Characterization of a New Chlorovirus Type with Permissive and Non-permissive Features on Phylogenetically Related Algal Strains

Authors

• Cristian F. Quispe, Escuela Agrícola Panamericana Zamorano
• Ahmed Esmael, University of Nebraska - LincolnFollow
• Olivia Sonderman, University of Nebraska - Lincoln
• Michelle McQuinn, University of Nebraska - Lincoln
• Irina Agarkova, University of Nebraska-LincolnFollow
• Mohammed Battah, Benha University
• Garry A. Duncan, Nebraska Wesleyan University
• David D. Dunigan, University of Nebraska-LincolnFollow
• Timothy P. L. Smith, USDA, Animal Research CenterFollow
• Cristina DeCastro, University of Napoli
• Immacolata Speciale, University of Napoli
• Fangrui Ma, University of Nebraska - Lincoln
• James L. Van Etten, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

2017

Citation

Virology. 2017 January ; 500: 103–113

Comments

HHS Public Access

doi:10.1016/j.virol.2016.10.013

Abstract

A previous report indicated that prototype chlorovirus PBCV-1 replicated in two Chlorella variabilis algal strains, NC64A and Syngen 2-3, that are ex-endosymbionts isolated from the protozoan Paramecium bursaria. Surprisingly, plaque-forming viruses on Syngen 2-3 lawns were often higher than on NC64A lawns from indigenous water samples. These differences led to the discovery of viruses that exclusively replicate in Syngen 2-3 cells, named Only Syngen (OSy) viruses. OSy-NE5, the prototype virus for the proposed new species, had a linear dsDNA genome of 327 kb with 44-nucleotide-long, incompletely base-paired, covalently closed hairpin ends. Each hairpin structure was followed by an identical 2,612 base-paired inverted sequence after which the DNA sequence diverged. OSy-NE5 encoded 357 predicted CDSs and 13 tRNAs. Interestingly, OSy-NE5 attached to and initiated infection in NC64A cells but infectious progeny viruses were not produced; thus OSy-NE5 replication in NC64A is blocked at some later stage of replication.