Diversity of Marine-Derived Fungal Cultures Exposed by DNA Barcodes: The Algorithm Matters.

Marine fungi are an understudied group of eukaryotic microorganisms characterized by unresolved genealogies and unstable classification. Whereas DNA barcoding via the nuclear ribosomal internal transcribed spacer (ITS) provides a robust and rapid tool for fungal species delineation, accurate classification of fungi is often arduous given the large number of partial or unknown barcodes and misidentified isolates deposited in public databases. This situation is perpetuated by a paucity of cultivable fungal strains available for phylogenetic research linked to these data sets.

'Sponge-specific' bacteria are widespread (but rare) in diverse marine environments.

Numerous studies have reported the existence of sponge-specific 16S ribosomal RNA (rRNA) gene sequence clusters, representing bacteria found in sponges but not detected in other environments, such as seawater. The advent of deep-sequencing technologies allows us to examine the rare microbial biosphere in order to establish whether these bacteria are truly sponge specific, or are more widely distributed but only at abundances below the detection limit of conventional molecular approaches. We screened >12 million publicly available 16S rRNA gene pyrotags derived from 649 seawater, sediment, hydrothermal vent and coral samples from temperate, tropical and polar regions.

DNA adducts and polycyclic aromatic hydrocarbon (PAH) tissue levels in blue mussels (Mytilus spp.) from Nordic coastal sites.

DNA adducts in gills and digestive gland, as well as polycyclic aromatic hydrocarbon (PAH) tissue levels were analysed in blue mussels (Mytilus spp.) from Nordic coastal areas (Iceland, Norway and Sweden) with diffuse or point sources of PAHs of various origins. Both DNA adduct and PAH tissue levels were generally low, indicating low PAH exposure to the mussels in the areas studied.

Seasonal and intertidal impact on DNA adduct levels in gills of blue mussels (Mytilus edulis L.).

The aim of this study was to elucidate possible seasonal variation in DNA adduct levels in blue mussels (Mytilus edulis), and to investigate the impact of intertidal exposure on the DNA adduct levels, i.e. to explore if DNA adduct levels in mussels in the intertidal zone differ from those in the subtidal zone.