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.