CHARACTERIZATION OF ISOGENIC CARP (CYPRINUS-CARPIO L.) LINES WITH A GENETICALLY-DETERMINED HIGH OR LOW ANTIBODY-PRODUCTION

Antibody production to dinitrophenyl-keyhole limpet haemocyanin (DNP-K LH) served as the immune parameter to divergently select carp (Cyprinu s carpio L.) to produce high- and low-responder F-1 hybrid lines, Anti body production to trinitrophenyl-lipopolysaccharide (TNP-LPS) and to DNP-KLH were similar in magnitude. By contrast, some high-responder li nes were low responders to DNP-human serum albumin, and vice versa. Lo w-responder carp were relatively susceptible to infection with the par asite Trypanoplasma borreli. This suggested that at least one gene wit h a major influence on resistance differed between the two homozygous parents (69, 85) used to generate the high- and low-responder homozygo us families, respectively. The isogenic lines showed no within-line va riation in DNA fingerprints, but differed with respect to their MhcCyc a-DAB genes.