Synthetic profiles of polypeptides of human oocytes and normal and abnormal preimplantation embryos

There is considerable variation in the rate of development in vitro of indi vidual preimplantation human embryos. The relationship between the rate of development and patterns of polypeptide synthesis in individual embryos was examined using SDS-PAGE and autoradiography. After incubation in [S-35]met hionine, 19 polypeptide bands were identified that change between fertiliza tion and the morula stage. Although changes in two of the bands occurred in embryos that were developing normally and in ageing oocytes, and are thus independent of fertilization, the changes identified in the remaining 17 ba nds occurred only after fertilization. in embryos that were developing abno rmally, as assessed by delayed cleavage, cleavage arrest or extensive fragm entation, the alteration in polypeptide synthetic profiles increased with i ncreasing abnormality.