26 research outputs found
Characterization of bacterial operons consisting of two tubulins and a kinesin-like gene by the novel Two-Step Gene Walking method
Tubulins are still considered as typical proteins of Eukaryotes. However, more recently they have been found in the unusual bacteria Prosthecobacter (btubAB). In this study, the genomic organization of the btub-genes and their genomic environment were characterized by using the newly developed Two-Step Gene Walking method. In all investigated Prosthecobacters, btubAB are organized in a typical bacterial operon. Strikingly, all btub-operons comprise a third gene with similarities to kinesin light chain sequences. The genomic environments of the characterized btub-operons are always different. This supports the hypothesis that this group of genes represents an independent functional unit, which was acquired by Prosthecobacter via horizontal gene transfer. The newly developed Two-Step Gene Walking method is based on randomly primed polymerase chain reaction (PCR). It presents a simple workflow, which comprises only two major steps—a Walking-PCR with a single specific outward pointing primer (step 1) and the direct sequencing of its product using a nested specific primer (step 2). Two-Step Gene Walking proved to be highly efficient and was successfully used to characterize over 20 kb of sequence not only in pure culture but even in complex non-pure culture samples
Fast X-Ray Fluorescence Microtomography of Hydrated Biological Samples
Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples
Identification of GBV-D, a Novel GB-like Flavivirus from Old World Frugivorous Bats (Pteropus giganteus) in Bangladesh
Bats are reservoirs for a wide range of zoonotic agents including lyssa-, henipah-, SARS-like corona-, Marburg-, Ebola-, and astroviruses. In an effort to survey for the presence of other infectious agents, known and unknown, we screened sera from 16 Pteropus giganteus bats from Faridpur, Bangladesh, using high-throughput pyrosequencing. Sequence analyses indicated the presence of a previously undescribed virus that has approximately 50% identity at the amino acid level to GB virus A and C (GBV-A and -C). Viral nucleic acid was present in 5 of 98 sera (5%) from a single colony of free-ranging bats. Infection was not associated with evidence of hepatitis or hepatic dysfunction. Phylogenetic analysis indicates that this first GBV-like flavivirus reported in bats constitutes a distinct species within the Flaviviridae family and is ancestral to the GBV-A and -C virus clades
Archäologie und Neues Testament. Von der Palästinawissenschaft zur lokalgeschichtlichen Methode
Witulski T, Pilhofer P. Archäologie und Neues Testament. Von der Palästinawissenschaft zur lokalgeschichtlichen Methode. In: Alkier S, Brucker R, eds. Exegese und Methodendiskussion. Texte und Arbeiten zum neutestamentlichen Zeitalter. Vol 23. Tübingen/Basel: Francke; 1998: 237-255
Lukian
Im Jahre 167 n. Chr. beging in Olympia der wandernde Philosoph Peregrinos, der sich selbst Proteus nannte, Selbstmord, indem er sich am Ende der olympischen Spiele öffentlich selbst verbrannte. Unter den Augenzeugen dieser Tat war auch der Schriftsteller Lukian von Samosata, der seinem Freund Kronius in seiner Schrift Der Tod des Peregrinos von dem Ereignis berichtet. Aber nicht nur die Umstände des Verbrennungstodes sind Inhalt des Werkes; Lukian lässt auch das Leben dieses zu Lebzeiten berühmten und nach seinem Tode kultisch verehrten Mannes Revue passieren. In seiner Inszenierung, die an Peregrinus kein gutes Haar lässt, kommen dabei zunächst ein glühender Anhänger, dann ein Verächter des Peregrinos zu Wort, schließlich Lukian selbst, der in gewohnt scharfer und spöttischer Manier stets brillant formulierend berichtet und kommentiert. Dabei trifft sein Spott neben den Kynikern auch die Christen, in deren Reihen Peregrinos eine kurze aber bemerkenswerte Karriere machte. Dies hat dem Autor nicht nur im mittelalterlichen Lexikon des Suidas die Androhung ewiger Verdammnis eingebracht, es hat auch dem hier vorliegenden Werk stets das Interesse der Theologen und Historiker gesichert