Biology of the Ectoplacental Cone

Author(s):  
Estela Bevilacqua ◽  
Aline R. Lorenzon ◽  
Carla L. Bandeira ◽  
Mara S. Hoshida
Keyword(s):  
Development ◽  
1978 ◽  
Vol 43 (1) ◽  
pp. 147-156
Author(s):  
R. F. Searle ◽  
E. J. Jenkinson

The binding pattern of a rabbit antiserum raised against mouse ectoplacental-cone trophoblast on component cell populations in the pre-implantation and early post-implantation mouse embryo has been examined at the electron-microscope level using an immunoperoxidase-labelling technique. Binding was not detectable on the 1-cell stage, appeared at low levels at the 8-cell stage ana was heavy on the trophectoderm and its trophoblast giant cell and extra-embryonic ectoderm descendants in the post-implantation embryo. In contrast, immunosurgically isolated 3½-day inner cell masses (ICM) showed only slight labelling, whilst ICM derivatives in the 7½-day embryo were unlabelled. The results indicate that the antiserum may be identifying a trophoblast-specific surface determinant(s), which appears with the differentiation of the trophectoderm and is maintained on some of the cell populations derived from this tissue at least until the early postimplantation stages.


Placenta ◽  
1993 ◽  
Vol 14 (2) ◽  
pp. 149-161 ◽  
Author(s):  
M.S. Yavarone ◽  
D.L. Shuey ◽  
T.W. Sadler ◽  
J.M. Lauder

2000 ◽  
Vol 24 (1) ◽  
pp. 95-108 ◽  
Author(s):  
N Sahgal ◽  
GT Knipp ◽  
B Liu ◽  
BM Chapman ◽  
G Dai ◽  
...  

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.


1991 ◽  
Vol 53 (5) ◽  
pp. 839-845 ◽  
Author(s):  
Masami AZUMA ◽  
Yoshiakira KANAI ◽  
Atsuo OGURA ◽  
Masamichi KUROHMARU ◽  
Yoshihiro HAYASHI

1989 ◽  
Vol 109 (6) ◽  
pp. 3015-3026 ◽  
Author(s):  
G H Kalimi ◽  
C W Lo

We characterized gap junctional communication in the extraembryonic tissues of the 7.5-d gastrulating mouse embryo. At this stage of development, the extraembryonic tissues form a large part of the conceptus, and link the embryo proper to the maternal tissue. Using Lucifer yellow injections, cells in most extraembryonic tissues were observed to be very well dye coupled, the only exception being the peripheral regions of the ectoplacental cone. Of particular interest was the fact that no dye coupling was detected between the three major extraembryonic tissues. Thus, the extraembryonic ectoderm (EEC), the extraembryonic endoderm (EEN), and the ectoplacental cone (EPC) corresponded to separate communication compartments, with the EPC being further subdivided into three compartments. Interestingly, the EEN was observed to exhibit a very low level of dye coupling with the adjacent visceral embryonic endoderm (EN), and consistent with the latter dye coupling results was the finding that the EEN was ionically coupled to the EN, but not with any other extraembryonic tissues. However, in the EPC, ionic coupling studies show that the central region was well coupled ionically to the EEC, but only weakly coupled to the peripheral EPC. These findings, in conjunction with our previous study (1988. J. Cell Biol. 107:241-255), demonstrate that the 7.5-d mouse conceptus is subdivided into at least nine major Lucifer yellow-delineated communication compartments, with ionic coupling across some of these compartments effectively unifying the embryo into two large domains corresponding to the embryo proper and the major extraembryonic tissues.


Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 227-237 ◽  
Author(s):  
M.A. Nieto ◽  
M.F. Bennett ◽  
M.G. Sargent ◽  
D.G. Wilkinson

The genetic analysis of dorsoventral patterning in Drosophila has identified a zinc-finger gene, snail, that is required for mesoderm formation. The cloning and nuclease protection analysis of a Xenopus homologue of this gene has suggested a possible role in the mesoderm of vertebrates. Here, we describe the cloning of a murine homologue of snail, Sna, and in situ hybridisation studies of its developmental expression. Sequence analysis reveals substantial conservation of the second to fifth zinc fingers, but not of the first zinc finger in the Sna gene. Expression occurs in the ectoplacental cone, parietal endoderm, embryonic and extraembryonic mesoderm, in neural crest and in condensing precartilage. Based on the timing and spatial restriction of expression in embryonic mesoderm, we suggest that Sna might be required for the early development of this tissue, as is the case for its Drosophila counterpart. In addition, we propose that Sna might have an analogous role in the development of neural crest. The expression in condensing precartilage indicates that this gene also has a later function in chondrogenesis.


Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 279-312
Author(s):  
R. L. Gardner ◽  
M. H. Johnson

1. Inner cell mass (ICM) and trophoblast were isolated from 3½-day post-coitum mouse blastocysts by microsurgery. 2. Trophoblastic fragments formed vesicles in culture but did not aggregate with other such fragments. They proved as effective as intact blastocysts in inducing decidua in recipient uteri, but thereafter failed to proliferate. 3. Isolated ICMs remained as solid balls of cells that readily aggregated in pairs or groups in culture but failed to induce implantation changes in receptive uteri. 4. Possible explanations for the failure of isolated trophoblast to proliferate after implantation are discussed. It is argued that presence of ICM tissue is necessary for trophoblast proliferation, and suggested that the ICM exerts its effect by controlling development of the ectoplacental cone.


Development ◽  
1981 ◽  
Vol 66 (1) ◽  
pp. 43-55
Author(s):  
J. Rossant ◽  
K. M. Vijh

Embryos homozygous for the velvet coat mutation, Ve/Ve, were recognized at 6·5 days post coitum by the reduced size of the ectodermal portions of the egg cylinder and the loose, columnar nature of the overlying endoderm. Later in development ectoderm tissues were sometimes entirely absent. Abnormalities appeared in the ectoplacental cone at 8·5 days but trophoblast giant cells and parietal endoderm appeared unaffected. Homozygotes could not be unequivocally identified at 5·5 days nor at the blastocyst stage but were recognized in blastocyst outgrowths by poor development of the inner cell mass derivatives, It has previously been suggested that Ve may exert its action at the blastocyst stage by reducing the size of the inner cell mass, but no evidence for such a reduction was found. Most of the observations on Ve/Ve homozygotes are, however, consistent with the hypothesis that Ve exerts its action primarily on later primitive ectoderm development.


Sign in / Sign up

Export Citation Format

Share Document