Parasite, mosquito genomes complete malaria picture.

2002 NOV 6 - (NewsRx.com & NewsRx.net) -- Genome sequences of Plasmodium falciparum, the most lethal malaria-causing parasite, and Anopheles gambiae, a mosquito that transmits the parasite to humans, are now complete, two international research teams announced in October 2002.

The simultaneous publication in Science of the Anopheles genome and in Nature of the Plasmodium genome was marked by press conferences held in Washington, DC, and London.

"The sequencing of both P. falciparum and its insect vector heralds a new era in the fight against malaria. When joined with information we have about the human genome, a much fuller understanding of this disease and its transmission is now possible," said Anthony S. Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID). "NIAID is proud to have contributed to this extraordinary scientific achievement, which will speed efforts to investigate and develop control strategies for this devastating disease."

The medical, social and economic ravages of malaria are most keenly felt in Africa, where 90% of the up to 2.7 million annual deaths worldwide from the disease occur. Most victims are children less than 5 years old; on average, a child succumbs to malaria every 30 seconds. Malaria causes cycles of fever and chills that accompany cyclical destruction of parasite-infected red blood cells.

Debilitating and life-threatening complications of malaria include severe anemia, cerebral malaria, and respiratory distress. The disease is caused by single-celled parasites of the genus Plasmodium, which are transmitted from person to person through the bite of an infected mosquito. The menace posed by malaria is increasing with the spread of drug-resistant parasite strains and insecticide-resistant mosquitoes. No vaccine exists.

The sequencing of P. falciparum resulted from an international collaboration established in 1996. Besides NIAID, consortium support came from the Wellcome Trust, the Burroughs Wellcome Fund and the U.S. Department of Defense. Sequencers worked at the Institute for Genomic Research (TIGR) in Rockville, Maryland, the Stanford Genome Center in Palo Alto, California, and the Wellcome Trust Sanger Institute in the United Kingdom. The lead investigator, Malcolm Gardner, PhD, of TIGR, coauthored the Nature paper with 44 researchers working in sites in the United States, the United Kingdom and Australia.

Researchers overcame significant technical challenges on the way to this accomplishment. Perhaps because of its unusual composition, Plasmodium's genetic material cannot be separated into a mixture of long, medium, and short lengths. Rather, the parasite's DNA breaks up into very short lengths only. Placing such tiny strips back into their original sequence is difficult, just as repairing a vase that has smashed into hundreds of bits is ...