London: In a startling discovery that has
implications for combating malaria, scientists have found that
two strains of Africa`s most notorious malaria mosquito appear
to be evolving into two genetically distinct species.
The evolution means the insects could become immune to
strategies adopted to control malaria which kills thousands of
people around the world, especially in Asian and African
Researchers at the Imperial College London who studied
Anopheles gambiae mosquito, chiefly responsible for spreading
malaria in sub-Saharan Africa, found that two strains of the
mosquito were rapidly diverging in their genetic make-up,
despite appearing physically identical.
Dr Maria Lawniczak, a member in the research team, 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," Dr Lawniczak
was quoted as saying by the Daily Mail.
According to the scientists, genetic differences between
the two strains, known as M and S, were scattered throughout
the insects` DNA.
The changes had occurred in areas likely to affect
development, feeding behaviour, and reproduction, they said.
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
"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."
The scientists detailed their findings in the journal