Present address, Fei Zhu: Department of Pharmaceutical Sciences, University of Maryland, Baltimore, USA
Eukaryotic picoplankton communities of the Mediterranean Sea in summer assessed by molecular approaches (DGGE, TTGE, QPCR)
Article first published online: 10 JAN 2006
FEMS Microbiology Ecology
Volume 55, Issue 3, pages 403–415, March 2006
How to Cite
Marie, D., Zhu, F., Balagué, V., Ras, J. and Vaulot, D. (2006), Eukaryotic picoplankton communities of the Mediterranean Sea in summer assessed by molecular approaches (DGGE, TTGE, QPCR). FEMS Microbiology Ecology, 55: 403–415. doi: 10.1111/j.1574-6941.2005.00058.x
Editor: Riks Laanbroek
- Issue published online: 10 JAN 2006
- Article first published online: 10 JAN 2006
- Received 29 April 2005; revised 21 September 2005; accepted 13 October 2005.
- pelagic ecosystems;
- flow cytometry;
- 18S rRNA;
The composition and abundance of eukaryotic picoplankton (defined here as cells smaller than 3 μm) was investigated in the Morocco upwelling and throughout the Mediterranean Sea in late summer using flow cytometry and molecular methods (gradient gel electrophoresis and quantitative PCR). The picoplankton displayed characteristics typical of oligotrophic oceanic areas with concentrations down to 1000 cells mL−1 in the Eastern Basin. The most abundant eukaryotic sequences recovered by gradient gel electrophoresis were related to uncultivated marine groups: alveolates I (16%) and II (26%) and a newly discovered group (env Nansha, 17%) for which sequences have been recently obtained from the South China Sea and that could be related to Acantharians. Prasinophyceae (photosynthetic green algae) accounted for 10% of the sequences, whereas Cercozoa, Stramenopiles, Polycystinea, dinoflagellates and ciliates provided minor contributions. The use of quantitative PCR coupled with taxon-specific primers allowed us to estimate the relative abundance of several taxa belonging to the Prasinophyceae. Of the three genera assessed, Bathycoccus appeared as the most abundant, forming localized maxima at depth.