Biochemical Characterization of an ecotype cichlid from Epe Lagoon ‘Wesafu’ and <em>Oreochromis niloticus</em> using Sodium dodecyl sulphate polyacrylamide gel electrophoresis

Abstract

The abundance of a yet to be identified cichlid in Epe Lagoon commonly referred to as Wesafu and the large size/weight it attains in the wild elicited interest in the fish for domestication, culture and possible species identification and naming. Characterization of Wesafu and O. niloticus biochemically using SDS-PAGE was carried out to analyze protein mixtures in the two species qualitatively and to determine their relative protein  molecular mass. After centrifugation for 15min at 1000 rpm, blood sera from the two species were electrophoretically run simultaneously on 5.5% SDS polyacrylamide gel following the procedure of [Avtalion et al., (1976); Betiku and Omitogun, (2006)]. After electrophoretic separation, the gel was stained, destained, sealed in polythene bags and refrigerated. Gels produced were scored visually with presence (1) or absence (0) of band  classifications. Frequencies were determined by direct counting while genetic interpretation was based on frequency and relative banding intensity. Distinct bands (genetic markers) were observed between the two species. While Wesafu had between 10 and 11 bands, 9 bands was  recorded for O. niloticus. The 11th band in Wesafu was identified as a post albumin which is absent in O. niloticus. In O. niloticus, bands 1, 3 and 7 were present, but bands 2, 5, 6 and 8 were absent in few. Some individuals of Wesafu were found to possess weaker bands 3 and 7. The band frequency between samples studied indicated serum protein  polymorphism, which indicated genetic diversity between ‘Wesafu’ and O. niloticus.