Sequence analysis of an internal 9.72-kb segment from the 30-kb denitrification gene cluster of Pseudomonas stutzeri

AbstractThe DNA segment was sequenced that links the nir-nor and nos gene clusters for denitrification of Pseudomonas stutzeri ATCC 14405. Of 10 predicted gene products, four are putative membrane proteins. Sequence similarity was detected with the subunit III of cytochrome-c oxidase (ORF175), PQQ3 of the biosynthetic pathway for pyrrolo-quinoline quinone (ORF393), S-adenosylmethionine-dependent uroporphyrinogen-III C-methyltransferase (ORF278), the cytochrome cd1 nitrite reductase and the NirF protein involved in the biosynthesis of heme d1 (ORF507), LysR type transcriptional regulators (ORF286), short-chain alcohol dehydrogenases (ORF247), and a hypothetical protein, YBEC, of Escherichia coli (ORF57). The current data together with previous work establish a contiguous DNA sequence of 29.2 kb comprising the supercluster of nos-nir-nor genes for denitrification in this bacterium

High tandem repeat content in the genome of the short-lived annual fish Nothobranchius furzeri: a new vertebrate model for aging research

A genomic analysis of the annual fish Nothobranchius furzeri, a vertebrate with the shortest known life span in captivity and which may provide a new model organism for aging research

The diagnostic MRCP examination: overcoming technical challenges to ensure clinical success

The magnetic resonance cholangiopancreatography (MRCP) examination has all but replaced the diagnostic endoscopic retrograde cholangiopancreatography (ERCP) examination for imaging the biliary tree and pancreatic ducts in many practical aspects of the clinical setting. Despite this increase in popularity, many magnetic resonance imaging (MRI) radiographers still find aspects of the MRCP examination quite challenging. The aim of this tutorial paper is to provide useful technical advice on how to overcome such perceived challenges and thus produce a successful diagnostic MRCP examination. This paper will be of interest to novice MRI radiographers who are at the beginning of their learning curve in MRCP examination. Other MRI radiographers who are interested in practical tips for protocol variations may also find the paper useful

Insight into cross-talk between intra-amoebal pathogens

Abstract: Background: Amoebae are phagocytic protists where genetic exchanges might take place between amoeba-resistant bacteria. These amoebal pathogens are able to escape the phagocytic behaviour of their host. They belong to different bacterial phyla and often show a larger genome size than human-infecting pathogens. This characteristic is proposed to be the result of frequent gene exchanges with other bacteria that share a sympatric lifestyle and contrasts with the genome reduction observed among strict human pathogens.Results: We sequenced the genome of a new amoebal pathogen, Legionella drancourtii, and compared its gene content to that of a Chlamydia-related bacterium, Parachlamydia acanthamoebae. Phylogenetic reconstructions identified seven potential horizontal gene transfers (HGTs) between the two amoeba-resistant bacteria, including a complete operon of four genes that encodes an ABC-type transporter. These comparisons pinpointed potential cases of gene exchange between P. acanthamoebae and Legionella pneumophila, as well as gene exchanges between other members of the Legionellales and Chlamydiales orders. Moreover, nine cases represent possible HGTs between representatives from the Legionellales or Chlamydiales and members of the Rickettsiales order.Conclusions: This study identifies numerous gene exchanges between intracellular Legionellales and Chlamydiales bacteria, which could preferentially occur within common inclusions in their amoebal hosts. Therefore it contributes to improve our knowledge on the intra-amoebal gene properties associated to their specific lifestyle

Adventitial transplantation of blood outgrowth endothelial cells in porcine haemodialysis grafts alleviates hypoxia and decreases neointimal proliferation through a matrix metalloproteinase-9-mediated pathway—a pilot study

Purpose. We hypothesized that adventitial transplantation of blood outgrowth endothelial cells (BOEC) to the vein-to-graft anastomosis of polytetrafluoroethylene grafts will reduce neointimal hyperplasia by reducing hypoxia inducible factor-1α (HIF-1α), by increasing angiogenesis in a porcine model of chronic renal insufficiency with haemodialysis polytetrafluoroethylene grafts. Because matrix metalloproteinases (MMPs) have been shown to be involved with angiogenesis, the expression of MMPs and their inhibitors was determined

The transcription factor Spores Absent A is a PKA dependent inducer of Dictyostelium sporulation

Abstract Sporulation in Dictyostelium fruiting bodies evolved from amoebozoan encystation with both being induced by cAMP acting on PKA, but with downstream components still being unknown. Using tagged mutagenesis to find missing pathway components, we identified a sporeless mutant defective in a nuclear protein, SpaA. Expression of prespore genes was strongly reduced in spaA- cells, while expression of many spore stage genes was absent. Chromatin immunoprecipitation (ChIP) of a SpaA-YFP gene fusion showed that (pre)spore gene promoters bind directly to SpaA, identifying SpaA as a transcriptional regulator. SpaA dependent spore gene expression required PKA in vivo and was stimulated in vitro by the membrane-permeant PKA agonist 8Br-cAMP. The PKA agonist also promoted SpaA binding to (pre)spore promoters, placing SpaA downstream of PKA. Sequencing of SpaA-YFP ChIPed DNA fragments revealed that SpaA binds at least 117 (pre)spore promoters, including those of other transcription factors that activate some spore genes. These factors are not in turn required for spaA expression, identifying SpaA as the major trancriptional inducer of sporulation