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Marine sponge-associated bacteria are known as bio-active compound produce. We have constructed metagenome libraries of the bacteria and developed a metagenomic screening approach. Activity-based screening successfully identified novel genes and novel enzymes; however, the efficiency was only in 1 out of 104 clones. Therefore, in this study, we thought that bioinformatics could help to reduce screening efforts, and combined activity-based screening with database search. Neutrophils play an important role for the immune system to recognize excreted bacterial by-products as chemotactic factors and are recruited to infection sites to kill pathogens via phagocytosis. These excreted by-products are considered critical triggers that engage the immune system to mount a defense against infection, and identifying these factors may guide developments in medicine and diagnostics. We focused on genes encoding amino acid ligase and peptide synthetase and selected from an in-house sponge metagenome database. Cell-free culture medium of each was used in a neutrophil chemiluminescence assay in luminol reaction. The clone showing maximum activity had a genomic sequence expected to produce a molecule like a phospho-N-acetylmuramyl pentapeptide by the metagenome fragment analysis.  相似文献   
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Molecular attempt to identify prey organisms of lobster phyllosoma larvae   总被引:2,自引:0,他引:2  
ABSTRACT:   A molecular approach was adopted to investigate the natural diets of palinurid and scyllarid lobster phyllosoma larvae. The central domain of the 18S rDNA gene was amplified using nested polymerase chain reaction (PCR) and genomic DNA extracted from the larval hepatopancreas. The resulting 18S rDNA clones were screened using restriction fragment length polymorphism (RFLP) analysis, and then FASTA homology search and phylogenetic analysis were performed on the nucleotide sequences to identify the source of the eukaryotic organisms. The feasibility of this method was confirmed using the laboratory-reared phyllosoma larvae of the Japanese spiny lobster Panulirus japonicus that were fed either with common mussel Mytilus edulis gonads or with Artemia nauplii exclusively. Among the 804 clones isolated from five wild-caught mid- to late-stage phyllosoma larvae (three palinurids and two scyllarids), 0–132 clones per sample possessed restriction profiles distinct from those of the hosts. The Cnidaria and Urochordata DNA were identified from both the palinurid and the scyllarid larvae, which were thought to be prey animals for the mid- to late-stage phyllosoma larvae.  相似文献   
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Japanese star anise (Illicium anisatum L., JSA) is seriously damaged by a ringspot disease in Japan. Herein, to determine the causal agent using high-throughput sequencing, we discovered viral RNAs associated with JSA ringspot disease. We then determined the complete or near-complete nucleotide sequences of these RNAs using Sanger sequencing and RACE. The complementary strand of viral RNAs 1, 2, 3, 4, and 5 encoded a single protein, which shared sequence identity with P1 (RNA-dependent RNA polymerase), P2 (glycoprotein precursor), P3 (nucleocapsid protein), P4 (movement protein), and a protein with unknown function of emaraviruses (genus Emaravirus), respectively; however, the highest amino acid sequence identity for the P1–P5 proteins between JSARaV and known emaraviruses was 41.9%, 30.0%, 30.1%, 52.2%, and 38.0%, respectively, all of which were lower than the species demarcation criterion. Furthermore, RNA segments harbored conserved 12-nt terminal sequences at the 5′- and 3′-termini, and a high complementarity of approximately 20 nt in 5′- and 3′-terminal sequences. Transmission electron microscopy confirmed the presence of virus-like particles. JSA ringspot disease was found to be transmitted by an eriophyid mite (subclass Acari, superfamily Eriophyoidea) that belongs to the family Diptilomiopidae. Taken together, these results identified the virus responsible for the ringspot disease of JSA as a new member of the genus, Emaravirus, which we named as the Japanese star anise ringspot-associated virus (JSARaV). Moreover, this is the first report noting that eriophyid mites of the family Diptilomiopidae are capable of transmitting emaravirus.

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The study of spatial distribution of secondary metabolites within microbial cells facilitates the screening of candidate strains from marine environments for functional metabolites and allows for the subsequent assessment of the production of metabolites, such as antibiotics. This paper demonstrates the first application of Raman microspectroscopy for in situ detection of the antifungal antibiotic amphotericin B (AmB) produced by actinomycetes—Streptomyces nodosus. Raman spectra measured from hyphae of S. nodosus show the specific Raman bands, caused by resonance enhancement, corresponding to the polyene chain of AmB. In addition, Raman microspectroscopy enabled us to monitor the time-dependent change of AmB production corresponding to the growth of mycelia. The Raman images of S. nodosus reveal the heterogeneous distribution of AmB within the mycelia and individual hyphae. Moreover, the molecular association state of AmB in the mycelia was directly identified by observed Raman spectral shifts. These findings suggest that Raman microspectroscopy could be used for in situ monitoring of antibiotic production directly in marine microorganisms with a method that is non-destructive and does not require labeling.  相似文献   
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The impact of winter cover crops, specifically wheat (Triticum aestivum L.), red clover (Trifolium pratense L.), and rapeseed (Brassica napus L.) or winter fallow, on community composition of arbuscular mycorrhizal fungi (AMF) in subsequent soybean roots was investigated in a 5-year field trial on andosolic soils in Japan. Soybean roots were sampled at full-flowering and analyzed for AMF communities using a partial LSU rDNA region. Phylogenetic analysis detected 22 AMF phylotypes, including eight Glomus, three Gigaspora, two Scutellospora, three Acaulospora, two Rhizophagus, and one of Funneliformis, Diversispora, Paraglomus, and an unknown glomeromycete in the roots. The 5-year rotation of different winter cover crops or winter fallow did not impact the molecular diversity of AMF communities colonizing the roots of subsequent soybean. In all of the rotations, Glomus and Gigaspora phylotypes were common to soybean roots over the 5-year period. Redundancy analysis (RDA) demonstrated that AMF communities in the roots of subsequent soybean were not significantly different among winter cover crop rotations or fallow. However, AMF communities in soybean roots were clearly influenced by rotation year suggesting that climate or other environmental factors were more important than winter cover cropping system management.  相似文献   
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