title: High abundances of cyanomyoviruses in marine ecosystems demonstrate ecological relevance.
abstract: The distribution of cyanomyoviruses was estimated using a quantitative PCR (qPCR) approach that targeted the g20 gene as a proxy for phage. Samples were collected spatially during a > 3000 km transect through the Sargasso Sea and temporally during a gyre-constrained phytoplankton bloom within the southern Pacific Ocean. Cyanomyovirus abundances were lower in the Sargasso Sea than in the southern Pacific Ocean, ranging from 2.75 × 10(3) to 5.15 × 10(4) mL(-1) and correlating with the abundance of their potential hosts (Prochlorococcus and Synechococcus). Cyanomyovirus abundance in the southern Pacific Ocean (east of New Zealand) followed Synechococcus host populations in the system: this included a decrease in g20 gene copies (from 4.3 × 10(5) to 9.6 × 10(3) mL(-1) ) following the demise of a Synechococcus bloom. When compared with direct counts of viruses, observations suggest that the cyanomyoviruses comprised 0.5 to >25% of the total virus community. We estimated daily lysis rates of 0.2-46% of the standing stock of Synechococcus in the Pacific Ocean compared with c. < 1.0% in the Sargasso Sea. In total, our observations confirm this family of viruses is abundant in marine systems and that they are an important source of cyanobacterial mortality.
authors.affiliation: Department of Microbiology, The University of Tennessee, Knoxville, TN 37996-0845, USA.
authors.forename: Audrey R
authors.initials: AR
authors.lastname: Matteson
authors.forename: Janet M
authors.initials: JM
authors.lastname: Rowe
authors.forename: Alise J
authors.initials: AJ
authors.lastname: Ponsero
authors.forename: Tiana M
authors.initials: TM
authors.lastname: Pimentel
authors.forename: Philip W
authors.initials: PW
authors.lastname: Boyd
authors.forename: Steven W
authors.initials: SW
authors.lastname: Wilhelm
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification*; D000458:Cyanobacteria / Q000821:virology*; D017753:Ecosystem; D009792:Oceans and Seas; D010140:Pacific Ocean; D010839:Phytoplankton / Q000821:virology; D016133:Polymerase Chain Reaction; D048929:Prochlorococcus / Q000821:virology; D012623:Seawater / Q000382:microbiology / Q000821:virology; D046940:Synechococcus / Q000821:virology