A gradient-forming MipZ protein mediating the control of cell division in the magnetotactic bacterium Magnetospirillum gryphiswaldense

Cell division needs to be tightly regulated and closely coordinated with other cellular processes to ensure the generation of fully viable offspring. Here, we investigate division site placement by the cell division regulator MipZ in the alphaproteobacterium Magnetospirillum gryphiswaldense, a species that forms linear chains of magnetosomes to navigate within the geomagnetic field. We show that M. gryphiswaldense contains two MipZ homologs, termed MipZ1 and MipZ2. MipZ2 localizes to the division site, but its absence does not cause any obvious phenotype. MipZ1, by contrast, forms a dynamic bipolar gradient, and its deletion or overproduction cause cell filamentation, suggesting an important role in cell division. The monomeric form of MipZ1 interacts with the chromosome partitioning protein ParB, whereas its ATP-dependent dimeric form shows non-specific DNA-binding activity. Notably, both the dimeric and, to a lesser extent, the monomeric form inhibit FtsZ polymerization in vitro. MipZ1 thus represents a canonical gradient-forming MipZ homolog that critically contributes to the spatiotemporal control of FtsZ ring formation. Collectively, our findings add to the view that the regulatory role of MipZ proteins in cell division is conserved among many alphaproteobacteria. However, their number and biochemical properties may have adapted to the specific needs of the host organism

Microscopic theory of network glasses

A molecular theory of the glass transition of network forming liquids is developed using a combination of self-consistent phonon and liquid state approaches. Both the dynamical transition and the entropy crisis characteristic of random first order transitions are mapped out as a function of the degree of bonding and the density. Using a scaling relation for a soft-core model to crudely translate the densities into temperatures, the theory predicts that the ratio of the dynamical transition temperature to the laboratory transition temperature rises as the degree of bonding increases, while the Kauzmann temperature falls relative to the laboratory transition. These results indicate why highly coordinated liquids should be "strong" while van der Waals liquids without coordination are "fragile".Comment: slightly revised version that has been accepted for publication in Phys. Rev. Let

Registration of Great Northern Common Bean Cultivar ‘Coyne’ with Enhanced Disease Resistance to Common Bacterial Blight and Bean Rust

Great northern common bean (Phaseolus vulgaris L.) ‘Coyne’ (Reg. No. CV-287, PI 655574) was developed by the dry bean breeding program at the University of Nebraska Agricultural Research Division and released in 2008. It was bred specifically for adaptation to Nebraska growing conditions and for enhanced resistance to common bacterial blight (CBB), a major disease of common bean caused by the seed-borne bacterium Xanthomonas campestris pv. phaseoli (Smith) Dye, and bean common rust Uromyces appendiculatus (Pers.:Pers) Unger. Coyne is a great northern F7:8 line derived from a three-way cross (G95023/Weihing//BelMiNeb-RMR-11). The first cross was made in winter 2003. The F7:8 was tested in advanced yield trials at Scottsbluff and Mitchell, NE, and in growers’ fields in Nebraska. Yield of Coyne was only 47 kg ha–1 lower than ‘Marquis’ in Morrill and Scotts Bluff, NE, counties. Reaction of Coyne to CBB under field conditions was consistent across 3 yr at the West Central Research and Extension Center, North Platte, NE, where fi eld disease ratings of 3.2, 3.5, and 4.4 were recorded in 2005, 2006, and 2007, respectively. Coyne has the Ur-3 and Ur-6 genes for resistance to common bean rust and carries the single dominant hypersensitive I gene that provides resistance to all non-necrotic strains of Bean common mosaic virus. Coyne has bright white seed, blooms 44 d after planting, and is a midseason bean, maturing 91 d after planting

An integrated genetic and physical map of the bovine X Chromosome

Genotypic data for 56 microsatellites (ms) generated from maternal full sib families nested within paternal half sib pedigrees were used to construct a linkage map of the bovine X Chromosome (Chr) (BTX) that spans 150 cM (ave. interval 2.7 cM). The linkage map contains 36 previously unlinked ms; seven generated from a BTXp library. Genotypic data from these 36 ms was merged into an existing linkage map to more than double the number of informative BTX markers. A male specific linkage map of the pseudoautosomal region was also constructed from five ms at the distal end of BTXq. Four informative probes physically assigned by fluorescence in situ hybridization defined the extent of coverage, confirmed the position of the pseudoautosomal region on the q-arm, and identified a 4.1-cM marker interval containing the centromere of BTX

Hantavirus (Bunyaviridae: Hantavirus) en roedores murinos de Sincelejo, departamento de Sucre

  The hantaviruses associated to the Sigmodontinae rodents, are emerging pathogens that cause the Cardiopulmonary Syndrome by Hantavirus (HCS) in the Americas. So far, Colombia has not reported confirmed cases of the disease; however, evidence has shown serological exposure to hantavirusin rodents and humans from two departments in the Caribbean Region, and molecular detection of viral genome in tissue samples of rodents in Antioquia. The aim of this research was to determinate the frequency of hantavirus specific antibodies in rodents from Sincelejo City. Animal samplings were performed with Sherman traps from March to July 2009. IgG antibodies against Sin Nombre Virus were detected in plasma by enzyme-linked immunosorbent assay(indirect ELISA). Sixty-one rodents were captured and identified as three speciesthree species, Musmusculus was the most abundant(91.8%). From the total of analyzed animals, only one exemplar, belonging to Rattusrattus specie (seroprevalence 1.64%), was positive to hantavirus. Serologic findings evidenced hantavirus infection among rodents of subfamily Murinae in Colombia. The presence of antibodies against the virus suggests that at least one hantavirus is circulating in rodents from North of Colombia.Los hantavirus, asociados a roedores de la subfamilia Sigmodontinae, son patógenosemergentes causantes de la zoonosis Síndrome Cardiopulmonar por Hantavirus (SCPH) en las Américas. Hasta la fecha, en Colombia no se han confirmado casos de la enfermedad; sin embargo, se ha demostrado la evidencia serológica de exposición a hantavirus en roedores y humanos de dos departamentos de la RegiónCaribe, y la detección molecular de genoma viral en muestras de tejido de roedores en Antioquia. El objetivo de esta investigación fue determinar la frecuencia de anticuerpos específicos contra hantavirus en roedores de la ciudad de Sincelejo, departamento de Sucre. Los muestreos de los animales fueron realizados con trampas Sherman, desde marzo hasta julio de 2009. Los anticuerpos IgG específicos contra el Virus Sin Nombre (VSN) fueron detectados en muestras de plasma medianteensayo de inmunoabsorción ligado aenzimas (ELISA indirecto). Secapturaron 61 roedores distribuidos en tres especies, de las cuales Mus musculusfue la más abundante (91.8%). Del total de animales analizados, un único ejemplar, clasificado dentrode la especie Rattusrattus (seroprevalencia de 1.64%), resultó positivo a hantavirus. Los hallazgos evidenciaron seropositividad a hantavirus en roedores de la subfamilia Murinae en Colombia. La detección de anticuerpos contra el virus refuerza la hipótesis que sugiere la circulación de al menos un hantavirus en roedores del norte colombiano

Necrostatin-1 supplementation enhances young porcine islet maturation and in vitro function

BACKGROUND: Necroptosis has been demonstrated to be a primary mechanism of islet cell death. This study evaluated whether the supplementation of necrostatin-1 (Nec-1), a potent inhibitor of necroptosis, to islet culture media could improve the recovery, maturation, and function of pre-weaned porcine islets (PPIs). METHODS: PPIs were isolated from pre-weaned Yorkshire piglets (8-15 days old) and either cultured in control islet culture media (n = 6) or supplemented with Nec-1 (100 µM, n = 5). On days 3 and 7 of culture, islets were assessed for recovery, insulin content, viability, cellular composition, GLUT2 expression in beta cells, differentiation of pancreatic endocrine progenitor cells, function, and oxygen consumption rate. RESULTS: Nec-1 supplementation induced a 2-fold increase in the insulin content of PPIs on day 7 of culture. When compared to untreated islets, Nec-1 treatment doubled the beta- and alpha-cell composition and accelerated the development of delta cells. Additionally, beta cells of Nec-1-treated islets had a significant upregulation in GLUT2 expression. The enhanced development of major endocrine cells and GLUT2 expression after Nec-1 treatment subsequently led to a significant increase in the amount of insulin secreted in response to in vitro glucose challenge. Islet recovery, viability, and oxygen consumption rate were unaffected by Nec-1. CONCLUSION: This study underlines the importance of necroptosis in islet cell death after isolation and demonstrates the novel effects of Nec-1 to increase islet insulin content, enhance pancreatic endocrine cell development, facilitate GLUT2 upregulation in beta cells, and augment insulin secretion. Nec-1 supplementation to culture media significantly improves islet quality prior to xenotransplantation