Fig. 7.
Adad2 mutant spermatids do not form PMSC and fail to undergo the histone to protamine transition. (A) Immunofluorescence of H3K27me3 and H3K9me3 in adult wild-type and Adad2M/M round spermatids showing mutant round spermatids lack an H3K9me3-only chromatin domain (H3K27me3, green; H3K9me3, red; DAPI, blue). (B) Immunofluorescence of H3K27me3 and H3K4me2 in adult wild-type and Adad2M/M round spermatids, demonstrating lack of H3K4me2 enrichment or exclusion in mutant round spermatids (H3K27me3, green; H3K4me2, red; DAPI, blue). In A and B, square indicates the area shown in the inset; arrowheads indicate the PMSC; arrows indicate the chromocenter; open arrowheads indicate the chromocenter-like foci. (C) Immunofluorescence of TNP1 (green) and SYCP3 (red). DAPI is in blue. Insets show stage-matched no anti-TNP1 controls in adult wild-type and mutant testis sections by stage. TNP1 is imported into the nucleus starting in stage XI in wild-type spermatids. It properly associates with the DAPI-dense regions of elongating spermatids by stage I and signal begins to dissipate by stage IV. These events are delayed or abnormal in mutant elongating spermatids.