Viral DNA Accumulation Regulates Replication Efficiency of Chlorovirus OSy-NE5 in Two Closely Related Chlorella variabilis Strains

Authors

Ahmed Esmael, University of Nebraska - Lincoln, Benha UniversityFollow
Irina V. Agarkova, University of Nebraska-LincolnFollow
David D. Dunigan, University of Nebraska-LincolnFollow
You Zhou, University of Nebraska - LincolnFollow
James L. Van Etten, University of Nebraska - LincolnFollow

Date of this Version

6-9-2023

Citation

Esmael, A.; Agarkova, I.V.; Dunigan, D.D.; Zhou, Y.; Van Etten, J.L. Viral DNA Accumulation Regulates Replication Efficiency of Chlorovirus OSy-NE5 in Two Closely Related Chlorella variabilis Strains. Viruses 2023, 15, 1341. https:// doi.org/10.3390/v15061341

Comments

Open access.

Abstract

Many chloroviruses replicate in Chlorella variabilis algal strains that are ex-endosymbionts isolated from the protozoan Paramecium bursaria, including the NC64A and Syngen 2-3 strains. We noticed that indigenous water samples produced a higher number of plaque-forming viruses on C. variabilis Syngen 2-3 lawns than on C. variabilis NC64A lawns. These observed differences led to the discovery of viruses that replicate exclusively in Syngen 2-3 cells, named Only Syngen (OSy) viruses. Here, we demonstrate that OSy viruses initiate infection in the restricted host NC64A by synthesizing some early virus gene products and that approximately 20% of the cells produce a small number of empty virus capsids. However, the infected cells did not produce infectious viruses because the cells were unable to replicate the viral genome. This is interesting because all previous attempts to isolate host cells resistant to chlorovirus infection were due to changes in the host receptor for the virus.