Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel.
Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.
Nat Microbiol. 2023 Feb;8(2):332-346. doi: 10.1038/s41564-022-01305-7. Epub 2023 Jan 26.
Virophages are small double stranded DNA (dsDNA) viruses that can only replicate in a host by co-infecting with another virus. Marine algae are commonly associated with virophage-like elements such as Polinton-like viruses (PLVs) that remain largely uncharacterized. Here we isolated a PLV that co-infects the alga Phaeocystis globosa with the Phaeocystis globosa virus-14T (PgV-14T), a close relative of the "Phaeocystis globosa virus-virophage" genomic sequence. We name this PLV 'Gezel-14T. Gezel is phylogenetically distinct from the Lavidaviridae family where all known virophages belong. Gezel-14T co-infection decreases the fitness of its viral host by reducing burst sizes of PgV-14T, yet insufficiently to spare the cellular host population. Genomic screens show Gezel-14T-like PLVs integrated into Phaeocystis genomes, suggesting that these widespread viruses are capable of integration into cellular host genomes. This system presents an opportunity to better understand the evolution of eukaryotic dsDNA viruses as well as the complex dynamics and implications of viral parasitism.
噬藻体是一种小型双链 DNA（dsDNA）病毒，只能通过与另一种病毒共同感染才能在宿主中复制。海洋藻类通常与类噬藻体元素如 Polinton-like viruses（PLVs）有关，这些元素在很大程度上仍未被充分描述。在这里，我们分离出一种 PLV，它与藻类聚球藻共同感染 Phaeocystis globosa 病毒-14T（PgV-14T），后者是“聚球藻病毒-噬藻体”基因组序列的近亲。我们将这种 PLV 命名为“Gezel-14T”。Gezel 在系统发育上与 Lavidaviridae 科不同，所有已知的噬藻体都属于该科。Gezel-14T 的共同感染通过降低 PgV-14T 的爆发大小来降低其病毒宿主的适应性，但不足以使细胞宿主群体免受影响。基因组筛选显示，Gezel-14T 样 PLVs 整合到聚球藻基因组中，表明这些广泛存在的病毒能够整合到宿主细胞的基因组中。该系统为更好地理解真核 dsDNA 病毒的进化以及病毒寄生的复杂动态和影响提供了机会。
