Characterization of chicken b-locus (IgG) allotypes.

Chicken allotypes b1 and b2 are controlled by allelic genes and associated with the IgG class of immunoglobulins. The determinants cannot be detected on either isolated heavy and light polypeptide chains or the enzymatic fragments. The results suggest that either the intact IgG molecule is required for their expression or the conditions normally used for isolation of the subunits destroy or modify the antigenic specificities in chickens.