Transmission of antibodies from mother to young: Evolutionary strategies in a proteolytic environment.

Transmission of antibody from mother to young is an essential process. Maternal proteins provide both food (if digested) and immune protection (undigested antibody) for the offspring. The processes for transfer changed and diversified during vertebrate evolution, using receptor-dependent and -independent mechanisms pre- and postnatally. Transmission frequently proceeds in a proteolytic environment and different mechanisms evolved for the protection of antibody. The present review focuses on the relationship of acquisition of passive immunity to other physiological processes.