PMID: 591427Nov 1, 1977

The sheep trophoblast and placental function: an ultrastructural study

Journal of Anatomy
D P Boshier, H Holloway


Both the uninucleate cubiodal epithelial cells and the binucleate giant cells of the sheep trophoblast undergo marked structural modifications during pregnancy. Uninucleate epithelial cells show ultrastructural features which may be correlated in temporal order, with the secretion of steroid hormones, the production of ovine placental lactogen, and the performance of normal non-endocrine placental activities. The binucleate cells appear to be of two main types, one concerned with glycogen storage, and the other with the synthesis of a glycoprotein secretory substance. The binucleate cells are always enclosed by a thin continuous lamina of cuboidal cell cytoplasm which separates them completely from the maternal syncytium and the fetal connective tissue. The cuboidal epithelial and binucleate giant cells may either be closely apposed or else separated by canals or spaces of varying complexity. The presence of these interfacial canals indicates that the ovine trophoblast is another example of an epithelium in which the local movement of water and solutes is mediated by standing gradient osmotic flow systems. Such flow systems may well be an integral part of eutherian placental transport mechanisms.

Related Concepts

Cell Nucleus
Cytoplasmic Granules
Intercellular Junctions
Electron Microscopy
Dall Sheep
Protein Biosynthesis

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Alzheimer's Disease: MS4A

Variants within the membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease in genome-wide association studies. Here is the latest research on Alzheimer's disease and MS4A.

Pediculosis pubis

Pediculosis pubis is a disease caused by a parasitic insect known as Pthirus pubis, which infests human pubic hair, as well as other areas with hair including eye lashes. Here is the latest research.

Rh Isoimmunization

Rh isoimmunization is a potentially preventable condition that occasionally is associated with significant perinatal morbidity or mortality. Discover the latest research on Rh Isoimmunization here.

Genetic Screens in iPSC-derived Brain Cells

Genetic screening is a critical tool that can be employed to define and understand gene function and interaction. This feed focuses on genetic screens conducted using induced pluripotent stem cell (iPSC)-derived brain cells. It also follows CRISPR-Cas9 approaches to generating genetic mutants as a means of understanding the effect of genetics on phenotype.

Enzyme Evolution

This feed focuses on molecular models of enzyme evolution and new approaches (such as adaptive laboratory evolution) to metabolic engineering of microorganisms. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Pharmacology of Proteinopathies

This feed focuses on the pharmacology of proteinopathies - diseases in which proteins abnormally aggregate (i.e. Alzheimer’s, Parkinson’s, etc.). Discover the latest research in this field with this feed.

Alignment-free Sequence Analysis Tools

Alignment-free sequence analyses have been applied to problems ranging from whole-genome phylogeny to the classification of protein families, identification of horizontally transferred genes, and detection of recombined sequences. Here is the latest research.