Antigenic Changes During Embryonic Development

Abstract

The genetic material of an egg and a sperm contains the information for all of antigens which will appear under normal conditions during embryonic development and during the whole of the life of the organism. In the beginning, however, both cells seem to be very poor antigenically, the egg in particular. Palm et al. (1971) have shown that an unfertilized mouse egg and a very early mouse embryo — at the level of a few cells — show negative membrane-fluorescence staining with otherwise positive anti-H-2 serum. Antisera prepared against weak histocompatibility antigens (H-1, H-6) produced a positive membrane fluorescence reaction with the unfertilized egg, and the embryo at the level of a few cells. We recently reported (Koldovsky et al., 1972) that guinea-pig antiserum prepared against unfertilized mouse eggs is highly cytotoxic for these eggs, but such an antiserum has no detectable cytotoxic activity against normal mouse cells from an adult animal. Unfertilized mouse eggs are also insensitive to the cytotoxic action of guinea-pig antiserum to mouse spleen cells or to mouse anti-H-2 antigen antibodies. The effect of guinea-pig antisera against unfertilized mouse eggs seems to be species-specific (rat, hamster, rabbit). This property is different from that of organ-specific antigens, which usually cross the species barrier.