Complete Genome Sequence of Hepatitis E Virus from Rabbits in the United States

Hepatitis E virus (HEV) is a single-strand positive-sense RNA virus in the family Hepeviridae. The disease caused by HEV, hepatitis E, is an important public health problem in developing countries of Asia and Africa and is also endemic in many industrialized countries, including the United States. HEV has been identified from several other animal species in addition to humans, including the pig, chicken, mongoose, deer, rabbit, ferret, bat, and fish. Here we report the complete genome sequence of the first strain of HEV from rabbits in the United States. Sequence and phylogenetic analyses revealed that the U.S. rabbit HEV is a distant member of the zoonotic genotype 3 HEV, thus raising a concern for potential zoonotic human infection. A unique 90-nucleotide insertion within the X domain of the ORF1 was identified in the rabbit HEV, and this insertion may play a role in the species tropism of HEV.     

Silicon accumulation and water uptake by wheat

Silicon (Si) content in cereal plants and soil-Si solubility may be used to estimate transpiration, assuming passive Si uptake. The hypothesis for passive-Si uptake by the transpiration stream was tested in wheat (Triticum aestivum cv. Stephens) grown on the irrigated Portneuf silt loam soil (Durixerollic calciorthid) near Twin Falls, Idaho. Treatments consisted of 5 levels of plant-available soil water ranging from 244 to 776 mm provided primarily by a line-source sprinkler irrigation system. Evapotranspiration was determined by the water-balance method and water uptake was calculated from evapotranspiration, shading, and duration of wet-surface soil. Water extraction occurred from the 0 to 150-cm zone in which equilibrium Si solubility (20°C) was 15 mg Si L^–1 in the A_p and B_k (0–58 cm depth) and 23 mg Si L^–1 in the B_kq (58–165 cm depth).At plant maturity, total Si uptake ranged from 10 to 32 g m^–2, above-ground dry matter from 1200 to 2100 g m^–2 and transpiration from 227 to 546 kg m^–2. Silicon uptake was correlated with transpiration (Si_up=–07+06T, r²=0.85) and dry matter yield with evapotranspiration (Y=119+303ET, r²=0.96). Actual Si uptake was 2.4 to 4.7 times that accounted for by passive uptake, supporting designation of wheat as a Si accumulator. The ratio of Si uptake to water uptake increased with soil moisture. The confirmation of active Si uptake precludes using Si uptake to estimate water use by wheat.     

Epigenetic and pharmacological control of pigmentation via Bromodomain Protein 9 (BRD9)

Lineage-specific differentiation programs are activated by epigenetic changes in chromatin structure. Melanin-producing melanocytes maintain a gene expression program ensuring appropriate enzymatic conversion of metabolites into the pigment, melanin, and transfer to surrounding cells. During neuroectodermal development, SMARCA4 (BRG1), the catalytic subunit of SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complexes, is essential for lineage specification. SMARCA4 is also required for development of multipotent neural crest precursors into melanoblasts, which differentiate into pigment-producing melanocytes. In addition to the catalytic domain, SMARCA4 and several SWI/SNF subunits contain bromodomains which are amenable to pharmacological inhibition. We investigated the effects of pharmacological inhibitors of SWI/SNF bromodomains on melanocyte differentiation. Strikingly, treatment of murine melanoblasts and human neonatal epidermal melanocytes with selected bromodomain inhibitors abrogated melanin synthesis and visible pigmentation. Using functional genomics, iBRD9, a small molecule selective for the bromodomain of BRD9 was found to repress pigmentation-specific gene expression. Depletion of BRD9 confirmed a requirement for expression of pigmentation genes in the differentiation program from melanoblasts into pigmented melanocytes and in melanoma cells. Chromatin immunoprecipitation assays showed that iBRD9 disrupts the occupancy of BRD9 and the catalytic subunit SMARCA4 at melanocyte-specific loci. These data indicate that BRD9 promotes melanocyte pigmentation whereas pharmacological inhibition of BRD9 is repressive.     

Adhesive properties associated with the Vir plasmid: a transmissible pathogenic characteristic associated with strains of invasive Escherichia coli

Escherichia coli strain S5 (O15:K+:H21) isolated from a septicaemic lamb and previously shown to possess a virulence plasmid, Vir, attached in vitro to calf epithelial tissue from the ileum, oesophagus and trachea in the presence of 0.5% (w/v) D-mannose. The Vir+ recombinant strains 711v and H209av, which had received the Vir plasmid(s) from strain S5, also attached to these epithelia but the parent strains 711 and H209a without the Vir plasmid were non-adhesive. The attachment of the Vir+ strain 711v to intestinal brush borders was inhibited by antiserum to live Vir+ strain H209av but not by antiserum to strain H209a lacking Vir. No adherence occurred with Vir+ organisms grown at 18 degrees C or after heating at 65 degrees C. Adhesion was unaffected by 0.5% (w/v) formaldehyde. Glucosamine, mannosamine, their N-acetyl derivatives and wheat germ lectin each inhibited attachment of Vir+ strain 711v to brush border epithelia.     

Conversion of two distinct Rhodopseudomonas capsulata isolates to the glycerol-utilizing phenotype

Abstract Previous studies employing a single strain of the photosynthetic bacterium Rhodopseudomonas capsulata have demonstrated that this organism, which normally is not capable of growth on glycerol, can gain glycerol-utilizing ability through mutational events. We have examined other strains of R. capsulata of divergent geographic origin, and have found that they could also be converted to a glycerol-catabolic phenotype. Mutant derivatives were found to express high constitutive levels of glycerophosphate dehydrogenase (GPD) and glycerokinase (GK) which were barely detectable in the parental strains. These results suggest that the ability to utilize glycerol after undergoing a gain of function mutation is a widespread property of R. capsulata .     

On the computation of in vivo transmural mean stress of patient-specific aortic wall

Biomechanics and Modeling in Mechanobiology - It is well known that residual deformations/stresses alter the mechanical behavior of arteries, e.g., the pressure–diameter curves. In an effort...