Synthesis and distribution of H-2 antigens in preimplantation mouse embryos.

Abstract

Synthesis of H-2 antigens by preimplantation mouse embryos was first detected at the late blastocyst stage. These antigens were detected using immune precipitation assays of extracts of embryos labeled by incorporation of radioactive amino acids but not by surface iodination. Experiments using isolated inner cell masses [ICM] and trophoblast vesicles indicated that it was the cells of the ICM that synthesized these antigens. H-2 antigens were not detected in either early blastocysts or at earlier cleavage stages.