The application of sodium dodecyl sulphate-polyacrylamide gel electrophoresis to the taxonomic identification of the total body protein band profiles of Diplostomum spp. metacercariae (Digenea), parasites of fish eyes.

Abstract

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis has been used to determine the metacercariae (Mc) total body protein band profiles of different Diplostomum spp. Four species of fish were investigated, roach (Rutilus rutilus) infected with D. spathaceum Mc, gywniad (Coregonus laveratus) infected with D. coregonus Mc, ruff (Gymnocephalus cernua) infected with a Diplostomum species related to D. gasterostei Mc, and perch (Perca fluviatilis) infected with D. gasterostei Mc. The four species of Diplostomum Mc were distinguished by three different bands of molecular weight, Mr 55,500, 53,500 and 52,000. A homology of polypeptide component distribution was evident for D. gasterostei Mc, from P. fluviatilis, and D. coregonus Mc, from C. laveratus, the latter showing reduced protein concentrations between bands Mr 32,000-40,000. Critical analysis of Mc polypeptide patterns showed no evidence of contamination with lens, retina or vitreous humour host eye protein. Gross morphological data for the parasites was also considered in relation to different band profiles obtained for the Diplostomum spp. Mc. Band profile analysis in conjunction with other taxonomic tests proved to be a useful tool in the identification of unknown species.