MOLECULAR EVIDENCE FROM SHORT INTERSPERSED ELEMENTS (SINES) THAT ONCORHYNCHUS-MASOU (CHERRY SALMON) IS MONOPHYLETIC

The genome of salmonid species contains numerous short interspersed re petitive elements (SINEs), which are known as members of the Hpa I fam ily of SINEs. We have isolated and characterized eight loci at which H pa I SINEs have been inserted in a species-specific manner in the geno me of Oncorhynchus masou (cherry salmon). All of these SINE units were fixed in each of the local populations examined. This observation sug gests 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 bef ore the divergence of subspecies. This provides unequivocal evidence t hat O. masou is monophyletic. These species-specific SINE units provid e a very convenient and reliable tool for identification of O. masou b y the polymerase chain reaction.