Humoral immunity in Antarctic fish: Serum immunoglobulin analysis in seven species and antigen‐induced response in Trematomus bernacchii (Teleostea, Notothenioidea)

Abstract

The immunoglobulin content in sera of red‐blooded Antarctic species (Trematomus pennelli, T. lepidorhinus, Gymnodraco acuticeps, and Cygnodraco mawsoni) and of icefish (Cryodmco antarcticus, Chaenodraco wilsonii, and Pagetopsis macropterus) was determined by indirect ELISA assay with a polyclonal antiteleost immunoglobulin antibody. Electrophoretic mobilities of immunoglobulin heavy and light chains were assessed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The immunoreactivity of these molecules to the polyclonal antibody was determined by immunoblotting. Specimens of T. bernacchii were immunised intraperitoneally with bovine γ‐globulin coupled 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 serum immunoglobulin content in Antarctic fish, and provide evidence for the mounting of an immune humoral response against an acellular antigen in an Antarctic teleost species.

Key words:

• Antarctic teleosts
• Fish
• Immune system
• Immunoglobulin
• Immunisation
• Icefish