Dermatan sulfate synergizes with heparin in murine sperm chromatin decondensation.

The mammalian sperm nucleus contains an unusually condensed chromatin, due to replacement of the majority of histones by protamines. However, soon after the spermatozoon penetrates the ooplasm at fertilization, decondensation of this densely packed chromatin must occur to allow formation of the male pronucleus and syngamy. Decondensation is accomplished by protamine disulfide bond reduction by oocyte glutathione and replacement of protamines by oocyte histones with the aid of an acceptor molecule.