Objective In dilution cultures, marine planktonic Archaea are subject to mortality due to viral lysis. It has been shown that the frequency of lysogenized bacterial cells increases with depth and that marine Archaea constitute a numerically dominant group in the meso- and bathypelagic zone. These recent findings serve as the motivation for the proposed project, which is addressing the lack of knowledge on the functional role of planktonic Archaea in the meso- and bathypelagic zone by studying the relationship to thei r viruses.The first objective is to determine the phylogenetic affiliation (Bacteria, Euryarchaeota, Crenarchaeota) of the lysogenized cells and to determine changes over depth. Objective one will be tackled by using a virus-dilution approach to measure t he fraction of lysogenized prokaryotic cells in combination with catalysed reporter deposition fluorescence in situ hybridisation (CARD-FISH) to determine the phylogenetic affiliation of the bacterial cells.The second objective is to determine the dynamic s of dominant populations of lytic and lysogenic viruses and their hosts over depth and across seasons in relation to total virio- and bacterioplankton community composition. This will be achieved by using population specific virioplankton probes, prepared by randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Subsequently, these probes will be used to identify dominant populations of lytic and lysogenic viruses by pulsed-field gel electrophoresis (PFGE) and hybridization analysis. Upon infection, lysogenic viruses integrate their genome into the genome of the host.Thus, it will also be possible to track the populations of lysogenized prokaryotes. The third objective is to determine the partial nucleotide sequences of the genomes of dominant lysogenic viruses by cloning and sequencing to assess the phylogenetic affiliation of these lysogenic viruses. For the first time, archaeal viruses and their hosts will be studied in a pelagic system. Fields of science natural sciencesbiological sciencesmicrobiologybacteriologynatural sciencesbiological sciencesmicrobiologyvirologynatural sciencesbiological sciencesgeneticsDNAnatural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changesnatural sciencesbiological sciencesgeneticsgenomes Keywords Marine microbial ecology Viral ecology Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Topic(s) MOBILITY-2.1 - Marie Curie Intra-European Fellowships (EIF) Call for proposal FP6-2002-MOBILITY-5 See other projects for this call Funding Scheme EIF - Marie Curie actions-Intra-European Fellowships Coordinator CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE Address 250 rue albert einstein Valbonne France See on map Links Website Opens in new window EU contribution € 0,00
