Date |
February 14, 2012 |
Speaker |
Dr. Pascal Hingamp, Aix-Marseille University, France
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Title |
What can metagenomics tell us about marine large eukaryotic viruses? Preliminary exploration of TARA -OCEANS genomic data
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Abstract |
The TARA-OCEANS expedition (1) - a three year circumglobal sampling of marine plankton - represents a
powerful opportunity to explore the diversity of marine large eukaryotic viruses. Indeed, by sampling
simultaneously across the whole plankton size range (0.2µm, 1.6µm, 5µm, 20µm, 180µm & 2mm), the
TARA-OCEANS sample collection overcomes limitations of studies focused on single plankton size ranges
by making possible the identification of both viruses and their potential hosts. Also, by choosing large scale
direct sequencing of environmental DNA, the TARA-OCEANS metagenomics experimental strategy
avoids the fundamental shortcoming of many genetic biodiversity studies which, by relying on ribosomal
RNA tag sequencing, are by definition blind to viruses. I will present preliminary results from the
metagenomic analysis of samples collected from the Mediterranean sea and Indian ocean during the first
year of the TARA cruise. The first observation is the much stronger variation in viral diversity across the
size fraction gradient than across diverse geographical locations. Opening the analysis to cellular life forms,
some strong co-occurrence signals present in the TARA-OCEANS metagenomic data might be indications
of novel virus-host interactions.
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