Pseudotolithus Species Identification using Isoelectric Focusing (IEF)

Abstract

Samples of croakers namely Pseudotolithus senegalensis, P. typus, P. brachygnathus, P.elongatus, P.epipercus and P. moorii of the family Sciaenidaewere subjected toisoelectric focusing methodology using LKB 2117 Multiphor 11 electrofocusing apparatus for electrofocusing and identification. A high resolution of pH gradient (pH 4 - 6) was necessary to distinguish the differences and similarities in the protein banding patterns among the Pseudotolithus sp. and to produce species specific patterns. The electrographs of P. senegalensis and P. typus showed minor variants between them but differed from the rest of the species. They were all species specific.Differences in the protein patterns at the cathode and the middle portions of the gels in all the species were observed. The migration of second to the last major band in P.epipercus had the least distance of migration towards the anode or acidic end. The densitometric tracings showed differences in their banding patterns as shown by graphical representations of the bands. There was a total of 2 major bands at the acidic or anode range in P. senegalensis, P. typus, P. epipercus and P. moorii and 3 in P. brachygnathus and P. elongatus.


Key words: Isoelectricfocusing,Pseudotolithus sp.,protein profile


Journal of Aquatic Sciences Vol.18(1) 2003: 39-42