title: Invasion and genome reproduction of the trophoblast cells of placenta junctional zone in the field vole, Microtus rossiaemeridionalis.
abstract: In the field vole Microtus rossiaemeridionalis, like in other rodents, invasive secondary giant trophoblast cells (SGTC) form a continuous layer at the foeto-maternal interface in the beginning of placentation. However, in the field vole, at midgestation, clusters of junctional zone (JZ) trophoblast non-giant cells interrupt SGTC layer and progressively replace SGTC at the border of decidua basalis. As a result, 'border' cells form a continuous stratum of cytokeratin-positive glycogen-rich cells at the foeto-maternal interface. SGTC plunge into JZ and line the lacunae with maternal blood. SGTC are bound by their highly cytokeratin-positive sprouts forming a framework that holds other trophoblast cell populations. According to DNA cytophotometry, the 'border' cells show the highest ploidy among the JZ cells (up to 46% of 8c cells). Thus, in M. rossiaemeridionalis the role of barrier between semiallogenic foetal and maternal tissues is shifted from the highly endopolyploid (32c-1024c) SGTC to the specific subpopulation of glycogen-rich non-giant (2c-16c) 'border' trophoblast cells that, however, exceed the ploidy of the deeply located and/or proliferative JZ trophoblast cells.
authors.affiliation: Laboratory of Cell Pathology, Institute of Cytology RAS, St.-Petersburg, Russia.
authors.forename: Tatiana G
authors.initials: TG
authors.lastname: Zybina
authors.forename: Grigori I
authors.initials: GI
authors.lastname: Stein
authors.forename: Kazimir M
authors.initials: KM
authors.lastname: Pozharisski
authors.forename: Eugenia V
authors.initials: EV
authors.lastname: Zybina
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000378:metabolism; D005260:Female; D016678:Genome; D007633:Keratins / Q000378:metabolism; D010920:Placenta; D011003:Ploidies; D011247:Pregnancy; D014327:Trophoblasts / Q000166:cytology* / Q000378:metabolism
chemical_list: D007633:Keratins
keywords: foeto-maternal interface; glycogen; invasion; polyploidisation; proliferation; trophoblast