Basilea kappa light chains of rabbit immunoglobulins.

Immunogenetics of the Basilea allotype were investigated. It was shown that the Basilea gene is controlled at a locus identical with, or closely linked to, the Ab kappa allotypic locus. Basilea-positive molecules have been physically separated by immunoabsorption from molecules carrying the lambda chain markers, c7 and c21. Injection of newborn Basilea homozygotes with anti-Basilea immune serum results in suppression of the synthesis of Basilea-positive molecules, but does not affect the synthesis of the lambda chain, or of the heavy chain allotypic markers. Allotype-suppressed Basilea homozygotes do not recognize either the Basilea allotype or the kappa isolate as 'self' and make anti-Basilea and anti-kappa antibody upon immunization with Basilea antigen. The specificity of this antibody was identical with that of a heterologous anti-kappa immune serum raised in a goat and made specific by absorption with purified lambda material. These results prove that Basilea gene products are of kappa isotype and are controlled at the Ab allotypic locus.