Down-regulation of Glucan, Water-Dikinase activity in wheat endosperm increases vegetative biomass and yield

A novel mechanism for increasing vegetative biomass and grain yield has been identified in wheat (Triticum aestivum). RNAi-mediated down-regulation of Glucan, Water-Dikinase (GWD), the primary enzyme required for starch phosphorylation, under the control of an endosperm-specific promoter, resulted in a decrease in starch phosphate content and an increase in grain size. Unexpectedly, consistent increases in vegetative biomass and grain yield were observed in subsequent generations. In lines where GWD expression was decreased, germination rate was slightly reduced. However, significant increases in vegetative growth from the two leaf stage were observed. In glasshouse pot trials, down-regulation of GWD led to a 29% increase in grain yield while in glasshouse tub trials simulating field row spacing and canopy development, GWD down-regulation resulted in a grain yield increase of 26%. The enhanced yield resulted from a combination of increases in seed weight, tiller number, spikelets per head and seed number per spike. In field trials, all vegetative phenotypes were reproduced with the exception of increased tiller number. The expression of the transgene and suppression of endogenous GWD RNA levels were demonstrated to be grain specific. In addition to the direct effects of GWD down-regulation, an increased level of α-amylase activity was present in the aleurone layer during grain maturation. These findings provide a potentially important novel mechanism to increase biomass and grain yield in crop improvement programmes.     

Reviewing the technological challenges associated with the development of a laparoscopic palpation device

Minimally invasive surgery (MIS) has heralded a revolution in surgical practice, with numerous advantages over open surgery. Nevertheless, it prevents the surgeon from directly touching and manipulating tissue and therefore severely restricts the use of valuable techniques such as palpation. Accordingly a key challenge in MIS is to restore haptic feedback to the surgeon. This paper reviews the state-of-the-art in laparoscopic palpation devices (LPDs) with particular focus on device mechanisms, sensors and data analysis. It concludes by examining the challenges that must be overcome to create effective LPD systems that measure and display haptic information to the surgeon for improved intraoperative assessment.     

Relationship between Body Mass Index,C-Peptide,and Delta-5-Desaturase Enzyme Activity Estimates in Adult Males

Obesity, in particular abdominal obesity, alters the composition of plasma and tissue fatty acids (FAs), which contributes to inflammation and insulin resistance. FA metabolism is modulated by desaturases and may affect adipokine and insulin secretion. Therefore, we examined relationships between adipokines, a marker of insulin production, and plasma FA desaturase enzyme activity estimates (EAEs) in obesity. Plasma phospholipid (PPL) FAs were isolated from 126 males (ages 48 to 65 years), derivatized, and analyzed using gas chromatography. Delta-6 desaturase (D6D) and delta-5 desaturase (D5D) EAEs were calculated as the ratio of PPL 20:3/18:2 and 20:4/20:3, respectively. In body mass index (BMI) and waist circumference (WC) adjusted polytomous logistic regression analyses, PPL FAs and FA desaturase EAEs were associated with C-peptide and adiponectin. Individuals with elevated D6D EAEs were less likely (OR 0.33) to have serum adiponectin concentrations > 5.37 μg/mL, compared with adiponectin concentrations ≤ 3.62 μg/mL. Individuals with increased D5D EAEs were less likely (OR 0.8) to have C-peptide concentrations ≥ 3.32 ng/mL, and > 1.80 and ≤ 3.29 ng/mL, compared with those with C-peptide ≤ 1.76 ng/mL. The proinflammatory cytokine tumor necrosis factor-α (TNF- α) was positively associated with C-peptide, but TNF- α was not associated with the D5D EAE. C-peptide and adiponectin concentrations are associated with specific PPL FAs and FA desaturase EAEs. The relationship between C-peptide concentrations and D5D EAEs remained significant after adjusting for BMI, WC, and TNF-α. Thus, future research should investigate whether D5D inhibition may occur through a C-peptide mediated pathway.     

Phylogeography of Emerita analoga (Crustacea,Decapoda, Hippidae), an eastern Pacific Ocean sand crab with long‐lived pelagic larvae

Aim Phylogeographic analyses have confirmed high dispersal in many marine taxa but have also revealed many cryptic lineages and species, raising the question of how population and regional genetic diversity arise and persist in dynamic oceanographic settings. Here we explore the geographic evolution of Emerita analoga, an inter‐tidal sandy beach crab with an exceptionally long pelagic larval phase and wide latitudinal, amphitropical, distribution. We test the hypothesis that eastern Pacific E. analoga constitute a single panmictic population and examine the location(s), timing and cause(s) of phylogeographic differentiation. Location Principally the eastern Pacific Ocean. Methods We sequenced cytochrome c oxidase subunit I (COI) from 742 E. analoga specimens collected between 1997 and 2000 and downloaded homologous sequences of congeners from GenBank. We reconstructed a phylogeny for Emerita species using maximum likelihood and Bayesian methods and estimated times to most recent common ancestors (TMRCAs), using a COI divergence rate of 1% Myr^?1 and timing of closure of the Central American Seaway. We constructed the COI haplotype network of E. analoga using statistical parsimony, calculated population genetic and spatial structure statistics in Arlequin , and estimated the demographic history of E. analoga using Bayesian skyline analysis. Results Population subdivision and allele frequency differences were insignificant among north‐eastern Pacific locations over 2000 km apart (Φ_ST = 0.00, P = 0.70), yet two distinct phylogroups were recovered from the north‐eastern and south‐eastern Pacific (Φ_CT = 0.87, P < 0.001). Amphitropical differentiation of these temperate clades occurred after TMRCA 1.9 ± 0.02 (mean ± SE) Ma and E. analoga has expanded into its present‐day north‐eastern Pacific range since c. 250 ka. Main conclusions Emerita analoga is not panmictic but is very widely dispersed and approaching genetic homogeneity, i.e. ‘eurymixis’, in the north‐eastern Pacific. North‐eastern and south‐eastern Pacific populations of E. analoga probably became isolated c. 1.5 Ma as the tropical eastern Pacific Ocean warmed and expanded, intensifying barriers to gene flow. The fragmentation of a widespread ancestral species previously connected by long‐distance gene flow (‘soft vicariance’) coincident with changing oceanographic conditions may be a common theme in the evolution of Emerita species and in other highly dispersive taxa. Highly dispersive species may differentiate because of, not despite, the dynamic oceanographic setting.     

Isoquinoline-based analogs of the cancer drug clinical candidate tipifarnib as anti-Trypanosoma cruzi agents

We developed a synthetic route to prepare isoquinoline analogs of the cancer drug clinical candidate tipifarnib. We show that these compounds kill Trypanosoma cruzi amastigotes grown in mammalian host cells at concentrations in the low nanomolar range. These isoquinolines represent new leads for the development of drugs to treat Chagas disease.     

Phase diagrams of lipid mixtures relevant to the study of membrane rafts

The present paper reviews the phase properties of phosphatidylcholine-sphingomyelin-cholesterol mixtures, that are often used as models for membrane "raft" microdomains. The available data based on X-ray, microscopic and spectroscopic observations, surface pressure and calorimetric measurements, and detergent solubilization assays, are critically evaluated and rationalized in terms of triangular phase diagrams. The remaining uncertainties are discussed specifically and separately from the data on which a consensus appears to exist.     

U2AF participates in the binding of TAP (NXF1) to mRNA.

TAP/NXF1 is a conserved mRNA export receptor serving as a link between messenger ribonucleoproteins (mRNPs) and the nuclear pore complex. The mechanism by which TAP recognizes its export substrate is unclear. We show here that TAP is added to spliced mRNP in human cells. We identified a distinct region of TAP that targets it to mRNP. Using yeast two-hybrid screens and in vitro binding studies, we found that this region coincides with a direct binding site for U2AF35, the small subunit of the splicing factor U2AF. This interaction is evolutionarily conserved across metazoa, indicating its significance. We further found in human cells that the exogenously expressed large U2AF subunit, U2AF65, accumulates in spliced mRNP, leading to the recruitment of U2AF35 and TAP. Similarly to TAP, U2AF65 stimulated directly the nuclear export and expression of an mRNA that is otherwise retained in the nucleus. Together with our finding that U2AF is continuously exported from the nucleus, these data suggest that U2AF participates in nuclear export, by facilitating TAP's addition to its mRNA substrates.     

Evaluation of the genotoxicity of piplartine, an alkamide of Piper tuberculatum, in yeast and mammalian V79 cells

The genus Piper belongs to the Piperaceae family, and includes species of commercial and medicinal importance. Chemical studies on Piper species resulted in the isolation of several biologically active molecules, including alkaloid amides, such as piplartine. This molecule, isolated from Piper tuberculatum, has significant cytotoxic activity against tumor cell lines, and presents antifungal, anti-platelet aggregation, anxiolytic, and antidepressant effects. In order to understand the biological properties of piplartine, this study investigated the genotoxicity and the induction of apoptosis by piplartine in V79 cells and its mutagenic and recombinogenic potential in Saccharomyces cerevisiae. Piplartine induced dose-dependent cytotoxicity in S. cerevisiae cultures in either stationary—or exponential growth phase. In addition, piplartine was not mutagenic when cells were treated during exponential-growth phase and kept in buffer solution, but it increased the frequencies of point, frameshift, and forward mutations when cells were treated in medium during growth. Piplartine treatment induced DNA strand breaks in V79 cells, as detected by neutral and alkaline comet assay. In cell cycle analysis, piplartine induced G2/M cell cycle arrest, probably as a consequence of the DNA damage induced and repair. Moreover, piplartine treatment induced apoptosis in a dose-dependent manner, as observed by a decrease in mitochondrial membrane potential and an increase in internucleosomal DNA fragmentation. These data suggest that the DNA damage caused by piplartine induces G2/M cell cycle arrest, followed by apoptosis. Moreover, we suggest that cells surviving piplartine-induced DNA damage can accumulate mutations, since this alkaloid was mutagenic and recombinogenic in S. cerevisiae assays.     

Synthesis and activity of 1-(3-amino-1-phenylpropyl)indolin-2-ones: a new class of selective norepinephrine reuptake inhibitors

Norepinephrine and serotonin play an important role in a wide variety of biological processes and are implicated in a number of neurological disorders. A novel class of 1-(3-amino-1-phenylpropyl)indolin-2-ones was designed and synthesized that displays potent norepinephrine reuptake inhibition while maintaining high selectivity (>100-fold) against the human serotonin and dopamine transporters.     

Antifungal skin bacteria,embryonic survival,and communal nesting in four-toed salamanders, <Emphasis Type="Italic">Hemidactylium scutatum</Emphasis>

We examined a novel hypothesis for the maintenance of communal nesting in the salamander, Hemidactylium scutatum, namely that communal nests are more likely than solitary nests to be associated with cutaneous antifungal bacteria, which can inhibit fungal infections of embryos. A communal nest contains eggs of two or more females of the same species. The nesting behavior of H. scutatum females and survival of embryos were determined by frequent nest surveys at three ponds. For communal nests, embryonic survival tended to be higher and catastrophic nest failure was lower. Pure bacterial cultures of resident species were obtained from the salamanders’ skins by swabbing and tested against a fungal pathogen of embryos (Mariannaea sp.) in laboratory assays. We found that 27% of females had skin bacteria inhibitory to Mariannaea sp. Communal nests were more likely to have at least one female with antifungal bacteria than were solitary nests. Using a culture-independent assay (denaturing gradient gel electrophoresis of 16S rRNA gene fragments), we found that bacterial species on females and embryos were more similar to each other than they were to bacterial species found in soil within the nest, suggesting that females transmitted skin bacteria to embryos. The presence of anti-Mariannaea skin bacteria identified from the laboratory assays did not prevent fungal presence in field nests. However, once a nest was visibly infected with fungi, presence of anti-Mariannaea bacteria was positively correlated with survival of embryos. Microbe transmission is usually thought to be a cost of group living, but communal nesting in H. scutatum may facilitate the transmission of antifungal bacteria to embryos.