Development and Function of the Immunoglobulin-Producing System

Abstract

Summary: The sera of normal chickens and of chickens bursectomized on the day of hatching contain both IgM and IgG antibodies after two injections of sheep erythrocytes. Chickens bursectomized before hatching either are nonresponders, synthesize IgM antibodies only, or synthesize low levels of both IgM and IgG antibodies. It is concluded that precursors of cells competent to synthesize IgM antibodies are activated through bursal influence prior to the activation of ability to synthesize IgG antibody. Similar specific immunoglobulin deficiency syndromes in human patients could result from developmental failures occurring at different times.