Investigation of cell fate decision in Schizosaccharomyces pombe by ncRNA annotation and statistical analyses

Studies in the fission yeast Schizosaccharomyces pombe (S. pombe) have done much to inform the view of heterochromatin and its control by the RNA interference (RNAi) machinery. Using cDNA synthesised from poly(A)-enriched RNA samples, numerous novel ncRNA loci were discovered, and the 50 and 30 ends of many other genes were refined in previous studies. Although some of these transcripts may encode novel proteins the function of the majority is yet to be determined. The authors have used strand-specific deep sequencing of RNA, irrespective of poly(A) status, to reveal a highly structured antisense programme that modulates gene expression to dictate cell fate decisions during sexual differentiation. They show that an extensive and elaborate array of ncRNA production accompanies sexual differentiation in the fission yeast S. pombe. Experimental manipulation suggests that these transcripts specifically regulate the function of the target genes.

Individual dinoflagellate cysts species of surface sediment samples from the Mediterranean Sea

To determine the relationship between the spatial dinoflagellate cyst distribution and oceanic environmental conditions, 34 surface sediments from the Eastern and Western Mediterranean Sea have been investigated for their dinoflagellate cyst content. Multivariate ordination analyses identified sea-surface temperature, chlorophyll-a , nitrate concentration, salinity, and bottom oxygen concentration as the main factors affecting dinoflagellate cyst distribution in the region. Based on the relative abundance data, two associations can be distinguished that can be linked with major oceanographic settings. (1) An offshore eastern Mediterranean regime where surface sediments are characterized by oligotrophic, warm, saline surface water, and high oxygen bottom water concentrations (Impagidinium species, Nematosphaeropsis labyrinthus, Pyxidinopsis reticulata and Operculodinium israelianum). Based on the absolute abundance, temperature is positively related to the cyst accumulation of Operculodinium israelianum. Temperature does not form a causal factor influencing the accumulation rate of the other species in this association. Impagidinium species and Nematosphaeropsis labyrinthus show a positive relationship between cyst accumulation and nitrate availability in the upper waters. (2) Species of association 2 have highest relative abundances in the Western Mediterranean Sea, Strait of Sicily/NW Ionian Sea, and/or the distal ends of the Po/Nile/Rhône River plumes. At these stations, surface waters are characterized by (relative to the other regime) higher productivity associated with lower sea-surface temperature, salinity, and lower bottom water oxygen concentrations (Selenopemphix nephroides, Echinidinium spp., Selenopemphix quanta, Quinquecuspis concreta, Brigantedinium spp. and Lingulodinium machaerophorum). Based on both the absolute and relative abundances, Selenopemphix nephroides is suggested to be a suitable indicator to trace changes in the trophic state of the upper waters. The distribution of Lingulodinium machaerophorum is related to the presence of river-influenced surface waters, notably the Nile River. We suggest that this species might form a suitable marker to trace past variations in river discharge, notably from the Nile.

Tab. 1: Radiocarbon ages of samples from the Canadian archipelago

A sediment-sampling program was carried out in the Nares Strait region during the Nares 2001 Expedition to obtain cores for high-resolution palaeoceanographic studies of late Pleistocene-Holocene climate change. Long cores (>4 m) were obtained from basins near Coburg Island, Jones Sound, John Richardson Fiord off Kane Basin, and in northeastern Hall Basin. Short cores and grab samples were taken on shelves east and west of northern Smith Sound and in Kennedy Channel. Detailed studies of sediment texture, stable isotopes, microfossils and palynomorphs were made on the longest cores from Jones Sound and Hall Basin at the southern and northern ends of the Nares Strait region.

Results from Purgatory Conglomerate investigations

Quartz Crystallographic Preferred Orientation (CPO) patterns are most commonly a result of deformation by dislocation creep. We investigated whether Dissolution-Precipitation Creep (DPC) a process that occur at lower differential stresses and temperatures, may result in CPO in quartz. Within the Purgatory Conglomerate, DPC led to quartz dissolution along cobble surfaces perpendicular to the shortening direction, and quartz precipitation in overgrowths at the ends of the cobbles (strain shadows), parallel to the maximum extension direction. The Purgatory Conglomerate is part of the SE Narragansett basin where strain intensity increases from west to east and is associated with top-to-the-west transport and folding during the Alleghanian orogeny. Quartz c-axis orientations as revealed by Electron Backscatter Diffraction (EBSD) methods, were random in all analyzed domains within the cobbles and strain shadows irrespective of the intensity of strain or metamorphic grade of the sample. Quartz dissolution probably occurred exclusively along the cobbles' margins, leaving the remaining grains unaffected by DPC. The fact that quartz precipitated in random orientations may indicate that the strain shadows were regions of little or no differential stress.

GLOBEC-Germany - Integrated Datasets

The international Global Ocean Ecosystem Dynamics (GLOBEC) programme was initiated in 1991 by the Scientific Committee on Oceanic Research (SCOR) and the Intergovernmental Oceanographic Commission (IOC) of the UNESCO. It was a core project of the International Geosphere-Biosphere Project (IGBP) with its research topics aiming at understanding how global change impacts abundance, diversity and productivity of marine populations (Barange & Harris 2003). GLOBEC-Germany was the national German contribution to this core project focussing on the Baltic Sea and North Sea, to which Germany has adjoining coastlines. The two seas exhibit a gradient from marine (North Sea) to almost fresh water conditions (outer ends of the Baltic Sea). Main topic of the project was the investigation of interactions between zooplankton and fish under the influence of physical processes (Alheit 2004). Main sampling areas were located in the southern North Sea and German Bight, as well as in the Bornholm Basin in the Baltic Sea (Tamm et al. 2007).