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. Overall design: 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