GEN | News Highlights:Five Malaria Genomes SequencedPosted: September 7, 2012
Scientists have sequenced the entire genomes of five Plasmodium vivax strains taken from the blood of patients on different continents, providing a wealth of new data to help in the future mapping of malarial parasite traits such as drug resistance, and determine how different strains are geographically distributed. The work, by researchers at Case Western Reserve University and the Cleveland Clinic Lerner Research Institute, has identified over 80,000 SNPs that can form the basis of association studies and population surveys to study the diversity of P. vivax in a single region.
Critically, the results also demonstrate that P. vivax isolates from patients in Madagasar, Cambodia, and South America are genetically surprisingly similar, and exhibit little evidence of local adaptation. One possibility for the relative lack of genetic diversity is that the P. vivax population has only recent origins, and has just dispersed rapidly across the world without major loss of diversity or influence from natural selection. A second possibility for the observed allele sharing, however, is that there’s been a continuous gene flow in the current P. vivax population. “P. vivax is now a cosmopolitan parasite that can be easily spread throughout the world by way of dormant hypnozoites,” the investigators suggest.
“If this second hypothesis is true, it holds bleak prospects for P. vivax malaria elimination,” the researchers add. “With high level of gene flow, genetic polymorphisms conferring drug resistance or novel invasion mechanisms could spread across the world and further complicate control strategies.”