Nature Structural & Molecular Biology, Published online: 17 June 2025; doi:10.1038/s41594-025-01572-yConstitutive heterochromatin can promote piRNA transcription, a crucial step in genome defense. Two studies now show that piRNA transcription in Drosophila is regulated by the dual histone marks H3K27me3 and H3K9me3, and piRNA transcription in Caenorhabditis elegans is enhanced by H3K27me3, gene clustering and phase separation.

Nature Structural & Molecular Biology - Constitutive heterochromatin can promote piRNA transcription, a crucial step in genome defense. Two studies now show that piRNA transcription in...