title: The sperm nuclear basic proteins (SNBPs) of the sponge Neofibularia nolitangere: implications for the molecular evolution of SNBPs.
abstract: We have isolated and characterized for the first time, the SNBPs from an organism (Neofibularia nolitangere) of the phylum Porifera (Sponges). We have shown that these proteins consist of histones which, as expected, exhibit an amino acid composition very similar to that of other eukaryotic histones. The finding of histones in the sperm of these primitive organisms provides support to the notion that histones (SNBPs of the histone, H, type) were the proteins present at the onset of SNBP evolution. In contrast, a discrete number of alternative SNBP types (protamine-like, PL; protamine, P, types) seem to have appeared later on in the course of evolution and are found in both protostomes and deuterostomes, most likely as a result of processes of parallel evolution.
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada, V8W 3P6.
authors.forename: J
authors.initials: J
authors.lastname: Ausió
authors.forename: M L
authors.initials: ML
authors.lastname: Van Veghel
authors.forename: R
authors.initials: R
authors.lastname: Gomez
authors.forename: D
authors.initials: D
authors.lastname: Barreda
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005075:Biological Evolution; D002467:Cell Nucleus / Q000737:chemistry; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D006657:Histones / Q000235:genetics*; D008297:Male; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000235:genetics*; D011161:Porifera / Q000235:genetics*; D011479:Protamines / Q000235:genetics*; D013094:Spermatozoa / Q000737:chemistry
chemical_list: D000596:Amino Acids; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009687:Nuclear Proteins; D011479:Protamines