Identification and genetic control of three rabbit gamma-A immunoglobulin allotypes.

Abstract

Summary Cross-immunization of rabbits with purified colostral γA immunoglobulin resulted in the production of three precipitating alloantibodies, which identified three γA immunoglobulin allotypes designated f1, f2 and f3. That these alloantibodies are specific for γA immunoglobulin was indicated by the similar precipitin arcs observed on immunoelectrophoresis when anti-f1, anti-f2 anti-f3, and goat anti-γA reacted with serum, whey or a highly purified colostral γA fraction. By immunoelectrophoresis with heterologous multispecific antisera to rabbit whey or serum and by ultracentrifugal analysis ( s 0 20, w = 10.9), the isolated γA appeared to be free of other serum proteins. By immunoelectrophoresis with anti- a and anti- b allotype antisera, the isolated γA immunoglobulins were also shown to possess heavy chain a locus and light chain b locus allotypic specificities. Allotype analysis of 521 progeny from eight mating combinations indicated that the allotypes f1, f2, and f3 are controlled by three allelic genes. This γA locus, designated f , was not closely linked to the X chromosome, the a or b immunoglobulin loci, the z α 2 macroglobulin locus, the h haptoglobin locus or the q lipoprotein locus. Thus, in addition to the previously described unlinked a and b loci which are known to control allotypic specificities on the heavy and light chains of γA immunoglobulins, a third unlinked f locus is also involved in the control of serum and secretory γA immunoglobulins. This f locus, unlike the a and b loci, does not appear to be involved in the control of γG and γM immunoglobulins.