Influenza A virus infection in zebrafish recapitulates mammalian infection and sensitivity to anti-influenza drug treatment

Seasonal influenza virus infections cause annual epidemics and sporadic pandemics. These present a global health concern, resulting in substantial morbidity, mortality and economic burdens. Prevention and treatment of influenza illness is difficult due to the high mutation rate of the virus, the emergence of new virus strains and increasing antiviral resistance. Animal models of influenza infection are crucial to our gaining a better understanding of the pathogenesis of and host response to influenza infection, and for screening antiviral compounds. However, the current animal models used for influenza research are not amenable to visualization of host-pathogen interactions or high-throughput drug screening. The zebrafish is widely recognized as a valuable model system for infectious disease research and therapeutic drug testing. Here, we describe a zebrafish model for human influenza A virus (IAV) infection and show that zebrafish embryos are susceptible to challenge with both influenza A strains APR8 and X-31 (Aichi). Influenza-infected zebrafish show an increase in viral burden and mortality over time. The expression of innate antiviral genes, the gross pathology and the histopathology in infected zebrafish recapitulate clinical symptoms of influenza infections in humans. This is the first time that zebrafish embryos have been infected with a fluorescent IAV in order to visualize infection in a live vertebrate host, revealing a pattern of vascular endothelial infection. Treatment of infected zebrafish with a known anti-influenza compound, Zanamivir, reduced mortality and the expression of a fluorescent viral gene product, demonstrating the validity of this model to screen for potential antiviral drugs. The zebrafish model system has provided invaluable insights into host-pathogen interactions for a range of infectious diseases. Here, we demonstrate a novel use of this species for IAV research. This model has great potential to advance our understanding of influenza infection and the associated host innate immune response.KEY WORDS: Influenza, Zebrafish, Virus, Innate immunity     

No genetic bottleneck or associated microparasite loss in invasive populations of a freshwater amphipod

Understanding what factors determine the success of an invasive species in its adopted range is crucial from an evolutionary ecology point of view, because it can provide insights into which biological characteristics are required for survival in varied environmental conditions. Successful establishment may depend on both maintaining genetic diversity, which will allow the species to evolve and/or adapt to new environments, and the presence or absence of natural enemies such as parasites. We tested these two hypotheses by studying populations of the amphipod crustacean Dikerogammarus villosus . This Ponto-Caspian invader has rapidly and successfully invaded western Europe and threatens macroinvertebrate biodiversity in its adopted ranges. It is a unique system to study since both its colonisation history and its geographic origins are well-known. Using samples from the whole geographic range of the invasion route, and using four molecular markers, we found no evidence for genetic bottlenecks during the invasion of D. villosus in western Europe, despite slight variations in allelic proportions according to spatio-temporal subdivisions of our dataset. In addition, we analysed the prevalence and diversity of parasites across its native and adopted range. We found no macro-parasites, and no significant parasite loss of microsporidian parasites during the invasive process. Our data suggest that D. villosus invasion was either massive, or recurrent, or both, allowing a parasitic cortege to follow the host. The maintenance of genetic diversity may have contributed to its success, including the variation in resistance in the face of the natural enemies.     

Greenhouse Gas Profile of a Plastic Material Derived from a Genetically Modified Plant

Abstract: This article reports an assessment of the global warming potential associated with the life cycle of a biopolymer (poly(hydroxyalkanoate) or PHA) produced in genetically engineered corn developed by Monsanto. The grain corn is harvested in a conventional manner, and the polymer is extracted from the corn stover (i.e., residues such as stalks, leaves and cobs), which would be otherwise left on the field. While corn farming was assessed based on current practice, four different hypothetical PHA production scenarios were tested for the extraction process. Each scenario differed in the energy source used for polymer extraction and compounding, and the results were compared to polyethylene (PE). The first scenario involved burning of the residual biomass (primarily cellulose) remaining after the polymer was extracted from the stover. In the three other scenarios, the use of conventional energy sources of coal, oil, and natural gas were investigated. This study indicates that an integrated system, wherein biomass energy from corn stover provides energy for polymer processing, would result in a better greenhouse gas profile for PHA than for PE. However, plant-based PHA production using fossil fuel sources provides no greenhouse gas advantage over PE, in fact scoring worse than PE. These results are based on a "cradle-to-pellet" modeling as the PHA end-of-life was not quantitatively studied due to complex issues surrounding the actual fate of postconsumer PHA.     

SINGLE LOCUS MICROSATELLITES IN GRACILARIALES (RHODOPHYTA): HIGH LEVEL OF GENETIC VARIABILITY WITHIN GRACILARIA GRACILIS AND CONSERVATION IN RELATED SPECIES1

Four single locus microsatellites identified in the red alga Gracilaria gracilis (Stackhouse) Steentoft, Irvine, et Farnham (Rhodophyta) were examined for allelic diversity at different spatial and taxonomic levels. First, because simple morphological diagnostic characters are often missing within the Gracilariaceae, we developed a simple and rapid method based on rDNA ITS size variation in order to verify the taxonomic status of the samples used in this study. All European (including Mediterranean samples), Argentinian, and Namibian samples used in our study were confirmed to be a homogenous G. gracilis group. By contrast, our results on rDNA ITS sizes showed that Gracilaria from Japan, initially identified as G. gracilis, was different from the rest of the G. gracilis group. Secondly, microsatellite polymorphism and conservation at the species level was tested on the worldwide collection of G. gracilis and within a single population. The loci Gv1AAG and Gv1AAC showed no allelic variation, whereas two others, Gv1CT and Gv2CT, were highly polymorphic. All microsatellite loci were conserved within G. gracilis, except in the sample from Japan. The taxonomic status of G. gracilis from Japan is thus questionable. This study revealed a high level of within-population polymorphism (52 alleles for Gv1CT and 12 for Gv2CT). Moreover, the combination of these two loci was shown to be very powerful for identifying individuals within a population, that is, 93% of the individuals were characterized by a unique genotype. Finally, conservation of the four loci was tested in taxonomically related species of Gracilaria (G. chilensis, G. pacifica, and G. tikvahiae) and two Gracilariopsis species (Gs. sp. and Gs. longissima). The results suggest that the polymorphic locus Gv2CT may provide a valuable genetic marker within the different species of the Gracilariaceae.     

Bifunctional plant defence enzymes with chitinase and ribosome inactivating activities from Trichosanthes kirilowii cell cultures

Three bifunctional plant enzymes (named TKC 15, TKC 28-I, and TKC 28-II) with both chitinase and RIP activity were purified from the medium of Trichosanthes kirilowii plant cell cultures. Highly purified preparations of these proteins exhibited endochitolytic activity as well as the specific 28S rRNA N-glycosidase activity characteristic of ribosome inactivating proteins (RIPs). In addition to providing a competitive advantage to the plant, these enzymes offer the possibility of improved antifungal protection when expressed in transgenic plants.     

Data quality and uncertainty in LCI

It has recently been acknowledged that the quality of data used in Life Cycle Assessment (LCA) is one of the most important limiting factors to the application of the methodology. Early approaches dealing with this problem solely based on Data Quality Indicators (DQI) have revealed their limitations, and stochastic models are increasingly proposed as an alternative. Although facing methodological and practical difficulties, for instance the characterization of the distribution of input data, these stochastic models can significantly enhance decision-making in LCA. Uncertainty and data quality, however, are two distinct attributes. No matter how sophisticated the stochastic models are, they do not address the issue of the adequacy of the data used with regard to the goal of the study. Actual data on the distribution of SO emissions for US coal fired power plants for instance, would be of low quality for a European study. It is therefore believed that mixed approaches DQI/stochastic models should be developed in the future.     

The SMC-5/6 Complex and the HIM-6 (BLM) Helicase Synergistically Promote Meiotic Recombination Intermediate Processing and Chromosome Maturation during Caenorhabditis elegans Meiosis

Meiotic recombination is essential for the repair of programmed double strand breaks (DSBs) to generate crossovers (COs) during meiosis. The efficient processing of meiotic recombination intermediates not only needs various resolvases but also requires proper meiotic chromosome structure. The Smc5/6 complex belongs to the structural maintenance of chromosome (SMC) family and is closely related to cohesin and condensin. Although the Smc5/6 complex has been implicated in the processing of recombination intermediates during meiosis, it is not known how Smc5/6 controls meiotic DSB repair. Here, using Caenorhabditis elegans we show that the SMC-5/6 complex acts synergistically with HIM-6, an ortholog of the human Bloom syndrome helicase (BLM) during meiotic recombination. The concerted action of the SMC-5/6 complex and HIM-6 is important for processing recombination intermediates, CO regulation and bivalent maturation. Careful examination of meiotic chromosomal morphology reveals an accumulation of inter-chromosomal bridges in smc-5; him-6 double mutants, leading to compromised chromosome segregation during meiotic cell divisions. Interestingly, we found that the lethality of smc-5; him-6 can be rescued by loss of the conserved BRCA1 ortholog BRC-1. Furthermore, the combined deletion of smc-5 and him-6 leads to an irregular distribution of condensin and to chromosome decondensation defects reminiscent of condensin depletion. Lethality conferred by condensin depletion can also be rescued by BRC-1 depletion. Our results suggest that SMC-5/6 and HIM-6 can synergistically regulate recombination intermediate metabolism and suppress ectopic recombination by controlling chromosome architecture during meiosis.     

C-Peptide Level in Fasting Plasma and Pooled Urine Predicts HbA1c after Hospitalization in Patients with Type 2 Diabetes Mellitus

In this study, we investigate how measures of insulin secretion and other clinical information affect long-term glycemic control in patients with type 2 diabetes mellitus. Between October 2012 and June 2014, we monitored 202 diabetes patients who were admitted to the hospital of Asahi Life Foundation for glycemic control, as well as for training and education in diabetes management. We measured glycated hemoglobin (HbA1c) six months after discharge to assess disease management. In univariate analysis, fasting plasma C-peptide immunoreactivity (F-CPR) and pooled urine CPR (U-CPR) were significantly associated with HbA1c, in contrast to ΔCPR and C-peptide index (CPI). This association was strongly independent of most other patient variables. In exploratory factor analysis, five underlying factors, namely insulin resistance, aging, sex differences, insulin secretion, and glycemic control, represented patient characteristics. In particular, insulin secretion and resistance strongly influenced F-CPR, while insulin secretion affected U-CPR. In conclusion, the data indicate that among patients with type 2 diabetes mellitus, F-CPR and U-CPR may predict improved glycemic control six months after hospitalization.     

Presence of Various Carbohydrate Moieties Including β-Galactose and N-Acetylglucosamine Residues on Solubilized Porcine Brain Neurokinin-1/Substance P Receptors

Neurokinin-1 (NK-1)/substance P (SP) receptors were solubilized using 10 mM 3-[( cholamidopropyl)-dimethylammonio]-1- propanesulfate from porcine striatal membranes (solubilization yield, 80%). In solubilized preparations, [3H]SP apparently bound to a single class of high-affinity sites (KD = 0.82 +/- 0.13 nM) as in membrane homogenates. The ligand selectivity pattern observed in both membrane and solubilized receptor preparations indicated that [Sar9,Met(O2)11]SP = SP much greater than senktide = [Nle10]neurokinin A. This suggests the selective labeling of the NK-1 receptor class in both assays. Solubilized receptors were retained on agarose-coupled lectins that bind N-acetylglucosamine-galactose and beta-galactose (Ricinus communis I and Ricinus communis II), mannose (concanavalin A and lentil), and N-acetylglucosamine (wheat germ agglutinin) but not on lectins binding fucose (Lotus A) and N-acetylgalactosamine (Doli-chos biflorus A). Thus, it appears that porcine brain NK-1/SP receptors are enriched with various carbohydrate moieties, beta-galactose and N-acetylglucosamine-galactose residues being especially abundant. This situation is rather different from that in various other members of the rhodopsin seven-transmembrane receptor superfamily.