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 ...

Trout testis maturation is characterized by the complete replacement of the histones by the protamines. During this process, the protamines are extensively modified by enzymatic phosphorylation of their seryl residues. In addition, a methionyl residue is transiently incorporated at the NH2 terminus of newly synthesized protamine. However, these modifying groups are removed by the time that sper...

It was perhaps a lucky coincidence that the early attempts to establish the chemical composition of the cell nucleus were initially carried out on such diverse biological systems as salmon sperm heads (1) and geese and chicken erythrocytes (2). Examination of sperm and erythrocyte systems, respectively, lead to the protamine and histone concepts (3). We know with certainty that, with the except...