Diversity of prasinoviruses and their control through environmental factors

Projet en cours

Project affiliated to:
Project leader Université Pierre et Marie Curie / Observatoire Océanologique de Banyuls
Industrials partners Université de Lyon-1/Evolutionary Biology and Biometry Laboratory
Research partners SO
Budget 1 100 K€
Year of labeling 2012
Year of co-financing 2012

Viruses are recognized as major players in planktonic ecosystems. Recent studies have been conducted on medium and large scales. Of these, many are based on host cultures, thereby making it possible to isolate the virus from these hosts, but this is limited because of the diversity of viruses obtained. In addition, recent studies suggest that many viruses are highly specific to their hosts.

However, it is believed that virus diversity is so great that it is desirable to limit studies to a specific taxonomic group. The giant double-stranded DNA Viruses, Phycodnaviridae, which infect algae, are good candidates for such a study, because there is genomic data available and preliminary studies have already been carried out on their diversity. Amongst them are the prasinovirus which are prasinophyte viruses, an important component of picoplankton photosynthesis in oceans. The algae-prasinophyte-prasinovirus system has the advantage of including hosts and virus whose genome is completely sequenced (and currently published for 6 hosts and 7 viruses), particularly in the Golfe du Lion (north-western Mediterranean). The Golfe du Lion is characterized by contrasting environments, including eutrophic ponds connected to the sea, coastal sites rich in nutrients, and oligotrophic offshore habitats.

The Prasinophytes in the Golfe du Lion are mainly composed of three types, Ostreococcus, Micromonas and Bathycoccus, and at least one complete genome is available by type. Therefore the genomic tools for the identification of the viral diversity are already available for the host virus. Studying this in contrasting environments will allow an estimation of the influence of environmental factors on the diversity of the virus. This is the DECOVIR project’s objective.