Computer-assisted evaluation of isoelectric focusing patterns in electrophoretic gels: Identification of smoothhounds (Mustelus mustelus, Mustelus asterias) and comparison with lower value shark species

In this work, the most commercially important Selachian species, smooth-hou nd (Mustelus mustelus) and starry smoothhound (Mustelus asterias), have bee n identified by polyacrylamide isoelectric focusing (IEF-PAGE), along with several shark species of minor commercial value. In Italy, these two smooth hound species are commonly subjected to fraudulent substitution with lesser valued sharks. After the electrophoretic runs, the band patterns of the tw o Mustelus species were compared with those of dogfish (Scyliorhinus canicu la), spurdog (Squalus acanthias), blue shark (Prionace glauca) and black-mo uthed dogfish (Galeus melanostomus), both visually and with gel analysis so ftware. The actual isoelectric points were then submitted to cluster analys is to differentiate the single species, despite the possible occurrence of electrophoretic variations or protein polymorphism. Every shark showed spec ies-specific band patterns and could therefore be well differentiated, as c onfirmed by statistical analysis.