
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.03.611062
preprint
1
Article
Latent infection of an active giant endogenous virus in a unicellular green alga
Erazo-Garcia Maria P. http://orcid.org/0000-0002-0626-7166

Sheyn Uri http://orcid.org/0000-0002-0997-3533

Barth Zachary K. http://orcid.org/0000-0002-1321-306X

Craig Rory J. http://orcid.org/0000-0002-6262-0008

Wessman Petronella
Jivaji Abdeali M.
Ray W. Keith
Svensson-Coelho Maria http://orcid.org/0000-0002-2315-2416

Cornwallis Charlie K. http://orcid.org/0000-0003-1308-3995

Rengefors Karin http://orcid.org/0000-0001-6297-9734

Brussaard Corina P. D. http://orcid.org/0000-0002-6320-9229

Moniruzzaman Mohammad http://orcid.org/0000-0001-9337-3874

Aylward Frank O. http://orcid.org/0000-0002-1279-4050

03 9 2024
2024.09.03.611062https://creativecommons.org/licenses/by-nc/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which allows reusers to distribute, remix, adapt, and build upon the material in any medium or format for noncommercial purposes only, and only so long as attribution is given to the creator.
http://biorxiv.org/lookup/doi/10.1101/2024.09.03.611062
nihpp-2024.09.03.611062.pdf
Abstract

Latency is a common strategy in a wide range of viral lineages, but its prevalence in giant viruses remains unknown. Here we describe the activity and viral production from a 617 kbp integrated giant viral element in the model green alga Chlamydomonas reinhardtii . We resolve the integrated viral region using long-read sequencing and show that viral particles are produced and released in otherwise healthy cultures. A diverse array of viral-encoded selfish genetic elements are expressed during GEVE reactivation and produce proteins that are packaged in virions. In addition, we show that field isolates of Chlamydomonas sp. harbor latent giant viruses related to the C. reinhardtii GEVE that exhibit similar infection dynamics, demonstrating that giant virus latency is prevalent in natural host communities. Our work reports the largest temperate virus documented to date and the first active GEVE identified in a unicellular eukaryote, substantially expanding the known limits of viral latency.
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pmc
