Efforts to battle infectious diseases in developing countries
have crossed what many see as an important threshold with this
week's unveiling of the genetic blueprints for two key malarial
International teams of scientists have sequenced the genomes of
both the parasite responsible for malaria infections in humans and
of the mosquito that carries the parasite.
Armed with this information, scientists hope to unlock the
biochemical workings of the parasite and better understand its
interactions with mosquitoes and humans. That information can then
be used to develop new drugs, vaccines, and control strategies that
could dramatically reduce the disease's reach.
From 300 million to 500 million people a year contract malaria,
which kills as many as 2.7 million people annually, according to
public health officials.
Collectively, the genomes represent "a major milestone," says
Regina Rabinovich, director of the Malaria Vaccine Initiative. "This
is precisely the research we need to have happen."
The six-year, $17.9 million gene-sequencing work, led by labs in
the US, Britain, and Australia, also highlights the increasingly
important role genomics is playing in biomedical research.
Armed with cheaper, more efficient, and faster machines and
computers, scientists are sequencing the genomes of a range of other
infectious disease agents, many of which take their highest toll
among developing countries.
"There will be many more of these genomes to follow," says
Malcolm Gardner, a researcher at the Institute for Genomic Research
in Rockville, Md., and leader of the group that sequenced the
The researchers sequenced the genomes by separating the
organisms' chromosomes, long chains of DNA organized into genes. The
chains were randomly broken, and each segment was inserted into
bacteria and cloned. The segments were analyzed to tease out the
patterns of DNA's four chemical "bases." The teams then used
computers to sort through the information from the segments and put
the genetic Humpty Dumpty back together again in a virtual form.
The reassembled sequences were then checked for accuracy, Dr.
Gardner says, yielding a "final draft" of the parasite genome that
is 98 percent complete.
The work on malaria is being reported and analyzed in more than
30 papers appearing in today's edition of the journal Nature and
tomorrow's Science. …