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21-Oct-2010
Malaria-transmitting mosquito evolving, NIH grantees find
WHAT: Researchers funded by the National Institutes of Health have found that the major malaria-transmitting mosquito species, Anopheles gambiae, is evolving into two separate species with different traits, a development that could both complicate malaria control efforts and potentially require new disease prevention methods. Their findings were published in back-to-back articles in the October 22 issue of the journal Science.
A. gambiae is the most common vector of human malaria in sub-Saharan Africa, where rates of the disease are highest. The researchers compared the genomes of two emerging species, dubbed M and S. Given that M and S appear to be physically indistinguishable and interbreed often, they were unexpectedly different at the DNA level. They also were found to behave differently and thrive in different habitats. For example, in the absence of predators, S mosquitoes outcompeted M mosquitoes, but the outcome was reversed when predators were present.
As these two emerging species of mosquito evolve to develop new traits and behaviors, changes in disease transmission could result, the authors say. This could complicate malaria control efforts, which currently are based on the mosquitoes' patterns of behavior and vulnerability to insecticides.
Future research will further investigate these emerging species, exploring how they compete with one another in various habitats and the molecular basis of their evolution. The results will be used to refine existing malaria interventions and inform the development of new disease prevention strategies.
Eurekalert
Notorious malaria mosquito strains evolving
excerpt from the Guardian
Scientists studying the mosquito anopheles gambiae, which is chiefly responsible for spreading malaria in sub-Saharan Africa, found two strains were rapidly diverging in their genetic make-up, despite appearing physically identical.
Dr Maria Lawniczak, a member of the team from Imperial College London, said: "From our new studies, we can see that mosquitoes are evolving more quickly than we thought and that unfortunately, strategies that might work against one strain of mosquito might not be effective against another. It's important to identify and monitor these hidden genetic changes in mosquitoes if we are to succeed in bringing malaria under control by targeting mosquitoes." Genetic differences between the two strains, known as M and S, were scattered throughout the insects' DNA, said the researchers, writing in the journal Science.
The changes had occurred in areas likely to affect development, feeding behaviour, and reproduction.
A further study comparing the two strains showed they seemed to be evolving differently.
This was thought to be in response to different environmental factors such as larval habitats, infectious agents and predators.
Co-author Professor George Christophides, also from Imperial College, said: "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. We know that the best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease. 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-transmitting mosquito evolving, NIH grantees find
WHAT: Researchers funded by the National Institutes of Health have found that the major malaria-transmitting mosquito species, Anopheles gambiae, is evolving into two separate species with different traits, a development that could both complicate malaria control efforts and potentially require new disease prevention methods. Their findings were published in back-to-back articles in the October 22 issue of the journal Science.
A. gambiae is the most common vector of human malaria in sub-Saharan Africa, where rates of the disease are highest. The researchers compared the genomes of two emerging species, dubbed M and S. Given that M and S appear to be physically indistinguishable and interbreed often, they were unexpectedly different at the DNA level. They also were found to behave differently and thrive in different habitats. For example, in the absence of predators, S mosquitoes outcompeted M mosquitoes, but the outcome was reversed when predators were present.
As these two emerging species of mosquito evolve to develop new traits and behaviors, changes in disease transmission could result, the authors say. This could complicate malaria control efforts, which currently are based on the mosquitoes' patterns of behavior and vulnerability to insecticides.
Future research will further investigate these emerging species, exploring how they compete with one another in various habitats and the molecular basis of their evolution. The results will be used to refine existing malaria interventions and inform the development of new disease prevention strategies.
Eurekalert
Notorious malaria mosquito strains evolving
excerpt from the Guardian
Scientists studying the mosquito anopheles gambiae, which is chiefly responsible for spreading malaria in sub-Saharan Africa, found two strains were rapidly diverging in their genetic make-up, despite appearing physically identical.
Dr Maria Lawniczak, a member of the team from Imperial College London, said: "From our new studies, we can see that mosquitoes are evolving more quickly than we thought and that unfortunately, strategies that might work against one strain of mosquito might not be effective against another. It's important to identify and monitor these hidden genetic changes in mosquitoes if we are to succeed in bringing malaria under control by targeting mosquitoes." Genetic differences between the two strains, known as M and S, were scattered throughout the insects' DNA, said the researchers, writing in the journal Science.
The changes had occurred in areas likely to affect development, feeding behaviour, and reproduction.
A further study comparing the two strains showed they seemed to be evolving differently.
This was thought to be in response to different environmental factors such as larval habitats, infectious agents and predators.
Co-author Professor George Christophides, also from Imperial College, said: "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. We know that the best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease. 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."
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