Divergent selection for antibody production to produce standard carp ( Cyprinus carpio L.) lines for the study of disease resistance in fish

Abstract

Carp with an early/high or a late/low antibody response were reproduced gynogenetically, resulting in homozygous progenies. After an initial test of their immune responsiveness at 6 months of age, we chose to continue the selection procedure with high responder progeny No. 69 and low responder progeny No. 85. The antibody response of these groups, at 12 months of age, was shown to be consistent with the parental responder type. The realized heritability (h 2) was estimated at 0.29. Progeny No. 69 showed a higher antibody response than progeny No. 85, both at 21 and at 28 days after immunization with dinitrophenyl-keyhole limpet haemocyanin (DNP-KLH). The antibody response in progeny No. 85 did not significantly increase after 21 days, in accordance with this group's classification as late/low responders. Furthermore, a significantly lower percentage (11%) of the animals of this group were early/high responders, compared with progeny No. 69 (45%). Late/low responders, however, were found in almost equal numbers in both progenies. The possibility to reproduce both females and functional males with a high or a low antibody response, will result in standardized fish lines that might be important for experimental studies on the immunogenetics of disease resistance.