Kratosvirus quantuckense: the history and novelty of an algal bloom disrupting virus and a model for giant virus research

Abstract

Since the discovery of the first “giant virus,” particular attention has been paid toward isolating and culturing these large DNA viruses through Acanthamoeba spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the Nucleocytoviricota, environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal Nucleocytoviricota should be considered a focal point in viral ecology. In this review, we report on Kratosvirus quantuckense (née Aureococcus anophagefferens Virus), an algae-infecting virus of the Imitervirales. Current systems for study in the Nucleocytoviricota differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of K. quantuckense. Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.

Aureococcus anophagefferens strain CCMP1851: draft genome of a second Kratosvirus quantuckense- susceptible host strain for an emerging host–giant virus model system

“…We assembled a draft genome for an isolate of the marine algae Aureococcus anophagefferens (Pelagophyceae) ( 1 ). A. anophagefferens strain CCMP1851 is only the second strain with a genome made public that can be infected by the “giant” virus Kratosvirus quantuckense ( Nucleocytoviricota ) ( 2 – 5 ). It was isolated from the same bloom as the strain CCMP1850 (September 1998, Great South Bay, Long Island; NCMA, Bigelow), which is resistant to this virus ( 4 , 5 ).…”

The diel disconnect between cell growth and division inAureococcusis interrupted by giant virus infection

“…For the past two decades the brown tide bloom agent Aureococcus anophagefferens and “giant virus” Kratosvirus quantuckense (family Schizomimiviridae ) have been studied in detail (Sieburth et al, 1988; Rowe et al, 2008; Truchon et al, 2023). The pelagophyte A. anophagefferens was characterized in 1985 (Sieburth et al, 1988) and has continued to produce blooms along the East Coast of the United States (Narragansett Bay, Barnegat Bay, Long Island bays) (Bricelj and Lonsdale, 1997), off the coast of China (near Qinhuangdao); Bohai Sea) (Zhang et al, 2012) and a bay on the South West coast of South Africa (Saldanha Bay) (Probyn et al, 2010).…”