TY - JOUR T1 - Human sperm chromatin forms spatially restricted nucleosome domains consistent with programmed nucleosome positioning JF - bioRxiv DO - 10.1101/481028 SP - 481028 AU - Mei-Zi Zhang AU - Xiao-Min Cao AU - Feng-Qin Xu AU - Xiao-Wei Liang AU - Long-Long Fu AU - Fang-Zhen Sun AU - Xiu-Ying Huang AU - Wei-Hong Huang Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/12/29/481028.abstract N2 - In human sperm, a fraction of its chromatin retains nucleosomes that are positioned on specific sequences containing genes and regulatory units essential for embryonic development. This nucleosome positioning (NP) feature provides an inherited epigenetic mark for sperm. However, it is not known whether there is a structural constraint for these nucleosomes and, if so, how they are localized in a three-dimensional (3D) context of the sperm nucleus. In this study, we examine the 3D organization of sperm chromatin and specifically determine its 3D localization of nucleosomes using structured illumination microscopy. A fraction of the sperm chromatin form nucleosome domains (NDs), visible as microscopic puncta ranging from 40 μm to 700 μm in diameter, and these NDs are precisely localized in the postacrosome region (PAR), outside the sperm’s core chromatin. Further, NDs exist mainly in sperm from fertile men in a pilot survey with a small sample size. Together, this study uncovers a new spatially restricted sub-nuclear structure containing NDs that are consistent with NPs of the sperm, which might represent a novel mark for healthy sperm in human. ER -