First Characterization of Sphingomyeline Phosphodiesterase Expression in the Bumblebee, Bombus lantschouensis

  The bumblebee (Bombus lantschouensis Vogt) is an important pollinator of wild plants. Sphingomyelin phosphodiesterase (SMPD) is a hydrolase that plays a major role in sphingolipid metabolism reactions. We report the preparation and characterization of a polyclonal antibody for bumblebee SMPD. We then use the polyclonal antiserum to detect the SMPD protein at different development stages and in different tissues. Our results showed that a 1228bp fragment homologous with the B. terrestris SMPD gene was successfully amplified. The molecular weight of the fusion protein was about 70 kDa by SDS-PAGE. An effective polyclonal antibody against SMPD was also obtained from mice and found to have a higher specificity for bumblebee SMPD. Western blotting detection showed that SMPD was expressed at a high level in queen ovaries, although expression was lower in the midgut and venom gland. SMPD expression decreased from the egg stage until the pdd stage. We interpret our results as showing that the development of an effective polyclonal antiserum for the SMPD protein of a bumblebee, which provides a tool for exploring the function of the SMPD gene. In addition, the work has confirmed that SMPD should be considered as an important enzyme during bumblebee egg and larval stages

Alternative Splicing and Expression Profile Analysis of Expressed Sequence Tags in Domestic Pig

Domestic pig (Sus scrofa domestica) is one of the most important mammals to humans. Alternative splicing is a cellular mechanism in eukaryotes that greatly increases the diversity of gene products. Expression sequence tags (ESTs) have been widely used for gene discovery, expression profile analysis, and alternative splicing detection. In this study, a total of 712,905 ESTs extracted from 101 different non-normalized EST libraries of the domestic pig were analyzed. These EST libraries cover the nervous system, digestive system, immune system, and meat production related tissues from embryo, newborn, and adult pigs, making contributions to the analysis of alternative splicing variants as well as expression profiles in various stages of tissues. A modified approach was designed to cluster and assemble large EST datasets, aiming to detect alternative splicing together with EST abundance of each splicing variant. Much efforts were made to classify alternative splicing into different types and apply different filters to each type to get more reliable results. Finally, a total of 1,223 genes with average 2.8 splicing variants were detected among 16,540 unique genes. The overview of expression profiles would change when we take alternative splicing into account

Unraveling the diversity of sedimentary sulfate-reducing prokaryotes (SRP) across Tibetan saline lakes using epicPCR

Sulfate reduction is an important biogeochemical process in the ecosphere; however, the major taxa of sulfate reducers have not been fully identified. Here, we used epicPCR (Emulsion, Paired Isolation, and Concatenation PCR) technology to identify the phylogeny of sulfate-reducing prokaryotes (SRP) in sediments from Tibetan Plateau saline lakes. A total of 12,519 OTUs and 883 SRP-OTUs were detected in ten lakes by sequencing of 16S rRNA gene PCR amplicons and epicPCR products of fused 16S rRNA plus dsrB gene, respectively, with Proteobacteria, Firmicutes, and Bacteroidetes being the dominant phyla in both datasets. The 120 highly abundant SRP-OTUs (>1% in at least one sample) were affiliated with 17 described phyla, only 7 of which are widely recognized as SRP phyla. The majority of OTUs from both the whole microbial communities and the SRPs were not detected in more than one specific lake, suggesting high levels of endemism. The -diversity of the entire microbial community and SRP sub-community showed significant positive correlations. The pH value and mean water temperature of the month prior to sampling were the environmental determinants for the whole microbial community, while the mean water temperature and total nitrogen were the major environmental drivers for the SRP sub-community. This study revealed there are still many undocumented SRP in Tibetan saline lakes, many of which could be endemic and adapted to specific environmental conditions.Peer reviewe

Identification and determination of the major constituents in traditional Chinese medicine Longdan Xiegan Pill by HPLC-DAD-ESI-MS

AbstractA novel and sensitive HPLC-UV method has been developed for the simultaneous determination of twelve major compounds in Longdan Xiegan Pill. The chemical profile of the twelve compounds, including geniposidic acid (1), geniposide(2), gentiopicroside(3), liquiritin(4), crocin(5), baicalin(6), wogonoside(7), baicalein(8), glycyrrhizic acid (9), wogonin (10), oroxylin A (11) and aristolochic acid A (12), was acquired using high-performance liquid chromatography-diode array detector coupled with an electrospray tandem mass spectrometer (HPLC-DAD-ESI-MS). The analysis was performed on a Dikma Platisil ODS C18 column (250mm × 4. 6mm, 5μm) with a gradient solvent system of acetonitrile-0. 1% aqueous formic acid. The validation was carried out and the linearities (r>0. 9996), repeatability (RSD<1. 8%), intra- and inter-day precision (RSD< 1. 3%), and recoveries (ranging from 96. 6% to 103. 4%) were acceptable. The limits of detection (LOD) of these compounds ranged from 0.29 to 4. 17ng. Aristolochic acid A, which is the toxic ingredient, was not detected in all the batches of Longdan Xiegan Pill. Furthermore, hierarchical cluster analysis was used to evaluate the variation of the herbal prescription. The proposed method is simple, effective and suitable for the quality control of this traditional Chinese medicine (TCM)

Making 2‐D Materials Mechanochemically by Twin‐Screw Extrusion:Continuous Exfoliation of Graphite to Multi‐Layered Graphene

Mechanochemistry has developed rapidly in recent years for efficient chemicals and materials synthesis. Twin screw extrusion (TSE) is a particularly promising technique in this regard because of its continuous and scalable nature. A key aspect of TSE is that it provides high shear and mixing. Because of the high shear, it potentially also offers a way to delaminate 2‐D materials. Indeed, the synthesis of 2‐D materials in a scalable and continuous manor remains a challenge in their industrialization. Here, as a proof‐of‐principle, the automated, continuous mechanochemical exfoliation of graphite to give multi‐layer graphene (MLG, ≈6 layers) by TSE is demonstrated. To achieve this, a solid‐and‐liquid‐assisted extrusion (SLAE) process is developed in which organic additives such as pyrene are rendered liquid due to the high temperatures used, to assist with the exfoliation, and simultaneously solid sodium chloride is used as a grinding aid. This gave MLG in high yield (25 wt%) with a short residence time (8 min) and notably with negligible evidence for structural deterioration (defects or oxidation)

Utilizing Selected Di- and Trinucleotides of siRNA to Predict RNAi Activity

Small interfering RNAs (siRNAs) induce posttranscriptional gene silencing in various organisms. siRNAs targeted to different positions of the same gene show different effectiveness; hence, predicting siRNA activity is a crucial step. In this paper, we developed and evaluated a powerful tool named “siRNApred” with a new mixed feature set to predict siRNA activity. To improve the prediction accuracy, we proposed 2-3NTs as our new features. A Random Forest siRNA activity prediction model was constructed using the feature set selected by our proposed Binary Search Feature Selection (BSFS) algorithm. Experimental data demonstrated that the binding site of the Argonaute protein correlates with siRNA activity. “siRNApred” is effective for selecting active siRNAs, and the prediction results demonstrate that our method can outperform other current siRNA activity prediction methods in terms of prediction accuracy