Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Template‐free protein structure prediction and quality assessment with an all‐atom free‐energy model

Biophysical forcefields have contributed less than originally anticipated to recent progress in protein structure prediction. Here, we have investigated the selectivity of a recently developed all‐atom free‐energy forcefield for protein structure prediction and quality assessment (QA). Using a heuristic method, but excluding homology, we generated decoy‐sets for all targets of the CASP7 protein structure prediction assessment with <150 amino acids. The decoys in each set were then ranked by energy in short relaxation simulations and the best low‐energy cluster was submitted as a prediction. For four of nine template‐free targets, this approach generated high‐ranking predictions within the top 10 models submitted in CASP7 for the respective targets. For these targets, our de‐novo predictions had an average GDT_S score of 42.81, significantly above the average of all groups. The refinement protocol has difficulty for oligomeric targets and when no near‐native decoys are generated in the decoy library. For targets with high‐quality decoy sets the refinement approach was highly selective. Motivated by this observation, we rescored all server submissions up to 200 amino acids using a similar refinement protocol, but using no clustering, in a QA exercise. We found an excellent correlation between the best server models and those with the lowest energy in the forcefield. The free‐energy refinement protocol may thus be an efficient tool for relative QA and protein structure prediction. Proteins 2009. © 2009 Wiley‐Liss, Inc.     

Leaf architecture of some acanthaceae

Leaf architectural pattern has been studied in 27 genera and 35 species of the Acanthaceae. The major venation pattern conforms to pinnate camptodromous with eucamptodromous or festooned brochidodromous secondaries, pinnate craspedodromous inAcanthus ilicifolius and acrodromous inLepidagathis trinervis. Intersecondary veins are common. The marginal ultimate venation is looped. The areoles are variable in size. The vein endings are usually simple, linear or cuved or divide once or twice dichotomously. Isolated vein endings, tracheids, isolated free vein endings and extension cells are observed. Transfusion tracheids are seen inDicliptera verticillata. Miniature vessel elements with simple perforation plates are noticed lying free in the areole or at the end of tracheids inSeriocalyx scaber andThunbergia grandiflora.Elytraria acaulis, Nelsonia canescens andStaurogynae zeylanica exhibit venation pattern shown by majority of the taxa studied, of the Acanthaceae.     

Carbon‐Coated Li3Nd3W2O12: A High Power and Low‐Voltage Insertion Anode with Exceptional Cycleability for Li‐Ion Batteries

The synthesis of carbon‐coated Li₃Nd₃W₂O₁₂ (C‐Li₃Nd₃W₂O₁₂), a low voltage insertion anode (0.3 V vs. Li) for a Li‐ion battery, is reported to exhibit extraordinary performance. The low voltage reversible insertion provides an increase in the energy density of Li‐ion power packs. For instance, C‐Li₃Nd₃W₂O₁₂ delivered an energy density of ≈390 Wh kg^?1 (based on cathode mass loading) when coupled with an LiMn₂O₄ cathode with an operating potential of 3.4 V. Furthermore, excellent cycling profiles are observed for C‐Li₃Nd₃W₂O₁₂ anodes both in half and full‐cell configurations. The full‐cell is capable of delivering very stable cycling profiles at high current rates (e.g., 2 C), which clearly suggests the high power capability of such garnet‐type anodes.     

Aldose reductase mediates endotoxin-induced production of nitric oxide and cytotoxicity in murine macrophages

Aldose reductase (AR) is a ubiquitously expressed protein with pleiotrophic roles as an efficient catalyst for the reduction of toxic lipid aldehydes and mediator of hyperglycemia, cytokine, and growth factor-induced redox-sensitive signals that cause secondary diabetic complications. Although AR inhibition has been shown to be protective against oxidative stress signals, the role of AR in regulating nitric oxide (NO) synthesis and NO-mediated apoptosis has not been elucidated to date. We therefore investigated the role of AR in regulating lipopolysaccharide (LPS)-induced NO synthesis and apoptosis in RAW 264.7 macrophages. Inhibition or RNA interference ablation of AR suppressed LPS-stimulated production of NO and overexpression of iNOS mRNA. Inhibition or ablation of AR also prevented the LPS-induced apoptosis, cell cycle arrest, activation of caspase-3, p38-MAPK, JNK, NF-kappaB, and AP1. In addition, AR inhibition prevented the LPS-induced down-regulation of Bcl-xl and up-regulation of Bax and Bak in macrophages. L-Arginine increased and L-NAME decreased the severity of cell death caused by LPS and AR inhibitors prevented it. Furthermore, inhibition of AR prevents cell death caused by HNE and GS-HNE, but not GS-DHN. Our findings for the first time suggest that AR-catalyzed lipid aldehyde-glutathione conjugates regulate the LPS-induced production of inflammatory marker NO and cytotoxicity in RAW 264.7 cells. Inhibition or ablation of AR activity may be a potential therapeutic target in endotoximia and other inflammatory diseases.     

MicroRNA profiles in Sorghum exposed to individual drought or heat or their combination

Sorghum is largely grown for food, fodder and for biofuel production in semi-arid regions where the drought or high temperature or their combination co-occur. Plant microRNAs (miRNAs) are integral to the gene regulatory networks that control almost all biological processes including adaptation to stress conditions. Thus far, plant miRNA profiles under separate drought or heat stresses have been reported but not under combined drought and heat. In this study, we report miRNA profiles in leaves of sorghum exposed to individual drought or heat or their combination. Approximately 29 conserved miRNA families represented by 80 individual miRNAs, 26 families represented by 47 members of less conserved or sorghum-specific miRNA families as well as 8 novel miRNA families have been identified. Of these, 25 miRNAs were found to be differentially regulated in response to stress treatments. The comparative profiling revealed that the miRNA regulation was stronger under heat or combination of heat and drought compared to the drought alone. Furthermore, using degradome sequencing, 48 genes were confirmed as targets for the miRNAs in sorghum. Overall, this study provides a framework for understanding of the miRNA-guided gene regulations under combined stresses.

     

Surfactant Protein D Inhibits HIV-1 Infection of Target Cells via Interference with gp120-CD4 Interaction and Modulates Pro-Inflammatory Cytokine Production

Surfactant Protein SP-D, a member of the collectin family, is a pattern recognition protein, secreted by mucosal epithelial cells and has an important role in innate immunity against various pathogens. In this study, we confirm that native human SP-D and a recombinant fragment of human SP-D (rhSP-D) bind to gp120 of HIV-1 and significantly inhibit viral replication in vitro in a calcium and dose-dependent manner. We show, for the first time, that SP-D and rhSP-D act as potent inhibitors of HIV-1 entry in to target cells and block the interaction between CD4 and gp120 in a dose-dependent manner. The rhSP-D-mediated inhibition of viral replication was examined using three clinical isolates of HIV-1 and three target cells: Jurkat T cells, U937 monocytic cells and PBMCs. HIV-1 induced cytokine storm in the three target cells was significantly suppressed by rhSP-D. Phosphorylation of key kinases p38, Erk1/2 and AKT, which contribute to HIV-1 induced immune activation, was significantly reduced in vitro in the presence of rhSP-D. Notably, anti-HIV-1 activity of rhSP-D was retained in the presence of biological fluids such as cervico-vaginal lavage and seminal plasma. Our study illustrates the multi-faceted role of human SP-D against HIV-1 and potential of rhSP-D for immunotherapy to inhibit viral entry and immune activation in acute HIV infection.     

Bimodal oxygen uptake in a freshwater air-breathing fish,Notopterus chitala

Measurements of bimodal oxygen uptake have been made in a freshwater air-breathing fish,Notopterus chitala at 29.0±1(S.D.)°C. xhe mean oxygen uptake from continuously flowing water without any access to air, was found to be 3.58±0.37 (S.E.) ml O₂ · h^?1 and 56.84+4.29 (S.E.) ml O₂ · kg^?1 · h^?1 for a fish weighing 66.92 + 11.27 (S.E.) g body weight. In still water with access to air, the mean oxygen uptake through the gills were recorded to be 2.49 ± 0.31 (S.E.) ml O₂ · h^?1 and 38.78 ± 1.92 (S.E.) ml O₂ · kg^?1 · h^?1 and through the accessory respiratory organs (swim-bladder) 6.04±0.87 (S.E.) ml O₂ · h^?1 and 92.32±2.91 (S.E.) ml O₂ · kg^?1 · h^?1 for a fish averaging 66.92±11.27 (S.E.) g. Out of the total oxygen uptake (131.10 ml O₂ · kg^?1 · h^?1), about 70% was obtained through the aerial route and the remainder 30% through the gills.     

Tissue-specific role of glycogen synthase kinase 3beta in glucose homeostasis and insulin action

Dysregulation of the protein kinase glycogen synthase kinase 3 (GSK-3) has been implicated in the development of type 2 diabetes mellitus. GSK-3 protein expression and kinase activity are elevated in diabetes, while selective GSK-3 inhibitors have shown promise as modulators of glucose metabolism and insulin sensitivity. There are two GSK-3 isoforms in mammals, GSK-3α and GSK-3β. Mice engineered to lack GSK-3β die in late embryogenesis from liver apoptosis, whereas mice engineered to lack GSK-3α are viable and exhibit improved insulin sensitivity and hepatic glucose homeostasis. To assess the potential role of GSK-3β in insulin function, a conditional gene-targeting approach whereby mice in which expression of GSK-3β was specifically ablated within insulin-sensitive tissues were generated was undertaken. Liver-specific GSK-3β knockout mice are viable and glucose and insulin tolerant and display “normal” metabolic characteristics and insulin signaling. Mice lacking expression of GSK-3β in skeletal muscle are also viable but, in contrast to the liver-deleted animals, display improved glucose tolerance that is coupled with enhanced insulin-stimulated glycogen synthase regulation and glycogen deposition. These data indicate that there are not only distinct roles for GSK-3α and GSK-3β within the adult but also tissue-specific phenotypes associated with each of these isoforms.     

Molecular phylogeny of elasmobranchs inferred from mitochondrial and nuclear markers

The elasmobranchs (sharks, rays and skates) being the extant survivors of one of the earliest offshoots of the vertebrate evolutionary tree are good model organisms to study the primitive vertebrate conditions. They play a significant role in maintaining the ecological balance and have high economic value. Due to over-exploitation and illegal fishing worldwide, the elasmobranch stocks are being decimated at an alarming rate. Appropriate management measures are necessary for restoring depleted elasmobranch stocks. One approach for restoring stocks is implementation of conservation measures and these measures can be formulated effectively by knowing the evolutionary relationship among the elasmobranchs. In this study, a total of 30 species were chosen for molecular phylogeny studies using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA gene and nuclear Internal Transcribed Spacer 2. Among different genes, the combined dataset of COI and 12S rRNA resulted in a well resolved tree topology with significant bootstrap/posterior probabilities values. The results supported the reciprocal monophyly of sharks and batoids. Within Galeomorphii, Heterodontiformes (bullhead sharks) formed as a sister group to Lamniformes (mackerel sharks): Orectolobiformes (carpet sharks) and to Carcharhiniformes (ground sharks). Within batoids, the Myliobatiformes formed a monophyly group while Pristiformes (sawfishes) and Rhinobatiformes (guitar fishes) formed a sister group to all other batoids.