The SEG1 element: a new DNA region promoting stable mitotic segregation of plasmids in the zygomycete Absidia glauca.

Summary A series of new vectors for the model zygomycete Absidia glauca was constructed on the basis of the structural neomycin resistance (Neo^r) gene controlled by the promoter of the gene for elongation factor 1 (TEF). In order to select for transformed colonies with a stable Neo^r phenotype, spores from primary transformants were pooled and grown for two sporulation cycles under non-selective conditions. Southern blot analysis of DNA from single spore isolates originating from independent transformant pools allowed the identification of two autonomously replicating plasmids. Retransformation of Escherichia coli and restriction analysis of the two plasmids provided evidence for spontaneous in vivo insertion of a new DNA element (SEG1) from the A. glauca genome. The inserted regions in both plasmids are essentially identical and do not represent repetitive DNA. Compared with other autonomously replicating vectors, these SEG1-containing plasmids are mitotically extremely stable and are passed on to the vegetative spore progeny of a retransformed A. glauca strain. We assume that SEG1 contains structural elements involved in partitioning and stable segregation of plasmids. For the construction of stable transformants of A. glauca, the SEG1 element may be regarded as a major breakthrough, because stabilization of transformed genetic traits by integration is difficult to achieve in all mucoraceous fungi and all known replicating plasmids are mitotically unstable.     

Oxygenation of malignant tumors after localized microwave hyperthermia

Summary The oxyhemoglobin saturation (HbO₂) of single red blood cells within tumor microvessels (diameter: 3–12 µm) of DS-Carcinosarcoma was studied using a cryophotometric micromethod. In untreated control tumors (mean tissue temperature approx. 35° C) the measured values scattered over the whole saturation range from zero to 100 sat.%, the mean being 51 sat.%. Upon heating at 40° C for 30 min, the oxygenation of the tumor tissue significantly improved as compared with control conditions. After 40° C-hyperthermia a mean oxyhemoglobin saturation of 66 sat.% was obtained. In contradistinction to this, after 43° C-hyperthermia the tumor oxygenation was significantly lower and reached a mean HbO₂ saturation value of 47 sat.%. A further temperature rise to 45° C caused the oxygenation to drop drastically (mean oxyhemoglobin saturation value: 24 sat.%). This is due to a severe restriction of nutritive blood flow.The changes in tumor oxygenation after hyperthermia seem to be predominantly mediated through changes in tumor blood flow, including tumor microcirculation, which showed a similar temperature dependence. Metabolic effects probably play a minor role in the oxyhemoglobin saturation distribution within tumor microvessels.Supported by the Deutsche Forschungsgemeinschaft (Va 57/2-1). Presented in part at the International Symposium on Biomedical Thermology, June 30 to July 4, 1981, Strasbourg, France     

Effects of retinoids on differentiation, lipid metabolism, epidermal growth factor, and low-density lipoprotein binding in squamous carcinoma cells

The relationship among keratinocyte differentiation capacity, lipid synthesis, low-density lipoprotein (LDL) metabolism, plasma membrane composition, and epidermal growth factor (EGF) binding has been studied in SCC-12F2 cells. The differentiation capacity of the cells, i.e., ionophore-induced cornified envelope formation, was inhibited by various retinoids and stimulated by hydrocortisone. Retinoids that caused a significant reduction of cornified envelope formation, i.e., retinoic acid and 13-cis-retinoic acid, caused only minor changes in lipid synthesis and plasma membrane composition. Arotinoid ethylsulfone, having a minor effect on cornified envelope formation, caused a drastic inhibition of cholesterol synthesis, resulting in changes in the plasma membrane composition. Hydrocortisone stimulated cornified envelope formation but had only minor effects on lipid synthesis and plasma membrane composition. Of all retinoids tested, only arotinoid ethylsulfone caused a drastic increase in EGF binding, while hydrocortisone had no effect. Retinoic acid, arotinoid ethylsulfone, and hydrocortisone had no effects on LDL binding and only minor effects on LDL degradation. These results clearly demonstrate that the plasma membrane composition is not related to keratinocyte differentiation capacity, but most likely does determine EGF binding. Furthermore, EGF binding does not determine keratinocyte differentiation capacity.     

Genetic Network Analyzer: qualitative simulation of genetic regulatory networks

MOTIVATION: The study of genetic regulatory networks has received a major impetus from the recent development of experimental techniques allowing the measurement of patterns of gene expression in a massively parallel way. This experimental progress calls for the development of appropriate computer tools for the modeling and simulation of gene regulation processes. RESULTS: We present Genetic Network Analyzer (GNA), a computer tool for the modeling and simulation of genetic regulatory networks. The tool is based on a qualitative simulation method that employs coarse-grained models of regulatory networks. The use of GNA is illustrated by a case study of the network of genes and interactions regulating the initiation of sporulation in Bacillus subtilis. AVAILABILITY: GNA and the model of the sporulation network are available at http://www-helix.inrialpes.fr/gna.     

Mediatietherapie bij ouderen met een persoonlijkheidsstoornis: Een verpleegkundige benadering

Behavioural counselling by nurses can enhance quality of life in elderly with a personality disorder. Although nurses have a crucial role in day-to-day treatment, there is a lack of evidence-based approaches. Based on the cognitive therapy, the treatment protocol Cognitive Model for Behavioural Interventions (CoMBI) provides an alternative nursing approach for personality disorders.     

A novel approach for multi-domain and multi-gene family identification provides insights into evolutionary dynamics of disease resistance genes in core eudicot plants

Background

Recent advances in DNA sequencing techniques resulted in more than forty sequenced plant genomes representing a diverse set of taxa of agricultural, energy, medicinal and ecological importance. However, gene family curation is often only inferred from DNA sequence homology and lacks insights into evolutionary processes contributing to gene family dynamics. In a comparative genomics framework, we integrated multiple lines of evidence provided by gene synteny, sequence homology and protein-based Hidden Markov Modelling to extract homologous super-clusters composed of multi-domain resistance (R)-proteins of the NB-LRR type (for NUCLEOTIDE BINDING/LEUCINE-RICH REPEATS), that are involved in plant innate immunity.

Results

To assess the diversity of R-proteins within and between species, we screened twelve eudicot plant genomes including six major crops and found a total of 2,363 NB-LRR genes. Our curated R-proteins set shows a 50% average for tandem duplicates and a 22% fraction of gene copies retained from ancient polyploidy events (ohnologs). We provide evidence for strong positive selection and show significant differences in molecular evolution rates (Ka/Ks-ratio) among tandem- (mean = 1.59), ohnolog (mean = 1.36) and singleton (mean = 1.22) R-gene duplicates. To foster the process of gene-edited plant breeding, we report species-specific presence/absence of all 140 NB-LRR genes present in the model plant Arabidopsis and describe four distinct clusters of NB-LRR “gatekeeper” loci sharing syntenic orthologs across all analyzed genomes.

Conclusion

By curating a near-complete set of multi-domain R-protein clusters in an eudicot-wide scale, our analysis offers significant insight into evolutionary dynamics underlying diversification of the plant innate immune system. Furthermore, our methods provide a blueprint for future efforts to identify and more rapidly clone functional NB-LRR genes from any plant species.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-966) contains supplementary material, which is available to authorized users.     

Amazonian Anthrosols Support Similar Microbial Communities that Differ Distinctly from Those Extant in Adjacent, Unmodified Soils of the Same Mineralogy

We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity. Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present in the anthrosols for both the Bacteria and Archaea suggests that the microbial community composition in these soils is controlled more strongly by their historical soil management than by soil type or current land use. The anthrosols had consistently higher concentrations of incompletely combusted organic black carbon material (BC), higher soil pH, and higher concentrations of P and Ca compared to their respective adjacent soils. Such characteristics may help to explain the longevity and distinctiveness of the anthrosols in the Amazonian landscape and guide us in recreating soils with sustained high fertility in otherwise nutrient-poor soils in modern times.