DNA-interacting proteins in the sperm nuclei (also called SBNPs, and/or protamines) constitute the most heterogeneous group of proteins performing an identical function: the packing of sperm DNA in a reduced volume. They have undergone a great number of evolutionary changes, many of which remain not understood.
The work that we present here reviews and unifies the compositional and structural studies previously done concerning molluscan protamines belonging to the phylogenetic line leading from the archaeogastropods to cenogastropods (mesogastropods and neogastropods). We show that, during the emergence of cenogastropods, a radical change in the molecular model of sperm nuclear proteins has ocurred, associated with other important evolutionary variations at higher levels of biological organization, including chromatin condensation during spermiogenesis, spermatozoon type and the biology of reproduction.
Buy this Article