Isolation and characterization of a single‐stranded RNA virus that infects the marine planktonic diatom C haetoceros sp. ( SS08 ‐ C03 )

• Published in: Phycological research Vol. 61; no. 1; pp. 27 - 36
• Main Authors: Tomaru, Yuji, Toyoda, Kensuke, Kimura, Kei, Takao, Yoshitake, Sakurada, Kiyonari, Nakayama, Natsuko, Nagasaki, Keizo
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• ISSN: 1322-0829; 1440-1835
• DOI: 10.1111/j.1440-1835.2012.00670.x

Summary Diatoms are the major primary producers in the world's aquatic environment; hence, their dynamics are an important focus in current studies. Viruses, along with other physical, chemical, and biological factors, have recently been recognized as potential factors of diatom mortality. We isolated and characterized a new diatom virus ( Csp03RNAV ) that causes lysis of the marine planktonic diatom C haetoceros sp. strain SS08 ‐ C03 isolated from H iroshima B ay, J apan. Here, we present the physiology, morphology, and genome characteristics of this virus. Csp03RNAV was isolated from surface waters of Y atsushiro S ea, J apan. Virions were icosahedral and 32 nm in diameter, and accumulated in the cytoplasm of the host cells. The latent period was estimated to be <48 h. Csp03RNAV harbors a single‐stranded RNA genome, which has 9417 bases encoding two open reading frames that code for putative replication‐related proteins and putative structural proteins, respectively. The monophyly of Csp03RNAV and the other known diatom‐infecting single‐stranded RNA viruses (genus B acillarnavirus ), R hizosolenia setigera RNA virus, C haetoceros socialis f. radians RNA virus, and C haetoceros tenuissimus RNA virus was strongly supported by phylogenetic analysis based on the amino acid sequence of the RNA ‐dependent RNA polymerase domain. On the basis of these results, Csp03RNAV is considered to be a new member of the genus B acillarnavirus .