(n.) The outer layer of the blastoderm; the epiblast; the ectoderm.
(n.) The outer envelope of a cell; the cell wall.
Example Sentences:
(1) Three main groups are described : ectoblastic, mesoblastic and entoblastic phacomatoses.
(2) Ectoblast cells were isolated and cultured with ECM taken from the embryonal regions.
(3) Ectoblastic cells explanted from the animal pole of young Xenopus laevis gastrulae have been cultured in vitro.
(4) The epiblastic cells treated with dorsal ECM, mainly located at the interphase between the invaginating blastoporal lip and the overlying ectoblast differentiated morphologically into neural, mesenchyme and pigment cells.
(5) The amount of cement gland in the ectoblastic explants varied according to the egg-batch and on the average accounted for 55 percent of the total tissue.
(6) Three monoclonal antibodies 5.1.H, 8.7.D and 13.7.A raised against semi-purified Tera 1 membrane fractions recognize distinct onco-foetal antigens which are developmentally regulated on cells such as Tera 2 clone 13 and appear to be restricted in their expression to undifferentiated ectoblastic cells and certain organized cystic structures mimicking the foetal intestine.
(7) Most of this undifferentiated tissue originates from the adjacent layer of the ectoblast.
(8) The facial complex and the brain develop separately from a common embryonic structure called ectoblast.
(9) This means that all or almost all of the competent superficial layer of the ectoblastic cells underwent differentiation into cement gland.
(10) The human skin and the mammary gland in the woman and the man--all of them ectoblastic-origin tissues, rich in stromal structures and belonging to the IIIrd step of Mârza's classification (Vth note) -- were investigated using the method of the microscopic conventional fields.
(11) Ectoblastic derivatives (ectodermal and neuroectodermal components) constitute more than 90% of all structures in the murine teratocarcinoma derived from the PCC4-aza-1 line.
(12) Although the treatment changed the fate of some ectoblastic tissues, it was unable to force endodermal or mesodermal tissues of the blastoporal lip to differentiate into cement gland.
(13) It is now postulated rather that, being derived at different periods of time from the embryonic epiblast--or perhaps, more accurately, ectoblast--they share a common neuroendocrine programme which is manifested by their possession of the acronymous amine-handling characteristics of the series and whose final expression is determined by microenvironmental circumstances.
Epiblast
Definition:
(n.) The outer layer of the blastoderm; the ectoderm. See Blastoderm, Delamination.
Example Sentences:
(1) Expansion of the cell sheet following attachment, and the fusion of epiblasts advancing toward each other, does not require the presence of mineralocorticoid.
(2) At the midgastrula stage the epiblast cells have the highest dry weight due to the highest protein concentration in the cytoplasm and the biggest cell volume.
(3) Proliferation occurs throughout the extra-embryonic epiblast during the expansion period.
(4) These observations are consistent with an epiblast origin for the avian germ line, and are strikingly similar to those reported for the early mouse embryo using the same antibody (Hahnel & Eddy, 1986).
(5) IGFBP-2 mRNA was detected throughout the epiblast of the egg cylinder as early as e7, when IGF-II expression was restricted to trophectoderm and other extraembryonic cells.
(6) It is also noted that the inadequate differentiation of the epiblast and endoderm would not have been apparent without microscopic examination.
(7) Both X chromosomes continued to replicate synchronously in the embryonic ectoderm or epiblast at this stage.
(8) The resulting space is not homologous with the primordial amniotic cavity; instead, it is a transitory tropho-epiblastic cavity.
(9) After the yolk has been covered, the epiblast continues to grow, with proliferation restricted largely to band just distal to the advancing edge of the area vasculosa.
(10) Primordial germ cells in the mouse are known to be derived from the epiblast.
(11) In general, the dorsoventral orientation of the previously induced epiblast was retained, but the orientation of the competent epiblast cells was more flexible and could be influenced by the neighbouring neuralised cells.
(12) The results of this study show that the epiblast cells of chick blastoderm at Hamburger-Hamilton stage 1 contain macrobodies which themselves contain particles resembling the 'lining bodies' described by Bellairs.
(13) At one time presumed to be derived from a common "neural" ancestor, all are now deemed to be "neuroendocrine-programmed," arising either in the embryonic epiblast itself or in one of its principal descendants.
(14) Epiblastic cells never gave rise to skeletal myotubes.
(15) The definitive amniotic epithelium forms by the upfolding and mitotic proliferation of the margins of the epiblastic disc; this process is completed in 11-day rhesus, and 9-day human, blastocysts.
(16) At 108 h and 120 h pc the polar trophoblast (Rauber's layer) is an intact epithelium overlying the epiblast of the inner cell mass.
(17) The epiblast cells of the optic bud do not migrate into the brain and the lamina is formed by the proliferation of the central imaginal disc.
(18) By the time of primitive streak formation (stage 4-5) the dorsal surface of the epiblast displayed increased binding sites, while the frequency of sites on the ventral surface of the endoblast was reduced.
(19) A microinjection technique is described for fate mapping the epiblast of avian embryos.
(20) Injection in situ of a short-term lineage label (horse radish peroxidase) into single epiblast cells at 6.7 days p.c.