REACTIONS OF SERA FROM IMMUNIZED AND EXPERIMENTALLY INFECTED THICK-LIPPED GREY MULLET, CHELON LABROSUS (RISSO, 1826), WITH ISOLATED PROTEINS OF CRYPTOCOTYLE-LINGUA (CREPLIN, 1825)

The reactions of sera from thick-lipped grey mullet, Chelon labrosus ( Risso, 1826), experimentally infected with metacercariae of the digene an Cryptocotyle lingua (Creplin, 1825) were compared with those from m ullet and rabbits immunised with sonicated cercariae using Western blo tting. SDS-PAGE revealed 35 proteins from the redia and cercaria respe ctively and 20 from the metacercaria of C. lingua. Antisera from rabbi ts reacted most strongly and with the greatest number of proteins. Com mon antigens exist between all three stages of the life cycle. Cross-r eactivity was also detected between C. lingua and the first intermedia te molluscan host, Littorina littorea. The failure of sera from fish e xposed to metacercarial infection to react with some parasite proteins may suggest a role for the metacercarial cyst wall in evasion of the host response. (C) 1996 Academic Press Limited