Production of Mercaptoethanol Sensitive,Slowly Sedimenting Antibody in the Duck. ∗ †

Abstract

Discussion and conclusions

The above data indicate the presence of mercaptoethanol sensitive, slowly sedimenting anti-BSA antibody in the duck which by gel filtration and radio-immunoelectrophoresis did not behave like a mammalian 7S γ globulin. The gel filtration experiment suggested that the antibody was somewhat larger in size than the 7S proteins and the radioimmunoelectrophoretic patterns localized the antibody activity to a protein which migrated separately from the 7S γ globulin line. This antibody bears a striking resemblance in some of its characteristics to the β ₂A (γ1A) immunoglobulin described in the mammal. Although the evidence is still not complete, data obtained with ragweed skin-sensitizing antibody indicate that β ₂A (γ1A) antibodies are a) larger than 7S(8), and b) mercaptoethanol sensitive(9).

Mercaptoethanol sensitive, slowly sedimenting antibody has been recently observed in non-mammalian vertebrates such as the chicken(2,3), frog and goldfish(1), and turtle. The finding of this class of antibody in inframammalian species to the apparent exclusion in the cold blooded vertebrates at least of 7S mercaptoethanol resistant antibody suggests that this class of antibody represents a stage in the evolution of the immune response which in the mammal has become largely superceded by mercaptoethanol resistant 7S γ globulin.