M. Hamada et al., DETECTION OF THE ONGOING SORTING OF ANCESTRALLY POLYMORPHIC SINES TOWARD FIXATION OR LOSS IN POPULATIONS OF 2 SPECIES OF CHARR DURING SPECIATION, Genetics, 150(1), 1998, pp. 301-311
The FokI family of short interspersed repetitive elements (SINEs) has
been found only in the genomes of charr fishes (genus Salvelinus). In
an analysis of the insertion of FokI SINEs using PCR, we characterized
six loci at which FokI SINEs have been inserted into the genomes of S
alvelinus alpinus (Arctic charr) and/or S. malma (Dolly Varden). An an
alysis of one locus (Fok-223) suggested that a sister relationship exi
sts between S. alpinus and S. malma and the SINE at this locus might h
ave been inserted in a common ancestor of these two species, being fix
ed in all extant populations examined. By contrast, SINEs at two other
loci (Fok-211 and Fok-206) were present specifically in the genome of
S. alpinus; with polymorphism among populations of this species. More
over, the presence or absence of the SINEs of the other three loci (Fo
k-214, Fok-217, and Fok-600) varied among populations of these two spe
cies. The most plausible interpretation of this result is that SINEs,
which were ancestrally polymorphic in the genome of a common ancestor
of these two species, are involved in an ongoing process of differenti
al sorting and subsequent fixation in the various populations of each
species.