Germ cell nucleosomes contain remodeled core protein complex.

Electrophoretic analysis of the nucleosomal histones from MN1 and MN2 subpopulations of the seminiferous tubules in gels containing either 6.25 or 2.5 M urea revealed the presence of testis specific histone H2S, H1 and protein 'A' in addition to the somatic histones in the core protein complex. Size analysis indicated the presence of a 150-160 bp DNA segment in the MNI subpopulation, whereas, an approx 180 bp DNA fragment was present in the MN2 subpopulation of both liver and tubule nucleosomes. These data suggest an extensive remodeling of the nucleosomal core protein complex during mammalian spermatogenesis.