Characterization of nucleohistone and nucleoprotamine components in the mature human sperm nucleus

Aim： To simultaneously determine the localization of histones and protamines within human sperm nuclei. Methods： Immunofluorescence of the core histones and protamines and fluorescence in situ hybridization of the telomere region of chromosome 16 was assessed in decondensed human sperm nuclei. Results： Immunofluorescent localization of histones, protamine 1 （PRM1） and protamine 2 （PRM2） along with fluorescence in situ hybridization localization of chromosome 16 telomeric sequences revealed a discrete distribution in sperm nuclei. Histones localized to the posterior ring region （i.e. the sperm nuclear annulus）, whereas PRM1 and PRM2 appeared to be dispersed throughout the entire nucleus. Conclusion： The co-localization of the human core sperm histones with the telomeric regions of chromosome 16 is consistent with the reorganization of specific non-protamine regions into a less compacted state.