ULTRASTRUCTURAL-STUDY OF PRE-IMPLANTATION UTERINE EMBRYOS OF RHESUS-MONKEY

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  • 1 January 1978
    • journal article
    • research article
    • Vol. 126  (MAY) , 209-220
Abstract
Six preimplantation embryos were recovered by uterine flushing from rhesus monkeys and examined by EM. Cleavage-stage embryos showed no striking differences between inside and outside blastomeres, all of them displaying primitive junctional complexes, heteromorphic mitochondria, large ovid nuclei and a few polyribosomes. Zonal blastocysts had distinctive trophectoderm and inner cell mass [ICM] areas in which tight junctional complexes and occasional desmosomes were observed at cell membrane junctions. Such embryos also contained numerous polyribosome complexes and cisternae of rough endoplasmic reticulum, which some ICM cells displayed large autophagic vacuoles. Hatched blastocysts showed an increased number and length of microvilli on the free surface of the embryo, and trophectoderm cells contained microfibrillar bundles not seen in equivalent regions of zonal blastocysts. Most of the listed ultrastructural features of the rhesus preimplantation embryo are present in similar embryos of other mammalian species.