Epichloe canadensis, a new interspecific epichloid hybrid symbiotic with Canada wildrye (Elymus canadensis)

Many Epichlo? endophytes found in cool-season grasses are interspecific hybrids possessing much or all of the genomes of two or three progenitors. Here we characterize Epichlo? canadensis sp. nov., a hybrid species inhabiting the grass species Elymus canadensis native to North America. Three distinct morphotypes were identified that were separated into two groups by molecular phylogenetic analysis. Sequence analysis of the translation elongation factor 1-α (tefA) and β-tubulin (tubB) genes revealed two copies in all isolates examined. Phylogenetic analyses indicated that allele 1 of each gene was derived from Epichlo? amarillans and allele 2 from Epichlo? elymi. This is the first documentation of an interspecific hybrid endophyte derived from parents of strictly North American origins. Alkaloid gene profiling using primers specific to genes in the peramine, loline, indole-diterpene and ergot alkaloid pathways may indicate chemotypic variation in the ergot alkaloid and loline pathways between the assigned morphotypes. All isolates have the gene enabling the production of peramine but lack genes in the indole-diterpene biosynthesis pathway. Morphology and phylogenetic evidence support the designation of isolates from El. canadensis as a new interspecific hybrid species.     

Influenza A virus neuraminidase protein enhances cell survival through interaction with carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) protein

The influenza virus neuraminidase (NA) protein primarily aids in the release of progeny virions from infected cells. Here, we demonstrate a novel role for NA in enhancing host cell survival by activating the Src/Akt signaling axis via an interaction with carcinoembryonic antigen-related cell adhesion molecule 6/cluster of differentiation 66c (C6). NA/C6 interaction leads to increased tyrosyl phosphorylation of Src, FAK, Akt, GSK3β, and Bcl-2, which affects cell survival, proliferation, migration, differentiation, and apoptosis. siRNA-mediated suppression of C6 resulted in a down-regulation of activated Src, FAK, and Akt, increased apoptosis, and reduced expression of viral proteins and viral titers in influenza virus-infected human lung adenocarcinoma epithelial and normal human bronchial epithelial cells. These findings indicate that influenza NA not only aids in the release of progeny virions, but also cell survival during viral replication.     

Novel fluorophores for labeling of nucleosides and oligonucleotides

Five novel fluorophores have been synthesized and their comparative fluorescence has been studied in different organic solvents and aqueous solutions of inorganic ions. Out of these, two highly sensitive fluorophores have been used to label phosphoramidites and oligodeoxyribonucleotides. The fluorescently labelled amidites and oligodeoxyribonucleotides showed good fluorescence signals.     

Alkaline phosphatase: keeping the peace at the gut epithelial surface

Vertebrate intestinal surfaces are in constant contact with a vast consortium of commensal bacteria. To preserve mutually beneficial host-microbial relationships, gut epithelia have evolved strategies to limit the proinflammatory potential of resident gut microbes. In this issue of Cell Host & Microbe, Bates and colleagues report that intestinal alkaline phosphatase, whose expression is induced during establishment of the microbiota, dephosphorylates lipopolysaccharide and promotes mucosal tolerance to commensal bacteria in zebrafish.     

Targeting prokaryotic choline oxidase into chloroplasts enhance the potential of photosynthetic machinery of plants to withstand oxidative damage

Chloroplasts from plants of transgenic lines expressing prokaryotic choline oxidase gene (the codA_ps gene; GenBank accession number-AY589052) and wild-type of chickpea and Indian mustard were evaluated for their efficacy to withstand photoinhibitory damage, by exposing them to high light intensity (～1200 μmol m^?2 s^?1 photon flux density) at 10 and 25 °C. Western analysis confirmed presence of choline oxidase in chloroplasts of only transgenic lines. The loss in PS II activity in chloroplasts of wild-type exposed to high light intensity was significantly higher than that in chloroplasts of transgenic chickpea as well as Indian mustard. Although, chloroplasts of both wild-type and transgenic chickpea as well as Indian mustard were more sensitive to photoinhibitory damage at 10 than at 25 °C, the damage recorded in chloroplasts harboring choline oxidase was significantly lower than those of wild-type. High light promotes H₂O₂ production in chloroplasts more significantly at low temperature (10 °C) than at 25 °C. We compared low temperature accelerated photoinhibition of chloroplasts with that caused due to exogenously applied H₂O₂. Although exogenous H₂O₂ accelerated high light intensity induced loss in PS II activity of chloroplasts of wild-type, it caused only a little alteration in PS II activity of chloroplasts from transgenic lines of both chickpea and Indian mustard, demonstrating that the chloroplasts harboring choline oxidase are better equipped to resist photoinhibition. We hypothesize that H₂O₂ produced by choline oxidase as a byproduct during synthesis of glycinebetaine is responsible for building stronger antioxidant system in chloroplasts of transgenic lines compared to that of wild-type.     

Protective effect of Morus rubra L. leaf extract on diet-induced atherosclerosis in diabetic rats

The antiatherosclerotic effect of aqueous leaves extract of Morus rubra was studied in streptozotocin-induced diabetic rats fed with atherosclerotic (Ath) diet [1.5 ml olive oil containing 8 mg (3, 20,000 IU) vitamin D2 and 40 mg cholesterol] for 5 consecutive days. A short-term toxicity assessment was also conducted in healthy rats to examine toxic effects of the extract. Oral administration of extract to diabetic rats (100, 200 and 400 mg/kg body weight per day for a period of 30 days) produced significant (p<0.001) fall in fasting blood glucose (FBG) in a dose-dependent manner. Treatment with the extract (400 mg/kg) showed significant (p<0.001) improvement in body weight and serum lipid profile i.e., total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol, when compared with diabetic control. Endothelial dysfunction parameters (sVCAM-1, Fibrinogen, total NO levels and oxidized LDL), apolipoprotein A and apolipoprotein B were significantly (p<0.001) reversed to near normal, following treatment with the extract. Thus, our study shows that aqueous leaf extract of Morus rubra (400 mg/kg) significantly improves the homeostasis of glucose and fat and possesses significant anti-atherosclerotic activity.     

A system for identifying named entities in biomedical text: how results from two evaluations reflect on both the system and the evaluations

We present a maximum entropy-based system for identifying named entities (NEs) in biomedical abstracts and present its performance in the only two biomedical named entity recognition (NER) comparative evaluations that have been held to date, namely BioCreative and Coling BioNLP. Our system obtained an exact match F-score of 83.2% in the BioCreative evaluation and 70.1% in the BioNLP evaluation. We discuss our system in detail, including its rich use of local features, attention to correct boundary identification, innovative use of external knowledge resources, including parsing and web searches, and rapid adaptation to new NE sets. We also discuss in depth problems with data annotation in the evaluations which caused the final performance to be lower than optimal.     

Disruption of Autoregulatory Feedback by a Mutation in a Remote,Ultraconserved PAX6 Enhancer Causes Aniridia

The strictly regulated expression of most pleiotropic developmental control genes is critically dependent on the activity of long-range cis-regulatory elements. This was revealed by the identification of individuals with a genetic condition lacking coding-region mutations in the gene commonly associated with the disease but having a variety of nearby chromosomal abnormalities, collectively described as cis-ruption disease cases. The congenital eye malformation aniridia is caused by haploinsufficiency of the developmental regulator PAX6. We discovered a de novo point mutation in an ultraconserved cis-element located 150 kb downstream from PAX6 in an affected individual with intact coding region and chromosomal locus. The element SIMO acts as a strong enhancer in developing ocular structures. The mutation disrupts an autoregulatory PAX6 binding site, causing loss of enhancer activity, resulting in defective maintenance of PAX6 expression. These findings reveal a distinct regulatory mechanism for genetic disease by disruption of an autoregulatory feedback loop critical for maintenance of gene expression through development.