Malarial parasite diversity in chimpanzees: the value of comparative approaches to ascertain the evolution of Plasmodium falciparum antigens

Malaria Journal

Research

M Andreína Pacheco¹  Ananias A Escalante²  Michael Cranfield³  Kenneth Cameron⁴ 

[1] Center for Evolutionary Medicine and Informatics, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA;Center for Evolutionary Medicine and Informatics, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA;School of Life Sciences, Arizona State University, Tempe, Arizona, USA;Gorilla Doctors, Wildlife Health Department, University of California Davis, Davis, USA;Wildlife Health Program, Wildlife Conservation Society, Brazzaville, Republic of Congo;

关键词: Antigen;    Chimpanzee;    Co-evolution;    Circumsporozoite protein;    Dihydrofolate reductase-thymidylate synthase;    Malaria;    Merozoite surface protein 2;    Mitochondrion genome;    Pan troglodytes;    Parasite evolution;    Plasmodium;    Plasmodium;    Plasmodium falciparum;    Var2CSA;   

DOI  :  10.1186/1475-2875-12-328

 received in 2013-06-23, accepted in 2013-09-13,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundPlasmodium falciparum shares its most recent common ancestor with parasites found in African apes; these species constitute the so-called Laverania clade. In this investigation, the evolutionary history of Plasmodium lineages found in chimpanzees (Pan troglodytes) was explored.MethodsHere, the remainders of 74 blood samples collected as part of the chimpanzees’ routine health examinations were studied. For all positive samples with parasite lineages belonging to the Laverania clade, the complete mitochondrial genome (mtDNA), the gene encoding dihydrofolate reductase-thymidylate synthase (dhfr-ts), the chloroquine resistance transporter (Pfcrt), the circumsporozoite protein (csp), merozoite surface protein 2 (msp2), and the DBL-1 domain from var2CSA were amplified, cloned, and sequenced. Other Plasmodium species were included in the mtDNA, dhfr-ts, and csp analyses. Phylogenetic and evolutionary genetic analyses were performed, including molecular clock analyses on the mtDNA.Results/ConclusionsNine chimpanzees were malaria positive (12.2%); four of those infections were identified as P. falciparum, two as a Plasmodium reichenowi- like parasite or Plasmodium sp., one as Plasmodium gaboni, and two as Plasmodium malariae. All P. falciparum isolates were resistant to chloroquine indicating that the chimpanzees acquired such infections from humans in recent times. Such findings, however, are not sufficient for implicating chimpanzees as an animal reservoir for P. falciparum.Timing estimates support that the Laverania clade has co-existed with hominids for a long-period of time. The proposed species P. gaboni, Plasmodium billbrayi, and Plasmodium billcollinsi are monophyletic groups supporting that they are indeed different species.An expanded CSP phylogeny is presented, including all the Laverania species and other malarial parasites. Contrasting with other Plasmodium, the Laverania csp exhibits great conservation at the central tandem repeat region. Msp2 and var 2CSA, however, show extended recent polymorphism in P. falciparum that likely originated after the P. reichenowi-P. falciparum split. The accumulation of such diversity may indicate adaptation to the human host. These examples support the notion that comparative approaches among P. falciparum and its related species will be of great value in understanding the evolution of proteins that are important in parasite invasion of the human red blood cell, as well as those involved in malaria pathogenesis.

【 授权许可】

Unknown   
© Pacheco et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.