divergences in the diseases and predators each
mosquito strain must combat.
The research team included scientists from the University of
Notre Dame, the J.C. Venter Institute, Washington University and
the Broad Institute.
For more on malaria, visit the
U.S. National Institutes of Health.