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A layer of ectodermal epithelium covering the outer surface of the chorion and chorionic villi of many mammals.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the exterior layer of cells in the embryos of mammals. The trophoblast is isolated in the blastocyst stage and makes possible contact between the embryo and the mother’s system by allowing nutrients to pass from the mother to the embryo. The part of the trophoblast located above the embryonic shield is called Rauber’s layer. The trophoblast that is lined internally with mesenchymal cells is called the chorion. The trophoblast plays a role in the implantation of the embryo in the uterine wall and the formation of the placenta.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Our results also demonstrated that miR-411, like miR-376c (shown before (22) and here), can promote trophoblast cell proliferation, migration, and invasion.
Our results also showed that under low oxygen tension, there was increased in proliferation of trophoblast; which would lead to increased in thickness of trophospongium zone, and decreased in differentiation of trophoblast; which would lead to decreased in the number of giant cells.
The layer between 45% and 35% Percoll contained the trophoblast cells; this was collected, suspended in DMEM, and centrifuged at 1200 rpm at room temperature for 10 min.
HLA-G immunoreactivity is specific for intermediate trophoblast in gestational trophoblastic disease and can serve as a useful marker in differential diagnosis.
The blastocyst is surrounded by trophoblast and thus everything will tend to the formation of chorionic villi; however, the trophoblast from which the implantation began can grow further, causing greater branching of its chorionic villi.
Activation of distinct extracellular matrix (ECM) components and/or proteolytic degradation as well as the controlled variation in the cell-ECM and cell-cell interactions are important factors involved in inadequate remodeling of the spiral arteries and abnormal invasion of the trophoblast in PE (8, 9).
Accreta complicating complete placenta previa is characterized by reduced systemic levels of vascular endothelial growth factor and by epithelial-to-mesenchymal transition of the invasive trophoblast. Am J Obstet Gynecol 2011;204:411.e1-411.e11.
Tissues were washed extensively with PBS and (i) immediately snap frozen in liquid nitrogen and stored at -80[degrees]C for analysis of protein expression by Western blotting or for Ras activity as detailed below, (ii) fixed and paraffin embedded for immunohistochemical analysis, (iii) immediately used for explant studies, or (iv) for trophoblast cell studies as detailed below.
In mice, the placenta is composed of trophoblast giant cells (TGC), spongiotrophoblast cells (ST), and glycogen trophoblast cells [8].
NK receptor ligands are expressed in invading placental trophoblast cells, as reported by Vacca [22].
At the stage of 8 blastomeres, the blastocyst divides into embryoblast and trophoblast. Trophoblast forms villi and first primary, containing only the trophoblast, then secondary, containing the stroma (embryonic mesenchyme), and later tertiary, containing the vessels (Figures 1(a) and 1(b)).
One of the most probable pathomechanisms of PE development is connected with inadequate maternal blood flow in the placenta, caused by deficient spiral artery remodeling and shallow trophoblast invasion.