Abstract
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 cemponent 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 C8α-γ deficiency were obtained from a cross between low CH50 individuals (male : 5.9 U/ml × female : 5.6 U/ml) . From other crosses (male : 3.2 U/ml×female : 5.6, 5.7 U/ml), five rabbits with a hereditary C6 deficiency were obtained. 5) The frequencies of C8α-γ 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.
