Latent expression of group c allotypes in rabbits

Rabbits deficient in both c7 and c21 allotypes were found in a certain colony of partially inbred rabbits and appeared to lack IgG with gamma light chain. In this colony, the gamma-chain level in the serum was low as an inherited character, and the mode of hereditary transmission of group c allotype expression was not apparent from available breeding data. These rabbits and other random-bred rabbits under conditions of suppressed T-cell functions produced group c allotypes which otherwise never appeared.