SS2.06 Microbial Diversity in Time and Space
Date: Tuesday, June 11, 2002
Time: 11:15:00 AM
Location: Lecture Theatre
 
ChenF, Center of Marine Biotechnology, University of Maryland, Baltimore, USA, chenf@umbi.umd.edu
 
Unexpected genetic diversity found in marine virus communities
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It is now known that viruses outnumber bacteria in marine environments and could play important roles on regulating microbial production and community structure. However, the efforts to understand the complex interactions between viruses and hosts in marine microbial communities are greatly impeded by the lack of studies on genetic diversity of viruses in natural environments. Partial viral capsid assembly gene (g20) was amplified from cyanophage isolates and natural virus communities by PCR with primers designed for cyanomyovirus, a dominant group of viruses which infect marine Synechococcus spp. Among 207 clonal g20 sequences recovered from six natural virus communities, only 30% of them were clustered with known cyanophage isolates. It is likely that the majority of unidentified g20 clones represent cyanophages that infect different Synechococcus strains or other closely related cyanobacteria like Prochlorococcus. Cyanophages infecting a single Synechococcus strain are highly diverse in seawater, suggesting that rapid genetic exchange could be an important mechanism for marine phage to co-exist with resistant bacteria in natural environments.