Acetylation of histone H4 at lysine 44 facilitates meiotic recombination by creating accessible chromatin [ChIP-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. One sample, H4K44ac chIP from 4hrs sporulation yeast and one background H4 chIP from the same, two replicates each Two replicates each of H3K4me3 and H3K56ac chIP-seq in WT and H4K44->R mutant yeast, with two replicates of H3 chIP-seq in each genetic background Two replicates each of Rad51 chIP-seq in WT and H4K44->R mutant yeast with a single replicate of accompanying input DNA in each genetic background