Profiles of active acetylated and methylated histone marks at the HS22 hot spot in early meiotic prophase. (A) Representative normalized native ChIP profiles of the active H3K9Ac, H4K5Ac, H4K8Ac, H4K16Ac, and H4K91Ac acetylated histone marks are shown for spermatogonium, preleptotene, leptotene-zygotene, and pachytene-diplotene meiotic cells for the HS22 hot spot. (B) Representative normalized native ChIP profiles of the active H3K4Me2, H3K36Me3, and H3K79Me1 methylated histone marks are shown for spermatogonium, preleptotene, leptotene-zygotene, and pachytene-diplotene meiotic cells for the HS22 hot spot. Normalized histone modification profiles in panels A and B were obtained as described in the legend to Fig. 2. ChIP profiles shown are the averages for three independent, normalized ChIP experiments. The statistical significance of the histone mark enrichments within the HS22 hot spot core and P values were defined using the Mann-Whitney test as described in the legend to Fig. 2. *, P < 0.05; **, P < 0.01. Red shading, hot spot core; red line, stage where Spo11 generates DSBs.