Our current knowledge about nucleocytoplasmic large DNA viruses (NCLDVs) is largely derived from viral isolates that are co-cultivated with protists and algae. Here we reconstructed 2,074 NCLDV genomes from sampling sites across the globe by building on the rapidly increasing amount of publicly available metagenome data. This led to an 11-fold increase in phylogenetic diversity and a parallel 10-fold expansion in functional diversity. Analysis of 58,023 major capsid proteins from large and giant viruses using metagenomic data revealed the global distribution patterns and cosmopolitan nature of these viruses. The discovered viral genomes encoded a wide range of proteins with putative roles in photosynthesis and diverse substrate transport processes, indicating that host reprogramming is probably a common strategy in the NCLDVs. Furthermore, inferences of horizontal gene transfer connected viral lineages to diverse eukaryotic hosts. We anticipate that the global diversity of NCLDVs that we describe here will establish giant viruses—which are associated with most major eukaryotic lineages—as important players in ecosystems across Earth’s biomes.

我们目前对核胞质大 DNA 病毒 (NCLDV) 的了解主要来自与原生生物和藻类共培养的病毒分离株。在这里，我们利用快速增加的公开宏基因组数据，从全球采样点重建了 2,074 个 NCLDV 基因组。这导致系统发育多样性增加了 11 倍，功能多样性也相应增加了 10 倍。使用宏基因组数据对来自大型和巨型病毒的 58,023 个主要衣壳蛋白进行分析，揭示了这些病毒的全球分布模式和世界性本质。所发现的病毒基因组编码了多种在光合作用和多种底物运输过程中具有推定作用的蛋白质，表明宿主重编程可能是 NCLDV 中的常见策略。此外，水平基因转移的推论将病毒谱系与不同的真核宿主联系起来。我们预计，我们在此描述的 NCLDV 的全球多样性将使巨型病毒（与大多数主要真核生物谱系相关）成为地球生物群落生态系统中的重要参与者。