DOCSLIB.ORG

Functional Genomics in Trypanosoma Brucei Identifies Evolutionarily Conserved Components of Motile Flagella

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Functional Genomics in Trypanosoma Brucei Identifies Evolutionarily Conserved Components of Motile Flagella 478 Research Article Functional genomics in Trypanosoma brucei identifies evolutionarily conserved components of motile flagella Desiree M. Baron1, Katherine S. Ralston1, Zakayi P. Kabututu1 and Kent L. Hill1,2,* 1Department of Microbiology, Immunology, and Molecular Genetics and 2Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA *Author for correspondence (e-mail: [email protected]) Accepted 1 November 2006 Journal of Cell Science 120, 478-491 Published by The Company of Biologists 2007 doi:10.1242/jcs.03352 Summary Cilia and flagella are highly conserved, complex organelles knockdown mutants. Epitope tagging, fluorescence involved in a variety of important functions. Flagella are localization and biochemical fractionation demonstrated required for motility of several human pathogens and flagellar localization for several TbCMF proteins. Finally, ciliary defects lead to a variety of fatal and debilitating ultrastructural analysis identified a family of novel TbCMF human diseases. Many of the major structural components proteins that function to maintain connections between of cilia and flagella are known, but little is known about outer doublet microtubules, suggesting that they are the regulation of flagellar beat. Trypanosoma brucei, the first identified components of nexin links. Overall, our causative agent of African sleeping sickness, provides an results provide insights into the workings of the eukaryotic excellent model for studying flagellar motility. We have flagellum, identify several novel human disease gene used comparative genomics to identify a core group of 50 candidates, reveal unique aspects of the trypanosome genes unique to organisms with motile flagella. These flagellum and underscore the value of T. brucei as an genes, referred to as T. brucei components of motile flagella experimental system for studying flagellar biology. (TbCMF) include 30 novel genes, and human homologues of many of the TbCMF genes map to loci associated with human ciliary diseases. To characterize TbCMF protein Supplementary material available online at function we used RNA interference to target 41 TbCMF http://jcs.biologists.org/cgi/content/full/120/3/478/DC1 genes. Sedimentation assays and direct observation Journal of Cell Science demonstrated clear motility defects in a majority of these Key words: Flagellum, Motility, Trypanosome, Nexin Introduction morphogenesis, cytokinesis and host-parasite interactions Eukaryotic cilia and flagella are complex, highly conserved, (Hill, 2003; Kohl et al., 2003; Ralston et al., 2006). Recent microtubule-based structures that are important in a number of work strongly suggests that flagellar motility is required for biological processes. Cilia and flagella drive cellular viability in the bloodstream stage of the T. brucei lifecycle movement of unicellular eukaryotes, including several (Broadhead et al., 2006; Ralston et al., 2006; Ralston and Hill, important human pathogens. Examples include multiflagellate 2006). Therefore, in protozoan parasites the flagellum is organisms such as Giardia lamblia and Trichomonas vaginalis, essential for disease pathogenesis and parasite development. which respectively, cause epidemic diarrhea and Flagella and cilia are also important for normal human trichomoniasis, the latter being the most common, non-viral, physiology and ciliary defects lead to a wide variety of diseases sexually transmitted disease in the world (Rughooputh and and developmental abnormalities (Afzelius, 2004; Pan et al., Greenwell, 2005). Kinetoplastid parasites, which cause 2005; Snell et al., 2004). In humans, one of the most familiar African sleeping sickness, Chagas disease and leishmaniasis, flagellum-related disorders is male infertility, in which all depend on a single flagellum for cell motility in their insect flagellated sperm lack effective motility (Sapiro et al., 2002). vectors and mammalian hosts. Motile flagella also play a Motile cilia are also important for moving fluids across the prominent role in the mating cycle of apicomplexan parasites surface of epithelial cells of the respiratory tract and female that cause malaria and toxoplasmosis (Ferguson, 2002; reproductive tract, as well as ependymal cells that line the Vlachou et al., 2006). Notably, the role of flagellar motility in ventricles of the brain and nodal cells of the developing embryo protozoa is not limited to cell movement, but also contributes (Afzelius, 2004). The importance of these functions is to nutrient uptake (Williams et al., 2006) and cell division evidenced by clinical features of immotile cilia syndrome (also (Brown et al., 1999; Ralston et al., 2006). For example in known as primary ciliary dyskinesia, PCD), which include Trypanosoma brucei, the causative agent of African sleeping respiratory deficiencies, hydrocephalus and situs inversus sickness, the flagellum is now recognized to be a (Afzelius et al., 2001). In addition to their role as organelles of multifunctional organelle with crucial roles in cell motility, cell motility, human cilia serve sensory and transport functions and T. brucei components of motile flagella 479 loss of this functionality underlies major human diseases of these 41 TbCMF genes demonstrated a role in flagellar including retinopathies, polycystic kidney disease and Bardet- motility in the majority of cases. Ultrastructural and motility Biedl syndrome (Pan et al., 2005; Pazour and Witman, 2003; analyses identified one family of novel TbCMF proteins that Wang et al., 2006). appear to function as part of the nexin links. The proteins The axoneme of motile cilia typically contains nine outer identified in this study are important for understanding doublet microtubules arranged around a pair of singlet flagellar motility in microbial pathogenesis and human microtubules. Dynein arms protruding from one outer doublet physiology. toward the adjacent doublet provide the motive force for flagellar motility (Summers and Gibbons, 1971). Radial spokes Results extend inward from the outer doublets to the central pair Comparative genomics identifies conserved components apparatus and are required for motility (Witman et al., 1978). of motile flagella Connecting the outer doublets to one another are nexin links We performed an ‘in silico’ screen using available genome (Warner, 1976), which are thought to help maintain outer- databases to identify genes that are conserved uniquely among doublet organization (Cibert, 2001; Lindemann, 2004). In its organisms with motile flagella (Fig. 1). Our screen led to the simplest form, flagellar movement can be described as the identification of 50 predicted T. brucei proteins that are sliding of outer doublet microtubules relative to one another conserved in Trypanosoma cruzi, Leishmania major, powered by the dynein arms (Brokaw, 1972; Satir, 1968; Chlamydomonas reinhardtii, Homo sapiens, Mus musculus, Shingyoji et al., 1977; Summers and Gibbons, 1971). Ciona intestinalis and Drosophilia melanogaster, and are not Attachment of doublets to the basal body and to each other found in Caenorhabditis elegans or Arabidopsis thaliana (Fig. limits sliding and this produces a bend, which is propagated 1, supplementary material Table S1). We refer to this group of along the axoneme through the coordinated activation and proteins as TbCMF proteins deactivation of dyneins. Although dynein arms, radial spokes As expected, the set of TbCMF proteins includes and the central pair apparatus have been well studied, homologues of proteins previously demonstrated through relatively little is known about proteins responsible for the genetic and biochemical studies to be bona fide flagellar coordinated regulation of sliding and resisting forces necessary components, as well as proteins identified in recent genomic for wave propagation. Genetic and biochemical studies in and flagellar proteomic analyses (supplementary material Chlamydomonas reinhardtii suggest that regulation is achieved Table S2) (Avidor-Reiss et al., 2004; Broadhead et al., 2006; in part by the dynein regulatory complex (DRC), which acts as Li et al., 2004; Ostrowski et al., 2002; Pazour et al., 2005; a reversible inhibitor of dynein (Huang et al., 1982; Piperno et Smith et al., 2005). Previously characterized flagellar proteins al., 1992; Gardner et al., 1994). Modeling studies suggest that that met the screen criteria include radial spoke proteins (RSP3, beat regulation also involves transverse forces supplied by the 4 and 6), DRC proteins (TPN), protofilament ribbon proteins elastic nexin links in response to axonemal curvature (Cibert, (Rib72 and Rib43a), an MBO2 homologue, and several 2001; Lindemann, 2004). Only one subunit of the DRC is axonemal dynein subunits (IC140, IC138, IC78, LC7a, LC7b known (Ralston et al., 2006; Rupp and Porter, 2003) and the and LC1). A group of predicted dynein heavy chain proteins Journal of Cell Science composition of nexin links is completely unknown, therefore, were originally identified in the screen, but were not included identification of proteins specifically important for flagellar in the final dataset, because our analysis did not distinguish beat and regulation represents a major challenge for them unambiguously from cytoplasmic dynein sequences. The understanding flagellum function. TbCMF dataset was enriched for proteins containing WD We previously demonstrated that the DRC is an repeats, leucine-rich repeats, EF hand calcium-binding evolutionarily conserved system for dynein regulation and that domains and
Load more

Recommended publications
  • Related Protozoan Pathogens, Different Diseases
    Kinetoplastids: related protozoan pathogens, different diseases Ken Stuart, … , Steve Reed, Rick Tarleton J Clin Invest. 2008;118(4):1301-1310. https://doi.org/10.1172/JCI33945. Review Series Kinetoplastids are a group of flagellated protozoans that include the species Trypanosoma and Leishmania, which are human pathogens with devastating health and economic effects. The sequencing of the genomes of some of these species has highlighted their genetic relatedness and underlined differences in the diseases that they cause. As we discuss in this Review, steady progress using a combination of molecular, genetic, immunologic, and clinical approaches has substantially increased understanding of these pathogens and important aspects of the diseases that they cause. Consequently, the paths for developing additional measures to control these “neglected diseases” are becoming increasingly clear, and we believe that the opportunities for developing the drugs, diagnostics, vaccines, and other tools necessary to expand the armamentarium to combat these diseases have never been better. Find the latest version: https://jci.me/33945/pdf Review series Kinetoplastids: related protozoan pathogens, different diseases Ken Stuart,1 Reto Brun,2 Simon Croft,3 Alan Fairlamb,4 Ricardo E. Gürtler,5 Jim McKerrow,6 Steve Reed,7 and Rick Tarleton8 1Seattle Biomedical Research Institute and University of Washington, Seattle, Washington, USA. 2Swiss Tropical Institute, Basel, Switzerland. 3Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. 4School of Life Sciences, University of Dundee, Dundee, United Kingdom. 5Departamento de Ecología, Genética y Evolución, Universidad de Buenos Aires, Buenos Aires, Argentina. 6Sandler Center for Basic Research in Parasitic Diseases, UCSF, San Francisco, California, USA.
    [Show full text]
  • Flagellum Couples Cell Shape to Motility in Trypanosoma Brucei
    Flagellum couples cell shape to motility in Trypanosoma brucei Stella Y. Suna,b,c, Jason T. Kaelberd, Muyuan Chene, Xiaoduo Dongf, Yasaman Nematbakhshg, Jian Shih, Matthew Doughertye, Chwee Teck Limf,g, Michael F. Schmidc, Wah Chiua,b,c,1, and Cynthia Y. Hef,h,1 aDepartment of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA 94305; bDepartment of Microbiology and Immunology, James H. Clark Center, Stanford University, Stanford, CA 94305; cSLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025; dDepartment of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030; eVerna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030; fMechanobiology Institute, National University of Singapore, Singapore 117411; gDepartment of Mechanical Engineering, National University of Singapore, Singapore 117575; and hDepartment of Biological Sciences, Center for BioImaging Sciences, National University of Singapore, Singapore 117543 Contributed by Wah Chiu, May 17, 2018 (sent for review December 29, 2017; reviewed by Phillipe Bastin and Abraham J. Koster) In the unicellular parasite Trypanosoma brucei, the causative Cryo-electron tomography (cryo-ET) allows us to view 3D agent of human African sleeping sickness, complex swimming be- supramolecular details of biological samples preserved in their havior is driven by a flagellum laterally attached to the long and proper cellular context without chemical fixative and/or metal slender cell body. Using microfluidic assays, we demonstrated that stain. However, samples thicker than 1 μm are not accessible to T. brucei can penetrate through an orifice smaller than its maxi- cryo-ET because at typical accelerating voltages (≤300 kV), few mum diameter.
    [Show full text]
  • Identification of a Novel Fused Gene Family Implicates Convergent
    Chen et al. BMC Genomics (2018) 19:306 https://doi.org/10.1186/s12864-018-4685-y RESEARCH ARTICLE Open Access Identification of a novel fused gene family implicates convergent evolution in eukaryotic calcium signaling Fei Chen1,2,3, Liangsheng Zhang1, Zhenguo Lin4 and Zong-Ming Max Cheng2,3* Abstract Background: Both calcium signals and protein phosphorylation responses are universal signals in eukaryotic cell signaling. Currently three pathways have been characterized in different eukaryotes converting the Ca2+ signals to the protein phosphorylation responses. All these pathways have based mostly on studies in plants and animals. Results: Based on the exploration of genomes and transcriptomes from all the six eukaryotic supergroups, we report here in Metakinetoplastina protists a novel gene family. This family, with a proposed name SCAMK,comprisesSnRK3 fused calmodulin-like III kinase genes and was likely evolved through the insertion of a calmodulin-like3 gene into an SnRK3 gene by unequal crossover of homologous chromosomes in meiosis cell. Its origin dated back to the time intersection at least 450 million-year-ago when Excavata parasites, Vertebrata hosts, and Insecta vectors evolved. We also analyzed SCAMK’s unique expression pattern and structure, and proposed it as one of the leading calcium signal conversion pathways in Excavata parasite. These characters made SCAMK gene as a potential drug target for treating human African trypanosomiasis. Conclusions: This report identified a novel gene fusion and dated its precise fusion time
    [Show full text]
  • Extensive Molecular Tinkering in the Evolution of the Membrane Attachment Mode of the Rheb Gtpase
    www.nature.com/scientificreports OPEN Extensive molecular tinkering in the evolution of the membrane attachment mode of the Rheb Received: 14 December 2017 Accepted: 15 March 2018 GTPase Published: xx xx xxxx Kristína Záhonová1, Romana Petrželková1, Matus Valach 2, Euki Yazaki3, Denis V. Tikhonenkov4, Anzhelika Butenko1, Jan Janouškovec5, Štěpánka Hrdá6, Vladimír Klimeš1, Gertraud Burger 2, Yuji Inagaki7, Patrick J. Keeling8, Vladimír Hampl6, Pavel Flegontov1, Vyacheslav Yurchenko1 & Marek Eliáš1 Rheb is a conserved and widespread Ras-like GTPase involved in cell growth regulation mediated by the (m)TORC1 kinase complex and implicated in tumourigenesis in humans. Rheb function depends on its association with membranes via prenylated C-terminus, a mechanism shared with many other eukaryotic GTPases. Strikingly, our analysis of a phylogenetically rich sample of Rheb sequences revealed that in multiple lineages this canonical and ancestral membrane attachment mode has been variously altered. The modifcations include: (1) accretion to the N-terminus of two diferent phosphatidylinositol 3-phosphate-binding domains, PX in Cryptista (the fusion being the frst proposed synapomorphy of this clade), and FYVE in Euglenozoa and the related undescribed fagellate SRT308; (2) acquisition of lipidic modifcations of the N-terminal region, namely myristoylation and/ or S-palmitoylation in seven diferent protist lineages; (3) acquisition of S-palmitoylation in the hypervariable C-terminal region of Rheb in apusomonads, convergently to some other Ras family proteins; (4) replacement of the C-terminal prenylation motif with four transmembrane segments in a novel Rheb paralog in the SAR clade; (5) loss of an evident C-terminal membrane attachment mechanism in Tremellomycetes and some Rheb paralogs of Euglenozoa.
    [Show full text]
  • Non-Leishmania Parasite in Fatal Visceral Leishmaniasis–Like Disease, Brazil
    DISPATCHES Non-Leishmania Parasite in Fatal Visceral Leishmaniasis–Like Disease, Brazil Sandra R. Maruyama,1 Alynne K.M. de Santana,1,2 performed whole-genome sequencing of 2 clinical isolates Nayore T. Takamiya, Talita Y. Takahashi, from a patient with a fatal illness with clinical characteris- Luana A. Rogerio, Caio A.B. Oliveira, tics similar to those of VL. Cristiane M. Milanezi, Viviane A. Trombela, Angela K. Cruz, Amélia R. Jesus, The Study Aline S. Barreto, Angela M. da Silva, During 2011–2012, we characterized 2 parasite strains, LVH60 Roque P. Almeida,3 José M. Ribeiro,3 João S. Silva3 and LVH60a, isolated from an HIV-negative man when he was 64 years old and 65 years old (Table; Appendix, https:// Through whole-genome sequencing analysis, we identified wwwnc.cdc.gov/EID/article/25/11/18-1548-App1.pdf). non-Leishmania parasites isolated from a man with a fatal Treatment-refractory VL-like disease developed in the man; visceral leishmaniasis–like illness in Brazil. The parasites signs and symptoms consisted of weight loss, fever, anemia, infected mice and reproduced the patient’s clinical mani- festations. Molecular epidemiologic studies are needed to low leukocyte and platelet counts, and severe liver and spleen ascertain whether a new infectious disease is emerging that enlargements. VL was confirmed by light microscopic exami- can be confused with leishmaniasis. nation of amastigotes in bone marrow aspirates and promas- tigotes in culture upon parasite isolation and by positive rK39 serologic test results. Three courses of liposomal amphotericin eishmaniases are caused by ≈20 Leishmania species B resulted in no response.
    [Show full text]
  • The Trypanosoma Brucei Subpellicular Microtubule Array Is Organized Into Functionally Discrete
    bioRxiv preprint doi: https://doi.org/10.1101/2020.11.09.375725; this version posted November 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 The Trypanosoma brucei subpellicular microtubule array is organized into functionally discrete 2 subdomains defined by microtubule associated proteins 3 4 Amy N. Sinclair1,#, Christine T. Huynh1, Thomas E. Sladewski1, Jenna L. Zuromski2, Amanda E. 5 Ruiz2, and Christopher L. de Graffenried1,†,* 6 7 1. Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, 8 02912 9 2. Department of Pathology and Laboratory Medicine, Center for International Health Research, 10 Brown University, Providence, RI 02903 11 *To whom correspondence should be addressed. Phone: +1 (401) 863-6148 E-mail: 12 [email protected]. 13 #. ORCID: 0000-0001-6688-6754 14 †. ORCID: 0000-0003-3386-6487 15 16 Short title: Subpellicular array subdomains in T. brucei 17 18 Abbreviations: Flagellum attachment zone (FAZ), microtubule associated protein (MAP), 19 nucleus (N), kinetoplast (K), immunogold electron microscopy (iEM), transmission electron 20 microscopy (TEM), RNA interference (RNAi), mNeonGreen (mNG), maltose binding protein 21 (MBP), total internal reflection fluorescence microscopy (TIRF) 22 23 Keywords: cytoskeleton, microtubules, microtubule associated proteins, subpellicular 24 microtubule array, trypanosomatid, cell morphology bioRxiv preprint doi: https://doi.org/10.1101/2020.11.09.375725; this version posted November 9, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.
    [Show full text]
  • The Lysis of Trypanosoma Brucei Brucei by Hun1an Serun1
    © 1996 Nature Publishing Group http://www.nature.com/naturebiotechnology • REVIEW ARTICLE The lysis of Trypanosoma brucei brucei by hun1an serun1 Stephen Tomlinson* and Jayne Raper1 Departments of Pathology and 'Medical and Molecular Parasitology, NYU Medical Center, New York, NY 10016. *Corresponding author ( e-mail: [email protected]). Received 25 January 1996; accepted 4 April 1996. The natural immunity of humans to the cattle pathogen Trypanosoma brucei brucei, but not to the morphologically indistiguishable human pathogens T. brucei gambiense and T. brucei rhodesiense, is due to the selective killing of the parasite by normal human serum. The factor in human serum that mediates lysis of T. brucei brucei has long been attributed to a minor subclass of high density lipopro­ tein (HDL). Evidence indicates that the trypanolytic activity of isolated human HDL is due to peroxidase activity of an associated haptoglobin-related protein-hemoglobin complex. However, recent data sug­ gest that the trypanolytic activity of HDL may be completely inhibited in whole human serum, and that trypanolytic activity of norman human serum is due to a second, less well-defined factor of high molec­ ular weight. Current research aimed at understanding the mechamisms of cytotoxicity and the affected metabolic pathways may open new approaches for the development of specific drugs and vaccines against trypanosomiasis. Keywords: Trypanosoma, high density lipoprotein, haptoglobin, serum lysis African trypanosomes and disease An intriguing phenomenon associated with natural immunity Trypanosomiasis is a major health and economic problem in to these parasites is the complement-independent selective killing Africa. The affected areas extend over more than 10 million km2 by normal human serum (NHS) of the cattle pathogen T.
    [Show full text]
  • New Tools and Knowledge to Reduce Bottlenecks in Drug Discovery
    G C A T T A C G G C A T genes Review Of Drugs and Trypanosomatids: New Tools and Knowledge to Reduce Bottlenecks in Drug Discovery Arijit Bhattacharya 1 , Audrey Corbeil 2, Rubens L. do Monte-Neto 3 and Christopher Fernandez-Prada 2,* 1 Department of Microbiology, Adamas University, Kolkata, West Bengal 700 126, India; [email protected] 2 Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC J2S 2M2, Canada; [email protected] 3 Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte MG 30190-009, Brazil; rubens.monte@fiocruz.br * Correspondence: [email protected]; Tel.: +1-450-773-8521 (ext. 32802) Received: 4 June 2020; Accepted: 26 June 2020; Published: 29 June 2020 Abstract: Leishmaniasis (Leishmania species), sleeping sickness (Trypanosoma brucei), and Chagas disease (Trypanosoma cruzi) are devastating and globally spread diseases caused by trypanosomatid parasites. At present, drugs for treating trypanosomatid diseases are far from ideal due to host toxicity, elevated cost, limited access, and increasing rates of drug resistance. Technological advances in parasitology, chemistry, and genomics have unlocked new possibilities for novel drug concepts and compound screening technologies that were previously inaccessible. In this perspective, we discuss current models used in drug-discovery cascades targeting trypanosomatids (from in vitro to in vivo approaches), their use and limitations in a biological context, as well as different
    [Show full text]
  • African Trypanosomiasis: Extracellular Vesicles Shed by Trypanosoma Brucei Brucei Manipulate Host Mononuclear Cells
    biomedicines Article African Trypanosomiasis: Extracellular Vesicles Shed by Trypanosoma brucei brucei Manipulate Host Mononuclear Cells Tatiana Dias-Guerreiro 1,†, Joana Palma-Marques 1,†, Patrícia Mourata-Gonçalves 1, Graça Alexandre-Pires 2 , Ana Valério-Bolas 1 , Áurea Gabriel 1 , Telmo Nunes 3, Wilson Antunes 4, Isabel Pereira da Fonseca 2, Marcelo Sousa-Silva 1,5 and Gabriela Santos-Gomes 1,* 1 Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), 1349-008 Lisboa, Portugal; [email protected] (T.D.-G.); [email protected] (J.P.-M.); [email protected] (P.M.-G.); [email protected] (A.V.-B.); [email protected] (Á.G.); [email protected] (M.S.-S.) 2 Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, 1300-477 Lisboa, Portugal; [email protected] (G.A.-P.); [email protected] (I.P.d.F.) 3 Microscopy Center, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisboa, Portugal; [email protected] 4 Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Laboratório de Imagem Nano-Morfológica e Espectroscopia de Raios-X, 1100-471 Lisboa, Portugal; [email protected] 5 Centro de Ciências da Saúde, Departamento de Analises Clínicas e Toxicológicas, Universidade Federal do Rio Grande do Norte, Natal 59078-970, Brazil Citation: Dias-Guerreiro, T.; * Correspondence: [email protected]; Tel.: +351-21-365-26-00; Fax: +351-21-363-21-05 Palma-Marques, J.; † These two authors contributed equally to this study and are considered co-first authors.
    [Show full text]
  • Gene Co-Expression Network Analysis of Trypanosoma Brucei in Tsetse Fly
    Mwangi et al. Parasites Vectors (2021) 14:74 https://doi.org/10.1186/s13071-021-04597-6 Parasites & Vectors RESEARCH Open Access Gene co-expression network analysis of Trypanosoma brucei in tsetse fy vector Kennedy W. Mwangi1,2* , Rosaline W. Macharia3 and Joel L. Bargul1,2 Abstract Background: Trypanosoma brucei species are motile protozoan parasites that are cyclically transmitted by tsetse fy (genus Glossina) causing human sleeping sickness and nagana in livestock in sub-Saharan Africa. African trypano- somes display digenetic life cycle stages in the tsetse fy vector and in their mammalian host. Experimental work on insect-stage trypanosomes is challenging because of the difculty in setting up successful in vitro cultures. Therefore, there is limited knowledge on the trypanosome biology during its development in the tsetse fy. Consequently, this limits the development of new strategies for blocking parasite transmission in the tsetse fy. Methods: In this study, RNA-Seq data of insect-stage trypanosomes were used to construct a T. brucei gene co- expression network using the weighted gene co-expression analysis (WGCNA) method. The study identifed signif- cant enriched modules for genes that play key roles during the parasite’s development in tsetse fy. Furthermore, potential 3′ untranslated region (UTR) regulatory elements for genes that clustered in the same module were identi- fed using the Finding Informative Regulatory Elements (FIRE) tool. Results: A fraction of gene modules (12 out of 27 modules) in the constructed network were found to be enriched in functional roles associated with the cell division, protein biosynthesis, mitochondrion, and cell surface. Additionally, 12 hub genes encoding proteins such as RNA-binding protein 6 (RBP6), arginine kinase 1 (AK1), brucei alanine-rich pro- tein (BARP), among others, were identifed for the 12 signifcantly enriched gene modules.
    [Show full text]
  • Red Algal Parasites: Models for a Life History Evolution That Leaves Photosynthesis Behind Again and Again
    Prospects & Overviews Review essays Red algal parasites: Models for a life history evolution that leaves photosynthesis behind again and again Nicolas A. Blouinà and Christopher E. Lane Many of the most virulent and problematic eukaryotic Introduction pathogens have evolved from photosynthetic ancestors, such as apicomplexans, which are responsible for a Parasitology is one of the oldest fields of medical research and continues to be an essential area of study on organisms wide range of diseases including malaria and toxoplas- that kill millions annually, either directly or through mosis. The primary barrier to understanding the early agricultural loss. In the early genomics era, parasites were stages of evolution of these parasites has been the diffi- some of the initial eukaryotes to have their genomes culty in finding parasites with closely related free-living sequenced. The combination of medical interest and small lineages with which to make comparisons. Parasites genome size (due to genome compaction [1]) has resulted found throughout the florideophyte red algal lineage, in a relatively large number of sequenced genomes from these taxa. The range of relationships that exist between however, provide a unique and powerful model to inves- parasites and comparative free-living taxa, however, compli- tigate the genetic origins of a parasitic lifestyle. This is cates understanding the evolution of eukaryotic parasitism. because they share a recent common ancestor with an In some cases (such as apicomplexans, which cause extant free-living red algal species and parasitism has malaria, cryptosporidiosis and toxoplasmosis, among other independently arisen over 100 times within this group. diseases) entire lineages appear to have a common parasitic ancestor [2].
    [Show full text]
  • Rnai in Arthropods: Insight Into the Machinery and Applications for Understanding the Pathogen-Vector Interface
    Genes 2012, 3, 702-741; doi:10.3390/genes3040702 OPEN ACCESS genes ISSN 2073-4425 www.mdpi.com/journal/genes Review RNAi in Arthropods: Insight into the Machinery and Applications for Understanding the Pathogen-Vector Interface Annette-Christi Barnard 1, Ard M. Nijhof 2, Wilma Fick 3, Christian Stutzer 1 and Christine Maritz-Olivier 3,* 1 Department of Biochemistry, University of Pretoria, Pretoria, 0002, South Africa; E-Mails: [email protected] (A.C.B.); [email protected] (C.S.) 2 Institut für Parasitologie und Tropenveterinärmedizin, Freie Universität Berlin, Königsweg 67, 14163, Berlin, Germany; E-Mail: [email protected] 3 Department of Genetics, University of Pretoria, Pretoria, 0002, South Africa; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +27-012-420-3945; Fax: +27-012-362-5327. Received: 3 September 2012; in revised form: 19 October 2012 / Accepted: 23 October 2012 / Published: 6 November 2012 Abstract: The availability of genome sequencing data in combination with knowledge of expressed genes via transcriptome and proteome data has greatly advanced our understanding of arthropod vectors of disease. Not only have we gained insight into vector biology, but also into their respective vector-pathogen interactions. By combining the strengths of postgenomic databases and reverse genetic approaches such as RNAi, the numbers of available drug and vaccine targets, as well as number of transgenes for subsequent transgenic or paratransgenic approaches, have expanded. These are now paving the way for in-field control strategies of vectors and their pathogens. Basic scientific questions, such as understanding the basic components of the vector RNAi machinery, is vital, as this allows for the transfer of basic RNAi machinery components into RNAi-deficient vectors, thereby expanding the genetic toolbox of these RNAi-deficient vectors and pathogens.
    [Show full text]