Development and genetic differences of complement activity in rabbits

Biology and Diseases of Rabbits

Beginning in 1931, an inbred rabbit colony was developed at the Phipps Institute for the Study, Treatment and Prevention of Tuberculosis at the University of Pennsylvania. This colony was used to study natural resistance to infection with tuberculosis (Robertson et al., 1966). Other inbred colonies or well-defined breeding colonies were also developed at the University of Illinois College of Medicine Center for Genetics, the Laboratories of the International Health Division of The Rockefeller Foundation, the University of Utrecht in the Netherlands, and Jackson Laboratories. These colonies were moved or closed in the years to follow. Since 1973, the U.S. Department of Agriculture has reported the total number of certain species of animals used by registered research facilities (1997). In 1973, 447,570 rabbits were used in research. There has been an overall decrease in numbers of rabbits used. This decreasing trend started in the mid-1990s. In 2010, 210,172 rabbits were used in research. Despite the overall drop in the number used in research, the rabbit is still a valuable model and tool for many disciplines.

Genetic polymorphism of the sixth component of complement (C6) in the pig

Using agarose gel isoelectric focusing and immunoblotting with rabbit anti-rabbit C6, a genetic polymorphism has been found in the sixth component of complement (C6) in six breeds of pigs. The C6 locus was highly polymorphic. Family data indicated that pig C6 phenotypes were inherited by means of five codomonant alleles named C6A, C6B, C6C, C6D and C6E at a single autosomal locus. C6 deficiency in two of 241 individuals tested was found, which suggested the presence of a null allele in pig populations. Marked breed differences among the gene frequencies and heterozygosities at C6 locus were observed.

C6-deficiency in rabbit serum and its restoration by normal rabbit serum or by normal bovine serum

The sera from 12 out of 29 half-sibs of the New Zealand White breed of rabbit were inactive, when used as complement, in blood-typing tests of bovine erythrocytes. This defect was found to be due to a deficiency in the activity of the component C6. A dilution of 1:380 of pooled normal rabbit sera and a dilution of 1:520 of pooled normal bovine sera were capable of restoring, to 63%, the haemolytic capacity of the defective rabbit sera. The rate of haemolysis varied from 4% to 100% when the defective sera were restored by sera from different sets of monozygous bovine twins.