DNA identification by PCR-RFLP relies on the presence of restriction
cutting sites in the amplified DNA sequence. In the
absence of an expected cutting site, which may result from a
sequence polymorphism, authentication of a specimen is not
possible. The PCR products of E. sinensis differed from those of
E. japonica at 33 nucleotides for the 1024 bp sequences of the cyt b
gene analyzed from four adult individuals of each species (Fig. 2).
These 33 polymorphic sites between the two mitten crab species
allowed for the determination of the restriction enzyme that produced
cuts in different positions between the species. A detailed
comparison of restriction maps scanned with the Genetyx program
identified only one restriction endonuclease, MboII, producing
distinct species-specific restriction patterns to reliably differentiate