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Hume JCC, Tunnicliff M, Ranford-Cartwright LC, Day KP. Susceptibility of Anopheles gambiae and Anopheles stephensi to tropical isolates of Plasmodium falciparum. Malar J 2007; 6:139. [PMID: 17958900 PMCID: PMC2148056 DOI: 10.1186/1475-2875-6-139] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 10/24/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The susceptibility of anopheline mosquito species to Plasmodium infection is known to be variable with some mosquitoes more permissive to infection than others. Little work, however, has been carried out investigating the susceptibility of major malaria vectors to geographically diverse tropical isolates of Plasmodium falciparum aside from examining the possibility of infection extending its range from tropical regions into more temperate zones. METHODS This study investigates the susceptibility of two major tropical mosquito hosts (Anopheles gambiae and Anopheles stephensi) to P. falciparum isolates of different tropical geographical origins. Cultured parasite isolates were fed via membrane feeders simultaneously to both mosquito species and the resulting mosquito infections were compared. RESULTS Infection prevalence was variable with African parasites equally successful in both mosquito species, Thai parasites significantly more successful in An. stephensi, and PNG parasites largely unsuccessful in both species. CONCLUSION Infection success of P. falciparum was variable according to geographical origin of both the parasite and the mosquito. Data presented raise the possibility that local adaptation of tropical parasites and mosquitoes has a role to play in limiting gene flow between allopatric parasite populations.
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Affiliation(s)
- Jennifer C C Hume
- Peter Medawar Building for Pathogen Research and Department of Zoology, South Park road, University of Oxford, Oxford OX1 3SY, UK.
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Hagner SC, Misof B, Maier WA, Kampen H. Bayesian analysis of new and old malaria parasite DNA sequence data demonstrates the need for more phylogenetic signal to clarify the descent of Plasmodium falciparum. Parasitol Res 2007; 101:493-503. [PMID: 17393186 DOI: 10.1007/s00436-007-0499-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2006] [Accepted: 02/09/2007] [Indexed: 11/27/2022]
Abstract
Molecular systematic studies published during the last 15 years to clarify the phylogenetic relationships among the malaria parasites have led to two major hypotheses on the descent of Plasmodium falciparum: One supports an avian origin as a result of a relatively recent host switch, and another one favours the evolutionary development of P. falciparum together with its human host from primate ancestors. In this paper, we present phylogenetic analyses of three different Plasmodium genes, the nuclear 18 small sub-unit (SSU) ribosomal ribonucleic acid (rRNA), the mitochondrial cytochrome b (cyt b) and the plastid caseinolytic protease C (ClpC) gene, using numerous haemosporidian parasite DNA sequences obtained from the GenBank as well as several new sequences for major malaria parasites including the avian one Plasmodium cathemerium, which has never been considered in molecular phylogenetic analyses before. Most modern and sophisticated DNA substitution models based on Bayesian inference analysis were applied to estimate the cyt b and ClpC phylogenetic trees, whereas the 18 SSU rRNA gene was examined with regards to its secondary structure using PHASE software. Our results indicate that the data presently available are generally neither sufficient in number nor in information to solve the problem of the phylogenetic origin of P. falciparum.
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Affiliation(s)
- S C Hagner
- Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany.
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Roy SW, Ferreira MU, Hartl DL. Evolution of allelic dimorphism in malarial surface antigens. Heredity (Edinb) 2006; 100:103-10. [PMID: 17021615 DOI: 10.1038/sj.hdy.6800887] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The extensive sequence variation in most surface antigens of Plasmodium falciparum is one of the major factors why clinical immunity to malaria develops only after repeated infections with the same species over several years. For some P. falciparum surface antigens, all observed alleles clearly fall into two allelic classes, with divergence between classes dwarfing divergence within classes. We discuss the ways in which such allelic dimorphism deviates from the expected shape of the genealogy of genes under either neutral evolution or standard balancing selection, and present a simple test, based on coalescent theory, to detect this deviation in samples of DNA sequences. We review previous hypotheses for the origin and evolution of allelic dimorphism in malarial antigens and discuss the difficulties of explaining the available data under these proposals. We conclude by offering several possible classes of explanations for allelic dimorphism, which are worthy of further theoretical and empirical exploration.
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Affiliation(s)
- S W Roy
- Allan Wilson Centre for Molecular Ecology and Evolution, Massey University, Palmerston North, New Zealand
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Morrison DA, Höglund J. Testing the hypothesis of recent population expansions in nematode parasites of human-associated hosts. Heredity (Edinb) 2005; 94:426-34. [PMID: 15674388 DOI: 10.1038/sj.hdy.6800623] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
It has been predicted that parasites of human-associated organisms (eg humans, domestic pets, farm animals, agricultural and silvicultural plants) are more likely to show rapid recent population expansions than are parasites of other hosts. Here, we directly test the generality of this demographic prediction for species of parasitic nematodes that currently have mitochondrial sequence data available in the literature or the public-access genetic databases. Of the 23 host/parasite combinations analysed, there are seven human-associated parasite species with expanding populations and three without, and there are three non-human-associated parasite species with expanding populations and 10 without. This statistically significant pattern confirms the prediction. However, it is likely that the situation is more complicated than the simple hypothesis test suggests, and those species that do not fit the predicted general pattern provide interesting insights into other evolutionary processes that influence the historical population genetics of host-parasite relationships. These processes include the effects of postglacial migrations, evolutionary relationships and possibly life-history characteristics. Furthermore, the analysis highlights the limitations of this form of bioinformatic data-mining, in comparison to controlled experimental hypothesis tests.
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Affiliation(s)
- D A Morrison
- Department of Parasitology (SWEPAR), National Veterinary Institute and Swedish University of Agricultural Sciences, 751 89 Uppsala, Sweden.
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Polley SD, Weedall GD, Thomas AW, Golightly LM, Conway DJ. Orthologous gene sequences of merozoite surface protein 1 (MSP1) from Plasmodium reichenowi and P. gallinaceum confirm an ancient divergence of P. falciparum alleles. Mol Biochem Parasitol 2005; 142:25-31. [PMID: 15907558 DOI: 10.1016/j.molbiopara.2005.02.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Revised: 02/18/2005] [Accepted: 02/21/2005] [Indexed: 10/25/2022]
Abstract
Merozoite surface protein 1 (MSP 1) of Plasmodium falciparum has a major allelic dimorphism in the majority of its sequence, the origin and significance of which is obscure. Here, the cloning and sequencing of the msp1 gene from P. reichenowi (a chimpanzee parasite that is the nearest relative of P. falciparum) and P. gallinaceum (a malaria parasite of birds) is reported. P. reichenowi msp1 is most closely related to one allelic type (K1) of P. falciparum. The other P. falciparum major allelic type (MAD20) is very divergent from these sequences, although not as divergent as msp1 of P. gallinaceum. Assuming a date of 6 million years ago (mya) for the divergence of the P. falciparum K1 and the P. reichenowi msp1 genes (on the basis of previous estimates for these parasite species as well as host divergence times), the most recent common ancestor of the dimorphic region of msp1 would date to approximately 27mya. Thus, the P. falciparum msp1 dimorphism is confirmed as one of the oldest polymorphisms known with the exception of self-incompatibility S genes in Solanaceae. In contrast with the major allelic dimorphism, the polymorphisms present in the relatively conserved C terminus of P. falciparum msp1 appear to have arisen since the divergence of the P. falciparum and P. reichenowi msp1 genes.
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Affiliation(s)
- Spencer D Polley
- London School of Hygiene and Tropical Medicine, Department of Infectious and Tropical Diseases, Keppel Street, London WC1E 7HT, UK.
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Ferreira MU, da Silva Nunes M, Wunderlich G. Antigenic diversity and immune evasion by malaria parasites. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2005; 11:987-95. [PMID: 15539495 PMCID: PMC524792 DOI: 10.1128/cdli.11.6.987-995.2004] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900 São Paulo (SP), Brazil.
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Bourgon R, Delorenzi M, Sargeant T, Hodder AN, Crabb BS, Speed TP. The serine repeat antigen (SERA) gene family phylogeny in Plasmodium: the impact of GC content and reconciliation of gene and species trees. Mol Biol Evol 2004; 21:2161-71. [PMID: 15306658 DOI: 10.1093/molbev/msh228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Plasmodium falciparum is the parasite responsible for the most acute form of malaria in humans. Recently, the serine repeat antigen (SERA) in P. falciparum has attracted attention as a potential vaccine and drug target, and it has been shown to be a member of a large gene family. To clarify the relationships among the numerous P. falciparum SERAs and to identify orthologs to SERA5 and SERA6 in Plasmodium species affecting rodents, gene trees were inferred from nucleotide and amino acid sequence data for 33 putative SERA homologs in seven different species. (A distance method for nucleotide sequences that is specifically designed to accommodate differing GC content yielded results that were largely compatible with the amino acid tree. Standard-distance and maximum-likelihood methods for nucleotide sequences, on the other hand, yielded gene trees that differed in important respects.) To infer the pattern of duplication, speciation, and gene loss events in the SERA gene family history, the resulting gene trees were then "reconciled" with two competing Plasmodium species tree topologies that have been identified by previous phylogenetic studies. Parsimony of reconciliation was used as a criterion for selecting a gene tree/species tree pair and provided (1) support for one of the two species trees and for the core topology of the amino acid-derived gene tree, (2) a basis for critiquing fine detail in a poorly resolved region of the gene tree, (3) a set of predicted "missing genes" in some species, (4) clarification of the relationship among the P. falciparum SERA, and (5) some information about SERA5 and SERA6 orthologs in the rodent malaria parasites. Parsimony of reconciliation and a second criterion--implied mutational pattern at two key active sites in the SERA proteins-were also seen to be useful supplements to standard "bootstrap" analysis for inferred topologies.
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Affiliation(s)
- Richard Bourgon
- Department of Statistics, University of California, Berkeley, USA
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Affiliation(s)
- David J Conway
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Baum J, Thomas AW, Conway DJ. Evidence for diversifying selection on erythrocyte-binding antigens of Plasmodium falciparum and P. vivax. Genetics 2003; 163:1327-36. [PMID: 12702678 PMCID: PMC1462517 DOI: 10.1093/genetics/163.4.1327] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Malaria parasite antigens involved in erythrocyte invasion are primary vaccine candidates. The erythrocyte-binding antigen 175K (EBA-175) of Plasmodium falciparum binds to glycophorin A on the human erythrocyte surface via an N-terminal cysteine-rich region (termed region II) and is a target of antibody responses. A survey of polymorphism in a malaria-endemic population shows that nucleotide alleles in eba-175 region II occur at more intermediate frequencies than expected under neutrality, but polymorphisms in the homologous domains of two closely related genes, eba-140 (encoding a second erythrocyte-binding protein) and psieba-165 (a putative pseudogene), show an opposite trend. McDonald-Kreitman tests employing interspecific comparison with the orthologous genes in P. reichenowi (a closely related parasite of chimpanzees) reveal a significant excess of nonsynonymous polymorphism in P. falciparum eba-175 but not in eba-140. An analysis of the Duffy-binding protein gene, encoding a major erythrocyte-binding antigen in the other common human malaria parasite P. vivax, also reveals a significant excess of nonsynonymous polymorphisms when compared with divergence from its ortholog in P. knowlesi (a closely related parasite of macaques). The results suggest that EBA-175 in P. falciparum and DBP in P. vivax are both under diversifying selection from acquired human immune responses.
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Affiliation(s)
- Jake Baum
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom.
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Hume JCC, Lyons EJ, Day KP. Human migration, mosquitoes and the evolution of Plasmodium falciparum. Trends Parasitol 2003; 19:144-9. [PMID: 12643998 DOI: 10.1016/s1471-4922(03)00008-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To date, coalescent analysis of the Plasmodium falciparum genome sequence has failed to provide a unifying theory regarding the parasite's evolution. While a better understanding of the evolution of the malaria genome will undoubtedly clarify the current controversy, the importance of the parasite's interplay with both the human host and mosquito vector cannot be underestimated. Changes in the population biology or ecology of either one of these species have consequences for malaria transmission and this was never more apparent than in the environmental changes brought about by the advent of agriculture.
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Affiliation(s)
- Jennifer C C Hume
- Peter Medawar Building for Pathogen Research, Department of Zoology, University of Oxford, Oxford, UK OX1 3SY.
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Putaporntip C, Jongwutiwes S, Sakihama N, Ferreira MU, Kho WG, Kaneko A, Kanbara H, Hattori T, Tanabe K. Mosaic organization and heterogeneity in frequency of allelic recombination of the Plasmodium vivax merozoite surface protein-1 locus. Proc Natl Acad Sci U S A 2002; 99:16348-53. [PMID: 12466500 PMCID: PMC138614 DOI: 10.1073/pnas.252348999] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The organization and allelic recombination of the merozoite surface protein-1 gene of Plasmodium vivax (PvMsp-1), the most widely prevalent human malaria parasite, were evaluated in complete nucleotide sequences of 40 isolates from various geographic areas. Alignment of 31 distinct alleles revealed the mosaic organization of PvMsp-1, consisting of seven interallele conserved blocks flanked by six variable blocks. The variable blocks showed extensive variation in repeats and nonrepeat unique sequences. Numerous recombination sites were distributed throughout PvMsp-1, in both conserved blocks and variable block unique sequences, and the distribution was not uniform. Heterozygosity of PvMsp-1 alleles was higher in Asia (0.953 +/- 0.009) than in Brazil (0.813 +/- 0.047). No identical alleles were shared between Asia and Brazil, whereas all but one variable block nonrepeat sequence found in Brazil occurred in Asia. These observations suggest that P. vivax populations in Asia are ancestral to Brazilian populations, and that PvMsp-1 has heterogeneity in frequency of allelic recombination events. Recurrent origins of new PvMsp-1 alleles by repeated recombination events were supported by a rapid decline in linkage disequilibrium between pairs of synonymous sites with increasing nucleotide distance, with little linkage disequilibrium at a distance of over 3 kb in a P. vivax population from Thailand, evidence for an effectively high recombination rate of the parasite. Meanwhile, highly reduced nucleotide diversity was noted in a region encoding the 19-kDa C-terminal epidermal growth factor-like domain of merozoite surface protein-1, a vaccine candidate.
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Affiliation(s)
- Chaturong Putaporntip
- Laboratory of Biology and Department of Mathematics, Osaka Institute of Technology, Osaka 535-8585, Japan
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