Immunolabelling of fish host molecules on the tegumental surface of Ligula intestinalis (Cestoda: Pseudophyllidea).

Immunoblotting, SDS-PAGE and western blotting procedures were used to demonstrate cross-reactivity of a polyclonal anti-carp IgM antibody with components of roach serum. The polyclonal antibody labelled 2 major bands in both immune and normal roach sera corresponding to molecular masses of approximately 90 and 65 kDa. One of these bands (65 kDa) was considered to be heavy chain of fish immunoglobulin whilst the identity of the other remains uncertain. This cross-reaction has been exploited in immunofluorescence and immunogold labelling studies to localize fish host molecules on the tegumental membrane of Ligula intestinalis freshly removed from roach fry. Immunogold studies revealed a low level of host molecules to be associated mainly with the microthrix spines of the tegument with less gold labelling being observed on the microthrix shafts.