Chorioallantoic Placenta

2017 ◽  
Author(s):  
John H. Duffus ◽  
Michael Schwenk ◽  
Douglas M. Templeton
Keyword(s):  
Chorioallantoic Placenta

Cellular Contacts Within the Interhemal Membrane of the Rat Placenta at Term

1974 ◽  
Vol 32 ◽  
pp. 146-147
Author(s):  
William P. Jollie
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Capillary Endothelium ◽  
En Bloc ◽  
Aldehyde Fixation ◽  
Chorioallantoic Placenta

By routine EM preparative techniques, the tissues which, collectively, separate maternal and fetal bloods in the fully formed chorioallantoic placenta of the rat have been shown to consist of three chorionic layers, or trophoblast, and a layer of allantoic capillary endothelium [Fig. 1]. Relationships between these layers are best demonstrated by special techniques, viz., cacodylate-buffered aldehyde fixation, collidine-buffered osmium tetroxide postfixation, and en bloc staining with uranyl acetate. By using this method on placentas at term, the cells of the outermost chorionic layer (Trophoblast 1) appear to be attached to each other by means of maculae adherentes which sometimes occur in clusters [Fig. 2].

scholarly journals New exon ignites accelerated evolution of placental gene Nrk in the ancestral lineage of eutherians

2021 ◽  
Author(s):  
Guopeng Liu ◽  
Chunxiao Zhang ◽  
Yuting Wang ◽  
Guangyi Dai ◽  
Shu-Qun Liu ◽  
...  
Keyword(s):  
Positive Selection ◽  
Fitness Landscape ◽  
Induction Of Labor ◽  
Placental Development ◽  
Terrestrial Vertebrates ◽  
Regulatory Domains ◽  
Ancestral Lineage ◽  
Accelerated Evolution ◽  
Rate Test ◽  
Chorioallantoic Placenta

AbstractAccelerated evolution is often driven by the interaction between environmental factors and genes. However, it remains unclear whether accelerated evolution can be ignited. Here, we focused on adaptive events during the emergence of chorioallantoic placenta. We scanned the chromosome X and identified eight accelerated regions in the ancestral lineage of eutherian mammals. Five of these regions (P = 5.61 × 10−11 ~ 9.03 × 10−8) are located in the five exons of Nik-related kinase (Nrk), which is essential in placenta development and fetoplacental induction of labor. Moreover, a eutherian-specific exogenous exon lack of splice variant was found to be conserved. Structure modelling of NRK suggests that the accelerated exons and the eutherian-specific exon could change the enzymatic activity of eutherian NRK. Since the eutherian-specific exon was surrounded by accelerated exons, it indicates that the accelerated evolution of Nrk may be ignited by the emergence of the new exon in the ancestral lineage of eutherian mammals. The new exon might shift the function of Nrk and provide a new fitness landscape for eutherian species to explore. Although multiple exons were accelerated in both of the Nrk catalytic and regulatory domains, positive selection can only be revealed on the regulatory domain if the branch specific nonsynonymous and synonymous rate test was performed by PAML. Thus, it may be important to detect accelerated evolution when studying positive selection on coding regions. Overall, this work suggests that the fundamental process of placental development and fetoplacental induction of labor has been targeted by positive Darwinian selection. Identifying positively selected placental genes provides insights into how eutherian mammals gain benefits from the invasive chorioallantoic placenta to form one of the most successful groups among terrestrial vertebrates.

Activity and protein localization of multiple glutamate transporters in gestation day 14 vs. day 20 rat placenta

1998 ◽  
Vol 274 (3) ◽  
pp. C603-C614 ◽  
Author(s):  
James C. Matthews ◽  
Mark J. Beveridge ◽  
Marc S. Malandro ◽  
Jeffrey D. Rothstein ◽  
Martha Campbell-Thompson ◽  
...  
Keyword(s):  
Steady State ◽  
Fetal Development ◽  
Cellular Localization ◽  
Glutamate Uptake ◽  
Protein Localization ◽  
Basal Membrane ◽  
Mrna Levels ◽  
Transport Activity ◽  
Chorioallantoic Placenta ◽  
Apical Membranes

Concentrative absorption of glutamate by the developing placenta is critical for proper fetal development. The expression of GLAST1, GLT1, EAAC1, and EAAT4, known to be capable ofd-aspartate-inhibitable and Na+-coupled glutamate transport (system [Formula: see text]), was evaluated in day 14 vs. day 20 rat chorioallantoic placenta. Steady-state mRNA levels were greater at day 20 for all transporters. Immunohistochemistry determined that the expression of GLAST1, GLT1, and EAAC1 was greater throughout the day 20 placenta and was asymmetric with respect to cellular localization. EAAT4 protein was not detected. System[Formula: see text] activity was responsible for most of the Na+-dependent glutamate uptake and was greater in day 20 than in day 14apical and basal membrane subdomains of the labyrinth syncytiotrophoblast. Greater quantities of EAAC1 and GLAST1 protein were identified on day 20, and quantities were greater in basal than in apical membranes. GLT1 expression, unchanged in apical membranes, was decreased in basal membranes. These data correlate transporter mRNA and protein content with transport activity and demonstrate an increasing capacity for glutamate absorption by the developing placenta.

scholarly journals Transplacental Uptake of Glucose Is Decreased in Embryonic Lethal Connexin26-deficient Mice

1998 ◽  
Vol 140 (6) ◽  
pp. 1453-1461 ◽  
Author(s):  
Heinz-Dieter Gabriel ◽  
Dirk Jung ◽  
Christoph Bützler ◽  
Achim Temme ◽  
Otto Traub ◽  
...  
Keyword(s):  
Placental Transfer ◽  
Maternal Blood ◽  
Wild Type ◽  
Waste Products ◽  
Morphological Alterations ◽  
Gene Coding ◽  
Junctional Protein ◽  
Chorioallantoic Placenta ◽  
Gap Junctional ◽  
Glucose Analogue

Mice that harbor a targeted homozygous defect in the gene coding for the gap junctional protein connexin26 died in utero during the transient phase from early to midgestation. From day 10 post coitum onwards, development of homozygous embryos was retarded, which led to death around day 11 post coitum. Except for growth retardation, no gross morphological alterations were detected between homozygous connexin26-defective embryos and wild-type littermates. At day 9 postcoitum, when chorioallantoic placenta started to function, connexin26 was weakly expressed in the yolk sac epithelium, between syncytiotrophoblasts I and II in the labyrinth region of the placenta, and in the skin of the embryo. At day 10 post coitum, expression of connexin26 in the placenta was much stronger than at the other locations. To analyze involvement of connexin26 in the placental transfer of nutrients, we have measured embryonic uptake of the nonmetabolizable glucose analogue 3-O-[14C]methylglucose, injected into the maternal tail vein. At day 10 post coitum, viable, homozygous connexin26-defective embryos accumulated only ∼40% of the radioactivity measured in wild-type and heterozygous littermates of the same size. We conclude that the uptake of glucose, and presumably other nutrients as well, from maternal blood into connexin26-deficient mouse embryos was severely impaired and apparently not sufficient to support the rapid organogenesis during midgestation. Our results suggest that connexin26 gap junction channels likely fulfill an essential role in the transfer of maternal nutrients and embryonic waste products between syncytiotrophoblast I and II in the labyrinth layer of the mouse placenta.

scholarly journals Uterine Natural Killer Cells Are Targets for a Trophoblast Cell-Specific Cytokine, Prolactin-Like Protein A*

Endocrinology ◽  
1999 ◽  
Vol 140 (6) ◽  
pp. 2711-2720 ◽  
Author(s):  
Heiner Müller ◽  
Bing Liu ◽  
B. Anne Croy ◽  
Judith R. Head ◽  
Joan S. Hunt ◽  
...  
Keyword(s):  
Natural Killer ◽  
Nk Cell ◽  
Specific Interaction ◽  
Protein A ◽  
Trophoblast Cell ◽  
Surface Marker ◽  
Trophoblast Cells ◽  
New Paradigm ◽  
Uterine Natural Killer Cells ◽  
Chorioallantoic Placenta

Abstract PRL-like protein A (PLP-A) is a member of the PRL family expressed in trophoblast cells coincident with establishment of the chorioallantoic placenta. The purpose of this investigation was to identify targets for PLP-A. Using an alkaline phosphatase-tagging strategy, we show that PLP-A specifically interacts with a population of natural killer (NK) lymphocytes within the mesometrial compartment of decidua from pregnant and pseudopregnant rats. These observations are supported by the codistribution of PLP-A targets with cells expressing the rat NK cell surface marker, gp42, the absence of PLP-A binding in conceptuses from NK cell-deficient tgε26 mice, and the specific interaction of PLP-A with a rat NK cell line, RNK-16. We have further demonstrated that PLP-A effectively suppresses RNK-16 cell cytolytic activities. Our results provide evidence for a new paradigm of embryonic-maternal communication involving a PLP-A signaling pathway between trophoblast cells and uterine NK lymphocytes.

Identification of two new nonclassical members of the rat prolactin family

2000 ◽  
Vol 24 (1) ◽  
pp. 95-108 ◽  
Author(s):  
N Sahgal ◽  
GT Knipp ◽  
B Liu ◽  
BM Chapman ◽  
G Dai ◽  
...  
Keyword(s):  
Giant Cell ◽  
Cell Layer ◽  
Giant Cells ◽  
Trophoblast Giant Cell ◽  
Related Protein ◽  
Junctional Zone ◽  
Dbest Database ◽  
Chorioallantoic Placenta ◽  
Trophoblast Giant Cells ◽  
Ectoplacental Cone

The prolactin (PRL) family is comprised of a group of hormones/cytokines that are expressed in the anterior pituitary, uterus, and placenta. These proteins participate in the control of maternal and fetal adaptations to pregnancy. In this report, we have identified two new nonclassical members of the rat PRL family through a search of the National Center for Biotechnology Information dbEST database. The cDNAs were sequenced and their corresponding mRNAs characterized. Overall, the rat cDNAs showed considerable structural similarities with mouse proliferin-related protein (PLF-RP) and prolactin-like protein-F (PLP-F), consistent with their classification as rat homologs for PLF-RP and PLP-F. The expression of both cytokines/hormones was restricted to the placenta. The intraplacental sites of PLF-RP and PLP-F synthesis differed in the rat and the mouse. In the mouse, PLF-RP was expressed in the trophoblast giant cell layer of the midgestation chorioallantoic and choriovitelline placentas and, during later gestation, in the trophoblast giant cell and spongiotrophoblast layers within the junctional zone of the mouse chorioallantoic placenta. In contrast, in the rat, PLF-RP was first expressed in the primordium of the chorioallantoic placenta (ectoplacental cone region) and, later, exclusively within the labyrinth zone of the chorioallantoic placenta. In the mouse, PLP-F is an exclusive product of the spongiotrophoblast layer, whereas in the rat, trophoblast giant cells were found to be the major source of PLP-F, with a lesser contribution from spongiotrophoblast cells late in gestation. In summary, we have established the presence of PLF-RP and PLP-F in the rat.

The glial cells missing-1 protein is essential for branching morphogenesis in the chorioallantoic placenta

10.1038/77076 ◽  
2000 ◽  
Vol 25 (3) ◽  
pp. 311-314 ◽  
Author(s):  
Lynn Anson-Cartwright ◽  
Kerri Dawson ◽  
Doug Holmyard ◽  
Susan J. Fisher ◽  
Robert A. Lazzarini ◽  
...  
Keyword(s):  
Glial Cells ◽  
Branching Morphogenesis ◽  
Chorioallantoic Placenta
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