Humoral immunity in Antarctic fish: serum immunoglobulin analysis in sevenspecies and antigen-induced response in Trematomus bernacchii (Teleostea, Notothenioidea)

The immunoglobulin content in sera of red-blooded Antarctic species (Tremat omus pennelli, T. lepidorbinus, Gymnodraco acuticeps, and Cygnodraco mawson i) and of icefish (Cryodraco antarcticus, Cbaenodraco wilsonii, and Pagetop sis macropterus) was determined by indirect ELISA assay with a polyclonal a nti-teleost immunoglobulin antibody. Electrophoretic mobilities of immunogl obulin heavy and light chains were assessed by sodium dodecyl sulfate-polya crylamide gel electrophoresis. The immunoreactivity of these molecules to t he polyclonal antibody was determined by immunoblotting. Specimens of T. be rnacchii were immunised intraperitoneally with bovine gamma-globulin couple d to dinitrophenylphospate using non-classical adjuvants, and the presence of fish immunoglobulins specific for the injected antigen was monitored by indirect ELISA. The results obtained extend our previous observations on se rum immunoglobulin content in Antarctic fish, and provide evidence for the mounting of an immune humoral response against an acellular antigen in an A ntarctic teleost species.