Winter spatial distribution of fish larvae assemblages relative to the hydrography of the waters surrounding Taiwan

The aim of this study was to investigate the species composition and distribution of fish larvae in relation to hydrographic conditions in the waters surrounding Taiwan Island (TI) in February 2003. In total, 242 kinds of fish larvae belonging to 127 genera and 75 families were recognized. Among these, 109 taxa were identified to the family or genus level, others to the species level. The 12 predominant types, which constituted 71% of the total fish larvae, were Engraulis japonica, Scomber sp., Diaphus spp., Benthosema pterotum, Carangoides ferdau, Embolichthys mitsukurii, Maurolicus sp., unidentified Myctophidae, Gonostoma gracile, Trichiurus lepturus, unidentified Gobiidae, and Myctophum asperum. The distribution of fish larvae showed a clear association with water masses around TI, with higher abundances and lower species richness northwest of TI where the China Coastal Current prevails, and lower abundances and higher species diversity east of TI where the Kuroshio Current dominates. Cluster analysis distinguished three station groups and four species groups, and the distribution patterns of fish larvae also corresponded to hydrographic conditions. The total abundances of fish larvae and eight of the 12 predominant taxa showed significant and positive correlations with zooplankton abundance, which suggests that food source might be a key factor determining the abundance and distribution of fish larvae during the winter.     

Molecular Cloning of Novel Cellulase Genes <Emphasis Type="Italic">cel</Emphasis>9A and <Emphasis Type="Italic">cel</Emphasis>12A from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> GXN151 and Synergism of Their Encoded Polypeptides

A thermophilic bacterial strain GXN151 which could degrade Avicel efficiently was isolated and identified as Bacillus licheniformis. A genomic library of GXN151 was constructed and two novel endoglucanase genes designated cel9A and cel12A were isolated by screening the library on carboxylmethyl cellulase indicator plates. The analysis of amino acid sequences deduced from the genes indicated that Cel9A consisted of a catalytic domain belonging to glycosyl hydrolase family 9, a linker domain, and a carbohydrate binding module family 3 from N-terminal to C-terminal; Cel12A had only one catalytic domain belonging to glycosyl hydrolase family 12. The combinations of Cel9A and Cel12A produced by the recombinant E. coli exhibited synergistic action against substrates of carboxylmethyl cellulose as well as Avicel.     

Relating body size to the role of aquatic subsidies for the riparian spider <Emphasis Type="Italic">Nephila clavata</Emphasis>

We examined the relationship between body size of the riparian spider Nephila clavata and the contribution of allochthonous (aquatic insects) and autochthonous (terrestrial insects) sources to its diet using stable isotope analysis. During the study period from July to September, the body size of the females increased remarkably (about 60-fold) but that of males remained small. The biomass of both aquatic and terrestrial insects trapped on the spider webs increased with spider size, with the biomass of the former ranging between 30 and 70% of that of the terrestrial insects. The average relative contribution of aquatic insects to the diet of the spiders, calculated from δ¹³C values, was 40–50% in spiders in the early juvenile and juvenile stages, 35% in adult males and 4% in adult females. There was a significant negative relationship between the relative contribution of aquatic insects and body size of the female spiders. We conclude that aquatic insects might be an important seasonal dietary subsidy for small spiders and that these allochthonous subsidies may facilitate the growth of riparian spiders, which may in turn enable the spiders to feed on larger prey.     

<Emphasis Type="Italic">Narcissus tazetta</Emphasis> lectin shows strong inhibitory effects against respiratory syncytial virus,influenza A (H1N1, H3N2, H5N1) and B viruses

A mannose-binding lectin (Narcissus tazetta lectin [NTL]) with potent antiviral activity was isolated and purified from the bulbs of the Chinese daffodil Narcissus tazetta var. chinensis, using ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on mannose-agarose and fast protein liquid chromatography (FPLC)-gel filtration on Superose 12. The purified lectin was shown to have an apparent molecular mass of 26 kDa by gel filtration and 13 kDa by SDS-PAGE, indicating that it is probably a dimer with two identical subunits. The cDNA-derived amino acid sequence of NTL as determined by molecular cloning also reveals that NTL protein contains a mature polypeptide consisting of 105 amino acids and a C-terminal peptide extension. Three-dimensional modelling study demonstrated that the NTL primary polypeptide contains three subdomains, each with a conserved mannose-binding site. It shows a high homology of about 60%–80% similarity with the existing monocot mannose-binding lectins. NTL could significantly inhibit plaque formation by the human respiratory syncytial virus (RSV) with an IC₅₀ of 2.30 μg/ml and exhibit strong antiviral properties against influenza A (H1N1, H3N2, H5N1) and influenza B viruses with IC₅₀ values ranging from 0.20 μg/ml to 1.33 μg/ml in a dose-dependent manner. It is worth noting that the modes of antiviral action of NTL against RSV and influenza A virus are significantly different. NTL is effective in the inhibition of RSV during the whole viral infection cycle, but the antiviral activity of NTL is mainly expressed at the early stage of the viral cycle of influenza A (H1N1) virus. NTL with a high selective index (SI=CC₅₀/IC₅₀≥141) resulting from its potent antiviral activity and low cytotoxicity demonstrates a potential for biotechnological development as an antiviral agent.     

Lessons on Evolution from the Study of Edaphic Specialization

Plants adapted to special soil types are ideal for investigating evolutionary processes, including maintenance of intraspecific variation, adaptation, reproductive isolation, ecotypic differentiation, and the tempo and mode of speciation. Common garden and reciprocal transplant approaches show that both local adaptation and phenotypic plasticity contribute to edaphic (soil-related) specialization. Edaphic specialists evolve rapidly and repeatedly in some lineages, offering opportunities to investigate parallel evolution, a process less commonly documented in plants than in animals. Adaptations to soil features are often under the control of major genes and they frequently have direct or indirect effects on genes that contribute to reproductive isolation. Both reduced competitiveness and greater susceptibility to herbivory have been documented among some edaphic specialists when grown in ‘normal’ soils, suggesting that a high physiological cost of tolerance may result in strong divergent selection across soil boundaries. Interactions with microbes, herbivores, and pollinators influence soil specialization either by directly enhancing tolerance to extremes in soil conditions or by reducing gene flow between divergent populations. Climate change may further restrict the distribution of edaphic specialists due to increased competition from other taxa or, expand their ranges, if preadaptations to drought or other abiotic stressors render them more competitive under a novel climate.     

A green and effective method for the determination of metalaxyl enantiomers in tobacco and soil by supercritical fluid chromatography–tandem mass spectrometry

We reported a new methodology for the stereoselective determination of metalaxyl enantiomers in tobacco and soil. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for the extraction and clean-up of the tobacco and soil samples. Separation of the metalaxyl enantiomers was performed on an ACQUITY UPC2 Trefoil CEL1 chiral column coupled with supercritical fluid chromatography with tandem mass spectrometry (SFC-MS/MS), and the run time was only 5 minutes. Under the optimized conditions, the recoveries for the enantiomers were between 78.2% and 93.3% with intraday relative standard deviations (RSDs) ranging from 1.1% to 5.4%. The limit of detection (LOD) for the enantiomers in tobacco and soil varied from 0.005 to 0.007 mg/kg, and the limit of quantitation (LOQ) ranged from 0.017 to 0.020 mg/kg. In this method, only a small amount of methanol was consumed to obtain a rapid stereoselective separation. This proposed method showed good accuracy and precision and might be suitable for fast enantioselective determination of metalaxyl in food and environmental samples. The developed method was further validated by application to the analysis of authentic samples.     

Long-term platinum retention after treatment with cisplatin and oxaliplatin

Background  

The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin.     

花同源异型MADS-box 基因在被子植物中的功能保守性和多样性

MADS-box基因家族成员作为转录调控因子在被子植物花发育调控中发挥关键作用。本文以模式植物拟南芥(Arabidopsis thaliana) 和水稻 (Oryza sativa)为例, 综述了近10年来对被子植物(又称有花植物)两大主要类群——核心真 双子叶植物和单子叶植物花同源异型MADS-box基因的研究成果, 分析MADS-box基因在被子植物中的功能保守性和多样性,同时探讨双子叶植物花发育的ABCDE模型在多大程度上适用于单子叶植物。