Threatened fishes of the world: <Emphasis Type="Italic">Pseudophoxinus anatolicus</Emphasis> (Hanko 1924) (Cyprinidae), Central Anatolia,Turkey

Being an endemic and endangered fish species in Anatolia, P. anatolicus restricted to Lakes Akgöl, Bey?ehir, Çavu?cu, Akkaya Dam and Ere?li marshes as well as some other small marshes in Central Anatolia region, Turkey. Current population of P. anatolicus tends to decrease in the habitats. A detailed study of current population status, biology, ecology and life history of P. anatolicus is required. It should also be included into national threatened fish category.     

Screening microalgae for some potentially useful agricultural and pharmaceutical secondary metabolites

Nearly two hundred microalgal strains (174 Chlorophyta and 23 Cyanobacteria) were screened against some bacteria, filamentous fungi and yeasts using a disc-diffusion type bioassay. From this initial screening, 10 Chlorophyta strains from three genera (Desmococcus, Chlorella and Scenedesmus) were selected because of their high antimicrobial activity. These 10 strains were partially purified and tested using MIC antimicrobial and microtiter IC₅₀ anticancer assays. These preselected algal strains showed a high incidence of antibacterial activity against both Gram-positive (9 out of 10 species) and Gram-negative (7 out of 10 species) bacteria. The extracts were also effective against some tumour cell lines.     

Interrelationships between water use and growth traits in biomass-producing willows

Abstract Water use, drought response and growth were examined under controlled conditions in four interbreeding willow species from different geographical origins (two clones of Salix viminalis L., one clone of S. viminalis × S. schwerenii E. Wolf and one clone of S. purpurea L.). The levels of soil water depletion that plants could sustain without wilting varied markedly between the clones. The level of drought resistance expressed this way was positively related to resistance to xylem cavitation, negatively related to the maximum stomatal conductance, and positively related to early stomatal closure. The rate of stomatal closure, however, was negatively related to the resistance to xylem cavitation. Prior to drought, there were no significant differences between leaf-specific hydraulic conductances of the clones when whole plants were considered. However, there were differences if the roots and shoots were considered separately. Drought resistance was negatively related to maximum growth yields. This is probably because resources were diverted away from leaf production to the production of denser wood (wood density was positively related to cavitation resistance), and, for one clone, to the growth of a larger root system. In addition, because the level of drought resistance was negatively related to the maximum stomatal conductance, growth may have been adversely affected as a result of reduced photosynthesis. Given its high water extraction ability, one of the clones started to wilt sooner than expected, although only lateral shoots were affected. This appeared to indicate a strategy of sacrificing expendable shoots.     

HLA-B51 gene and its expression in association with Behçet’s Disease in Denizli Province of Turkey

Behçet’s Disease (BD) is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration, and uveitis with unknown pathogenesis. Many researchers have tried to investigate the association of HLA-B51 gene with the BD. We aimed to investigate the association of the HLA-B51 gene and its expression, also polymorphic structure by PCR, RT-PCR and sequence specific oligonucleotide primers and probes in BD patients (n: 35) and control group (n: 50). According to our results, we did not observe any association in between HLA-B51 gene, its polymorphism, expression and BD patients.     

Quantitative contributions of bacteria and of Deinococcus geothermalis to deposits and slimes in paper industry

Deinococcus geothermalis has frequently been isolated from pink colored deposits of paper industry processes. Laboratory studies have shown that D. geothermalis is capable of forming on nonliving surfaces patchy biofilms that are resistant to adverse agents such as extreme pH, desiccation, solubilising detergents and biocides. This study was done to quantitatively assess the role of D. geothermalis as a biofouler in paper industry. Colored deposits were collected from 24 European and North American paper and board machines and the densities of the bacterial 16S rRNA genes and those of the red slime producers D. geothermalis and Meiothermus spp. were measured by QPCR (quantitative real time PCR). D. geothermalis was found at nine machines, usually from splash area deposits, but its contribution was minor, 0.001–1%, to the total bacterial burden of 8.3 to log 10.5 log units per gram wet-weight of the deposits. When D. geothermalis was found in a measurable quantity, Meiothermus spp. also was found, often in bulk quantity (7–100% of the total bacteria). The data are in line with the properties of D. geothermalis known from laboratory biofilm studies, indicating this species is a pioneer coloniser of machine surfaces and may help other bacteria to adhere and grown into biofilms, rather than competing with them.     

Targeted disruption of homoserine dehydrogenase gene and its effect on cephamycin C production in Streptomyces clavuligerus

The aspartate pathway of Streptomyces clavuligerus is an important primary metabolic pathway which provides substrates for β-lactam synthesis. In this study, the hom gene which encodes homoserine dehydrogenase was cloned from the cephamycin C producer S. clavuligerus NRRL 3585 and characterized. The fully sequenced open reading frame encodes 433 amino acids with a deduced M _r of 44.9 kDa. The gene was heterologously expressed in the auxotroph mutant Escherichia coli CGSC 5075 and the recombinant protein was purified. The cloned gene was used to construct a plasmid containing a hom disruption cassette which was then transformed into S. clavuligerus. A hom mutant of S. clavuligerus was obtained by insertional inactivation via double crossover, and the effect of hom gene disruption on cephamycin C yield was investigated by comparing antibiotic levels in culture broths of this mutant and in the parental strain. Disruption of hom gene resulted in up to 4.3-fold and twofold increases in intracellular free l-lysine concentration and specific cephamycin C production, respectively, during stationary phase in chemically defined medium.     

Studies on mRNA Electroporation of Immature and Mature Dendritic Cells: Effects on their Immunogenic Potential

Previous studies have shown that mRNA-electroporated dendritic cells (DCs) are able to process and present tumor-associated antigens, leading to the activation of tumor-specific T cells in vitro and in vivo. However, the optimal maturation state of antigen loading and half-life of the mRNA-translated protein product and its immunogenic epitopes are significant parameters, which needs to be clarified in order to establish an effective electroporation protocol. In addition, despite extensive experimental investigations and their widespread application in research and clinical environments, little is known of the extent to which the immunological properties of DCs are influenced by electrical fields of critical strengths. We found that the mRNA transfection of DCs after maturation with short and low-voltage square-wave electrical pulses resulted in higher level of antigen expression and viability in addition to higher T-cell stimulatory ability compared to transfection of DCs prior to maturation. Mature mRNA-electroporated DCs showed long-lived expression of EGFP and were able to stimulate influenza matrix protein M1 (M1)-specific T cells up to 24 h after electroporation. However, when DCs were subjected to increasing electrical pulses the level of transgene expression was four-fold upregulated, equipping these DCs to be more potent in inducing M1-specific T cells. Also, the application of long electrical pulses induced further upregulation of HLA-DR, CD80, and CD86 expression in mature DCs, but did not promote phenotypic or functional maturation in immature DCs. These findings support the concept of mRNA transfection of DCs after maturation and also highlight the possibility to use long electrical pulses for further improvement of the immune responses by mRNA-transfected DCs.     

Evolution of brain region volumes during artificial selection for relative brain size

The vertebrate brain shows an extremely conserved layout across taxa. Still, the relative sizes of separate brain regions vary markedly between species. One interesting pattern is that larger brains seem associated with increased relative sizes only of certain brain regions, for instance telencephalon and cerebellum. Till now, the evolutionary association between separate brain regions and overall brain size is based on comparative evidence and remains experimentally untested. Here, we test the evolutionary response of brain regions to directional selection on brain size in guppies (Poecilia reticulata) selected for large and small relative brain size. In these animals, artificial selection led to a fast response in relative brain size, while body size remained unchanged. We use microcomputer tomography to investigate how the volumes of 11 main brain regions respond to selection for larger versus smaller brains. We found no differences in relative brain region volumes between large‐ and small‐brained animals and only minor sex‐specific variation. Also, selection did not change allometric scaling between brain and brain region sizes. Our results suggest that brain regions respond similarly to strong directional selection on relative brain size, which indicates that brain anatomy variation in contemporary species most likely stem from direct selection on key regions.     

Parametric studies on droplet generation reproducibility for applications with biological relevant fluids

Although the great potential of droplet based microfluidic technologies for routine applications in industry and academia has been successfully demonstrated over the past years, its inherent potential is not fully exploited till now. Especially regarding to the droplet generation reproducibility and stability, two pivotally important parameters for successful applications, there is still a need for improvement. This is even more considerable when droplets are created to investigate tissue fragments or cell cultures (e.g. suspended cells or 3D cell cultures) over days or even weeks. In this study we present microfluidic chips composed of a plasma coated polymer, which allow surfactants‐free, highly reproducible and stable droplet generation from fluids like cell culture media. We demonstrate how different microfluidic designs and different flow rates (and flow rate ratios) affect the reproducibility of the droplet generation process and display the applicability for a wide variety of bio(techno)logically relevant media.