Home
Marine microbiology
New marinforsk project on virus-host interactions

VirVar: Uncovering key players for regulation of phytoplankton function and structure: lessons to be learned from algal virus-haptophyte coexistence

New Marinforsk project, led by Ruth-Anne Sandaa (UiB) will explore the co-evolution of host resistance and virulence

VirVar illustration
The Red Queen effect (Van Valen, 1973), based on Lewis Carroll´s novel “Through the looking glass”, is often used as an allegory to metaphorically describe coevolution as an endless battle between viruses and hosts. Because viruses harm their hosts, natural selection favours host genes that make them resistant to viral infection. However, viruses will also be under selection to overcome host resistance. In this way, hosts and viruses may co-evolve in continuous arms races of defence and counter-defence.  In Carroll’s tale The Red Queen states that in her queendom it takes all the running you can do to stay in the same place. Likewise, in order for a virus or a host to survive in the arms race they have to be constantly changing (or running)
Photo:
Ruth Anne Sandaa

VirVar will provide knowledge of basic mechanisms in the relationship between viruses and their phytoplankton hosts and how this effect the primary production in the Ocean. Viruses are the most abundant biological entities on the planet. In one drop of seawater there is as many as one million viruses. This means that there are more viruses in one litre of seawater than humans on our planet. Most of these viruses infect microbes, that is bacteria, archaea and phytoplankton, the main primary producers of the world’s oceans. By infecting and killing these microbes, viruses affect all microbial processes, such as global fixation and cycling of key elements e.g. carbon, nitrogen and phosphorous. However, not all viruses cause harm to their hosts. Some have developed different ways to “live” in peace together with their host or even being beneficial for host survival. How these different forms of relationships are established, and how they affect the function of the host community, is however unknown. VirVar will focus on viral-host pairs with different relationships (high mortality-persistence) as model systems using key phytoplankton hosts of great importance for primary production in the world’s oceans. By using such unique virus-host model systems, combined with molecular biology, modeling and bioinformatics, the project will provide basic knowledge of factors important for development of the different stages in a virus-host relationship and investigate how these different stages affect the diversity of the primary producers in the ocean. This information is crucial for a better understanding of viral ecology in a changing ocean, but also for basic evolutionary understanding of all virus-host relationships, including pathogenic viruses for humans, animals or plants.

The new project brings together scientists from UiB, as well as the Universities of New Brunswick, Massachusetts Boston, Oslo and Kyoto and the Oceanological Observatory of Banyuls.