Do Antarctic populations represent local or widespread phylogenetic and ecological lineages? Complicated fate of bipolar moss concepts with <Emphasis Type="Italic">Drepanocladus longifolius</Emphasis> as a case study

Bipolar moss species, extreme examples of large and disjunctive geographical ranges, belong to the most important components of the vegetation cover in Antarctica. Their appropriate taxonomic interpretations are essential for fine-scale biogeographical considerations but our knowledge on their phylogenetic affinities still remains limited. Here, we address the history of the Antarctic populations of Drepanocladus longifolius, a moss species widely considered a bipolar taxon. First, based on a worldwide sampling, we verify its assumed bipolar status. Then, we ask whether its current Antarctic populations have persisted throughout at least the last major glaciation in situ or, alternatively, are they a recent, postglacial element. Phylogenetic analyses together with investigation of morphological characters were used to infer relationships among accessions representing the whole distribution range of the taxon. Morphological and phylogenetic data strictly segregated specimens from the Southern and the Northern Hemisphere, with an exception of Australian populations that were included in the latter group. The Antarctic, sub-Antarctic and South American populations belong to a single clade and are treated as D. longifolius s. str., which consequently is not a bipolar taxon. All Northern Hemisphere populations and the ones from Australia represent D. capillifolius, a lately neglected taxon, which thus displays a true bipolar distribution pattern but not comprising the Antarctic and South American populations. These results provide a sound example of key importance of a detailed taxonomical and phylogenetic treatment as a basis for biogeographical studies. In D. longifolius s. str., a homogeneity in all non-coding nuclear and plastid regions was observed throughout the whole range. It contrasted with the presence of one missense mutation in the rps4 gene in all examined Antarctic populations, which correlated with their distinct ecological situation. While identity of non-coding sequences in D. longifolius populations indicates a postglacial recruitment of extant Antarctic populations from extra-regional locations rather than a long-term in situ survival, the mutation in the rps4 gene may be hypothesised to reflect an adaptive response of plants to the Antarctic environment.     

Coscinodon monchiquensis R.D.Porley,Ochyra & Ignatova (Grimmiaceae), a new species from the Algarve,southern Portugal

Coscinodon monchiquensis is described as a new species from the Serra de Monchique in the western part of the Algarve region in southern Portugal. It differs from the widespread C. cribrosus in having only slightly plicate leaves (in the latter species the leaves are usually strongly plicate to the base), a weakly recurved leaf margin in the proximal ? and very fragile and markedly fenestrate peristome teeth which fall away after dehiscence giving the mature capsules a gymnostomous appearance. In cases where C. cribrosus has only weak plications to mid-leaf, the plane leaf margin at once separates it from C. monchiquensis. The affinities of C. monchiquensis are discussed, and molecular phylogenetic analysis of the nrITS region indicates its sister position to all other congeners. A key to the determination of European members of Coscinodon and similar taxa is given.     

NUCPLOT: a program to generate schematic diagrams of protein-nucleic acid interactions.

Proteins that bind to DNA are found in all areas of genetic activity within the cell. To help understand how these proteins perform their various functions, it is useful to analyse which residues are involved in binding to the DNA and how they interact with the bases and sugar-phosphate backbone of nucleic acids. Here we describe a program called NUCPLOT which can automatically identify these interactions from the 3D atomic coordinates of the complex from a PDB file and generate a plot that shows all the interactions in a schematic manner. The program produces a PostScript output file representing hydrogen, van der Waals and covalent bonds between the protein and the DNA. The resulting diagram is both clear and simple and allows immediate identification of important interactions within the structure. It also facilitates comparison of binding found in different structures. NUCPLOT is a completely automatic program, which can be used for any protein-DNA complex and will also work for certain protein-RNA structures.     

Mutants of Saccharomyces able to grow after inhibition of thymidine phosphate synthesis

Summary Several spontaneous mutants of Saccharomyces have been isolated that are able to grow in the presence of aminopterin and sulfanilamide when thymidine phosphate and adenine are added to the nutrient medium. The ability to grow under these conditions is caused by either one of three mutant recessive genes. These genes are linked to each other.     

In vitro virulence characteristics of rare serovars of <Emphasis Type="Italic">Salmonella enterica</Emphasis> isolated from sand lizards (<Emphasis Type="Italic">Lacerta agilis</Emphasis> L.)

The aim of this study was to estimate virulence potential of Salmonella enterica strains colonizing the gut of free-living sand lizards (Lacerta agilis L.). The strains belonged to three Salmonella serovars: Abony, Schleissheim, and Telhashomer. Adhesion and invasion abilities of the strains were determined in quantitative assays using the gentamicin protection method. Induction of apoptosis was assessed using HeLa cell monolayers. PCR assays were used for detection of 26 virulence genes localised within mobile elements: pathogenicity islands, virulence plasmids, and prophage sequences. In vitro studies revealed that all strains had adhesion and invasion abilities to human epithelial cells. The isolates were cytotoxic and induced apoptosis of the cells. The serovars differed in the number of virulence-associated genes: up to 18 genes were present in Salmonella Schleissheim, 17 in Salmonella Abony, whereas as few as six genes were found in Salmonella Telhashomer. Generally, Salmonella Abony and Salmonella Schleissheim did not differ much in gene content connected with the presence SPI-1 to -5. All of the strains lacked genes localised within bacteriophages and plasmids. The presence of virulence-associated genes and in vitro pathogenicity assays suggest that Salmonella sp. strains originating from autochthonous, free-living lizards can potentially infect and cause disease in humans.     

Plasma concentrations of amino acid and nicotinamide metabolites in rheumatoid arthritis – potential biomarkers of disease activity and drug treatment

This study aimed to evaluate changes in plasma amino acid and nicotinamide metabolites concentrations in rheumatoid arthritis (RA) in a search for potential biomarkers of the disease activity and the effect treatment. Analysis of plasma metabolite patterns with liquid chromatography/mass spectrometry revealed specific changes in RA as well as correlations with clinical parameters. Combined concentration parameter calculated as [aspartic acid]?+?[threonine]?+?[tryptophan]???[histidine]???[phenylalanine] offered the strongest correlation (p?<?0.001) with pain joint count, swollen joint count and DAS 28. Such analysis of amino acid and related metabolite pattern offers potential for diagnosis as well as for monitoring disease progression and therapy in RA.