A method for developing hereditary deficiency of complement component in the rabbit

A two-way selective experiment for total hemolytic complement activity (CH50) was carried out in a colony of New Zealand White rabbits for the purpose of developing hereditary deficiency of complement component and estimating the realized heritability (h2) of CH50. The results obtained were as follows. 1) The mean value of CH50 with a standard error (SE) in 203 adults rabbits was 9.0 +/- 0.2 U/ml, and the range of CH50 was 2 to 18 U/ml. 2) Individual differences of CH50 in rabbits were comparatively stable regardless of time and season. 3) The realized heritability (h2) of CH50 was estimated to approximately 0.3. 4) Two rabbits with a hereditary C8 alpha-gamma deficiency were obtained from a cross between low CH50 individuals (male: 5.9 U/ml X female: 5.6 U/ml). From other crosses (male: 3.2 U/ml X female: 5.6, 5.7 U/ml), five rabbits with a hereditary C6 deficiency were obtained. 5) The frequencies of C8 alpha-gamma and C6 deficient genes in the colony were estimated to at least 0.005, 0.003, respectively. 6) It was suggested that a downward selection for CH50 was a useful method for developing hereditary deficiency of complement component in the rabbit.