28 research outputs found

    The venom composition of the parasitic wasp Chelonus inanitus resolved by combined expressed sequence tags analysis and proteomic approach

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    <p>Abstract</p> <p>Background</p> <p>Parasitic wasps constitute one of the largest group of venomous animals. Although some physiological effects of their venoms are well documented, relatively little is known at the molecular level on the protein composition of these secretions. To identify the majority of the venom proteins of the endoparasitoid wasp <it>Chelonus inanitus </it>(Hymenoptera: Braconidae), we have randomly sequenced 2111 expressed sequence tags (ESTs) from a cDNA library of venom gland. In parallel, proteins from pure venom were separated by gel electrophoresis and individually submitted to a nano-LC-MS/MS analysis allowing comparison of peptides and ESTs sequences.</p> <p>Results</p> <p>About 60% of sequenced ESTs encoded proteins whose presence in venom was attested by mass spectrometry. Most of the remaining ESTs corresponded to gene products likely involved in the transcriptional and translational machinery of venom gland cells. In addition, a small number of transcripts were found to encode proteins that share sequence similarity with well-known venom constituents of social hymenopteran species, such as hyaluronidase-like proteins and an Allergen-5 protein.</p> <p>An overall number of 29 venom proteins could be identified through the combination of ESTs sequencing and proteomic analyses. The most highly redundant set of ESTs encoded a protein that shared sequence similarity with a venom protein of unknown function potentially specific of the <it>Chelonus </it>lineage. Venom components specific to <it>C. inanitus </it>included a C-type lectin domain containing protein, a chemosensory protein-like protein, a protein related to yellow-e3 and ten new proteins which shared no significant sequence similarity with known sequences. In addition, several venom proteins potentially able to interact with chitin were also identified including a chitinase, an imaginal disc growth factor-like protein and two putative mucin-like peritrophins.</p> <p>Conclusions</p> <p>The use of the combined approaches has allowed to discriminate between cellular and truly venom proteins. The venom of <it>C. inanitus </it>appears as a mixture of conserved venom components and of potentially lineage-specific proteins. These new molecular data enrich our knowledge on parasitoid venoms and more generally, might contribute to a better understanding of the evolution and functional diversity of venom proteins within Hymenoptera.</p

    Analysis of Virion Structural Components Reveals Vestiges of the Ancestral Ichnovirus Genome

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    Many thousands of endoparasitic wasp species are known to inject polydnavirus (PDV) particles into their caterpillar host during oviposition, causing immune and developmental dysfunctions that benefit the wasp larva. PDVs associated with braconid and ichneumonid wasps, bracoviruses and ichnoviruses respectively, both deliver multiple circular dsDNA molecules to the caterpillar. These molecules contain virulence genes but lack core genes typically involved in particle production. This is not completely unexpected given that no PDV replication takes place in the caterpillar. Particle production is confined to the wasp ovary where viral DNAs are generated from proviral copies maintained within the wasp genome. We recently showed that the genes involved in bracovirus particle production reside within the wasp genome and are related to nudiviruses. In the present work we characterized genes involved in ichnovirus particle production by analyzing the components of purified Hyposoter didymator Ichnovirus particles by LC-MS/MS and studying their organization in the wasp genome. Their products are conserved among ichnovirus-associated wasps and constitute a specific set of proteins in the virosphere. Strikingly, these genes are clustered in specialized regions of the wasp genome which are amplified along with proviral DNA during virus particle replication, but are not packaged in the particles. Clearly our results show that ichnoviruses and bracoviruses particles originated from different viral entities, thus providing an example of convergent evolution where two groups of wasps have independently domesticated viruses to deliver genes into their hosts

    Deep sequencing-based transcriptome analysis of Plutella xylostella larvae parasitized by Diadegma semiclausum

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    Background: Parasitoid insects manipulate their hosts' physiology by injecting various factors into their host upon parasitization. Transcriptomic approaches provide a powerful approach to study insect host-parasitoid interactions at the molecular level. In order to investigate the effects of parasitization by an ichneumonid wasp (Diadegma semiclausum) on the host (Plutella xylostella), the larval transcriptome profile was analyzed using a short-read deep sequencing method (Illumina). Symbiotic polydnaviruses (PDVs) associated with ichneumonid parasitoids, known as ichnoviruses, play significant roles in host immune suppression and developmental regulation. In the current study, D. semiclausum ichnovirus (DsIV) genes expressed in P. xylostella were identified and their sequences compared with other reported PDVs. Five of these genes encode proteins of unknown identity, that have not previously been reported

    Efficient ASIC implementation of a real-time depth mapping stereo vision system

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    This paper presents a fast and area-efficient implementation of a real-time stereo vision algorithm for spatial depth mapping. The design combines two well-known area-based approaches to stereo thatching and includes an occlusion detection method. Hardware efficiency is achieved by storing only partial images on-chip, avoiding full-sized frame buffers. A low-latency dataflow-oriented structure makes it possible to process 256 x 192 pixel Input streams with a rate In excess of 50 frames per second, amounting to more than 54 million pixel x disparity measurements per second (PDS) (for a 25-pixel disparity range), or roughly 18 GOPS. The design has been Integrated In a 0.25 mu m standard CMOS technology and occupies an area of less than 3 mm(2)

    Clinical Outcomes of Venous Thromboembolism in Patients with and without Cancer: The SWIss Venous ThromboEmbolism Registry (SWIVTER).

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    Background The association between cancer and venous thromboembolism (VTE) in producing adverse clinical outcomes requires further investigation. Methods In the Swiss Venous ThromboEmbolism Registry (SWIVTER), we compared adverse clinical outcomes between 493 patients with cancer-associated VTE and 1,569 VTE patients without cancer, and identified independent predictors of 90-day mortality. Results Among cancer patients, 351 (71%) had active disease at the time of VTE diagnosis and 232 (47%) had metastatic disease. Cancer patients more frequently had asymptomatic VTE (13 vs. 4%; p &lt; 0.001), iliofemoral deep vein thrombosis (42 vs. 32%; p = 0.017), and upper extremity deep vein thrombosis (16 vs. 7%; p &lt; 0.001). Cancer was associated with an increased risk of cumulative 90-day mortality (13.0 vs. 2.2%; hazard ratio [HR], 6.27; 95% confidence interval [CI], 4.13-9.50; p &lt; 0.001), recurrent VTE (4.7 vs. 2.3%; HR, 2.05; 95% CI, 1.21-3.45; p = 0.007), and bleeding requiring medical attention (5.7 vs. 3.3%; HR, 1.80; 95% CI, 1.13-2.86; p = 0.013). Among cancer patients, the strongest factor associated with mortality was metastatic disease (HR, 4.86; 95% CI, 2.68-8.81; p &lt; 0.001), whereas it was pulmonary embolism among noncancer patients (HR, 4.96; 95% CI, 1.50-16.45; p = 0.009). Symptomatic as compared with asymptomatic VTE predicted neither mortality (12.6 vs. 15.9%; HR, 0.76; 95% CI, 0.39-1.49; p = 0.42) nor recurrent VTE (4.7 vs. 4.8%; HR, 0.98; 95% CI, 0.29-3.31; p = 0.98) in cancer patients. Conclusion In SWIVTER, early mortality of cancer-associated VTE was mainly driven by the extent of cancer disease and not by VTE symptoms or severity

    Venous Thromboembolism and Renal Impairment: Insights from the SWIss Venous ThromboEmbolism Registry (SWIVTER).

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    Renal impairment (RI) has increased substantially over the last decades. In the absence of data from confirmatory research, real-life data on anticoagulation treatment and clinical outcomes of venous thromboembolism (VTE) in patients with RI are needed. In the SWIss Venous ThromboEmbolism Registry (SWIVTER), 2,062 consecutive patients with objectively confirmed VTE were enrolled. In the present analysis, we compared characteristics, initial and maintenance anticoagulation, and adjusted 90-day clinical outcomes of those with (defined as estimated creatinine clearance &lt; 30 mL/min) and without severe RI. Overall, 240 (12%) patients had severe RI; they were older, and more frequently had chronic and acute comorbidities. VTE severity was similar between patients with and without severe RI. Initial anticoagulation in patients with severe RI was more often performed with unfractionated heparin (44 vs. 24%), and less often with low-molecular-weight heparin (LMWH) (52 vs. 61%) and direct oral anticoagulants (DOACs; 4 vs. 12%). Maintenance anticoagulation in patients with severe RI was more frequently managed with vitamin K antagonists (70 vs. 60%) and less frequently with DOAC (12 vs. 21%). Severe RI was associated with increased risk of 90-day mortality (9.2 vs. 4.2%, hazard ratio [HR]: 2.27, 95% confidence interval [CI]: 1.41-3.65), but with similar risk of recurrent VTE (3.3 vs. 2.8%, HR: 1.19, 95% CI: 0.57-2.52) and major bleeding (2.1 vs. 2.0%, HR: 1.05, 95% CI: 0.41-2.68). In patients with severe RI, the use of LMWH versus any other treatment was associated with reduced mortality (HR: 0.37; 95% CI: 0.14-0.94; p = 0.036) and similar rate of major bleeding (HR: 0.59, 95% CI: 0.17-2.00; p = 0.39). Acute or chronic comorbidities rather than VTE severity or recurrence may explain increased early mortality in patients with severe RI. The higher rate of VTE recurrence, specifically fatal events, than major bleeding reinforces the need for effective anticoagulation in VTE patients with severe RI

    Clinical Outcomes of Incidental Venous Thromboembolism in Cancer and Noncancer Patients: The SWIss Venous ThromboEmbolism Registry (SWIVTER).

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    In patients with cancer-associated venous thromboembolism (VTE), the risk of recurrence is similar after incidental and symptomatic events. It is unknown whether the same applies to incidental VTE not associated with cancer. We compared baseline characteristics, anticoagulation therapy, all-cause mortality, and VTE recurrence rates at 90 days between patients with incidental (n = 131; 52% without cancer) and symptomatic (n = 1,931) VTE included in the SWIss Venous ThromboEmbolism Registry (SWIVTER). After incidental VTE, 114 (87%) patients received anticoagulation therapy for at least 3 months. The mortality rate was 9.2% after incidental and 8.4% after symptomatic VTE for hazard ratio (HR) 1.10 (95% confidence interval [CI] 0.49-2.50). After adjustment for competing risk of death, recurrence rate was 3.1 versus 2.8%, respectively, for sub-HR 1.07 (95% CI 0.39-2.93). These results were consistent among cancer (mortality: 15.9% vs. 12.6%; HR 1.32, 95% CI 0.67-2.59; recurrence: 4.8% vs. 4.7%; HR 1.02, 95% CI 0.30-3.42) and noncancer patients (mortality: 2.9% vs. 2.1%; HR 1.37, 95% CI 0.33-5.73; recurrence: 1.5% vs. 2.3%; HR 0.63, 95% CI 0.09-4.58). Patients with incidental VTE who received anticoagulation therapy for at least 3 months had lower mortality (4% vs. 41%) and recurrence rate (1% vs. 18%) compared with those who did not. In SWIVTER, more than half of incidental VTE events occurred in noncancer patients who often received anticoagulation therapy. Among noncancer patients, early mortality and recurrence rates were similar after incidental versus symptomatic VTE. Our findings suggest that anticoagulation therapy for incidental VTE may be beneficial regardless of the presence of cancer
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