Subcellular organization is important for all forms of life. Even viruses are known to create replication factories and adapt the microenvironment within their host cells in their favor 1, 2, 3. The diversity of viruses is immense, as is the diversity of the structures they make. Iridoviruses infecting insects create crystalline aggregates that organize virions during the infection, while some bacteriophages accomplish a similar organizational feat through the formation of bouquet-like structures (discussed below) 1, 4, 5. Diverse archaeal viruses build pyramidal structures in the host cell to localize their replication factories and mediate their eventual egress 1, 6, 7, 8. Many viruses remodel host cell membranes to make membrane-enclosed replication compartments, from giant mimiviruses infecting amoebae to poxviruses, polioviruses, and coronaviruses infecting animals 1, 2, 9, 10, 11. This organization is remarkable, as viruses often have small, streamlined genomes, yet there are numerous examples where they have evolved these complex and intricate replication mechanisms. Surprisingly, even some bacteriophages, which have long been assumed to have relatively simple organization, have been shown to assemble replication factories and remodel their host cells in intricate ways 2, 12, 13, 14, including by building proteinaceous nucleus-like replication compartments 1, 2, 15, 16, 17••. The phage nucleus replication strategy is especially intriguing due to the functional similarities it shares with the eukaryotic nucleus [18] and will be the topic of this review.