Premium
Immunoelectron microscopical distribution of histones H2B and H3 and protamines in the course of mouse spermiogenesis
Author(s) -
Biggiogera Marco,
Muller Sylviane,
Courtens Jean Luc,
Fakan Stanislav,
Romanini Maria Gabriella Manfredi
Publication year - 1992
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.1070200305
Subject(s) - protamine , spermiogenesis , histone , histone h2b , nucleus , chromatin , immunoelectron microscopy , microbiology and biotechnology , biology , spermatid , cell nucleus , chemistry , biochemistry , dna , antibody , genetics , sperm , heparin
We have followed the fine structural distribution of two nucleosomal core histones, H2B and H3, and of protamines in the course of mouse spermiogenesis by means of specific antibodies and ultrastructural immunocytochemistry. Our results demonstrate that the nuclear labeling density of histone H2B decreases during steps 6–8 and then increases again in step 9–10 spermatids, while the labeling for histone H3 is constant throughout this period. In step 12 spermatids, the anti‐H2B antibody labels mainly the central area of the nucleus. The first signs of protamine labeling are present in step 12 spermatids, where the gold grains can be found over the periphery of the nucleus. Later on, protamine labeling constantly increases and, by the end of spermiogenesis, the whole nucleus is labeled. We suggest that the morphological and structural differences between the central area and the periphery of mouse spermatids are, at least partly, due to a difference in the protein moiety associated with DNA. The central area, which is peculiar to the mouse and has been previously considered as a focus of chromatin condensation, represents, however, the last nuclear region containing histones and consequently the last area where the substitution of histones by protamines takes place.