Nucleocytoplasmic large DNA viruses (NCLDVs) are ubiquitous in marine environments and infect diverse eukaryotes. However, little is known about their biogeography and ecology in the ocean. By leveraging the Tara Oceans pole-to-pole metagenomic data set, we investigated the distribution of NCLDVs across size fractions, depths and biomes, as well as their associations with eukaryotic communities. Our analyses reveal a heterogeneous distribution of NCLDVs across oceans, and a higher proportion of unique NCLDVs in the polar biomes. The community structures of NCLDV families correlate with specific eukaryotic lineages, including many photosynthetic groups. NCLDV communities are generally distinct between surface and mesopelagic zones, but at some locations they exhibit a high similarity between the two depths. This vertical similarity correlates to surface phytoplankton biomass but not to physical mixing processes, which suggests a potential role of vertical transport in structuring mesopelagic NCLDV communities. These results underscore the importance of the interactions between NCLDVs and eukaryotes in biogeochemical processes in the ocean.

核质大 DNA 病毒 (NCLDV) 在海洋环境中普遍存在并感染多种真核生物。然而，人们对它们在海洋中的生物地理学和生态学知之甚少。通过利用TaraOceans 极对极宏基因组数据集，我们调查了 NCLDV 在大小分数、深度和生物群落中的分布，以及它们与真核生物群落的关联。我们的分析揭示了 NCLDV 在海洋中的异质分布，以及在极地生物群系中独特 NCLDV 的比例更高。NCLDV 家族的群落结构与特定的真核细胞谱系相关，包括许多光合群。NCLDV 群落在地表和中上层区域之间通常是不同的，但在某些位置，它们在两个深度之间表现出高度相似性。这种垂直相似性与表面浮游植物生物量相关，但与物理混合过程无关，这表明垂直运输在构建中层 NCLDV 群落中具有潜在作用。