Antibody diversity in fish. Isoelectrofocalisation study of individually-purified specific antibodies in three teleost fish species: Tench, carp and goldfish

Natural anti-DNP antibodies were isolated by affinity chromatography from individual sera of three Cyprinid fish species (carp, goldfish and tench) and their electrofocusing (IEF) spectra were analysed in reducing conditions. In addition, immune anti-penicilline and anti-BSA antibodies were isolated from individual and pooled tench sera, and studied by IEF techniques on reduced samples. Diversity rates appeared to be rather low in the three fish species, and striking similarities arised between individuals of a same species. These results can be interpreted by the existence of particular selective pressures operating in poikilothermic species as it was already suggested by Du Pasquier. No enhancement of antibody heterogeneity could be detected in the tetraploid (carp and goldfish) species. This result is also in accordance with the selection of a restricted germ-line determined antibody repertoire in lower vertebrates.