Complex virus-virus interactions can arise when multiple viruses coinfect the same host, impacting infection outcomes with broader ecological and evolutionary significance for viruses and host. Yet, our knowledge regarding virus competition is still limited, especially for single-celled eukaryotic host-virus systems. Here, we report on mutual interference of two dsDNA viruses, MpoV-45 T and MpoV-46 T, competing for their Arctic algal host Micromonas polaris. Both viruses affected each other’s gene expression and displayed reduced genome replication during coinfection. MpoV-45 T was the dominant virus, likely due to interference in the DNA replication of is competitor. Even when its coinfection was delayed, the dominant virus still prevailed while genome production of the other virus was strongly suppressed. This contrasts with typical superinfection exclusion, where the primary infection prevents secondary infection by other viruses. Higher temperature made the suppressed virus a stronger competitor, signifying that global warming is likely to alter virus-virus interactions in Arctic waters.

中文翻译：

---

温度调节重复感染北极病毒在单细胞藻类宿主中的优势


当多种病毒共同感染同一宿主时，可能会出现复杂的病毒-病毒相互作用，从而影响感染结果，对病毒和宿主具有更广泛的生态和进化意义。然而，我们关于病毒竞争的知识仍然有限，特别是对于单细胞真核宿主病毒系统。在这里，我们报告了两种 dsDNA 病毒 MpoV-45 T 和 MpoV-46 T 相互干扰，争夺北极藻类宿主北极小单胞菌。两种病毒都会影响彼此的基因表达，并在共感染期间表现出基因组复制减少。 MpoV-45 T 是主要病毒，可能是由于干扰了竞争对手的 DNA 复制。即使合并感染被延迟，优势病毒仍然占上风，而另一种病毒的基因组产生则受到强烈抑制。这与典型的双重感染排除形成鲜明对比，在典型的双重感染排除中，初次感染可防止其他病毒的继发感染。更高的温度使被抑制的病毒成为更强大的竞争对手，这意味着全球变暖可能会改变北极水域的病毒与病毒之间的相互作用。