Immunoglobulin classes in the hen's egg: Their segregation in yolk and white

Abstract

Abstract Hen's egg yolk contains at least two antigen‐binding subclasses of IgG, derived from the hen serum and transmitted to the chick. IgM and IgA, absent in yolk and in newly hatched chick serum, were detected in the white of unembryonated eggs, in the amniotic fluid of embryonating eggs and in the digestive tract of 19‐day embryos, which also contained IgG. The dual mode of transfer found for maternal Ig of different classes in the fowl is compared with the transfer of maternal immunity in mammals.