NUCLEIC-ACID IMMUNIZATION WITH A REPORTER GENE RESULTS IN ANTIBODY-PRODUCTION IN GOLDFISH (CARASSIUS-AURATUS L.)

Reporter genes are increasingly be ng used in order to assess new appr oaches to immunisation with nucleic acids. In the present work goldfis h (Carassius auratus L.) received the Escherichia coli beta-galactosid ase (beta-gal) reporter gene under control of the immediate early prom oter/enhancer of the human cytomegalovirus by intramuscular injection just anterior to the dorsal fin. beta-gal activity was detected at the site of injection after 4 days. Antibody to beta-gal was present in t he sera of fish killed at 4 and 8 weeks after DNA injection. In parall el experiments with mice only half the mice were positive for antibody , this being mainly of the IgG2a isotype, at 4 weeks after injection o f DNA into their anterior tibial muscles. This suggests goldfish can s eroconvert more readily than mice within 4 weeks of DNA injection usin g the beta-gal reporter gene. (C) 1998 Academic Press Limited.