Molecular evolutionary studies in human malaria parasites

Speaker Name: 
Anan�as A. Escalante, Division of Parasitic Diseases, Centers for Disease Control and Prevention
Start Time: 
Wednesday, March 5, 2003 - 4:00pm
End Time: 
Wednesday, March 5, 2003 - 5:00pm
Location: 
BE 360

Abstract

Malaria is a major public health problem in the tropics with 300 to 500 million reported cases annually. Human malaria is caused by four Plasmodium species with P.falciparum and P.vivax being responsible for most of the malaria morbidity and mortality. We will discuss our research agenda on molecular evolutionary studies applied to vaccine development and assessing the origin and dispersion of drug resistance. Summary of our data analyses on the genetic diversity of malarial antigens will be presented, including studies aimed at identifying polymorphic regions under positive natural selection that could be relevant in the development of an effective vaccine. The problem of assessing the effect of positive natural selection will be discussed using genes encoding MSP-1 and CSP antigens in P.falciparum. The use of tests such as the comparison of synonymous and nonsynonymous substitutions and the relevance of comparative studies will be discussed. We will also present data on the genetic diversity of P.vivax, including vaccine candidate antigens such as Pv25. Finally, the need for longitudinal studies is analyzed. Specifically, issues such as the parasite population structure, the relevance of inbreeding and sexual recombination will be discussed in the context of the origin and dispersion of drug resistance.