Acetylation of histone H4 at lysine 44 facilitates meiotic recombination by creating accessible chromatin [Mnase-seq]

Meiotic recombination hotspots are associated with histone post-translational modifications and open chromatin. However, it remains unclear how histone modifications and chromatin structure directly regulate meiotic recombination. Here, we identify acetylation of histone H4 at Lys44 (H4K44ac) as a new histone modification, occurring on the nucleosomal lateral surface. We show that H4K44ac is specific to yeast sporulation, rising during yeast meiosis and displaying genome-wide enrichment at recombination hotspots in meiosis. The H4K44 residue is required for normal meiotic recombination, for normal levels of double strand breaks during meiosis, and for optimal sporulation. Non-modifiable substitution H4K44R results in reduced MNase digestion and decreased binding of recombination-associated proteins at hotspots. Our results show that H4K44ac creates an accessible chromatin environment for key proteins to facilitate meiotic recombination. Two samples, one WT MNase-seq and one MNase-seq from yeast with a lysine->arginine mutation at H4K44, no replicates Two replicates each of MNase-seq in WT and H4K44->R mutant yeast grown in YPD or YPA.