Anatomy and Embryology

, Volume 179, Issue 6, pp 591–604

Fetal membranes and placenta of the african green monkey (Cercopithecus aethiops)

  • George E. O. Owiti
  • Ross P. Tarara
  • Andrew G. Hendrickx
Original Articles

DOI: 10.1007/BF00315701

Cite this article as:
Owiti, G.E.O., Tarara, R.P. & Hendrickx, A.G. Anat Embryol (1989) 179: 591. doi:10.1007/BF00315701


This study examined developmental changes in fetal membranes and placenta of Cercopithecus aethiops from a Carnegie developmental stage 12 embryo to nearterm fetuses. Ultrastructurally, yolk sac cells (endoderm and mesothelium) were similar to comparable stages in other primates. Endodermal cells had few apical microvilli, abundant rough-endoplasmic reticulum, electron dense mitochondria and dense bodies. In contrast, mesothelial cells were squamous with numerous microvilli, small mitochondria and a few short strands of rough endoplasmic reticulum. Amnion cells early in gestation were squamous with few microvilli, large glycogen deposits and poorly developed cytoplasmic components. Tight junctions and desmosomes held adjacent cells together. The basal surface was smooth and the basal lamina was distinct. As development proceeded the amniotic cells became cuboidal and possessed numerous microvilli. Cytoplasmic organelles were better developed and glycogen deposits increased by mid-gestation. A thick layer of microfibrils and collagen fibers was prominent below the basal lamina. Near-term, the glycogen had virtually disappeared and the amount of lipid droplets increased. Basal infoldings and podocytic processes and the extracellular matrix had increased. The smooth chorion consisted of pseudostratified columnar cells. Cells had short microvilli, numerous granules and vesicles of variable size and electron density in early gestation. With increasing age, amounts of granules and vesicles decreased, as the endoplasmic reticulum became prominent. The chorionic trophoblast was a continuous layer in mid-pregnancy and its cells had well-developed organelles and inclusions. Late in gestation, the trophoblastic layer became discontinuous and wide intercellular spaces and channels were present. In the placenta, the trophoblastic elements showed features characteristic of primate placenta.

Key words

Fetus Membranes Placenta Green monkey Ultrastructure 

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • George E. O. Owiti
    • 1
    • 2
    • 4
  • Ross P. Tarara
    • 3
  • Andrew G. Hendrickx
    • 4
  1. 1.California Primate Research CenterUniversity of CaliforniaDavisUSA
  2. 2.Department of Veterinary AnatomyUniversity of NairobiNairobiKenya
  3. 3.Institute of Primate ResearchNairobiKenya
  4. 4.Department of Human Anatomy, School of MedicineUniversity of CaliforniaDavisUSA