Description du projet
Décryptage de la physiologie et de l’écologie des virus marins parmi différents virus
Les virus ont un impact profond sur l’écosystème marin. Cependant, notre compréhension de la physiologie et de l’écologie des virus marins reste limitée. Des données récentes obtenues grâce à une méthode moléculaire nouvellement développée ont révélé des différences frappantes dans l’abondance sur le terrain de deux sous-types de podovirus de type T7 qui infectent les cyanobactéries marines. Ces sous-types ont également présenté des variations significatives en ce qui concerne les propriétés d’infection au cours d’études en laboratoire. Le projet PhageDiff, financé par l’UE, permettra de mieux comprendre les facteurs génétiques qui sous-tendent les différences physiologiques dans la dynamique d’infection entre des cyanophages de type T7 étroitement apparentés qui infectent des cyanobactéries marines telles que Synechococcus et Prochlorococcus. Le projet étudiera les conséquences écologiques de ces différences. Il mettra en lumière l’interaction complexe entre les virus marins et les cyanobactéries qui les hébergent.
Objectif
Viruses are extremely abundant in the oceans and majorly impact the marine ecosystem by influencing the abundance, diversity and evolution of their hosts. However, our understanding of marine viral physiology and ecology among different members of the virus community is conspicuously lacking. Preliminary data using a newly developed molecular method revealed drastic differences in field abundances of two subtypes of T7-like podoviruses that infect marine cyanobacteria. Moreover, these subtypes displayed large differences in infection properties in laboratory studies. The main objective of this proposal is to gain a deep understanding of the genetic basis for the physiological differences in infection dynamics among closely related T7-like cyanophages that infect the globally important marine cyanobacteria, Synechococcus and Prochlorococcus, and to ascertain the ecological consequences of these physiological differences. We hypothesize that a small set of genes, beyond the core replication and morphogenesis genes, differentially impact the dynamics of the infection process which, in-turn, defines the niche occupied by discrete members of this virus family. Our specific objectives are to identify the genes responsible for the physiological differences and determine their impact on infection dynamics. This will be achieved through the development of a phage gene inactivation system and the comparison of infection properties of mutant and wild-type phages. Furthermore, using our new molecular field method, we will assess the distribution patterns of different subtypes of T7-like cyanophages from within the mix of all viruses in the oceans. The unique combination of innovative molecular methods with physiological experimentation and ecological sampling will provide significant insight into both the biological functionality behind the diversity within an ecologically relevant phage family and the selection pressures that have led to their diversification and evolution.
Champ scientifique
Programme(s)
Régime de financement
ERC-COG - Consolidator GrantInstitution d’accueil
32000 Haifa
Israël