Molecular and functional analyses of incompatibility genes at het-6 in a population of Neurospora crassa

Two closely linked genes, un-24 and het-6, associated with the het-6 heterokaryon incompatibility functional haplotype were examined in 40 Neurospora crassa strains from a Louisiana sugarcane field. Partial diploid analyses were used to determine that half of the strains were functionally Oak Ridge (OR) and half were non-OR and indistinguishable from the standard Panama (PA) form. PCR-based markers were developed to identify polymorphisms within both un-24 and het-6. Two common forms of each gene occur based on these molecular markers. Rare forms of both un-24 and het-6 were identified as variants of the non-OR form by a DNA transformation assay. The heterokaryon incompatibility function of haplotypes, based on partial diploid analyses, was perfectly correlated with the PCR-based markers at both loci. This correlation indicates that the two loci are in severe linkage disequilibrium in this population sample and may act as an incompatibility gene complex. Southern hybridizations using OR- and PA-derived cloned probes from the region that spans un-24 and het-6 showed that the apparent absence of recombination in this approximately 25-kbp region is associated with low levels of overall sequence identity between the PA and OR forms.     

Biogenesis of a specialized plant-fungal interface during host cell internalization of Golovinomyces orontii haustoria

Powdery mildew fungi are biotrophic pathogens that require living plant cells for their growth and reproduction. Elaboration of a specialized cell called a haustorium is essential for their pathogenesis, providing a portal into host cells for nutrient uptake and delivery of virulence effectors. Haustoria are enveloped by a modified plant plasma membrane, the extrahaustorial membrane (EHM), and an extrahaustorial matrix (EHMx), across which molecular exchange must occur, but the origin and composition of this interfacial zone remains obscure. Here we present a method for isolating Golovinomyces orontii haustoria from Arabidopsis leaves and an ultrastructural characterization of the haustorial interface. Haustoria were progressively encased by deposits of plant cell wall polymers, delivered by secretory vesicles and multivesicular bodies (MVBs) that ultimately become entrapped within the encasement. The EHM and EHMx were not labelled by antibodies recognizing eight plant cell wall and plasma membrane antigens. However, plant resistance protein RPW8.2 was specifically recruited to the EHMs of mature haustoria. Fungal cell wall-associated molecular patterns such as chitin and β-1,3-glucans were exposed at the surface of haustoria. Fungal MVBs were abundant in haustoria and putative exosome vesicles were detected in the paramural space and EHMx, suggesting the existence of an exosome-mediated secretion pathway.     

Poly(ethylene oxide), a new slowing agent for protozoa.

The water-soluble, viscoelastic resin Polyox WSR 301), a poly(ethylene oxide) of high molecular weight (approximately 4 million) is introduces as a new slowing agent for protozoa. Generally, as the kinetic viscosity of the resin increased from 0.25% to 1% (w/v), the swimming velocity of Euglena gracilis, Didnium nasutum, Paramecium aurelia, Blepharisma undulans, and Prorodon platyodon decreased. The 1.0% solution had the highest viscosity and decreased velocity more effectively than 1.0% methyl cellulose and Protoslo solutions. The Polyox solutions differed from those of methyl cellulose and Protoslo by having, in addition to viscous drag, an elastic recoil that pulled the protozoa backwards when their swimming efforts stopped. The toxicity of these slowing agents was determined using 10 P. aurelia/test slide preparation. Paramecium numbers decreased in 1.0% methyl cellulose and Protoslo to nearly zero by 24 hr; in Polyox, not only were most these ciliates alive after 24 hr, but many survived for 96 hr and divisions occurred in 0.25% and 0.50% solutions.     

Radial Glial Cells: New Views on Old Questions

Neurochemical Research - Radial glial cells (RGC) are at the center of brain development in vertebrates, acting as progenitors for neurons and macroglia (oligodendrocytes and astrocytes) and as...     

Beneficial effects of peroxynitrite decomposition catalyst in a rat model of splanchnic artery occlusion and reperfusion.

The aim of the present study was to investigate the protective effect of the peroxynitrite decomposition catalyst 5,10,15, 20-tetrakis(2,4,6-trimethyl-3,5-disulfonatophenyl)-porphyrinato iron (III) (FeTMPS) in a model of splanchnic artery occlusion shock (SAO). SAO shock was induced in rats by clamping both the superior mesenteric artery and the celiac trunk for 45 min, followed by release of the clamp (reperfusion). At 60 min after reperfusion, animals were killed for histological examination and biochemical studies. There was a marked increase in the oxidation of dihydrorhodamine 123 to rhodamine (a marker of peroxynitrite-induced oxidative processes) in the plasma of the SAO-shocked rats after reperfusion, but not during ischemia alone. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine, an index of nitrogen species such as peroxynitrite, in the necrotic ileum in shocked rats. SAO-shocked rats developed a significant increase of tissue myeloperoxidase and malonaldehyde activity, and marked histological injury to the distal ileum. SAO shock was also associated with a significant mortality (0% survival at 2 h after reperfusion). Reperfused ileum tissue sections from SAO-shocked rats showed positive staining for P-selectin localized mainly in the vascular endothelial cells. Ileum tissue sections obtained from SAO-shocked rats and stained with antibody to ICAM-1 showed a diffuse staining. Administration of FeTMPS significantly reduced ischemia/reperfusion injury in the bowel, and reduced lipid and the production of peroxynitrite during reperfusion. Treatment with PN catalyst also markedly reduced the intensity and degree of P-selectin and ICAM-1 staining in tissue sections from SAO-shocked rats and improved survival. Our results clearly demonstrate that peroxynitrite decomposition catalysts exert a protective effect in SAO and that this effect may be due to inhibition of the expression of adhesion molecules and the tissue damage associated with peroxynitrite-related pathways.     

On a Fatal Case of <Emphasis Type=Italic>Candida krusei</Emphasis> Pleural Empyema in a Pregnant Woman with Spontaneous Esophagus Perforation

Introduction  

Candida empyema thoracis can be a consequence of operation, gastropleural fistula, and esophageal perforation. Case report and review of the literature. A fatal case of a 45-year-old pregnant woman with Candida krusei empyema thoracis secondary to spontaneous esophagus perforation associated with candida esophagitis is reported. The case is contextualized among similar cases found through a PubMed search.     

emperature and oil,and has a stable dis

ld,so we present the well logging series and gas drilling technique suited to Daqing area.Some proper logging evaluation approaches are used such as GR spectrometry log,CN log,induction log and NMR log,etc.well logging;technology;gas drilling;foam drilling;casing drilling;Daqing oilfield0测井技术Well Logging Technology20-22 104P631.8B019;B021;A011;A012;C;21;D3;A;B;B019_21;A011_D3;A012_C;B021_21;赵平;16-18 100高孔密复合射孔技术研究周志华;谭忠健;刘富奎;西安通源石油科技股份有限公司,中海石油(中国)有限公司天津分公司勘探部,中海石油(中国)有限公司天津分公司勘探部 陕西西安710065,天津300452,天津300452复合射孔;;高孔密;;p-t过程测试;;现场应用提出了一种新型装药结构并实现在高孔密条件下的复合射孔,所开发的产品进行了地面混凝土靶测试、地面动态压力-时间(p-t)过程测试和现场应用试验。试验结果表明,高孔密复合射孔器能够将高孔密的多孔道、多相位的射孔特点与高能气体压裂造缝机理有机地结合,形成了孔缝结合的深穿透、高孔密和多相位的沟通通道,有效地改善了近井带的渗流能力,实现了油井的高产和稳产。现场应用效果良好。On High Foramen Density Technology for the Fracture Perfo