Dissection of the general two-step di-C-glycosylation pathway for the biosynthesis of (iso)schaftosides in higher plants.

Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar residues. Herein, we report that the biosynthesis of (iso)schaftosides is sequentially catalyzed by two C-glycosyltransferases (CGTs), i.e., CGTa for C-glucosylation of the 2-hydroxyflavanone aglycone and CGTb for C-arabinosylation of the mono-C-glucoside. The two enzymes of the same plant exhibit high homology but remarkably different sugar acceptor and donor selectivities. A total of 14 CGTa and CGTb enzymes were cloned and characterized from seven dicot and monocot plants, including Scutellaria baicalensis, Glycyrrhiza uralensis, Oryza sativa ssp. japonica, and Zea mays, and the in vivo functions for three enzymes were verified by RNA interference and overexpression. Through transcriptome analysis, we found homologous genes in 119 other plants, indicating this pathway is general for the biosynthesis of (iso)schaftosides. Furthermore, we resolved the crystal structures of five CGTs and realized the functional switch of SbCGTb to SbCGTa by structural analysis and mutagenesis of key amino acids. The CGT enzymes discovered in this paper allow efficient synthesis of (iso)schaftosides, and the general glycosylation pathway presents a platform to study the chemical defense mechanisms of higher plants.

A Global Survey of the Full-Length Transcriptome of Apis mellifera by Single-Molecule Long-Read Sequencing.

As important pollinators, honey bees play a crucial role in both maintaining the ecological balance and providing products for humans. Although several versions of the western honey bee genome have already been published, its transcriptome information still needs to be refined. In this study, PacBio single-molecule sequencing technology was used to sequence the full-length transcriptome of mixed samples from many developmental time points and tissues of A. mellifera queens, workers and drones. A total of 116,535 transcripts corresponding to 30,045 genes were obtained. Of these, 92,477 transcripts were annotated. Compared to the annotated genes and transcripts on the reference genome, 18,915 gene loci and 96,176 transcripts were newly identified. From these transcripts, 136,554 alternative splicing (AS) events, 23,376 alternative polyadenylation (APA) sites and 21,813 lncRNAs were detected. In addition, based on the full-length transcripts, we identified many differentially expressed transcripts (DETs) between queen, worker and drone. Our results provide a complete set of reference transcripts for A. mellifera that dramatically expand our understanding of the complexity and diversity of the honey bee transcriptome.

Epithelia-Sensory Neuron Cross Talk Underlies Cholestatic Itch Induced by Lysophosphatidylcholine.

BACKGROUND & AIMS: Limited understanding of pruritus mechanisms in cholestatic liver diseases hinders development of antipruritic treatments. Previous studies implicated lysophosphatidic acid (LPA) as a potential mediator of cholestatic pruritus. METHODS: Pruritogenicity of lysophosphatidylcholine (LPC), LPA's precursor, was examined in naïve mice, cholestatic mice, and nonhuman primates. LPC's pruritogenicity involving keratinocyte TRPV4 was studied using genetic and pharmacologic approaches, cultured keratinocytes, ion channel physiology, and structural computational modeling. Activation of pruriceptor sensory neurons by microRNA-146a (miR-146a), secreted from keratinocytes, was identified by in vitro and ex vivo Ca2+ imaging assays. Sera from patients with primary biliary cholangitis were used for measuring the levels of LPC and miR-146a. RESULTS: LPC was robustly pruritic in mice. TRPV4 in skin keratinocytes was essential for LPC-induced itch and itch in mice with cholestasis. Three-dimensional structural modeling, site-directed mutagenesis, and channel function analysis suggested a TRPV4 C-terminal motif for LPC binding and channel activation. In keratinocytes, TRPV4 activation by LPC induced extracellular release of miR-146a, which activated TRPV1+ sensory neurons to cause itch. LPC and miR-146a levels were both elevated in sera of patients with primary biliary cholangitis with itch and correlated with itch intensity. Moreover, LPC and miR-146a were also increased in sera of cholestatic mice and elicited itch in nonhuman primates. CONCLUSIONS: We identified LPC as a novel cholestatic pruritogen that induces itch through epithelia-sensory neuron cross talk, whereby it directly activates skin keratinocyte TRPV4, which rapidly releases miR-146a to activate skin-innervating TRPV1+ pruriceptor sensory neurons. Our findings support the new concept of the skin, as a sensory organ, playing a critical role in cholestatic itch, beyond liver, peripheral sensory neurons, and central neural pathways supporting pruriception.

PEG-modified subunit vaccine encoding dominant epitope to enhance immune response against spring viraemia of carp virus.

Spring viraemia of carp (SVC) caused by spring viraemia of carp virus (SVCV) can infect almost all fish of cyprinids, which bring huge economic losses to aquaculture. Glycoprotein (G), as the most important antigenic determinant protein of SVCV, is widely considered as an effective method against SVCV. In our previous study, we found that G3 (131 aa) is the potential dominant antigen epitope that induces strong immune responses similar to G protein (510 aa). Here, in order to further improve the immune effect, we reported a subunit vaccine (PEG-G3) constructed by PEG-modified dominant epitope protein (G3). The results of serum antibody production, enzyme activities and immune-related genes expression showed that PEG-G3 induces significantly stronger immune protective responses against SVCV than G3. PEG modification significantly increased the serum antibody level of the vaccine, which increased significantly after immunization and reached the peak at 21 day post-vaccination. T-AOC and AKP activities in the lowest concentration group (5 µg) of PEG-G3 were significantly higher than those in the highest concentration group (20 µg) of G3. In PEG-G3 group, the expression of almost all genes increased at least 4 times compared with the control group. After 14-day challenge, the RPS (relative percentage survival) of the highest concentration of PEG-G3 group was 53.6%, while that of G3 group is 38.9%. Therefore, this work shows that PEG modification and dominant epitope screening may be effective methods to improve the immune protective effect of vaccines and to resist the infection of aquatic animal viral diseases.

Functional Characterization and Structural Basis of an Efficient Di-C-glycosyltransferase from Glycyrrhiza glabra.

A highly efficient di-C-glycosyltransferase GgCGT was discovered from the medicinal plant Glycyrrhiza glabra. GgCGT catalyzes a two-step di-C-glycosylation of flopropione-containing substrates with conversion rates of >98%. To elucidate the catalytic mechanisms of GgCGT, we solved its crystal structures in complex with UDP-Glc, UDP-Gal, UDP/phloretin, and UDP/nothofagin, respectively. Structural analysis revealed that the sugar donor selectivity was controlled by the hydrogen-bond interactions of sugar hydroxyl groups with D390 and other key residues. The di-C-glycosylation capability of GgCGT was attributed to a spacious substrate-binding tunnel, and the G389K mutation could switch di- to mono-C-glycosylation. GgCGT is the first di-C-glycosyltransferase with a crystal structure, and the first C-glycosyltransferase with a complex structure containing a sugar acceptor. This work could benefit the development of efficient biocatalysts to synthesize C-glycosides with medicinal potential.

Mutation topography and risk stratification for de novo acute myeloid leukaemia with normal cytogenetics and no nucleophosmin 1 (NPM1) mutation or Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD).

About 25% of patients with newly diagnosed acute myeloid leukaemia (AML) have normal cytogenetics and no nucleophosmin 1 (NPM1) mutation or Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD). The prognosis and best therapy for these patients is controversial. We evaluated 158 newly diagnosed adults with this genotype who achieved histological complete remission within two cycles of induction therapy and were assigned to two post-remission strategies with and without an allotransplant. Targeted regional sequencing at diagnosis was performed and data were used to estimate their prognosis, including relapse and survival. In multivariable analyses, having wild-type or mono-allelic mutated CCAAT/enhancer-binding protein alpha (CEBPA) [hazard ratio (HR) 2·39, 95% confidence interval (CI) 1·08-5·30; P = 0·032), mutated NRAS (HR 2·67, 95% CI 1·36-5·25; P = 0·004), mutated colony-stimulating factor 3 receptor (CSF3R) (HR 2·85, 95% CI 1·12-7·27; P = 0·028) and a positive measurable residual disease (MRD)-test after the second consolidation cycle (HR 2·88, 95% CI 1·32-6·30; P = 0·008) were independently correlated with higher cumulative incidence of relapse (CIR). These variables were also significantly associated with worse survival (HR 3·02, 95% CI 1·17-7·78, P = 0·022; HR 3·62, 95% CI 1·51-8·68, P = 0·004; HR 3·14, 95% CI 1·06-9·31, P = 0·039; HR 4·03, 95% CI 1·64-9·89, P = 0·002; respectively). Patients with ≥1 of these adverse-risk variables benefitted from a transplant, whereas the others did not. In conclusion, we identified variables associated with CIR and survival in patients with AML and normal cytogenetics without a NPM1 mutation or FLT3-ITD.

Osteoclast stimulatory transmembrane protein (OC-STAMP) is a promising molecular prognostic indicator for multiple myeloma.

BACKGROUND: Currently, the prognostic stratification and therapeutic evaluation systems for multiple myeloma (MM) lack specific molecular indicators. OC-STAMP is a new gene and is also highly expressed in MM. METHODS: A total of 160 MM patients have been investigated with both quantitative reverse transcription PCR (RT-qPCR), flow cytometry (FCM) and cytogenetic FISH on the same mononuclear cells isolated from bone marrow specimens. RESULTS: We found that OC-STAMP mRNA levels were significantly higher in newly diagnosed cases of MM than in healthy donors (median, 0.52% vs. 0.02%, P < .001). Moreover, the changes in the OC-STAMP mRNA levels paralleled the disease stages and minimal residual disease, as detected by FCM. Furthermore, we found that patients with high OC-STAMP mRNA levels were more likely to develop ≥3 bone lesions, be diagnosed with Durie-Salmon stages III, and have the P53 (17p13) deletion. In addition, advanced stage patients with high OC-STAMP mRNA levels had a lower 4-year progression-free survival (5.6% vs. 22.9%, P = .0055) and a worse 4-year overall survival (25.8% vs. 48.8%, P = .0137) compared to patients with low mRNA levels of this indicator. CONCLUSIONS: OC-STAMP may be a promising molecular indicator to monitor treatment effects and participate in the prognostic stratification of MM.

Chd7 Is Critical for Early T-Cell Development and Thymus Organogenesis in Zebrafish.

Coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies/deafness (CHARGE) syndrome is a congenital disorder affecting multiple organs and mainly caused by mutations in CHD7, a gene encoding a chromatin-remodeling protein. Immunodeficiency and reduced T cells have been noted in CHARGE syndrome. However, the mechanisms underlying T lymphopenia are largely unexplored. Herein, we observed dramatic decrease of T cells in both chd7knockdown and knockout zebrafish embryos. Unexpectedly, hematopoietic stem and progenitor cells and, particularly, lymphoid progenitor cells were increased peripherally in nonthymic areas in chd7-deficient embryos, unlikely to contribute to the T-cell decrease. Further analysis demonstrated that both the organogenesis and homing function of the thymus were seriously impaired. Chd7 might regulate thymus organogenesis through modulating the development of both neural crest cell-derived mesenchyme and pharyngeal endoderm-derived thymic epithelial cells. The expression of foxn1, a central regulator of thymic epithelium, was remarkably down-regulated in the pharyngeal region in chd7-deficient embryos. Moreover, the T-cell reduction in chd7-deficient embryos was partially rescued by overexpressing foxn1, suggesting that restoring thymic epithelium may be a potential therapeutic strategy for treating immunodeficiency in CHARGE syndrome. Collectively, the results indicated that chd7 was critical for thymic development and T-lymphopenia in CHARGE syndrome may be mainly attributed to the defects of thymic organogenesis. The current finding may benefit the diagnosis and therapy of T lymphopenia and immunodeficiency in CHARGE syndrome.

Short-Term Exposure to Lambda-Cyhalothrin Negatively Affects the Survival and Memory-Related Characteristics of Worker Bees Apis mellifera.

Pesticides are considered one of the major contemporary stressors of honey bee health. In this study, the effects of short-term exposure to lambda-cyhalothrin on lifespan, learning, and memory-related characteristics of Apis mellifera were systematically examined. Short-term exposure to lambda-cyhalothrin in worker bees reduced lifespan, affected learning and memory performance, reduced the homing ability, and influenced the expression levels of two learning and memory-related genes of A. mellifera. This research identifies the nature of the sublethal effects of lambda-cyhalothrin on bees and the level of exposure that can be harmful to bee health. This new information will assist in establishing guidelines for the safe use of lambda-cyhalothrin in the field.

A comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensis.

CONTEXT: Scutellaria baicalensis Georgi (Lamiaceae) is a popular medicinal plant. Its roots are used as the famous traditional Chinese medicine Huang-Qin, which is recorded in Chinese Pharmacopoeia, European Pharmacopoeia, and British Pharmacopoeia. OBJECTIVE: This review comprehensively summarizes research progress in phytochemistry, pharmacology, and flavonoid biosynthesis of S. baicalensis. METHODS: English and Chinese literature from 1973 to March 2018 was collected from databases including Web of Science, SciFinder, PubMed, Elsevier, Baidu Scholar (Chinese), and CNKI (Chinese). Scutellaria baicalensis, chemical constituents, phytochemistry, biological activities, and biosynthesis were used as the key words. RESULTS: A total of 126 small molecules (1-126) and 6 polysaccharides have been isolated from S. baicalensis. The small molecules can be classified into four structural types, namely, free flavonoids, flavonoid glycosides, phenylethanoid glycosides, and other small molecules. Extracts of S. baicalensis and its major chemical constituents have been reported to possess anti-viral, anti-tumor, anti-bacterial, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective activities. Key steps in the biosynthetic pathways of Scutellaria flavonoids have also been summarized. CONCLUSIONS: This article could be helpful for researchers who are interested in the chemical constituents, bioactivities, biosynthesis, and clinical applications of S. baicalensis.

Molecular cloning and expression analysis of the tyramine receptor genes in Apis cerana cerana.

Tyramine is a biological polyamine, which serves important functions as neurotransmitters, neuromodulators and neurohormone of the central nervous system. It participates in the regulation of various behavior and physiological processes in insects. For example, tyramine and its receptor genes are involved in the regulation of learning and memory in the animals. In this study, the full-length cDNA sequences of the tyramine receptor genes (Actyr1 and Actyr2) of the Chinese honeybee, Apis cerana cerana, were cloned and sequenced for the first time. Their expression patterns were examined in different tissues by qRT-PCR and localized in the head by in situ hybridization with digoxigenin (DIG)-labeled RNA probes. The full-length cDNAs of Actyr1 and Actyr2 are 1241 bp (GenBank accession no. KC814693) and 1270 bp (GenBank accession no.KC814693) in length and encode 297 amino acids and 399 amino acids, respectively. qRT-PCR results showed that the expression levels of both Actyr1 and Actyr2 were the highest in the head, followed by the abdomen, then the antennae and the lowest in the thorax. The expression level in the head was significantly higher than that in other tissues. Moreover, in situ hybridization showed that the expression of Actyr1 and Actyr2 genes were mainly localized to the Kenyon cells of the mushroom bodies and cells around the antennal lobes. These observations suggest that some interactions between these two genes in certain cells could be important in regulating various biological functions, such as learning and memory, in the honeybee.

Differential protein expression analysis following olfactory learning in Apis cerana.

Studies of olfactory learning in honeybees have helped to elucidate the neurobiological basis of learning and memory. In this study, protein expression changes following olfactory learning in Apis cerana were investigated using isobaric tags for relative and absolute quantification (iTRAQ) technology. A total of 2406 proteins were identified from the trained and untrained groups. Among these proteins, 147 were differentially expressed, with 87 up-regulated and 60 down-regulated in the trained group compared with the untrained group. These results suggest that the differentially expressed proteins may be involved in the regulation of olfactory learning and memory in A. cerana. The iTRAQ data can provide information on the global protein expression patterns associated with olfactory learning, which will facilitate our understanding of the molecular mechanisms of learning and memory of honeybees.

Neuropeptide VF Enhances Cannabinoid Agonist WIN55,212-2-Induced Antinociception in Mice.

BACKGROUND: Cannabinoids produce analgesia in several pain models, but the undesirable side effects from high doses of cannabinoid drugs limit their clinic use. Our recent results indicate that cannabinoid-induced antinociception was enhanced by neuropeptide VF (NPVF). Here, we investigate whether low-dose cannabinoid agonists combined with NPVF can produce effective antinociception with limited side effects. METHODS: The in vivo properties of (R)-(-1)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-napthalenylmethanone (WIN55,212-2) given alone and its combination with NPVF were evaluated in nociceptive modulation, locomotor activity, gastrointestinal transit, and tolerance development assays after intracerebroventricular administration in mice. RESULTS: In the radiant tail-flick test, the antinociception of combination of WIN55,212-2 and NPVF was more potent than that of cannabinoid agonist given alone, with an ED50 shift from 3.51 to 0.69 nmol; 9 nmol WIN55,212-2 alone and 3 nmol WIN55,212-2 combined with NPVF induced equivalent antinociception after supraspinal administration. The cannabinoid-potentiating effects of NPVF were reduced by both the cannabinoid receptor type 1 and the neuropeptide FF receptor antagonists. In the formalin assay, WIN55,212-2 combined with NPVF also significantly reduced pain-related behaviors. However, the combination of WIN55,212-2 with NPVF exerted significant hypoactivity in a manner similar to high doses of WIN55,212-2. It was important to note that the combination of WIN55,212-2 with NPVF produced nontolerance-forming antinociception and weaker inhibition of gastrointestinal transit compared with high dose of WIN55,212-2. CONCLUSIONS: These data suggest that the cannabinoid agonist combined with NPVF produces effective antinociception-lacking tolerance via both cannabinoid receptor type 1 and neuropeptide FF receptors in the brain.

Transcriptome differences in the hypopharyngeal gland between Western Honeybees (Apis mellifera) and Eastern Honeybees (Apis cerana).

BACKGROUND: Apis mellifera and Apis cerana are two sibling species of Apidae. Apis cerana is adept at collecting sporadic nectar in mountain and forest region and exhibits stiffer hardiness and acarid resistance as a result of natural selection, whereas Apis mellifera has the advantage of producing royal jelly. To identify differentially expressed genes (DEGs) that affect the development of hypopharyngeal gland (HG) and/or the secretion of royal jelly between these two honeybee species, we performed a digital gene expression (DGE) analysis of the HGs of these two species at three developmental stages (newly emerged worker, nurse and forager). RESULTS: Twelve DGE-tag libraries were constructed and sequenced using the total RNA extracted from the HGs of newly emerged workers, nurses, and foragers of Apis mellifera and Apis cerana. Finally, a total of 1482 genes in Apis mellifera and 1313 in Apis cerana were found to exhibit an expression difference among the three developmental stages. A total of 1417 DEGs were identified between these two species. Of these, 623, 1072, and 462 genes showed an expression difference at the newly emerged worker, nurse, and forager stages, respectively. The nurse stage exhibited the highest number of DEGs between these two species and most of these were found to be up-regulated in Apis mellifera. These results suggest that the higher yield of royal jelly in Apis mellifera may be due to the higher expression level of these DEGs. CONCLUSIONS: In this study, we investigated the DEGs between the HGs of two sibling honeybee species (Apis mellifera and Apis cerana). Our results indicated that the gene expression difference was associated with the difference in the royal jelly yield between these two species. These results provide an important clue for clarifying the mechanisms underlying hypopharyngeal gland development and the production of royal jelly.

Antinociceptive effects of central administration of the endogenous cannabinoid receptor type 1 agonist VDPVNFKLLSH-OH [(m)VD-hemopressin(α)], an N-terminally extended hemopressin peptide.

The cannabinoid system has been demonstrated to modulate the acute and chronic pain of multiple origins. Mouse VD-hemopressin(α) [(m)VD-Hpα], an 11-residue α-hemoglobin-derived peptide, was recently reported to function as a selective agonist of the cannabinoid receptor type 1 (CB1) in vitro. To characterize its behavioral and physiological properties, we investigated the in vivo effects of (m)VD-Hpα in mice. In the mouse tail-flick test, (m)VD-Hpα dose-dependently induced antinociception after supraspinal (EC50 = 6.69 nmol) and spinal (EC50 = 2.88 nmol) administration. The antinociceptive effects of (m)VD-Hpα (intracerebroventricularly and intrathecally) were completely blocked by N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3- carboxamide (AM251; CB1 antagonist), but not by 6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl(4-methoxyphenyl)-methanone (AM630; CB2 antagonist) or naloxone (opioid antagonist), showing its selectivity to the CB1 receptor. Furthermore, the central nervous system (CNS) effects of (m)VD-Hpα were evaluated in body temperature, locomotor activity, tolerance development, reward, and food intake assays. At the highly antinociceptive dose (3 × EC50), (m)VD-Hpα markedly exerted hypothermia and hypoactivity after supraspinal administration. Repeated intracerebroventricular injection of (m)VD-Hpα resulted in both development of tolerance to antinociception and conditioned place aversion. In addition, central injection of (m)VD-Hpα dose-dependently stimulated food consumption. These findings demonstrate that this novel cannabinoid peptide agonist induces CB1-mediated central antinociception with some CNS effects, which further supports a CB1 agonist character of (m)VD-Hpα. Moreover, the current study will be helpful to understand the in vivo properties of the endogenous peptide agonist of the cannabinoid CB1 receptor.

Cross-modal interaction between visual and olfactory learning in Apis cerana.

The power of the small honeybee brain carrying out behavioral and cognitive tasks has been shown repeatedly to be highly impressive. The present study investigates, for the first time, the cross-modal interaction between visual and olfactory learning in Apis cerana. To explore the role and molecular mechanisms of cross-modal learning in A. cerana, the honeybees were trained and tested in a modified Y-maze with seven visual and five olfactory stimulus, where a robust visual threshold for black/white grating (period of 2.8°-3.8°) and relatively olfactory threshold (concentration of 50-25%) was obtained. Meanwhile, the expression levels of five genes (AcCREB, Acdop1, Acdop2, Acdop3, Actyr1) related to learning and memory were analyzed under different training conditions by real-time RT-PCR. The experimental results indicate that A. cerana could exhibit cross-modal interactions between visual and olfactory learning by reducing the threshold level of the conditioning stimuli, and that these genes may play important roles in the learning process of honeybees.

Measurable residual disease testing by next generation sequencing is more accurate compared with multiparameter flow cytometry in adults with B-cell acute lymphoblastic leukemia.

Results of measurable residual disease (MRD)-testing by next-generation sequencing (NGS) correlate with relapse risk in adults with B-cell acute lymphoblastic leukemia (ALL) receiving chemotherapy or an allotransplant from a human leukocyte antigen (HLA)-identical relative or HLA-matched unrelated donor. We studied cumulative incidence of relapse (CIR) and survival prediction accuracy using a NGS-based MRD-assay targeting immunoglobulin genes after 2 courses of consolidation chemotherapy cycles in 93 adults with B-cell ALL most receiving HLA-haplotype-matched related transplants. Prediction accuracy was compared with MRD-testing using multi-parameter flow cytometry (MPFC). NGS-based MRD-testing detected residual leukemia in 28 of 65 subjects with a negative MPFC-based MRD-test. In Cox regression multi-variable analyses subjects with a positive NGS-based MRD-test had a higher 3-year CIR (Hazard Ratio [HR] = 3.37; 95% Confidence Interval [CI], 1.34-8.5; P = 0.01) and worse survival (HR = 4.87 [1.53-15.53]; P = 0.007). Some data suggest a lower CIR and better survival in NGS-MRD-test-positive transplant recipients but allocation to transplant was not random. Our data indicate MRD-testing by NGS is more accurate compared with testing by MPFC in adults with B-cell ALL in predicting CIR and survival. (Registered in the Beijing Municipal Health Bureau Registration N 2007-1007 and in the Chinese Clinical Trial Registry [ChiCTR-OCH-10000940 and ChiCTROPC-14005546]).

Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee (Apis mellifera).

The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.

Gene expression analysis following olfactory learning in Apis mellifera.

The honeybee has a strong learning and memory ability, and is recognized as the best model organism for studying the neurobiological basis of learning and memory. In this study, we analyzed the gene expression difference following proboscis extension response-based olfactory learning in the A. mellifera using a tag-based digital gene expression (DGE) method. We obtained about 5.71 and 5.65 million clean tags from the trained group and untrained group, respectively. A total of 259 differentially expressed genes were detected between these two samples, with 30 genes up-regulated and 229 genes down-regulated in trained group compared to the untrained group. These results suggest that bees tend to actively suppress some genes instead of activating previously silent genes after olfactory learning. Our DGE data provide comprehensive gene expression information for olfactory learning, which will facilitate our understanding of the molecular mechanism of honey bee learning and memory.

Design and synthesis of MnO2/Mn/MnO2 sandwich-structured nanotube arrays with high supercapacitive performance for electrochemical energy storage.

We demonstrate the design and fabrication of novel nanoarchitectures of MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays for supercapacitors. The crystalline metal Mn layers in the MnO(2)/Mn/MnO(2) sandwich-like nanotubes uniquely serve as highly conductive cores to support the redox active two-double MnO(2) shells with a highly electrolytic accessible surface area and provide reliable electrical connections to MnO(2) shells. The maximum specific capacitances of 937 F/g at a scan rate of 5 mV/s by cyclic voltammetry (CV) and 955 F/g at a current density of 1.5 A/g by chronopotentiometry were achieved for the MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays in solution of 1.0 M Na(2)SO(4). The hybrid MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays exhibited an excellent rate capability with a high specific energy of 45 Wh/kg and specific power of 23 kW/kg and excellent long-term cycling stability (less 5% loss of the maximum specific capacitance after 3000 cycles). The high specific capacitance and charge-discharge rates offered by such MnO(2)/Mn/MnO(2) sandwich-like nanotube arrays make them promising candidates for supercapacitor electrodes, combining high-energy densities with high levels of power delivery.