The Eurasian river otter
Lutra lutra is the most widely distributed otter species. The European subspecies
L. lutra lutra (Linnaeus, 1758) kept in European zoos has four strains; two of which (the A- and B-lines) have been introduced into zoos and aquariums in Japan. As the genetic backgrounds of, and differences between, these two strains were unknown, we identified partial nucleotide sequences (307bp) of the mitochondrial cytochrome
b gene from an A-line and a B-line individual,
A-line cyb and
B-line cyb, respectively, kept in an aquarium in Japan. The nucleotide sequence of the
A-line cyb and
B-line cyb showed 98.7% identity and are distinguishable by the restriction fragment length polymorphism analysis.
A-line cyb was 100% identical to the cytochrome b of
L. lutra lutra, whereas
B-line cyb failed to show 100% identity to the known nucleotide sequences on the database. The phylogenetic analysis of our sequences with those from a previous study revealed that the two strains had already been introduced into Japan by at latest the 1990s. These results suggest that there are slight differences between the A- and B-line individuals used in the present study. However, further investigations, including re-evaluation of the taxonomy of
L. lutra subspecies, are needed to clarify the differences between the two strains.
View full abstract