title: Real-time PCR detection of host-mediated cyanophage gene transcripts during infection of a natural Microcystis aeruginosa population.
abstract: The aim of this study was to develop a quantitative real-time reverse transcription-PCR (real-time RT-PCR) assay to detect and quantify mRNA of cyanophages within infected Microcystis aeruginosa cells in a freshwater pond. Laboratory-based data showed that the relative abundance of the cyanophage g91 mRNA within host cells increased before cyanophage numbers increased in culture. This transcriptional pattern indicated the kinetics of the viral infection suggesting the real-time RT-PCR method to be a potential tool for environmental monitoring of cyanophage infections. In this field survey, the numbers of infected M. aeruginosa cell populations estimated from cyanophage numbers were low at 0.01-2.9 cells mL(-1). The highest relative abundance of phage g91 RNA (10(-2) per rnpB transcript) was at about the same levels of expression as laboratory-based growth data for Ma-LMM01 (estimated density of infected host cells: 10(5) cells mL(-1)); and was observed when cyanophage numbers rapidly increased (as well as a decrease in host cell numbers). Quantification of cyanophage numbers is important to understand ecological relationships between the phage and its hosts. Our data suggest the quantification of phage gene transcripts within a natural host cell population to be a strong tool for investigating the quantitative effects of phage lysis during infection of the host population.
authors.affiliation: Division of the Aquatic Biology and Ecology, Center for Marine Environmental Studies (CMES), Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790–8577, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Yukari
authors.initials: Y
authors.lastname: Yoshida-Takashima
authors.forename: Aki
authors.initials: A
authors.lastname: Kashima
authors.forename: Shingo
authors.initials: S
authors.lastname: Hiroishi
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000254:growth & development*; D005618:Fresh Water / Q000382:microbiology*; D046931:Microcystis / Q000821:virology*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins