Molecular evidence from short interspersed elements (SINEs) that Oncorhynchus masou (cherry salmon) is monophyletic

The genome of salmonid species contains numerous short interspersed repetitive elements (SINEs), which are known as members of the Hpa I family of SINEs. We have isolated and characterized eight loci at which Hpa I SINEs have been inserted in a species-specific manner in the genome of Oncorhynchus masou (cherry salmon). All of these SINE units were fixed in each of the local populations examined. This observation suggests that the SINE insertion events must have occurred in the genome of the single ancestral species of all the subspecies of O. masou and that the SINEs must have spread throughout the various populations before the divergence of subspecies. This provides unequivocal evidence that O. masou is monophyletic. These species-specific SINE units provide a very convenient and reliable tool for identification of O. masou by the polymerase chain reaction.