Pleurochrysome: A Web Database of Pleurochrysis Transcripts and Orthologs Among Heterogeneous Algae.

Pleurochrysis is a coccolithophorid genus, which belongs to the Coccolithales in the Haptophyta. The genus has been used extensively for biological research, together with Emiliania in the Isochrysidales, to understand distinctive features between the two coccolithophorid-including orders. However, molecular biological research on Pleurochrysis such as elucidation of the molecular mechanism behind coccolith formation has not made great progress at least in part because of lack of comprehensive gene information. To provide such information to the research community, we built an open web database, the Pleurochrysome (http://bioinf.mind.meiji.ac.jp/phapt/), which currently stores 9,023 unique gene sequences (designated as UNIGENEs) assembled from expressed sequence tag sequences of P. haptonemofera as core information. The UNIGENEs were annotated with gene sequences sharing significant homology, conserved domains, Gene Ontology, KEGG Orthology, predicted subcellular localization, open reading frames and orthologous relationship with genes of 10 other algal species, a cyanobacterium and the yeast Saccharomyces cerevisiae. This sequence and annotation information can be easily accessed via several search functions. Besides fundamental functions such as BLAST and keyword searches, this database also offers search functions to explore orthologous genes in the 12 organisms and to seek novel genes. The Pleurochrysome will promote molecular biological and phylogenetic research on coccolithophorids and other haptophytes by helping scientists mine data from the primary transcriptome of P. haptonemofera.

Increasing contribution of coccolithophorids to the phytoplankton in the northeastern Black Sea.

During 2005-2011, 418 phytoplankton samples were collected in Novorossiysk and Tuapse ports and near the resort cities of Anapa and Gelendzhik in the northeastern Black Sea. The maximal values of both abundance and biomass of phytoplankton related to high nutrient concentration, probably due to anthropogenic load, were observed at Novorossiysk (5.82×105cells/l, 1.492g/m3); in other bays values were about three times lower. The annual cycle included two to four phytoplankton abundance peaks. Emiliania huxleyi was the most abundant coccolithophorid (1.15×105cells/l offshore and 2.20×104cells/l in bays and ports). In spring-summer it contributed up to 90% of the phytoplankton abundance offshore. The maximal abundance of E. huxleyi was observed offshore of Gelendzhik (up to 1.32×106cells/l); the minimum was in the coastal zone in the port of Novorossiysk (on average 7.7×103cells/l). Generally, the species appears to avoid eutrophic waters.