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Fornuskova A, Bryja J, Vinkler M, Macholán M, Piálek J. Contrasting patterns of polymorphism and selection in bacterial-sensing toll-like receptor 4 in two house mouse subspecies. Ecol Evol 2014; 4:2931-44. [PMID: 25165529 PMCID: PMC4130449 DOI: 10.1002/ece3.1137] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 05/09/2014] [Accepted: 05/14/2014] [Indexed: 02/02/2023] Open
Abstract
Detailed investigation of variation in genes involved in pathogen recognition is crucial for understanding co-evolutionary processes between parasites and their hosts. Triggering immediate innate response to invading microbes, Toll-like receptors (TLRs) belong presently among the best-studied receptors of vertebrate immunity. TLRs exhibit remarkable interspecific variation and also intraspecific polymorphism is well documented. In humans and laboratory mice, several studies have recently shown that single amino acid substitution may significantly alter receptor function. Unfortunately, data concerning polymorphism in free-living species are still surprisingly scarce. In this study, we analyzed the polymorphism of Toll-like receptor 4 (Tlr4) over the Palearctic range of house mouse (Mus musculus). Our results reveal contrasting evolutionary patterns between the two recently (0.5 million years ago) diverged house mouse subspecies: M. m. domesticus (Mmd) and M. m. musculus (Mmm). Comparison with cytochrome b indicates strong directional selection in Mmd Tlr4. Throughout the whole Mmd western Palaearctic region, a single variant of the ligand-binding region is spread, encoded mainly by one dominant haplotype (71% of Mmd). In contrast, Tlr4 in Mmm is much more polymorphic with several haplotypes at intermediate frequencies. Moreover, we also found clear signals of recombination between two principal haplogroups in Mmm, and we identified eight sites under positive selection in our dataset. Our results suggest that observed differences in Tlr4 diversity may be attributed to contrasting parasite-mediated selection acting in the two subspecies.
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Affiliation(s)
- Alena Fornuskova
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic Brno, Czech Republic ; Department of Botany and Zoology, Faculty of Science, Masaryk University Brno, Czech Republic ; Centre de Biologie pour la Gestion des Populations (CBGP), Institut National de la Recherche Agronomique (INRA), Campus International de Baillarguet Montferrier-sur-Lez, France
| | - Josef Bryja
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic Brno, Czech Republic ; Department of Botany and Zoology, Faculty of Science, Masaryk University Brno, Czech Republic
| | - Michal Vinkler
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
| | - Miloš Macholán
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic Brno, Czech Republic
| | - Jaroslav Piálek
- Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic Brno, Czech Republic
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Fadiel A, Isokpehi RD, Stambouli N, Hamza A, Benammar-Elgaaied A, Scalise TJ. Protozoan parasite aquaporins. Expert Rev Proteomics 2009; 6:199-211. [PMID: 19385945 DOI: 10.1586/epr.09.10] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Protozoan parasites are a major threat to human health with millions of fatalities worldwide, especially in nonindustrialized countries. Currently, there is no cure for many of these parasitic diseases. Consequently, there is an imperative to find treatment targets and develop novel drugs based on the proteins encoded in the genomes of these parasites. Aquaporins, members of membrane proteins discovered and characterized within the past 20 years, are the mechanism through which water is transported through living membranes. The presence of aquaporins explains disease etiology related to water physiology and presents new pharmacogenomic targets. In this article, we review the literature on aquaporins found in Apicomplexan, Kinetoplastida and Microsporidia parasites as potential drug targets. Furthermore, by analyzing protein motion dynamics, we identify impediments that need to be surmounted for developing effective drugs targeting the aquaglyceroporin of Plasmodium falciparum, the causative agent of the most fatal form of human malaria.
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Affiliation(s)
- Ahmed Fadiel
- Department of OBGYN, New York University School of Medicine, Bellevue Hospital Center, New York, NY 10016, USA.
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Kuo CH, Wares JP, Kissinger JC. The Apicomplexan whole-genome phylogeny: an analysis of incongruence among gene trees. Mol Biol Evol 2008; 25:2689-98. [PMID: 18820254 PMCID: PMC2582981 DOI: 10.1093/molbev/msn213] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/18/2008] [Indexed: 11/26/2022] Open
Abstract
The protistan phylum Apicomplexa contains many important pathogens and is the subject of intense genome sequencing efforts. Based upon the genome sequences from seven apicomplexan species and a ciliate outgroup, we identified 268 single-copy genes suitable for phylogenetic inference. Both concatenation and consensus approaches inferred the same species tree topology. This topology is consistent with most prior conceptions of apicomplexan evolution based upon ultrastructural and developmental characters, that is, the piroplasm genera Theileria and Babesia form the sister group to the Plasmodium species, the coccidian genera Eimeria and Toxoplasma are monophyletic and are the sister group to the Plasmodium species and piroplasm genera, and Cryptosporidium forms the sister group to the above mentioned with the ciliate Tetrahymena as the outgroup. The level of incongruence among gene trees appears to be high at first glance; only 19% of the genes support the species tree, and a total of 48 different gene-tree topologies are observed. Detailed investigations suggest that the low signal-to-noise ratio in many genes may be the main source of incongruence. The probability of being consistent with the species tree increases as a function of the minimum bootstrap support observed at tree nodes for a given gene tree. Moreover, gene sequences that generate high bootstrap support are robust to the changes in alignment parameters or phylogenetic method used. However, caution should be taken in that some genes can infer a "wrong" tree with strong support because of paralogy, model violations, or other causes. The importance of examining multiple, unlinked genes that possess a strong phylogenetic signal cannot be overstated.
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Bañuls AL, Hide M, Prugnolle F. Leishmania and the leishmaniases: a parasite genetic update and advances in taxonomy, epidemiology and pathogenicity in humans. ADVANCES IN PARASITOLOGY 2007; 64:1-109. [PMID: 17499100 DOI: 10.1016/s0065-308x(06)64001-3] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Leishmaniases remain a major public health problem today despite the vast amount of research conducted on Leishmania pathogens. The biological model is genetically and ecologically complex. This paper explores the advances in Leishmania genetics and reviews population structure, taxonomy, epidemiology and pathogenicity. Current knowledge of Leishmania genetics is placed in the context of natural populations. Various studies have described a clonal structure for Leishmania but recombination, pseudo-recombination and other genetic processes have also been reported. The impact of these different models on epidemiology and the medical aspects of leishmaniases is considered from an evolutionary point of view. The role of these parasites in the expression of pathogenicity in humans is also explored. It is important to ascertain whether genetic variability of the parasites is related to the different clinical expressions of leishmaniasis. The review aims to put current knowledge of Leishmania and the leishmaniases in perspective and to underline priority questions which 'leishmaniacs' must answer in various domains: epidemiology, population genetics, taxonomy and pathogenicity. It concludes by presenting a number of feasible ways of responding to these questions.
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Affiliation(s)
- Anne-Laure Bañuls
- Institut de Recherche pour le Développement, UMR CNRS/IRD 2724, Génétique et Evolution des Maladies Infectieuses, IRD Montpellier, 911 avenue Agropolis, 34394 Montpellier cedex 5, France
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Ventzki R, Stegemann J, Martinez L, de Marco A. Automated protein analysis by online detection of laser-induced fluorescence in slab gels and 3-D geometry gels. Electrophoresis 2006; 27:3338-48. [PMID: 16850506 DOI: 10.1002/elps.200600006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) still remains the most reliable and comprehensive analytical method for the evaluation of protein extracts. However, conventional SDS-PAGE is time-consuming and, thus, unpractical if several tens or hundreds of samples must be examined. We show that SDS-PAGE protein analysis can be automated using slab gel DNA sequencers and compare the instrument's performance with conventional SDS-PAGE in terms of resolution, sensitivity and sample capacity. Labeled protein bands are detected online by laser-induced fluorescence (LIF) and the acquired signals are electronically stored for further processing, avoiding gel staining and scanning. Appropriate software allows immediate display of recorded data and convenient evaluation. The method provides a higher sensitivity and dynamic range than conventional Coomassie-stained gels and the resolution of proteins with different masses is independent of the polyacrylamide concentration. Internal markers can also be used for direct quantification and assignment of the molecular masses. Additionally, we present a novel electrophoresis instrument for the simultaneous separation and online LIF detection of all samples of a microtiterplate in parallel lanes in a 3-D geometry gel cylinder. The specific gel thermostatting concept prevents irregular sample migration (smiling) and improves the reproducibility and comparability of individual separation patterns. In combination with the expected large capacity of 384 or 1,536 samples, this makes the instrument a valuable tool for high-throughput comparative screening applications.
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Affiliation(s)
- Robert Ventzki
- Scientific Core Facilities, Services & Technology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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Saville SP, Thomas DP, López-Ribot JL. Use of genome information for the study of the pathogenesis of fungal infections and the development of diagnostic tools. Rev Iberoam Micol 2005; 22:238-41. [PMID: 16499417 DOI: 10.1016/s1130-1406(05)70049-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
One of the most exciting advances in Mycology is the application of genomic approaches. The advent of genomics, together with post-genomic studies, promises to revolutionize the studies on the pathogenesis of fungal infections. Approaches include comparative genomics to identify sequences that contribute to infection and disease and functional genomics and proteomics to analyze global patterns of gene and protein expression involved in fungal pathogenesis.
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Affiliation(s)
- Stephen P Saville
- Department of Biology, The University of Texas at San Antonio, 6900 North Loop, 1604 West San Antonio, TX 78249, USA
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Worthey EA, Myler PJ. Protozoan genomes: gene identification and annotation. Int J Parasitol 2005; 35:495-512. [PMID: 15826642 DOI: 10.1016/j.ijpara.2005.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Revised: 01/25/2005] [Accepted: 02/06/2005] [Indexed: 12/01/2022]
Abstract
The draft sequence of several complete protozoan genomes is now available and genome projects are ongoing for a number of other species. Different strategies are being implemented to identify and annotate protein coding and RNA genes in these genomes, as well as study their genomic architecture. Since the genomes vary greatly in size, GC-content, nucleotide composition, and degree of repetitiveness, genome structure is often a factor in choosing the methodology utilised for annotation. In addition, the approach taken is dictated, to a greater or lesser extent, by the particular reasons for carrying out genome-wide analyses and the level of funding available for projects. Nevertheless, these projects have provided a plethora of material that will aid in understanding the biology and evolution of these parasites, as well as identifying new targets that can be used to design urgently required drug treatments for the diseases they cause.
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Affiliation(s)
- E A Worthey
- Seattle Biomedical Research Institute, 307 Westlake Ave N., Seattle, WA 98109-2591, USA
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Abstract
Genomic filtering is a rapid approach to identifying and prioritizing molecular targets for drug discovery. For infectious disease applications, comparative genomics filters allow the selection of pathogen-specific gene products, whereas functional genomics filters, such as RNA interference (RNAi), allow the selection of gene products essential for pathogen survival. The approach is especially applicable to antiparasitic drug discovery where the phylogenetic distance between parasite and host make the likelihood of drug cross-toxicity due to conservation of molecular targets greater than for more distantly related pathogens such as prokaryotes. This article discusses some of the inherent challenges of applying genomics to the early steps of drug discovery and describes one successful comparative and functional genomics filtering strategy that has been implemented to prioritize molecular targets and identify chemical leads for nematode control.
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Affiliation(s)
- James P McCarter
- Divergence Inc., 893 North Warson Road, St Louis, MO 63141, USA.
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Rich SM. The unpredictable past of Plasmodium vivax revealed in its genome. Proc Natl Acad Sci U S A 2004; 101:15547-8. [PMID: 15505201 PMCID: PMC524848 DOI: 10.1073/pnas.0405618101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Stephen M Rich
- Division of Infectious Diseases, Tufts University, North Grafton, MA 01536, USA.
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