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Demar Taylor - One of the best experts on this subject based on the ideXlab platform.
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ovarian ecdysteroidogenesis in both immature and mature stages of an acari Ornithodoros moubata
PLOS ONE, 2015Co-Authors: Mari H Ogihara, Demar Taylor, Juri Hikiba, Yutaka Suzuki, Hiroshi KataokaAbstract:Ecdysteroidogenesis is essential for arthropod development and reproduction. Although the importance of ecdysteroids has been demonstrated, there is little information on the sites and enzymes for synthesis of ecdysteroids from Chelicerates. Ecdysteroid functions have been well studied in the soft tick Ornithodoros moubata, making this species an excellent candidate for elucidating ecdysteroidogenesis in Chelicerates. Results showed that O. moubata has at least two ecdysteroidogenic enzymes, Spook (OmSpo) and Shade (OmShd). RNAi showed both enzymes were required for ecdysteroidogenesis. Enzymatic assays demonstrated OmShd has the conserved functions of ecdysone 20-hydroxylase. OmSpo showed specific expression in the ovaries of final nymphal and adult stages, indicating O. moubata utilizes the ovary as an ecdysteroidogenic tissue instead of specific tissues as seen in other arthropods. On the other hand, OmShd expression was observed in various tissues including the midgut, indicating functional ecdysteroids can be produced in these tissues. In nymphal stages, expression of both OmSpo and OmShd peaked before molting corresponding with high ecdysteroid titers in the hemolymph. In fed adult females, OmSpo expression peaked at 8–10 days after engorgement, while OmShd expression peaked immediately after engorgement. Mated females showed more frequent surges of OmShd than virgin females. These results indicate that the regulation of synthesis of ecdysteroids differs in nymphs and adult females, and mating modifies adult female ecdysteroidogenesis. This is the first report to focus on synthesis of ecdysteroids in ticks and provides essential knowledge for understanding the evolution of ecdysteroidogenesis in arthropods.
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Analysis of tissues for EcR and RXR nuclear receptor gene expression during vitellogenesis in the soft tick Ornithodoros moubata
Trends in Acarology, 2010Co-Authors: Mari Horigane, Demar TaylorAbstract:Vitellogenin (Vg) synthesis and oocyte development appear to be induced by ecdysteroids in the soft tick Ornithodoros moubata. Vg transcription in insects has been shown to be mediated by two nuclear receptors, an ecdysteroid receptor (EcR) and a retinoid X receptor (RXR). EcR and RXR expression in female ticks increase after engorgement. However, there is little information about EcR and RXR expression in tissues as related to reproduction. Therefore, the sites of EcR and RXR expression during vitellogenesis were determined. Expression levels of EcR and RXR were determined for salivary glands, midgut, ovary, anterior reproductive tract, fat body, muscle, and cuticle of mated females by reverse transcriptase RT-PCR and real-time PCR. Ovaries showed constant expression of EcR and RXR throughout the adult female stage. The fat body showed higher expression of EcR and RXR on one day after engorgement. The fat body of female ticks has been reported to be the organ of Vg synthesis. Therefore, increases in EcR and RXR of the fat body support the hypotheses that the site of Vg synthesis is the fat body and ecdysteroids regulate this synthesis in O. moubata. EcR and RXR in the ovary and anterior reproductive tract may also play roles in the regulation of oocyte development.
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characterization of a vitellogenin gene reveals two phase regulation of vitellogenesis by engorgement and mating in the soft tick Ornithodoros moubata acari argasidae
Insect Molecular Biology, 2010Co-Authors: T Shinoda, Mari Horigane, Hiroshi Honda, Demar TaylorAbstract:Synthesis of the precursor yolk protein vitellogenin (Vg) occurs after engorgement in haematophagous arthropods. We identified the Vg cDNA of the soft tick Ornithodoros moubata (OmVg) and compared its expression in mated and virgin females. Both mated and virgin females showed increases in OmVg expression after engorgement but expression was higher in mated females than virgin females particularly as time advanced. Delayed mating in virgin females induced an increase in OmVg expression. OmVg expression was observed in the midgut and fat body by whole mount in situ hybridization, but enlarged fat body with high expression occurred in only mated females during the late phase of vitellogenesis. Therefore, engorgement initially induces OmVg expression but mating is necessary for continued Vg expression to produce mature eggs.
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Isolation and expression of the retinoid X receptor from last instar nymphs and adult females of the soft tick Ornithodoros moubata (Acari: Argasidae).
General and comparative endocrinology, 2008Co-Authors: Mari Horigane, Yoshiro Nakajima, Kazumasa Ogihara, Demar TaylorAbstract:Retinoid X receptors (RXR) exist broadly from invertebrates to vertebrates, and play essential roles in physiological processes of these organisms. In arthropods, RXRs form a complex with the ecdysteroid receptor (EcR) and ecdysteroids to mediate the regulation of ecdysis and reproduction. Compared to EcR, RXR and its homologue ultraspiracle (USP) are much less well understood. Therefore, we identified RXR of the soft tick Ornithodoros moubata (OmRXR) and used real-time PCR to examine the expression of OmRXR. This is the first report of RXR from a soft tick. OmRXR showed higher homology to hard tick, crustacean and vertebrate RXRs than insect RXRs and USPs. OmRXR expression was observed during molting in the last instar nymphs coinciding with EcR expression and increases in ecdysteroid titers. Tick vitellogenesis normally occurs soon after engorgement and OmRXR expression coinciding with EcR expression and ecdysteroid titers in engorged females occurred before vitellogenin (Vg) synthesis and egg maturation. The ecdysteroid/EcR/RXR complex appears to be important in the regulation of molting and vitellogenesis of soft ticks.
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cloning and expression of the ecdysteroid receptor during ecdysis and reproduction in females of the soft tick Ornithodoros moubata acari argasidae
Insect Molecular Biology, 2007Co-Authors: Mari Horigane, Yoshiro Nakajima, Kazumasa Ogihara, T Shinoda, Demar TaylorAbstract:Molecular mechanisms of ecdysteroid regulation in development and reproduction have been thoroughly investigated in Diptera and Lepidoptera, but few studies report the molecular actions of ecdysteroids in hemimetabolous insects and more primitive arthropods. Ecdysteroids appear to be the main hormones regulating development and vitellogenesis in ticks. An ecdysteroid receptor that showed high homology with EcRs of other arthropods was isolated from Ornithodoros moubata (OmEcRA). OmEcR expression patterns coincided with ecdysteroid titres in the haemolymph during moulting and vitellogenesis and differed between mated and virgin females. Therefore, OmEcR appears to mediate the regulation of moulting and vitellogenesis by ecdysteroids in O. moubata females as seen in other arthropods.
Kurt Wüthrich - One of the best experts on this subject based on the ideXlab platform.
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NMR solution structure of the recombinant tick anticoagulant protein (rTAP), a factor Xa inhibitor from the tick Ornithodoros moubata.
FEBS letters, 1994Co-Authors: W. Antuch, Peter Güntert, Martin Billeter, T. Hawthorne, Hugo Grossenbacher, Kurt WüthrichAbstract:The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by 1H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36 degrees C. rTAP is a 60-residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two-stranded antiparallel beta-sheet with residues 22-28 and 32-38, and an alpha-helix with residues 51-60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the beta-sheet and the C-terminal alpha-helix as well as the N-terminal 20-residue segment preceding the beta-sheet adopt different three-dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz-type protein proteinase inhibitors.
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nmr solution structure of the recombinant tick anticoagulant protein rtap a factor xa inhibitor from the tick Ornithodoros moubata
FEBS Letters, 1994Co-Authors: W. Antuch, Peter Güntert, Martin Billeter, T. Hawthorne, Hugo Grossenbacher, Kurt WüthrichAbstract:The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by 1H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36°C. rTAP is a 60-residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two-stranded antiparallel β-sheet with residues 22–28 and 32–38, and an α-helix with residues 51–60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the β-sheet and the C-terminal α-helix as well as the N-terminal 20-residue segment preceding the β-sheet adopt different three-dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz-type protein proteinase inhibitors.
Masahito Fukunaga - One of the best experts on this subject based on the ideXlab platform.
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absence of transovarial transmission of borrelia duttonii a tick borne relapsing fever agent by the vector tick Ornithodoros moubata
Vector-borne and Zoonotic Diseases, 2008Co-Authors: Norihiko Tabuchi, Yoko Kataokaushijima, Alison Talbert, Harumi Mitani, Masahito FukunagaAbstract:We examined the vector competence of the tick, Ornithodoros moubata, using laboratory-reared gerbils as hosts. Transmission of the relapsing fever agent Borrelia duttonii occurred efficiently from infected ticks to uninfected gerbils and from infected gerbils to uninfected ticks. Spirochetes were maintained stably in the ticks for at least 3 months, but they disappeared from the bloodstream of infected gerbils after three episodes of spirochetemia. We also examined transovarial transmission of B. duttonii during the gonotrophic cycle and filial generation. No spirochetes could be detected from the offspring generation of the ticks by culture and polymerase chain reaction (PCR) methods, although spirochetes were still found in the female ticks. The results indicate that, because of the rarity of transovarial infection, the role of transovarial passage of B. duttonii to eggs and larval O. moubata ticks is limited in maintaining B. duttonii. Our findings strongly suggest that B. duttonii is maintained throug...
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Absence of Transovarial Transmission of Borrelia duttonii, a Tick-Borne Relapsing Fever Agent, by the Vector Tick Ornithodoros moubata
Vector borne and zoonotic diseases (Larchmont N.Y.), 2008Co-Authors: Norihiko Tabuchi, Alison Talbert, Harumi Mitani, Yoko Kataoka-ushijima, Masahito FukunagaAbstract:We examined the vector competence of the tick, Ornithodoros moubata, using laboratory-reared gerbils as hosts. Transmission of the relapsing fever agent Borrelia duttonii occurred efficiently from infected ticks to uninfected gerbils and from infected gerbils to uninfected ticks. Spirochetes were maintained stably in the ticks for at least 3 months, but they disappeared from the bloodstream of infected gerbils after three episodes of spirochetemia. We also examined transovarial transmission of B. duttonii during the gonotrophic cycle and filial generation. No spirochetes could be detected from the offspring generation of the ticks by culture and polymerase chain reaction (PCR) methods, although spirochetes were still found in the female ticks. The results indicate that, because of the rarity of transovarial infection, the role of transovarial passage of B. duttonii to eggs and larval O. moubata ticks is limited in maintaining B. duttonii. Our findings strongly suggest that B. duttonii is maintained through the O. moubata tick-human transmission cycle in tick-borne relapsing fever endemic areas.
Ricardo Perezsanchez - One of the best experts on this subject based on the ideXlab platform.
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sialotranscriptomics of the argasid tick Ornithodoros moubata along the trophogonic cycle
PLOS Neglected Tropical Diseases, 2021Co-Authors: Ana Oleaga, Beatriz Soriano, Carlos Llorens, Ricardo PerezsanchezAbstract:The argasid tick Ornithodoros moubata is the main vector of human relapsing fever (HRF) and African swine fever (ASF) in Africa. Salivary proteins are part of the host-tick interface and play vital roles in the tick feeding process and the host infection by tick-borne pathogens; they represent interesting targets for immune interventions aimed at tick control. The present work describes the transcriptome profile of salivary glands of O. moubata and assesses the gene expression dynamics along the trophogonic cycle using Illumina sequencing. De novo transcriptome assembling resulted in 71,194 transcript clusters and 41,011 annotated transcripts, which represent 57.6% of the annotation success. Most salivary gene expression takes place during the first 7 days after feeding (6,287 upregulated transcripts), while a minority of genes (203 upregulated transcripts) are differentially expressed between 7 and 14 days after feeding. The functional protein groups more abundantly overrepresented after blood feeding were lipocalins, proteases (especially metalloproteases), protease inhibitors including the Kunitz/BPTI-family, proteins with phospholipase A2 activity, acid tail proteins, basic tail proteins, vitellogenins, the 7DB family and proteins involved in tick immunity and defence. The complexity and functional redundancy observed in the sialotranscriptome of O. moubata are comparable to those of the sialomes of other argasid and ixodid ticks. This transcriptome provides a valuable reference database for ongoing proteomics studies of the salivary glands and saliva of O. moubata aimed at confirming and expanding previous data on the O. moubata sialoproteome.
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functional annotation and analysis of the Ornithodoros moubata midgut genes differentially expressed after blood feeding
Ticks and Tick-borne Diseases, 2017Co-Authors: Ana Oleaga, Raul Manzanoroman, Prosper Obolomvoulouga, Ricardo PerezsanchezAbstract:Abstract The argasid tick Ornithodoros moubata is the main vector of the African swine fever and the human relapsing fever in Africa. As part of the host-parasite-pathogen interface, the tick midgut expresses key proteins for tick survival and tick-borne pathogen transmission. Accordingly, midgut proteins are potential targets for the development of new drugs and vaccines aimed at tick control, and obtaining proteomic and transcriptomic data from the O. moubata midgut would facilitate the identification of such target candidates. With this aim, we have assembled and characterized the midgut transcriptome of O. moubata females before and 48 h after a blood meal, and identified the genes that are differentially expressed in the midgut after feeding. Overall, 23,863 transcripts were obtained, and of them, 9,164 were identified and annotated. The most represented molecular functions were catalytic and binding activities, and the most represented biological processes were metabolic, cellular and single-organism processes. KEGG analysis of the annotated sequences assigned up to 3,053 of them to 130 active pathways, among which, the top 30 pathways were mostly metabolic routes. Differential expression analysis between unfed and fed ticks detected 8,026 Differentially Expressed Genes (DEGs), 4,093 up-regulated and 3,933 down-regulated, respectively. The biological significance of these DEGs was further investigated using the KEEG, Pfam and GO databases. The functional groups of the genes/proteins predicted to be involved in the processes of blood digestion, nutrient transport and metabolism, and in responses related to defence and oxidative stress are discussed in more detail. This work reports the first midgut transcriptome analysis of an argasid tick species, and provides a wealth of novel molecular information about the argasid machinery involved in blood feeding and digestion. This information represents a starting point for the development of alternative strategies for tick control.
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self assembled protein arrays from an Ornithodoros moubata salivary gland expression library
Journal of Proteome Research, 2012Co-Authors: Raul Manzanoroman, Sergio Matarraz, Joshua Labaer, Alberto Orfao, Veronica Diazmartin, Maria Gonzalezgonzalez, Angel Francisco Alvarezprado, Ricardo Perezsanchez, Manuel FuentesAbstract:Protein interactions play a critical role in the regulation of many biological events and their study in a high-throughput format has become a key area of proteomic research. Nucleid Acid Programmable Protein Arrays (NAPPA) technology allows the construction of protein arrays from cDNA expression libraries in high-throughput cell-free systems to study protein interaction and functions. Tick saliva contains antihemostatic, anti-inflammatory, and immunosuppressive proteins that counteract the host hemostatic, immune, and inflammatory responses allowing the ingestion of host blood and facilitating its infection by the tick-borne pathogens. Identification of such proteins and their functions could help in the selection of antigenic targets for the development of antitick and transmission-blocking vaccines. With that aim, we have prepared a cDNA expression library from the salivary glands of Ornithodoros moubata and subsequently produced a self-assembled protein microarray using 480 randomly selected clones fr...
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cloning characterization and diagnostic performance of the salivary lipocalin protein tsgp1 from Ornithodoros moubata
Veterinary Parasitology, 2011Co-Authors: Veronica Diazmartin, Ana Oleaga, Raul Manzanoroman, Mar Sileslucas, Ricardo PerezsanchezAbstract:The argasid tick Ornithodoros moubata is distributed throughout South and East Africa and Madagascar, where it colonizes wild and domestic habitats and feeds on warthogs, domestic swine, and humans. This argasid transmits the spirochete Borrelia duttonii, causing East African tick-borne relapsing fever in humans, and the African swine fever virus, which causes a highly lethal haemorrhagic disease in pigs. Tick surveillance and the elimination of O. moubata from synanthropic environments (human dwellings and pigsties) would facilitate the control and prevention of these two diseases. Since direct surveillance methods are impractical in this context, the development of an indirect method for the detection of specific antibodies against tick salivary proteins in samples taken from animal or human hosts living in the area under study would provide a more convenient surveillance and diagnostic tool. Previous work has indicated that the 20A1 salivary antigen of O. moubata could be an optimal candidate for the development of a specific serological test and identified it as an orthologue of the Ornithodoros savignyi TSGP1 lipocalin. The objectives of the present work were to clone, sequence, and molecularly characterize the O. moubata TSGP1, as well as its production as a recombinant protein in order to assess its usefulness as a diagnostic antigen in an ELISA test for tick surveillance. Our results show that O. moubata TSGP1 (OmTSGP1) conserves the tertiary structure of lipocalins and contains the biogenic amine-binding motif. We also show that OmTSGP1 shares 65% sequence identity with the O. savignyi TSGP1, demonstrating that they represent orthologous proteins and suggesting they share identical function as biogenic amine scavengers. A recombinant form of OmTSGP1 was produced, showing 100% sensitivity and 99.4% specificity in an ELISA test for the detection of anti-O. moubata antibodies in pig sera. This recombinant antigen represents a promising epidemiological tool for O. moubata surveillance that may help to implement control measures against O. moubata-borne diseases.
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a proteomic approach to the identification of salivary proteins from the argasid ticks Ornithodoros moubata and Ornithodoros erraticus
Insect Biochemistry and Molecular Biology, 2007Co-Authors: Ana Oleaga, Andres Escuderopoblacion, Emilio Camafeita, Ricardo PerezsanchezAbstract:The saliva of ticks contains anti-haemostatic, anti-inflammatory and immunomodulatory molecules that allow these parasites to obtain a blood meal from the host and help tick-borne pathogens to infect the vertebrate host more efficiently. This makes the salivary molecules attractive targets to control ticks and tick-borne pathogens. Although Ornithodoros moubata and O. erraticus are important argasid ticks that transmit severe diseases, to date only a few of their salivary proteins have been identified. Here we report our initial studies using proteomic approaches to characterize the protein profiles of salivary gland extracts (SGE) from these two argasids. The present work describes the proteome of the SGEs of both tick species, their antigenic spots, and the identification of several of their proteins. The whole number of identifications was low despite the good general quality of the peptide mass maps obtained. In the O. moubata SGE, 18 isoforms of a protein similar to O. savignyi TSGP1 were identified. In the O. erraticus SGE we identified 6 novel proteins similar to unknown secreted protein DS-1 precursor, NADPH dehydrogenase subunit 5, proteasome alpha subunit, ATP synthase F0 subunit 6, lipocalin and alpha tubulin. Finally, the current drawbacks of proteomics when applied to the identification of acarine peptides and proteins are discussed.
W. Antuch - One of the best experts on this subject based on the ideXlab platform.
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NMR solution structure of the recombinant tick anticoagulant protein (rTAP), a factor Xa inhibitor from the tick Ornithodoros moubata.
FEBS letters, 1994Co-Authors: W. Antuch, Peter Güntert, Martin Billeter, T. Hawthorne, Hugo Grossenbacher, Kurt WüthrichAbstract:The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by 1H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36 degrees C. rTAP is a 60-residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two-stranded antiparallel beta-sheet with residues 22-28 and 32-38, and an alpha-helix with residues 51-60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the beta-sheet and the C-terminal alpha-helix as well as the N-terminal 20-residue segment preceding the beta-sheet adopt different three-dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz-type protein proteinase inhibitors.
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nmr solution structure of the recombinant tick anticoagulant protein rtap a factor xa inhibitor from the tick Ornithodoros moubata
FEBS Letters, 1994Co-Authors: W. Antuch, Peter Güntert, Martin Billeter, T. Hawthorne, Hugo Grossenbacher, Kurt WüthrichAbstract:The solution structure of the recombinant tick anticoagulant protein (rTAP) was determined by 1H nuclear magnetic resonance (NMR) spectroscopy in aqueous solution at pH 3.6 and 36°C. rTAP is a 60-residue protein functioning as a highly specific inhibitor of the coagulation protease factor Xa, which was originally isolated from the tick Ornithodoros moubata. Its regular secondary structure consists of a two-stranded antiparallel β-sheet with residues 22–28 and 32–38, and an α-helix with residues 51–60. The relative orientation of these regular secondary structure elements has nearly identical counterparts in the bovine pancreatic trypsin inhibitor (BPTI). In contrast, the loop between the β-sheet and the C-terminal α-helix as well as the N-terminal 20-residue segment preceding the β-sheet adopt different three-dimensional folds in the two proteins. These observations are discussed with regard to the implication of different mechanisms of protease inhibition by rTAP and by Kunitz-type protein proteinase inhibitors.