Abstract: Covalent post-translational modifications of histones have important functions in transcription, replication, repair, and other aspects of eukaryotic chromosome dynamics. Trimethylation of lysine-4 on histone H3 is enriched at actively transcribed loci in many organisms. The impact of this histone modification on transcription has been extensively studied, but less is known about its effects on other chromosomal processes. An intriguing new study in this issue of EMBO Journal demonstrates that H3 lysine-4 trimethylation is critical in budding yeast for formation of the programmed DNA double-strand breaks that initiate homologous recombination during meiosis. These findings have important implications for elucidating the previously recognized but little understood connections between meiotic break formation and transcriptional promoters in this organism.