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Sample records for stylirostris densovirus pstdnv

  1. Structure of Penaeus stylirostris Densovirus, a Shrimp Pathogen

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    Kaufmann, Bärbel; Bowman, Valorie D.; Li, Yi; Szelei, Jozsef; Waddell, Peter J.; Tijssen, Peter; Rossmann, Michael G. (INRS); (Purdue)

    2010-11-16

    Penaeus stylirostris densovirus (PstDNV), a pathogen of penaeid shrimp, causes significant damage to farmed and wild shrimp populations. In contrast to other parvoviruses, PstDNV probably has only one type of capsid protein that lacks the phospholipase A2 activity that has been implicated as a requirement during parvoviral host cell infection. The structure of recombinant virus-like particles, composed of 60 copies of the 37.5-kDa coat protein, the smallest parvoviral capsid protein reported thus far, was determined to 2.5-{angstrom} resolution by X-ray crystallography. The structure represents the first near-atomic resolution structure within the genus Brevidensovirus. The capsid protein has a {beta}-barrel 'jelly roll' motif similar to that found in many icosahedral viruses, including other parvoviruses. The N-terminal portion of the PstDNV coat protein adopts a 'domain-swapped' conformation relative to its twofold-related neighbor similar to the insect parvovirus Galleria mellonella densovirus (GmDNV) but in stark contrast to vertebrate parvoviruses. However, most of the surface loops have little structural resemblance to any of the known parvoviral capsid proteins.

  2. Bioinformatical analysis of nuclear localisation sequences in penaeid densoviruses.

    Science.gov (United States)

    Owens, Leigh

    2013-12-01

    Nuclear location sequences (NLSs) link proteins to importation molecules for transportation into the nucleus. A bioinformatical search of the penaeid parvoviruses was undertaken to look for NLS. All three ORFs of Penaeus merguiensis densovirus (PmergDNV) have functional NLS whilst only the two non-structural proteins of Penaeus stylirostris densovirus (PstDNV) appear to. In PmergDNV, NS1 has a NLS similar to DNA helicase Q1, NS2 is similar to Dorsal and VP1 is similar to SV40 T-antigen signal. In PstDNV, NS2 has a NLS that is an unrecognised pattern unless it is a monopartite Chelsky signal whilst NS1 has both a Dorsal and minute virus of mouse signals. The capsid protein NLS of PstDNV is likely to be inefficient. Spawner isolated mortality virus has a NLS like DNA helicase Q1. These NLSs affect the nature of inclusion bodies seen with light microscopy, basophilic in PmergDNV; eosinophilic in PstDNV and the site of encapsidation, nuclear in PmergDNV; cytoplasmic in PstDNV as seen with TEM. Many possible NLSs in penaeid parvoviruses are homologues to those in eukaryotic organisms and need to be tested experimentally. © 2013.

  3. A Novel Ambisense Densovirus, Acheta domesticus Mini Ambidensovirus, from Crickets

    OpenAIRE

    Pham, Hanh T.; Yu, Qian; Bergoin, Max; Tijssen, Peter

    2013-01-01

    International audience; The genome structure of Acheta domesticus mini ambidensovirus, isolated from crickets, resembled that of ambisense densoviruses from Lepidoptera but was 20% smaller. It had the highest (

  4. A Novel Ambisense Densovirus, Acheta domesticus Mini Ambidensovirus, from Crickets.

    Science.gov (United States)

    Pham, Hanh T; Yu, Qian; Bergoin, Max; Tijssen, Peter

    2013-11-07

    The genome structure of Acheta domesticus mini ambidensovirus, isolated from crickets, resembled that of ambisense densoviruses from Lepidoptera but was 20% smaller. It had the highest (<25%) protein sequence identity with the nonstructural protein 1 (NS1) of Iteravirus and VP of Densovirus members (both with 25% coverage) and smaller (0.2- versus 0.55-kb) Y-shaped inverted terminal repeats.

  5. Pseudoplusia includens densovirus genome organization and expression strategy.

    OpenAIRE

    Huynh, Oanh T H; Pham, Hanh T.; Yu, Qian; Tijssen, Peter

    2012-01-01

    International audience; The genome of a densovirus of a major phytophagous pest, Pseudoplusia includens, was analyzed. It contained 5,990 nucleotides (nt) and included inverted terminal repeats of 540 nt with terminal Y-shaped hairpins of 120 nt. Its DNA sequence and ambisense organization with 4 typical open reading frames demonstrated that it belonged to the genus Densovirus in the subfamily Densovirinae of the family Parvoviridae.

  6. Pseudoplusia includens densovirus genome organization and expression strategy.

    Science.gov (United States)

    Huynh, Oanh T H; Pham, Hanh T; Yu, Qian; Tijssen, Peter

    2012-12-01

    The genome of a densovirus of a major phytophagous pest, Pseudoplusia includens, was analyzed. It contained 5,990 nucleotides (nt) and included inverted terminal repeats of 540 nt with terminal Y-shaped hairpins of 120 nt. Its DNA sequence and ambisense organization with 4 typical open reading frames demonstrated that it belonged to the genus Densovirus in the subfamily Densovirinae of the family Parvoviridae.

  7. Transcription of densovirus endogenous sequences in the Myzus persicae genome.

    Science.gov (United States)

    Clavijo, Gabriel; van Munster, Manuella; Monsion, Baptiste; Bochet, Nicole; Brault, Véronique

    2016-04-01

    Integration of non-retroviral sequences in the genome of different organisms has been observed and, in some cases, a relationship of these integrations with immunity has been established. The genome of the green peach aphid, Myzus persicae (clone G006), was screened for densovirus-like sequence (DLS) integrations. A total of 21 DLSs localized on 10 scaffolds were retrieved that mostly shared sequence identity with two aphid-infecting viruses, Myzus persicae densovirus (MpDNV) and Dysaphis plantaginea densovirus (DplDNV). In some cases, uninterrupted potential ORFs corresponding to non-structural viral proteins or capsid proteins were found within DLSs identified in the aphid genome. In particular, one scaffold harboured a complete virus-like genome, while another scaffold contained two virus-like genomes in reverse orientation. Remarkably, transcription of some of these ORFs was observed in M. persicae, suggesting a biological effect of these viral integrations. In contrast to most of the other densoviruses identified so far that induce acute host infection, it has been reported previously that MpDNV has only a minor effect on M. persicae fitness, while DplDNV can even have a beneficial effect on its aphid host. This suggests that DLS integration in the M. persicae genome may be responsible for the latency of MpDNV infection in the aphid host.

  8. A new densovirus isolated from the mosquito Toxorhynchites splendens (Wiedemann) (Diptera: Culicidae).

    Science.gov (United States)

    Pattanakitsakul, Sa-Nga; Boonnak, Kobporn; Auethavornanan, Kusuma; Jairungsri, Aroonroong; Duangjinda, Thaneeya; Puttatesk, Punjaporn; Thongrungkiat, Supatra; Malasit, Prida

    2007-03-01

    A new densovirus was isolated and characterized in laboratory strains of Toxorhynchites splendens. The virus was detected by polymerase chain reaction (PCR) from mosquitoes reared in our laboratory. PCR fragments from each mosquito were compared by single strand conformation polymorphism (SSCP) assay and found to be indistinguishable. Thus, it is likely the densoviruses from these mosquitoes contain homologous nucleotide sequences. The PCR fragment corresponding to a 451 bp densovirus structural gene segment from each of 5 mosquitoes had 100% identical nucleotide sequences. Phylogenetic analysis of the structural gene sequence suggests the newly isolated densovirus is more closely related to Aedes aegypti densovirus (AaeDNV) than to Aedes albopictus densovirus (AalDNV). Analysis of offspring and predated larvae suggests that vertical and horizontal transmission are responsible for chronic infections in this laboratory strain of Toxorhynchites splendens. The virion DNA is 4.2 kb in size, is closely related to, but distinct from, known densoviruses in the genera Brevidensovirus and Contravirus. Thevirus is tentatively named Toxorhynchites splendens densovirus (TsDNV).

  9. Comparative bioaccumulation of trace metals in Penaeus stylirostris in estuarine and coastal environments

    Science.gov (United States)

    Páez-Osuna, F.; Ruiz-Fernández, C.

    1995-01-01

    Trace metal concentrations (Fe, Mn, Ni, Cu, Co, Cd, Cr and Zn) have been measured in estuarine and marine shrimp P. stylirostris collected in the Pacific coast of México. Estuarine individuals (juveniles) had higher concentrations of Fe and Mn than marine individuals (adults). Size-dependent relationships were observed and differed among the elements examined. A negative slope was found for Co, Fe, Mn and Ni in estuarine juvenile shrimps, while for Cu the opposite tendency occurred. In marine adults a positive slope was observed for Cd, Co, Cr and Cu. These findings may be due to two factors: (1) that P. stylirostris spends part of its life-cycle in estuarine/lagoon environments where it is more likely to be exposed to higher levels of bioavailable trace metals (natural and anthropogenic contributions) and/or (2) different metabolic requirements of young and older specimens, which is especially applicable to copper.

  10. Comparative Genomic Analysis of Acheta domesticus Densovirus Isolates from Different Outbreaks in Europe, North America, and Japan

    OpenAIRE

    Pham, Hanh T.; Iwao, Hajime; Szelei, Jozsef; Li, Yi; Liu, Kaiyu; Bergoin, Max; Tijssen, Peter

    2013-01-01

    The first densovirus from a cricket, Acheta domesticus densovirus (AdDNV) (Parvoviridae), was isolated in Europe in 1977 and has been studied previously. We compared seven additional AdDNV genomes isolated from 4 other European outbreaks, 2 major North American outbreaks, and a Japanese outbreak. Phylogenetic analysis suggested that the 2009 Japanese and North American outbreaks were not related.

  11. Comparative Genomic Analysis of Acheta domesticus Densovirus Isolates from Different Outbreaks in Europe, North America, and Japan.

    Science.gov (United States)

    Pham, Hanh T; Iwao, Hajime; Szelei, Jozsef; Li, Yi; Liu, Kaiyu; Bergoin, Max; Tijssen, Peter

    2013-08-15

    The first densovirus from a cricket, Acheta domesticus densovirus (AdDNV) (Parvoviridae), was isolated in Europe in 1977 and has been studied previously. We compared seven additional AdDNV genomes isolated from 4 other European outbreaks, 2 major North American outbreaks, and a Japanese outbreak. Phylogenetic analysis suggested that the 2009 Japanese and North American outbreaks were not related.

  12. First complete genome of an Ambidensovirus; Cherax quadricarinatus densovirus, from freshwater crayfish Cherax quadricarinatus.

    Science.gov (United States)

    Bochow, Shaun; Condon, Kelly; Elliman, Jennifer; Owens, Leigh

    2015-12-01

    In 1999, the causative agent of an epizootic in Cherax quadricarinatus was described, and given the provisional name Cherax quadricarinatus parvovirus-like. Sequencing of the 6334 nt genome identified three open-reading frames on the top strand coding NS3 (35.55 kDa), NS1 (67.36 kDa) and NS2 (35.18 kDa) and on the bottom strand a single open reading frame which most likely encodes 4 structural proteins. Motifs characteristic of the Densovirinae were found in the ORFs. Phylogenetic analysis of the amino acids in NS1 places the genome in the genus Ambidensovirus, most closely related to the marine sea star densovirus (75%, E=0.0) and distantly related to Acheta domestica densovirus (44.1%). The virus name is proposed as species Decapod ambidensovirus, variant Cherax quadricarinatus densovirus. This is the first Ambidensovirus to be found in decapod crustaceans and the first of the subfamily Densovirinae to be sequenced from a freshwater crayfish. Cherax quadricarinatus densovirus and sea star densovirus are the first highly related Densovirinae to infect phylogenetically disparate hosts and are thus far, unique among the Densovirinae. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Experimental evaluation of co-culture of juvenile sea cucumbers, Holothuria scabra (Jaeger), with juvenile blue shrimp, Litopenaeus stylirostris (Stimpson)

    OpenAIRE

    Purcell, S; Patrois, Jacques; Fraisse, N.

    2006-01-01

    The co-culture of juvenile sea cucumber Holothuria scabra (Jaeger), or 'sandfish', with juvenile blue shrimp Litopenaeus stylirostris (Stimpson) was tested by growing groups in co-culture and monoculture for 3 weeks in tanks with enriched sand substratum. Feed was supplied on trays, accessible only to shrimp. Survival of shrimp and sandfish was high in all treatments (73-100%). Growth of shrimp did not differ between monoculture and co-culture, but sandfish grew significantly slower in co-cul...

  14. Bacterial community characterization of water and intestine of the shrimp Litopenaeus stylirostris in a biofloc system.

    Science.gov (United States)

    Cardona, Emilie; Gueguen, Yannick; Magré, Kevin; Lorgeoux, Bénédicte; Piquemal, David; Pierrat, Fabien; Noguier, Florian; Saulnier, Denis

    2016-07-19

    Biofloc technology (BFT), a rearing method with little or no water exchange, is gaining popularity in aquaculture. In the water column, such systems develop conglomerates of microbes, algae and protozoa, together with detritus and dead organic particles. The intensive microbial community presents in these systems can be used as a pond water quality treatment system, and the microbial protein can serve as a feed additive. The current problem with BFT is the difficulty of controlling its bacterial community composition for both optimal water quality and optimal shrimp health. The main objective of the present study was to investigate microbial diversity of samples obtained from different culture environments (Biofloc technology and clear seawater) as well as from the intestines of shrimp reared in both environments through high-throughput sequencing technology. Analyses of the bacterial community identified in water from BFT and "clear seawater" (CW) systems (control) containing the shrimp Litopenaeus stylirostris revealed large differences in the frequency distribution of operational taxonomic units (OTUs). Four out of the five most dominant bacterial communities were different in both culture methods. Bacteria found in great abundance in BFT have two principal characteristics: the need for an organic substrate or nitrogen sources to grow and the capacity to attach to surfaces and co-aggregate. A correlation was found between bacteria groups and physicochemical and biological parameters measured in rearing tanks. Moreover, rearing-water bacterial communities influenced the microbiota of shrimp. Indeed, the biofloc environment modified the shrimp intestine microbiota, as the low level (27 %) of similarity between intestinal bacterial communities from the two treatments. This study provides the first information describing the complex biofloc microbial community, which can help to understand the environment-microbiota-host relationship in this rearing system.

  15. Induction of ovarian maturation and spawning by combined treatment of serotonin and a dopamine antagonist, spiperone in Litopenaeus stylirostris and Litopenaeus vannamei

    NARCIS (Netherlands)

    Alfaro Montoya, J.; Zuniga, G.; Komen, J.

    2004-01-01

    The study was designed to develop a reliable technique for inducing ovarian maturation and spawning in Litopenaeus stylirostris and Litopenaeus vannamei, as an alternative to the traditional and destructive eyestalk ablation. Two combinations of molecules were evaluated: (a) serotonin (5-HT) at 50

  16. PHYLOGENETIC ANALYSIS REVEALS GENETIC VARIATIONS OF DENSOVIRUS ISOLATED FROM FIELD MOSQUITOES IN BANGKOK AND SURROUNDING REGIONS.

    Science.gov (United States)

    Boonnak, Kobporn; Suttitheptumrong, Aroonroong; Jotekratok, Ubonwan; Pattanakitsakul, Sa-Nga

    2015-03-01

    Screening for densoviruses (DNVs) from Aedes, Culex and Toxorhynchites mosquitoes collected in Bangkok and surrounding regions identified two clades of Aedes DNV; Ae. aegypti DNV (AaeDNV) and Ae. albopictus DNV (AalDNV) by PCR-restriction fragment length polymorphism (PCR-RFLP). From nucleotide sequencing and phylogenetic analysis of PCR amplicons of a fragment of DNV capsid gene, these DNVs were shown to be new DNV genetic variations similar to AaeDNV. Isolation and identification of densoviruses from indigenous field mosquitoes reside in natural habitat should be helpful in monitoring the distribution of DNVs in important mosquitoes, especially Ae. aegypti and Ae. albopictus, vector for dengue and yellow fever viruses.

  17. Does damming of the Colorado River affect the nursery area of blue shrimp Litopenaeus stylirostris (Decapoda: Penaeidae in the Upper Gulf of California?

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    Eugenio Alberto Aragón-Noriega

    2000-12-01

    Full Text Available After damming the Colorado River the freshwater flow was reduced to 1 % of its virgin flow to the Upper Gulf of California (UGC. The ecological effects need to be properly documented. The UGC is the nursery area for Litopenaeus stylirostris, the most profitable fishery in the zone. In order to know the relative abundance of L. stylirostris postlarval stage we conducted a sampled survey every 14 days in 1993, 1994 and 1997, plus an intensive sampling during a complete tide cycle in July 1995 and 1996. We did 10 min trawls each hour during the flood tide. Relative abundance of postlarvae was higher (pEl represamiento del Río Colorado ha ocasionado que el flujo de agua dulce sobre el Alto Golfo de California (AGC se haya reducido hasta el 1 % del flujo original. Se ha documentado el efecto de la reducción de agua dulce sobre las condiciones hidrográficas del AGC, pero las repercusiones ecológicas no se han descrito apropiadamente. El AGC ha sido área de crianza para especies comerciales como el camarón Litopenaeus stylirostris. Se hicieron recolectas de postlarvas de L. stylirostris en el AGC durante cinco años consecutivos. Los muestreos fueron catorcenalmente en los años de 1993, 1994 y 1997 y se realizó una recolecta diaria durante 15 días consecutivos en los años 1995 y 1996. Para ello se arrastró una red de plancton de 505 µ durante 10 min cada hora durante el flujo de marea. La abundancia relativa de las postlarvas de camarón en esta zona viaria considerablemente en años cuando el flujo de agua dulce incrementa. La abundancia es mayor hasta en un 200 % (p < 0.05 cuando existe descarga de agua dulce al AGC.

  18. The use of insects as a bioassay for Penaeus merguiensis densovirus (PmergDNV).

    Science.gov (United States)

    La Fauce, Kathy A; Owens, Leigh

    2008-05-01

    The lack of available cell lines has hampered the study of viral diseases in crustaceans. This is particularly important for aquaculture which has been plagued by viral diseases since its rapid expansion to meet with the growing demand for seafood products. This study was designed to find an alternative bioassay to cell lines by investigating the use of insects as potential animal models for Penaeus merguiensis densovirus (PmergDNV). Acheta domesticus (house cricket) and Tenebrio molitor (mealworms) were challenged with approximately 1x10(6) virions of PmergDNV by inoculation. PmergDNV was detected in 20% of Tenebrio molitor and 86.6% of Acheta domesticus challenged with PmergDNV. During a subsequent time course experiment, there was a non significant increase in PmergDNV titres (10(4-5) virions), reaching a maximum peak at day 5 (10(6) copies). A threshold of PmergDNV DNA level equal to or greater than 10(3) virions was necessary for mortality in Acheta domesticus. As the inoculum increased from 10(3) DNA copies to 10(4), 10(5), 10(6), mortality increased from 20% to 60%, 80% and 100%, respectively. This is the first evidence that insects may be directly used to study viruses from crustaceans and concludes Acheta domesticus may be used as a potential model to study Penaeus merguiensis densovirus.

  19. Densovirus associated with sea-star wasting disease and mass mortality

    Science.gov (United States)

    Hewson, Ian; Button, Jason B.; Gudenkauf, Brent M.; Miner, Benjamin; Newton, Alisa L.; Gaydos, Joseph K.; Wynne, Janna; Groves, Cathy L.; Hendler, Gordon; Murray, Michael; Fradkin, Steven; Breitbart, Mya; Fahsbender, Elizabeth; Lafferty, Kevin D.; Kilpatrick, A. Marm; Miner, C. Melissa; Raimondi, Peter T.; Lahner, Lesanna L.; Friedman, Carolyn S.; Danielson, Stephen D.; Haulena, Martin; Marliave, Jeffrey; Burge, Colleen A.; Eisenlord, Morgan E.; Harvell, C. Drew

    2015-01-01

    Populations of at least 20 asteroid species on the Northeast Pacific Coast have recently experienced an extensive outbreak of sea-star (asteroid) wasting disease (SSWD). The disease leads to behavioral changes, lesions, loss of turgor, limb autotomy, and death characterized by rapid degradation (“melting”). Here, we present evidence from experimental challenge studies and field observations that link the mass mortalities to a densovirus (Parvoviridae). Virus-sized material (i.e., killed (i.e., control) virus-sized inoculum remained asymptomatic. Viral metagenomic investigations revealed the sea star-associated densovirus (SSaDV) as the most likely candidate virus associated with tissues from symptomatic asteroids. Quantification of SSaDV during transmission trials indicated that progression of SSWD paralleled increased SSaDV load. In field surveys, SSaDV loads were more abundant in symptomatic than in asymptomatic asteroids. SSaDV could be detected in plankton, sediments and in nonasteroid echinoderms, providing a possible mechanism for viral spread. SSaDV was detected in museum specimens of asteroids from 1942, suggesting that it has been present on the North American Pacific Coast for at least 72 y. SSaDV is therefore the most promising candidate disease agent responsible for asteroid mass mortality.

  20. Genetic variability of Myzus persicae nicotianae densovirus based on partial NS and VP gene sequences.

    Science.gov (United States)

    Song, X R; Tang, S H; Tang, Z Q; Yang, X M; Wang, X W; Wang, X F; Xu, P J; Ren, G W

    2016-11-21

    We previously described a novel densovirus [Myzus persicae nicotianae densovirus (MpnDV)] infecting M. persicae nicotianae (Hemiptera: Aphididae) with 34% prevalence. This single-stranded DNA virus has a 5480-nucleotide ambisense genome and belongs to the Densovirinae subfamily within the family Parvoviridae. In the present study, we estimated the genetic diversity of MpnDV using partial nonstructural protein (NS) and capsid protein (VP) gene sequences from 10 locations in China. First, we identified MpnDV-positive samples by amplifying a 445-bp fragment with primers MpDVF/MpDVR. Subsequently, we amplified and sequenced COI genes with primers MpCOIF/ MpCOIR, and partial NS and VP sequences with primers MpnDVF1/MpnDVR1. The respective 655-, 1461-, and 423-bp COI, NS, and VP fragments were used to analyze the genetic diversity of MpnDV using MEGA 6.0 and DnaSP 5.0. The high level of identity shared by all COI sequences (>99%) suggested that the aphids sampled were of the same species, and indicated population homogeneity across the 10 locations investigated. The nucleotide diversity of MpnDV sequences (0.0020 ± 0.0025) was significantly higher than that of the COI genes (0.0002 ± 0.0005). The pairwise fixation index for MpnDV was 0.832, and the total gene flow was 0.05. Phylogenetic analysis revealed that the MpnDV haplotypes clustered according to geographical location, except for those from the Liaoning and Shanxi provinces. In conclusion, MpnDV demonstrated a low level of gene flow and high genetic diversity, suggesting that it is vertically transmitted, and implying that endosymbiotic viruses could be used as markers in studies of insect population genetics.

  1. Characterization and Distribution Analysis of a Densovirus Infecting Myzus persicae nicotianae (Hemiptera: Aphididae).

    Science.gov (United States)

    Tang, Shihao; Song, Xueru; Xue, Lin; Wang, Xinwei; Wang, Xiufang; Xu, Pengjun; Ren, Guangwei

    2016-04-01

    Densoviruses (DVs) are a group of viruses that contain a linear single-stranded DNA genome between 4–6 kb in length. Herein, we report a DV with a 5,480-nt genome, isolated from tobacco aphid (Myzus persicae nicotianae Blackman), named MpnDV. Unlike the genome of M. persicae densovirus (MpDV), which possesses five open reading frames (ORFs), the genome of MpnDV contains four putative ORFs—the nonstructural protein 1 (NS1) and NS2 from MpnDV are 98- and 52-amino acids longer than those of MpDV, respectively, at the N-terminus, and the capsid proteins (VP) are 102 amino acids longer at the C-terminus than those of MpDV. Mapping of the MpnDV transcripts by RACE method indicated that the ORF of NS2 started at nt 340 and the right two putative ORFs were combined together by deleting two introns, one of 95 bp located at nt 2,932–3,026 and the other of 145 bp located at nt 4,715–4,859, suggesting transcript mapping was necessary for analyzing of genome organization. Alignment analysis indicated that MpnDV shows 97% sequence identity with MpDV, and that the shortened ORFs resulted from nucleotide indels, suggesting MpnDV and MpDV were two isolates of the same virus. Thus, MpnDV and MpDV clustered together in a tree-based analysis. The prevalence of MpnDV infection in wild populations of tobacco aphids differed among 29 locations; 34% of the 622 individuals sampled were positive. The genome organization, transcript strategy, and widespread distribution in wild populations suggest that MpnDV might possess a biological function different from that of MpDV.

  2. The Acheta domesticus Densovirus, Isolated from the European House Cricket, Has Evolved an Expression Strategy Unique among Parvoviruses▿†

    Science.gov (United States)

    Liu, Kaiyu; Li, Yi; Jousset, Françoise-Xavière; Zadori, Zoltan; Szelei, Jozsef; Yu, Qian; Pham, Hanh Thi; Lépine, François; Bergoin, Max; Tijssen, Peter

    2011-01-01

    The Acheta domesticus densovirus (AdDNV), isolated from crickets, has been endemic in Europe for at least 35 years. Severe epizootics have also been observed in American commercial rearings since 2009 and 2010. The AdDNV genome was cloned and sequenced for this study. The transcription map showed that splicing occurred in both the nonstructural (NS) and capsid protein (VP) multicistronic RNAs. The splicing pattern of NS mRNA predicted 3 nonstructural proteins (NS1 [576 codons], NS2 [286 codons], and NS3 [213 codons]). The VP gene cassette contained two VP open reading frames (ORFs), of 597 (ORF-A) and 268 (ORF-B) codons. The VP2 sequence was shown by N-terminal Edman degradation and mass spectrometry to correspond with ORF-A. Mass spectrometry, sequencing, and Western blotting of baculovirus-expressed VPs versus native structural proteins demonstrated that the VP1 structural protein was generated by joining ORF-A and -B via splicing (splice II), eliminating the N terminus of VP2. This splice resulted in a nested set of VP1 (816 codons), VP3 (467 codons), and VP4 (429 codons) structural proteins. In contrast, the two splices within ORF-B (Ia and Ib) removed the donor site of intron II and resulted in VP2, VP3, and VP4 expression. ORF-B may also code for several nonstructural proteins, of 268, 233, and 158 codons. The small ORF-B contains the coding sequence for a phospholipase A2 motif found in VP1, which was shown previously to be critical for cellular uptake of the virus. These splicing features are unique among parvoviruses and define a new genus of ambisense densoviruses. PMID:21775445

  3. The Acheta domesticus densovirus, isolated from the European house cricket, has evolved an expression strategy unique among parvoviruses.

    Science.gov (United States)

    Liu, Kaiyu; Li, Yi; Jousset, Françoise-Xavière; Zadori, Zoltan; Szelei, Jozsef; Yu, Qian; Pham, Hanh Thi; Lépine, François; Bergoin, Max; Tijssen, Peter

    2011-10-01

    The Acheta domesticus densovirus (AdDNV), isolated from crickets, has been endemic in Europe for at least 35 years. Severe epizootics have also been observed in American commercial rearings since 2009 and 2010. The AdDNV genome was cloned and sequenced for this study. The transcription map showed that splicing occurred in both the nonstructural (NS) and capsid protein (VP) multicistronic RNAs. The splicing pattern of NS mRNA predicted 3 nonstructural proteins (NS1 [576 codons], NS2 [286 codons], and NS3 [213 codons]). The VP gene cassette contained two VP open reading frames (ORFs), of 597 (ORF-A) and 268 (ORF-B) codons. The VP2 sequence was shown by N-terminal Edman degradation and mass spectrometry to correspond with ORF-A. Mass spectrometry, sequencing, and Western blotting of baculovirus-expressed VPs versus native structural proteins demonstrated that the VP1 structural protein was generated by joining ORF-A and -B via splicing (splice II), eliminating the N terminus of VP2. This splice resulted in a nested set of VP1 (816 codons), VP3 (467 codons), and VP4 (429 codons) structural proteins. In contrast, the two splices within ORF-B (Ia and Ib) removed the donor site of intron II and resulted in VP2, VP3, and VP4 expression. ORF-B may also code for several nonstructural proteins, of 268, 233, and 158 codons. The small ORF-B contains the coding sequence for a phospholipase A2 motif found in VP1, which was shown previously to be critical for cellular uptake of the virus. These splicing features are unique among parvoviruses and define a new genus of ambisense densoviruses.

  4. Primer registro de la utilización de harinas de Salicornia bigelovii y Scomber japonicus en dietas prácticas para el cultivo súper-intensivo de camarón Litopenaeus stylirostris First record on the use of Salicornia bigelovii and Scomber japonicus fishmeals as feed for Litopenaeus stylirostris under super-intensive farming

    Directory of Open Access Journals (Sweden)

    Manuel de J . Acosta-Ruiz

    2011-11-01

    Full Text Available Se evaluó el efecto de las harinas de Salicornia bigelovii (SA y Scomber japonicus, semiprocesada (HPS como ingredientes en la formulación de dietas para camarón azul Litopenaeus stylirostris, en cultivo súper-intensivo. Se formularon tres diferentes dietas isoproteicas (40% e isocalóricas (6 kcal g-1: (DSA, (DHPS, basal (DBA y una dieta control (DCO. El peso obtenido con DSA y DHPS (0,9 ± 0,014 y 0,8 ± 0,015 g fue similar a la dieta comercial DCO (0,9 ± 0,07 g, no existieron diferencias significativas (P > 0,05 en talla (cm, peso (g y factor de conversión alimenticio (FCA. Los resultados obtenidos sugieren que DSA y DHPS son factibles de utilizar en la formulación de dietas para camarón por ser ingredientes de bajo costo que pueden sustituir a la harina de maíz y pescado tradicional, respectivamente sin efectos detrimentales en el crecimiento y supervivencia.The effect of semi-processed fishmeals (HPS made using Salicornia bigelovii (SA and Scomber japonicusas ingredients in the formulation of diets for blue shrimp Litopenaeus stylirostris undersuper-intensive farming was evaluated. Three different isoproteinic (40% and isocaloric (6 kcal g-1 diets were formulated: DSA, DHPS, basal (DBA; a fourth control diet (DCO was also used. The weights obtained with DSA and DHPS (0.9 ± 0.014 and 0.8 ± 0.015 g were similar to those obtained with the commercial diet (DCO; 0.9 ± 0.07 g, and no significant differences (P > 0.05 were found for size (cm, weight (g, and the feed conversion ratio (FCR. The results suggest that the use of DSA and DHPS in the formulation of diets for shrimp is feasibleas these are low-cost ingredients that can be used as substitutes for cornstarch and traditional fishmeal, respectively, without detrimental effects for shrimp growth and survival.

  5. Susceptibility of North-American and European crickets to Acheta domesticus densovirus (AdDNV) and associated epizootics.

    Science.gov (United States)

    Szelei, J; Woodring, J; Goettel, M S; Duke, G; Jousset, F-X; Liu, K Y; Zadori, Z; Li, Y; Styer, E; Boucias, D G; Kleespies, R G; Bergoin, M; Tijssen, P

    2011-03-01

    The European house cricket, Acheta domesticus L., is highly susceptible to A. domesticus densovirus (AdDNV). Commercial rearings of crickets in Europe are frequently decimated by this pathogen. Mortality was predominant in the last larval stage and young adults. Infected A. domesticus were smaller, less active, did not jump as high, and the adult females seldom lived more than 10-14 days. The most obvious pathological change was the completely empty digestive caecae. Infected tissues included adipose tissue, midgut, epidermis, and Malpighian tubules. Sudden AdDNV epizootics have decimated commercial mass rearings in widely separated parts of North America since the autumn of 2009. Facilities that are producing disease-free crickets have avoided the importation of crickets and other non-cricket species (or nonliving material). Five isolates from different areas in North America contained identical sequences as did AdDNV present in non-cricket species collected from these facilities. The North American AdDNVs differed slightly from sequences of European AdDNV isolates obtained in 1977, 2004, 2006, 2007 and 2009 and an American isolate from 1988. The substitution rate of the 1977 AdDNV 5kb genome was about two nucleotides per year, about half of the substitutions being synonymous. The American and European AdDNV strains are estimated to have diverged in 2006. The lepidopterans Spodoptera littoralis and Galleria mellonella could not be infected with AdDNV. The Jamaican cricket, Gryllus assimilis, and the European field cricket, Gryllus bimaculatus, were also found to be resistant to AdDNV. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Suppression of Penaeus merguiensis densovirus following oral delivery of live bacteria expressing dsRNA in the house cricket (Acheta domesticus) model.

    Science.gov (United States)

    La Fauce, Kathy; Owens, Leigh

    2013-02-01

    Penaeus merguiensis densovirus (PmergDNV) is a serious pathogen of the banana prawn, Penaeus merguiensis leading to at least 28% production loss due to reduced growth rates and mortality of juveniles. In the present study, we reduced PmergDNV titres and subsequent mortality by feeding Acheta domesticus (previously determined as an appropriate animal model for P. merguiensis) with dsRNA specific to the capsid protein by mixing it into their food. Feeding A. domesticus with PmergDNV-specific dsRNA in advance of viral challenge increased their longevity, decreased mortality by 84.4% and reduced viral loads 24-fold below the threshold level required for mortality. Mortalities and viral loads were significantly (both P < 0.001) lower in treatments challenged with PmergDNV following exposure to bacterially expressed PmergDNV-dsRNA. This is the first study to demonstrate gene silencing via RNAi against PmergDNV in vivo through oral administration of live bacteria expressing dsRNA in a model system. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Cloning and characterization of the densoviruses susceptible gene ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Lane M, DNA maker; Lane 1: pMD19-T/+nsd-2 digested with BamHI and XhoI generated two fragments: pMD19-T (2.7 Kbp) and +nsd-2 (1900 bp). Figure 2. Expression profile of +nsd-2 of by RT-PCR. (A). cDNAs isolated from different larval tissues of silkworm. Lane. 1: Malpighian tube, Lane 2: midgut, ...

  8. Cloning and characterization of the densoviruses susceptible gene ...

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... ligase and Escherichia coli (DH5α strain) was used for plasmid amplification, and MiniBEST Plasmid Purification Kit (Takara) was used for purification. The DNA sequencing was performed by. Shanghai Sangon Biological Engineering Technology and Services. Co., Ltd. For the +nsd-2 gene expression, the ...

  9. Trophic status of earthen ponds used for semi-intensive shrimp (Litopenaeus stylirostris, Stimpson, 1874) farming in New Caledonia (Pacific Ocean).

    Science.gov (United States)

    Pusceddu, Antonio; Della Patrona, Luc; Beliaeff, Benoit

    2011-10-01

    We have investigated temporal variability in the quantity and biochemical composition of sediment organic matter along with variables proxies of water eutrophication (e.g., inorganic nutrient and chlorophyll-a) at two shrimp farms located in the Southern coast of New Caledonia and characterised by clear differences in shrimp feeding practices and levels of initial trophic conditions. The results of our study reveal that the trophic status of the water column increased during the rearing cycle at both sites, determining a general, though moderated, eutrophication. However, the water column trophic descriptors did not allow to discriminate differences in the trophic status among the investigated sites or between sites in the same farming plant, even if they were subjected to different feeding practices and largely different initial characteristics of the sediment. Temporal variations in biopolymeric C and phytopigment sedimentary contents (used as proxies of benthic eutrophication) varied inconsistently among sites. The multivariate analyses did not identify significant temporal patterns in the benthic trophic status, but allowed discriminating the four investigated sites. The semi-intensive shrimp farming significantly contributed to changing the water column and sediments trophic status of the earthen ponds, but the extent of those changes was not consistently observed in all ponds. In any of the investigated ponds the trophic status exceeded concerning thresholds over which hypoxia or anoxia could occur. We conclude that the established semi-intensive practices adopted so far for shrimp farming activities in the earthen ponds of New Caledonia are able to maintain the status of the ponds below the eutrophication levels over which dystrophic crises could sharply abate most of the reared biomass. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Influence of oceanographic processes on the early life stages of the blue shrimp ( Litopenaeus stylirostris) in the Upper Gulf of California

    Science.gov (United States)

    Calderon-Aguilera, L. E.; Marinone, S. G.; Aragón-Noriega, E. A.

    2003-02-01

    The possible relationship between circulation patterns and the recruitment of early stages of penaeid shrimp in the Upper Gulf of California was explored by collecting postlarvae (mesh size 0.505 mm) simultaneously in two locations, one off the coast of Sonora (Golfo de Santa Clara: 31°44'49ʺN-114°33'12ʺW) and the other off the Baja California peninsula (San Felipe: 31°11'8.3ʺ N-114°53'13.9ʺW) during two complete fortnightly cycles (July 12-27, 1995 and June 30-July 16, 1996). Individuals with cephalothoracic length from 0.8 to 3.91 mm without a clear size-increasing pattern were found throughout the sampling period, suggesting continuous recruitment to the area. The circulation in the study area was simulated with a three-dimensional baroclinic model forced with tides and climatological hydrography at the mouth of the Gulf of California, and winds and heat and freshwater fluxes at the sea-air interface. Spawning stock surveys have shown that maximum concentration of mature females is near the coast of Sonora (mainland Mexico). The model predicts surface currents of about 8 cm s -1 and suggests that postlarvae found off the coast of the peninsula may come from a different reproductive unit than those found off the mainland coast. This may explain why postlarvae found in Golfo de Santa Clara (mainland) are larger (and, presumably, older) than those found in San Felipe (Baja California). Possible relationships among circulation patterns, lunar cycle, former Colorado River runoffs and time of spawning are discussed.

  11. Rearing effect of biofloc on antioxidant and antimicrobial transcriptional response in Litopenaeus stylirostris shrimp facing an experimental sub-lethal hydrogen peroxide stress.

    Science.gov (United States)

    Cardona, Emilie; Saulnier, Denis; Lorgeoux, Bénédicte; Chim, Liet; Gueguen, Yannick

    2015-08-01

    This study compares the antioxidant and antimicrobial transcriptional expression of blue shrimps reared according to two different systems, BioFloc Technology (BFT) and Clear sea Water (CW) and their differential responses when facing an experimental sublethal hydrogen peroxide stress. After 30 days of rearing, juvenile shrimps were exposed to H2O2 stress at a concentration of 30 ppm during 6 h. The oxidative stress caused by H2O2 was examined in the digestive glands of the shrimp, in which antioxidant enzyme (AOE) and antimicrobial peptide (AMP) gene expression were analysed by quantitative real-time PCR. Results showed that rearing conditions did not affect the expression of genes encoding AOEs or AMPs. However, H2O2 stress induced a differential response in expression between shrimps from the two rearing treatments (BFT and CW). Comparative analysis of the expression profiles indicates that catalase transcripts were significantly upregulated by H2O2 stress for BFT shrimps while no change was observed for CW shrimps. In contrast, H2O2 caused down-regulation of superoxide dismutase and glutathione transferase transcripts and of the three AMP transcripts studied (penaeidin 2 and 3, and crustin) for CW shrimps, while no effect was observed on BFT shrimp transcript levels. These results suggested that BFT shrimps maintained antioxidant and AMP responses after stress and therefore can effectively protect their cells against oxidative stress, while CW shrimp immune competence seems to decrease after stress. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Dicty_cDB: Contig-U10817-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available mes corniger microsatellite Ncor1 sequence. 42 3e-04 2 ( AF192260 ) Periplaneta fuliginosa denso...virus, complete genome. 44 3e-04 2 ( AB028936 ) Periplaneta fuliginosa densovirus ORF-beta, O

  13. Dicty_cDB: AHA838 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available sequence. 452 0.0 13 AF192260 |AF192260.1 Periplaneta fuliginosa densovirus, complete genome. 44 7e-06 3 AB...028936 |AB028936.1 Periplaneta fuliginosa densovirus ORF-beta, ORF-alpha, ORF-gamma, ORF-1, ORF-3, ORF-2 gen

  14. Dicty_cDB: Contig-U14991-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available one mth2-77l23, complete se... 44 6.0 1 ( DJ084883 ) Bombyx densovirus type-2 sus...ceptibility gene and ... 44 6.0 1 ( DJ084878 ) Bombyx densovirus type-2 susceptibility gene and ... 44 6.0 1

  15. Toxicity of the organophosphorous insecticide metamidophos (o,s-dimethyl phosphoramidothioate) to larvae of the freshwater prawn and the blue shrimp

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, L.M.; Sanchez, J. (Monterrey Institute of Technology, Sonora (Mexico))

    1989-08-01

    The organophosphorous insecticide O,S-dimethyl phosphoramidothioate (Metamidophos, Tamaron, Monitor, Hamidop) is widely used for pest control in tropical crops. If washed down to streams and estuaries its residues could adversely affect populations of commercially important crustaceans, like those of the palaemonid prawn Macrobrachium rosenbergii and the penaeid shrimp Penaeus stylirostris. This paper presents information on the toxicity of O,S-dimethyl phosphoramidothioate to larvae of M. rosenbergii and P. stylirostris.

  16. Dicty_cDB: Contig-U14249-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available cter sp. FRC-32, complete ... 33 4.8 AF036333_7( AF036333 |pid:none) Diatraea saccharalis densovirus co... 3...e) Diatraea saccharalis densovirus co... 33 6.3 ( O71155 ) RecName: Full=Coat protein VP1/VP2/VP3/VP4; AltNa...3 AF179414_1( AF179414 |pid:none) Dendroides canadensis antifreeze p... 33 6.3 AF036333_6( AF036333 |pid:non

  17. Dicty_cDB: AFL413 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available oideum chromosome 2 map 4657875-4914984 strain AX4, complete sequence. 40 2e-07 13 AF192260 |AF192260.1 Periplaneta fuliginosa denso...virus, complete genome. 44 3e-04 2 AB028936 |AB028936.1 Periplaneta fuliginosa den...sovirus ORF-beta, ORF-alpha, ORF-gamma, ORF-1, ORF-3, ORF-2 genes, complete cds. 44

  18. 77 FR 4993 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation and...

    Science.gov (United States)

    2012-02-01

    ... includes certain warmwater shrimp and prawns, whether frozen, wild-caught (ocean harvested) or farm-raised... shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis... Certain Alloy Steel Wire Rod From Mexico, 75 FR 67685 (November 3, 2010). In accordance with the above...

  19. 75 FR 52718 - Certain Frozen Warmwater Shrimp From India: Final Results of Antidumping Duty Changed...

    Science.gov (United States)

    2010-08-27

    ... warmwater shrimp and prawns, whether wild-caught (ocean harvested) or farm-raised (produced by aquaculture...), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis), and Indian white prawn... Tube From Mexico, 74 FR 41681, 41682 (Aug., 18, 2009). This cash deposit requirement shall remain in...

  20. 76 FR 20318 - Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation and Preliminary...

    Science.gov (United States)

    2011-04-12

    ... warmwater shrimp and prawns, whether wild-caught (ocean harvested) or farm-raised (produced by aquaculture... schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis), and Indian... Changed Circumstances Review: Carbon and Certain Alloy Steel Wire Rod From Mexico, 75 FR 67685 (November 3...

  1. 75 FR 74684 - Notice of Final Results of Antidumping Duty Changed Circumstances Review: Certain Frozen...

    Science.gov (United States)

    2010-12-01

    ... certain frozen warmwater shrimp and prawns, whether wild-caught (ocean harvested) or farm-raised (produced... shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis... Tube from Mexico, 74 FR 41681, 41682 (Aug. 18, 2009). Consequently, the Department will instruct U.S...

  2. 78 FR 33347 - Certain Frozen Warmwater Shrimp From Ecuador: Preliminary Negative Countervailing Duty Determination

    Science.gov (United States)

    2013-06-04

    ... (Trachypenaeus curvirostris), southern white shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis), and Indian white prawn (Penaeus indicus). Frozen shrimp and... Investigation 3. Injury Test 4. Subsidies Valuation 5. Analysis of Programs 6. Disclosure and Public Comment 7...

  3. 78 FR 33346 - Certain Frozen Warmwater Shrimp From the People's Republic of China: Preliminary Countervailing...

    Science.gov (United States)

    2013-06-04

    ... curvirostris), southern white shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis), and Indian white prawn (Penaeus indicus). Frozen shrimp and prawns that... Investigation 3. Injury Test 4. Subsidies Valuation 5. Use of Facts Otherwise Available and Adverse Inferences 6...

  4. 78 FR 33350 - Certain Frozen Warmwater Shrimp From Thailand: Preliminary Countervailing Duty Determination

    Science.gov (United States)

    2013-06-04

    ... curvirostris), southern white shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris), western white shrimp (Penaeus occidentalis), and Indian white prawn (Penaeus indicus). Frozen shrimp and prawns that... Investigation 3. Injury Test 4. Subsidies Valuation 5. Analysis of Programs 6. ITC Notification 7. Disclosure...

  5. 76 FR 23972 - Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China, Thailand, and...

    Science.gov (United States)

    2011-04-29

    ... Vietnam (Vietnam) would be likely to lead to continuation or recurrence of dumping and of material injury... to continuation or recurrence of material injury to an industry in the United States within a... (Trachypenaeus curvirostris), southern white shrimp (Penaeus schmitti), blue shrimp (Penaeus stylirostris...

  6. Evidence of co-infection of chikungunya and densonucleosis viruses in C6/36 cell lines and laboratory infected Aedes aegypti (L. mosquitoes

    Directory of Open Access Journals (Sweden)

    Singh Dinesh K

    2010-10-01

    Full Text Available Abstract Background Densonucleosis viruses are the etiological agents of insect's disease. We have reported the isolation of densovirus from India and its distribution among the natural populations of Aedes aegypti mosquitoes across the country. Since densonucleosis virus persistently infects mosquito populations, and is demonstrated to negatively affect multiplication of dengue virus in Aedes albopictus, it would be interesting to study if this virus has a role in determining the susceptibility of the vector mosquito Ae. aegypti to chikugunya virus. Methods Mosquito cell lines and adult Ae. aegypti mosquitoes infected with densovirus were superinfected with Chikungunya virus and both the viruses were quantitated by determining their genomic copy number by real time amplification. Comparison was made between the log of genomic copy numbers of the viruses in the presence and absence of each other. Results The log of copy number of the viruses did not vary due to co-infection. Even though the RNA copy number of chikungunya virus increased over the period of time, no change was observed in the RNA copy number between the control and the co-infected group on any given day. Similarly, DNA copy number of densovirus also remained unchanged between the control and the co-infected groups. Conclusion Chikungunya virus neither stimulates the replication of densovirus nor is its own replication suppressed due to co-infection. Ae. aegypti mosquitoes with densovirus infection were as susceptible to infection by chikungunya virus as the uninfected mosquitoes.

  7. Insect cell transformation vectors that support high level expression and promoter assessment in insect cell culture

    Science.gov (United States)

    A somatic transformation vector, pDP9, was constructed that provides a simplified means of producing permanently transformed cultured insect cells that support high levels of protein expression of foreign genes. The pDP9 plasmid vector incorporates DNA sequences from the Junonia coenia densovirus th...

  8. Characterization of viral RNA splicing using whole-transcriptome datasets from host species.

    Science.gov (United States)

    Zhou, Chengran; Liu, Shanlin; Song, Wenhui; Luo, Shiqi; Meng, Guanliang; Yang, Chentao; Yang, Hua; Ma, Jinmin; Wang, Liang; Gao, Shan; Wang, Jian; Yang, Huanming; Zhao, Yun; Wang, Hui; Zhou, Xin

    2018-02-19

    RNA alternative splicing (AS) is an important post-transcriptional mechanism enabling single genes to produce multiple proteins. It has been well demonstrated that viruses deploy host AS machinery for viral protein productions. However, knowledge on viral AS is limited to a few disease-causing viruses in model species. Here we report a novel approach to characterizing viral AS using whole transcriptome dataset from host species. Two insect transcriptomes (Acheta domesticus and Planococcus citri) generated in the 1,000 Insect Transcriptome Evolution (1KITE) project were used as a proof of concept using the new pipeline. Two closely related densoviruses (Acheta domesticus densovirus, AdDNV, and Planococcus citri densovirus, PcDNV, Ambidensovirus, Densovirinae, Parvoviridae) were detected and analyzed for AS patterns. The results suggested that although the two viruses shared major AS features, dramatic AS divergences were observed. Detailed analysis of the splicing junctions showed clusters of AS events occurred in two regions of the virus genome, demonstrating that transcriptome analysis could gain valuable insights into viral splicing. When applied to large-scale transcriptomics projects with diverse taxonomic sampling, our new method is expected to rapidly expand our knowledge on RNA splicing mechanisms for a wide range of viruses.

  9. Prevalencia y distribución de los principales agentes etiológicos que afectan los langostinos silvestres en Tumbes, Perú

    Directory of Open Access Journals (Sweden)

    Rubén Alfaro Aguilera

    2011-05-01

    Full Text Available Se determinó la prevalencia y distribución de diferentes agentes patógenos en langostinos silvestres, en la zona de esteros de la Región Tumbes - Perú, entre marzo y diciembre de 2009. Los canales de marea considerados en este estudio fueron: Boca del Río Tumbes, El Alcalde, Jelí, El Bendito, Envidia, Soledad y Algarrobo. Se colectó un total de 1926 langostinos entre juveniles y pre-adultos de las especies Litopenaeus vannamei, L. stylirostris y Farfantepenaeus californiensis. Utilizando la técnica de la PCR, se detectó la presencia de los patógenos NHPB (0,62%, IHHNV (0,31%, BP (1,61% y WSV (2,75%; no se encontró infección por TSV. Las tres especies en estudio fueron positivas a WSV y BP, presentándose la mayor prevalencia de infección por WSV (2,98% en la especie L. stylirostris y por BP (2,66% en L. vannamei. La NHPB fue detectada en las especies L. vannamei y L. stylirostris con 0,77% y 0,43% de prevalencia respectivamente. Se obtuvo una prevalencia de 0,52% para IHHNV en L. vannamei. Las más altas prevalencias de las infecciones por WSV, BP, NHPB e IHHNV se registraron en los canales de marea El Alcalde (10,79%, Algarrobo (4,51%, Envidia (2,26% y Jelí (5,05%. Los datos señalan la presencia constante de diversos patógenos virales y bacterianos en diferentes especies de peneidos y su amplia distribución a lo largo del litoral tumbesino, lo que constituye un riesgo potencial para el desarrollo de la acuicultura en la región, y podría afectar las poblaciones naturales de langostinos.

  10. Mercury and selenium concentrations in marine shrimps of NW Mexico: health risk assessment.

    Science.gov (United States)

    Frías-Espericueta, M G; Ramos-Magaña, B Y; Ruelas-Inzunza, J; Soto-Jiménez, M F; Escobar-Sánchez, O; Aguilar-Juárez, M; Izaguirre-Fierro, G; Osuna-Martínez, C C; Voltolina, D

    2016-11-01

    We determined total Hg and Se contents of hepatopancreas, exoskeleton, and muscle, and the Se:Hg molar ratios in the muscle of shrimps Farfantepenaeus californiensis and Litopenaeus stylirostris caught in NE Pacific Mexican waters. Total Hg mean values in muscle, hepatopancreas, and exoskeleton were 0.31 ± 0.26, 0.28 ± 0.29, and 0.24 ± 0.06 μg g(-1), and 0.46 ± 0.46, 0.41 ± .034, and 0.24 ± 0.06 μg g(-1) for F. californiensis and L. stylirostris, respectively. In all tissues, the mean concentrations of Se tended to be close to one order of magnitude higher than the respective Hg values. In F. californiensis, the hepatopancreas of the larger commercial size had significantly (p human consumption.

  11. [Exploitation of the shrimp trawl fishery in the period 1991-1999 at the Gulf of Nicoya, Costa Rica].

    Science.gov (United States)

    Tabash Blanco, Farid A

    2007-03-01

    In Costa Rica, the Gulf of Nicoya shrimp fishery originated in 1952 and represented one of the most important economic activities in the region. Nevertheless, overfishery reduced the captured volumes to levels that prevent this commercial activity. I analyzed official fishery statistics between 1991 and 1999. These species involved are: two species of white shrimp, (Litopenaeus occidentalis and L. stylirostris), the "titi" shrimp (Xiphopenaeus riveti), the brown shrimp (Farfantepenaeus californiensis), the "pinki" shrimp (F. brevirostris) and the "fidel" shrimp (Solenocera agassizi). All the species reached the Maximum Sustainable Yield in the decades of 1970 and 1980 and are now found at over-exploitation levels. I recommend that this shrimp trawl fishery be completely closed down.

  12. History and Current Status of Development and Use of Viral Insecticides in China

    Directory of Open Access Journals (Sweden)

    Xiulian Sun

    2015-01-01

    Full Text Available The use of insect viruses as biological control agents started in the early 1960s in China. To date, more than 32 viruses have been used to control insect pests in agriculture, forestry, pastures, and domestic gardens in China. In 2014, 57 products from 11 viruses were authorized as commercial viral insecticides by the Ministry of Agriculture of China. Approximately 1600 tons of viral insecticidal formulations have been produced annually in recent years, accounting for about 0.2% of the total insecticide output of China. The development and use of Helicoverpa armigera nucleopolyhedrovirus, Mamestra brassicae nucleopolyhedrovirus, Spodoptera litura nucleopolyhedrovirus, and Periplaneta fuliginosa densovirus are discussed as case studies. Additionally, some baculoviruses have been genetically modified to improve their killing rate, infectivity, and ultraviolet resistance. In this context, the biosafety assessment of a genetically modified Helicoverpa armigera nucleopolyhedrovirus is discussed.

  13. The Structure and Host Entry of an Invertebrate Parvovirus

    Science.gov (United States)

    Meng, Geng; Zhang, Xinzheng; Plevka, Pavel; Yu, Qian; Tijssen, Peter

    2013-01-01

    The 3.5-Å resolution X-ray crystal structure of mature cricket parvovirus (Acheta domesticus densovirus [AdDNV]) has been determined. Structural comparisons show that vertebrate and invertebrate parvoviruses have evolved independently, although there are common structural features among all parvovirus capsid proteins. It was shown that raising the temperature of the AdDNV particles caused a loss of their genomes. The structure of these emptied particles was determined by cryo-electron microscopy to 5.5-Å resolution, and the capsid structure was found to be the same as that for the full, mature virus except for the absence of the three ordered nucleotides observed in the crystal structure. The viral protein 1 (VP1) amino termini could be externalized without significant damage to the capsid. In vitro, this externalization of the VP1 amino termini is accompanied by the release of the viral genome. PMID:24027306

  14. New findings and a new species of the genus Ammothea (Pycnogonida, Ammotheidae), with an updated identification key to all Antarctic and sub-Antarctic species

    Science.gov (United States)

    Cano-Sánchez, E.; López-González, P. J.

    2014-03-01

    Specimens of the pycnogonid genus Ammothea collected during the Polarstern cruise XXIII/8 (23 November 2006-30 January 2007) were studied. Nine species were recognized in this collection: Ammothea bentartica, A. bicorniculata, A. carolinensis, A. clausi, A. longispina, A. minor, A. spinosa, A. striata and A. tibialis. Three of them ( A. bentartica, A. bicorniculata and A. tibialis) are reported for the second time, enlarging their known geographical and bathymetric range. In the present contribution, the observed morphological variability of all collected Ammothea species is described and discussed. For the identification and description of the material, different museum specimens were consulted. Among them, we have consulted part of the Discovery collection housed at the Natural History Museum in London. That material was initially identified by Isabella Gordon, a reputed author in the field of pycnogonid taxonomy. A new species, based on a museum specimen previously highly confused in the literature, is proposed in the present contribution as Ammothea isabellae n. sp. The new taxon is compared with its closest congeners, especially with A. longispina and A. stylirostris. Finally, we propose an updated dichotomous key to species covering all currently known Antarctic and sub-Antarctic Ammothea species.

  15. Virulence of an emerging pathogenic lineage of Vibrio nigripulchritudo is dependent on two plasmids.

    Science.gov (United States)

    Le Roux, Frédérique; Labreuche, Yannick; Davis, Brigid M; Iqbal, Naeem; Mangenot, Sophie; Goarant, Cyrille; Mazel, Didier; Waldor, Matthew K

    2011-02-01

    Vibrioses are the predominant bacterial infections in marine shrimp farms. Vibrio nigripulchritudo is an emerging pathogen of the cultured shrimp Litopenaeus stylirostris in New Caledonia and other regions in the Indo-Pacific. The molecular determinants of V. nigripulchritudo pathogenicity are unknown; however, molecular epidemiological studies have revealed that recent pathogenic V. nigripulchritudo isolates from New Caledonia all cluster into a monophyletic clade and contain a small plasmid, pB1067. Here, we report that a large plasmid, pA1066 (247 kb), can also serve as a marker for virulent V. nigripulchritudo, and that an ancestral version of this plasmid was likely acquired prior to other virulence-linked markers. Additionally, we demonstrate that pA1066 is critical for the full virulence of V. nigripulchritudo in several newly developed experimental models of infection. Plasmid pB1067 also contributes to virulence; only strains containing both plasmids induced the highest level of shrimp mortality. Thus, it appears that these plasmids, which are absent from non-pathogenic isolates, may be driving forces, as well as markers, for the emergence of a pathogenic lineage of V. nigripulchritudo.

  16. Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

    Science.gov (United States)

    Ng, Terry Fei Fan; Willner, Dana L.; Lim, Yan Wei; Schmieder, Robert; Chau, Betty; Nilsson, Christina; Anthony, Simon; Ruan, Yijun; Rohwer, Forest; Breitbart, Mya

    2011-01-01

    Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes. PMID:21674005

  17. Selection of reference genes for analysis of stress-responsive genes after challenge with viruses and temperature changes in the silkworm Bombyx mori.

    Science.gov (United States)

    Guo, Huizhen; Jiang, Liang; Xia, Qingyou

    2016-04-01

    Viruses and high temperature (HT) are the primary threats to silkworms. Changes in the expression of stress-response genes can be measured using quantitative polymerase chain reaction (qPCR) after exposure to viruses or HT. However, appropriate reference genes (RGs) for qPCR data normalization have not been established in this organism. In this study, we summarized the RGs used in the previous silkworm studies after infection with Bombyx mori nucleopolyhedrovirus (BmNPV), B. mori cytoplasmic polyhedrosis virus (BmCPV), or B. mori densovirus (BmDNV) or after HT treatment. The expression levels of these RGs were extracted from silkworm transcriptome data to screen for candidate RGs that were unaffected by the experimental conditions. Actin-1 (A1), actin-3 (A3), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and translation initiation factor 4a (TIF-4A) were selected for further qPCR verification. The results of RNA-seq and qPCR showed that GAPDH and TIF-4A were suitable RGs after BmNPV challenge or HT stress, whereas TIF-4A was an appropriate RG for BmCPV or BmDNV-Z challenge in silkworms. These results suggested that TIF-4A may be the most appropriate RG for gene expression analysis after challenge with viruses or HT in silkworms.

  18. Persistent, triple-virus co-infections in mosquito cells

    Directory of Open Access Journals (Sweden)

    Malasit Prida

    2010-01-01

    Full Text Available Abstract Background It is known that insects and crustaceans can carry simultaneous, active infections of two or more viruses without showing signs of disease, but it was not clear whether co-infecting viruses occupied the same cells or different cells in common target tissues. Our previous work showed that successive challenge of mosquito cell cultures followed by serial, split-passage resulted in stabilized cultures with 100% of the cells co-infected with Dengue virus (DEN and an insect parvovirus (densovirus (DNV. By addition of Japanese encephalitis virus (JE, we tested our hypothesis that stable, persistent, triple-virus co-infections could be obtained by the same process. Results Using immunocytochemistry by confocal microscopy, we found that JE super-challenge of cells dually infected with DEN and DNV resulted in stable cultures without signs of cytopathology, and with 99% of the cells producing antigens of the 3 viruses. Location of antigens for all 3 viruses in the triple co-infections was dominant in the cell nuclei. Except for DNV, this differed from the distribution in cells persistently infected with the individual viruses or co-infected with DNV and DEN. The dependence of viral antigen distribution on single infection or co-infection status suggested that host cells underwent an adaptive process to accommodate 2 or more viruses. Conclusions Individual mosquito cells can accommodate at least 3 viruses simultaneously in an adaptive manner. The phenomenon provides an opportunity for genetic exchange between diverse viruses and it may have important medical and veterinary implications for arboviruses.