The placenta of the four‐eyed opossum (philander opossum)Philander opossum)

  title={The placenta of the four‐eyed opossum (philander opossum)Philander opossum)},
  author={Allen C. Enders and Robert K. Enders},
  journal={The Anatomical Record},
The placental membranes of the four‐eyed opossum were studied by light and electron microscopy. The individual fetuses in each uterus were surrounded by amnion, had allantoic sacs of approximately the same size as each fetus, and were situated in a common yolk sac cavity. The extent of the choriovitelline placenta was marked by a prominent sinus terminalis, and at this margin there was a region where the trophoblast cells penetrated folds of the endometrium. Elsewhere the choriovitelline… 

Ultrastructure of the placenta of the tammar wallaby, Macropus eugenii: comparison with the grey short‐tailed opossum, Monodelphis domestica

The extended secretory phase of the tammar uterus and the maternal recognition of early pregnancy appear to be derived characters of macropodid marsupials.

The allantois of the north american opossum (didelphis virginiana) with preliminary observations on the yolk sac endoderm and trophectoderm

The opossum allantois functions primarily in the storage of urinary wastes during prenatal life, and it is thought that exchange between the developing fetus and mother occurs primarily through the activity of cells that form the trophoblast.

Ultrastructure of the placenta of Antarctic seals during the first third of pregnancy.

The chorioallantoic placenta from six crabeater seals and two leopard seals was lobulated, zonary, labyrinthine and endotheliochorial, and it is suggested that the deposits of granular bodies show the sites of iron storage in the placentas.

Ultrastructural observations on the chorioallantoic placenta of the golden-rumped elephant shrew, Rhynchocyon chrysopygus

Electron-dense particles resembling iron deposits are demonstrable in the fetal mesenchyme of the labyrinthine zone of the elephant shrew.

Early ontogeny and placentation of the grey short‐tailed opossum, Monodelphis domestica (Didelphidae: Marsupialia): contribution to the reconstruction of the marsupial morphotype

The results of this study provide the first detailed ultrastructural description of a trophoblastic syncytium in a marsupial and the first original documentation of an invasive trophectoderm and an inflammatory reaction at parturition in M. domestica.

The fine structure of the chinchilla placenta.

The structure of the placental labyrinth, interlobular or "coarse" syncytium, visceral (splanchnopleuric) yolk sac, giant cells and subplacenta of the chinchilla was studied with the electron microscope and was found to be hemomonochorial.

Ultrastructural Changes in the Uterine Luminal and Glandular Epithelium during the Oestrous Cycle of the Marsupial Monodelphis domestica (Grey Short-Tailed Opossum)

Ultrastructural changes in the endometrium associated with the oestrous cycle were studied in the South American marsupial Monodelphis domestica, where solitary cilia are only found in the immature uterus or after ovariectomy and mechanisms for the remodelling of the luminal and glandular epithelium are especially conspicuous.

Gestation and placentation in two New World opossums: Didelphis virginiana and Monodelphis domestica.

Gestation and placentation, including the ultrastructural features of trophoblastic apposition to the uterine mucosa, are very similar in Didelphis and Monodelphis, providing a basis for comparison in future studies of didelphid marsupials.

The role of mammalian foetal membranes in early embryogenesis: Lessons from marsupials

Marsupials can inform us about the role of foetal membranes and histotrophic nutrition in early embryogenesis, knowledge that can translate to eutherians.



An electron microscopic visualization of transport across rat visceral yolk sac.

  • R. Lambson
  • Biology
    The American journal of anatomy
  • 1966
Transport of large protein molecules through visceral endodermal cells involves an apical tubular system, large storage vacuoles, and smaller vesicles which appear to migrate basally near the end of pregnancy, when normally antibodies are being transferred in the largest quantities to the fetus.

Cytological aspects of trophoblast-uterine interaction in early implantation.

It is suggested that the capacity of trophoblast to form junctions with epithelial cells is an important part of the implantation process, facilitating penetration of the endometrium without dislodgment of the blastocyst.

Fluid transport in the rabbit gallbladder. A combined physiological and electron microscopic study.

It is concluded that the intercellular compartment fulfills the conditions for the middle compartment of the Curran model and that active transport of solute across the lateral plasma membrane into the inter cellular space may be responsible for fluid absorption by the gall bladder.

The Mammals of North America

The mammals of North America , The mammals of North America , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی