Estimation of nuclear DNA content of various bamboo and rattan species

We determined the nuclear DNA content (genome size) of over 35 accessions each of bamboo and rattan species from Southeast Asia. The 2C DNA per nucleus was quantified by flow cytometry. The fluorescence of nuclei isolated from the leaves and stained with propidium iodide was measured. The genome size of the bamboo species examined was between 2.5 and 5.9 pg DNA per 2C nucleus. The genome size of the rattan species examined ranged from 1.8 to 10.5 pg DNA per 2C nucleus. This information will be useful for scientists working in diverse areas of plant biology such as biotechnology, biodiversity, genome analysis, plant breeding, physiology and molecular biology. Such data may be utilized to attempt to correlate the genome size with the ploidy status of bamboo species in cases where ploidy status has been reported.     

Recombinant dengue virus type 3 envelope domain III protein from Escherichia coli

Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. The envelope protein of dengue virus is the major antigen to elicit neutralizing antibody response and protective immunity in hosts. Optimization of culture media was carried out for enhanced production of recombinant dengue virus type 3 envelope domain III (rDen 3 EDIII) protein in E. coli. Further, batch and fed-batch cultivation process were also developed in optimized medium. After fed-batch cultivation, the dry cell weight was about 22.80 g/L of culture. The rDen 3 EDIII protein was purified using immobilized metal affinity chromatography. This process produced ～649 mg of purified rDen 3 EDIII protein per liter of culture. The purity of the protein was determined by SDS-PAGE analysis and the reactivity was checked by Western blotting as well as ELISA. These results show that the purified protein may be used for the dengue diagnosis or further prophylactic studies for dengue infection.     

Protein carbonylation and metal-catalyzed protein oxidation in a cellular perspective

Proteins can become oxidatively modified in many different ways, either by direct oxidation of amino acid side chains and protein backbone or indirectly by conjugation with oxidation products of polyunsaturated fatty acids and carbohydrates. While reversible oxidative modifications are thought to be relevant in physiological processes, irreversible oxidative modifications are known to contribute to cellular damage and disease. The most well-studied irreversible protein oxidation is carbonylation. In this work we first examine how protein carbonylation occurs via metal-catalyzed oxidation (MCO) in vivo and in vitro with an emphasis on cellular metal ion homeostasis and metal binding. We then review proteomic methods currently used for identifying carbonylated proteins and their sites of modification. Finally, we discuss the identified carbonylated proteins and the pattern of carbonylation sites in relation to cellular metabolism using the mitochondrion as a case story.     

From pattern to process: species and functional diversity in fungal endophytes of Abies beshanzuensis

The biodiversity-functional relationship in fungal ecology was recently developed and debated, but has rarely been addressed in endophytes. In this study, an integrative culture system was designed to capture a rich fungal consortium from the conifer Abies beshanzuensis. Results indicate an impressive diversity of fungal lineages (a total of 84 taxa classified in Dikarya) and a relatively high proportion of hitherto unknown species (27.4%). The laccase gene was used as a functional marker due to its involvement in lignocellulose degradation. Remarkable diversity of laccase genes was found across a wide range of taxa, with at least 35 and 19 distinct sequences in ascomycetes and basidiomycetes respectively, were revealed. Many groups displayed variable ability to decompose needles. Furthermore, many ascomycetes, including three volatile-producing Muscodor species (Xylariaceae), showed the ability to inhibit pathogens. Notably, most laccase-producing species showed little or no antibiosis and vice versa. Clavicipitalean and ustilaginomycetous fungi, specifically toxic to insects, were inferred from taxonomic information. Intra-specific physiological variation in Pezicula sporulosa, a second dominant species, was clearly high. We conclude that a suite of defensive characteristics in endophytes contributes to improving host fitness under various stresses and that a diversity of laccase genes confers an ecological advantage in competition for nutrients. Intra-specific diversity may be of great ecological significance for ecotypic adaptation. These findings suggest a fair degree of functional complementarity rather than redundancy among endemic symbionts of natural plant populations.     

Working memory in attention deficit/hyperactivity disorder is characterized by a lack of specialization of brain function

Working memory impairments are frequent in Attention Deficit/Hyperactivity Disorder (ADHD) and create problems along numerous functional dimensions. The present study utilized the Visual Serial Addition Task (VSAT) and functional magnetic resonance imaging (fMRI) to explore working memory processes in thirteen typically developing (TD) control and thirteen children with ADHD, Combined type. Analysis of Variance (ANOVA) was used to examine both main effects and interactions. Working memory-specific activity was found in TD children in the bilateral prefrontal cortex. In contrast the within-group map in ADHD did not reveal any working-memory specific regions. Main effects of condition suggested that the right middle frontal gyrus (BA6) and the right precuneus were engaged by both groups during working memory processing. Group differences were driven by significantly greater, non-working memory-specific, activation in the ADHD relative to TD group in the bilateral insula extending into basal ganglia and the medial prefrontal cortex. A region of interest analysis revealed a region in left middle frontal gyrus that was more active during working memory in TD controls. Thus, only the TD group appeared to display working memory-modulated brain activation. In conclusion, children with ADHD demonstrated reduced working memory task specific brain activation in comparison to their peers. These data suggest inefficiency in functional recruitment by individuals with ADHD represented by a poor match between task demands and appropriate levels of brain activity.     

Gold nanoparticle-based surface-enhanced Raman scattering for noninvasive molecular probing of embryonic stem cell differentiation

This study reports the use of gold nanoparticle-based surface-enhanced Raman scattering (SERS) for probing the differentiation of mouse embryonic stem (mES) cells, including undifferentiated single cells, embryoid bodies (EBs), and terminally differentiated cardiomyocytes. Gold nanoparticles (GNPs) were successfully delivered into all 3 mES cell differentiation stages without affecting cell viability or proliferation. Transmission electron microscopy (TEM) confirmed the localization of GNPs inside the following cell organelles: mitochondria, secondary lysosome, and endoplasmic reticulum. Using bright- and dark-field imaging, the bright scattering of GNPs and nanoaggregates in all 3 ES cell differentiation stages could be visualized. EB (an early differentiation stage) and terminally differentiated cardiomyocytes both showed SERS peaks specific to metabolic activity in the mitochondria and to protein translation (amide I, amide II, and amide III peaks). These peaks have been rarely identified in undifferentiated single ES cells. Spatiotemporal changes observed in the SERS spectra from terminally differentiated cardiomyocyte tissues revealed local and dynamic molecular interactions as well as transformations during ES cell differentiation.     

Effect of CO2 on the germination of conidiospores of Aspergillus niger

Summary The effect of different concentrations of CO₂ on the germination of conidiospores of Aspergillus niger A 5 has been studied using Pardee's buffer mixtures which maintain constant CO₂ tensions. The beneficial effect of CO₂ on germination is maximum at 0.5% CO₂ concentration, when 70–90% of the spores germinate within 6 hours, whereas in controls with air containing 0.03% CO₂ there is only 15–20% germination at 6 hours. At higher CO₂ concentrations this beneficial effect of CO₂ on germination diminishes and at 3% there is a complete inhibition of spore germination.The spore density and the ph of the medium have a noticeable effect on germination rates in presence of 0.5% CO₂. The germination rates decrease at spore densities higher than 5 · 10⁵/ml and at a ph of 6.8.Communication No. 431.