(n.) The inner layer of the skin or integument of an animal.
(n.) The innermost layer of the blastoderm and the structures derived from it; the hypoblast; the entoblast. See Illust. of Ectoderm.
Example Sentences:
(1) In contrast, F9ACC19, an endodermal cell line derived from F9 cells, synthesizes only minor amounts of lactosaminoglycans and a high proportion of smaller glycopeptides.
(2) Both genes are expressed in the fetal liver, gut, and visceral endoderm of the yolk sac and are repressed shortly after birth in the liver and gut.
(3) Examination of the two types of tissue fragments revealed that IS-treated ICMs almost invariably retained viable endoderm cells whereas MS-isolated ectoderms did so only exceptionally.
(4) LIF inhibits differentiation under several conditions which lead to endodermal and mesodermal cell lineages including skeletal and cardiac muscle.
(5) This epithelial cell was tentatively identified as primitive extraembryonic endoderm by its ultrastructural appearance and its possession of cytokeratin intermediate filaments.
(6) The majority of testicular germ cell tumors in adults are accompanied by neoplastic intratubular germ cells; these cells were uniformly absent in ten pure yolk sac tumors (endodermal sinus tumors) of the testicle in children studied morphologically and immunohistochemically.
(7) After the treatment in toto of the embryos from various species of Anura by cAMP, the number of primordial germ cells (PGC) in genital ridges is strongly reduced; the most part of the PGC are found in the endoderm.
(8) Our experience suggests that the optimal management of patients with primary mediastinal endodermal sinus tumor requires an aggressive multidisciplinary approach guided by the extent of the tumor and the serum tumor marker levels.
(9) The tissues of the endodermal and mesodermal origin were also present in small quantities.
(10) Although the liver first forms as a discrete epithelial bud of endodermal tissue at stage 12-14 (45-53 h after laying), canaliculi were first detected by our antibodies at low levels in 4-day embryos and at high levels in stage 27 (5 days after laying) and later embryos.
(11) The cell cycle time of the gland cells appears to be longer than that of the epithelial cells of the endoderm throughout the animal.
(12) As development proceeded during primitive streak stages, the visceral and parietal endoderm became positively stained.
(13) The F9 cell is a mouse embryonal teratocarcinoma which can be induced to differentiate into visceral endoderm by treatment with retinoic acid (RA).
(14) Multiple hamartoma syndrome, also known as Cowden's disease, is a rare genodermatosis with multiple organ system involvement affecting tissues derived from ectodermal, endodermal, and mesodermal tissue layers.
(15) This finding suggests the identification of a cell population that is analogous to parietal endoderm in some eutherian animals.
(16) We recently showed that yolk sac is involved in the control of metabolism and action of vitamin D in the fetoplacental unit, since its endodermal cells contain a 24-hydroxylase for vitamin D metabolites and the 1,25-dihydroxyvitamin D receptor.
(17) These data thus demonstrate the production and presence of RBP mRNA and TTR mRNA, and the synthesis and secretion of RBP and TTR, by F9 cell embryoid bodies (specifically by visceral endoderm-like cells).
(18) We conclude that yolk-sac-derived teratomas are of endodermal origin because of the fact that the paternal X chromosome is inactivated in the yolk sac endoderm, whereas in the yolk sac mesoderm, as in the embryo, the inactivation is at random.
(19) A particularly interesting proteinase active at alkaline pH values is detected in the trophoblast-endoderm complex.
(20) It is therefore considered that, although there is good evidence that serum AAT is produced by endodermal sinus tumour elements, serum AAT is not a useful monitor of disease activity in these patients, especially when compared with serum AFP, the value of which is well recognized.
Gastrula
Definition:
(n.) An embryonic form having its origin in the invagination or pushing in of the wall of the planula or blastula (the blastosphere) on one side, thus giving rise to a double-walled sac, with one opening or mouth (the blastopore) which leads into the cavity (the archenteron) lined by the inner wall (the hypoblast). See Illust. under Invagination. In a more general sense, an ideal stage in embryonic development. See Gastraea.
(a.) Of or pertaining to a gastrula.
Example Sentences:
(1) Results obtained from cumulative labeling and pulse-labeling and chase experiments with cells from late gastrulae, yolk plug-stage embryos, and neurulae showed that the 30S RNA is an intermediate in rRNA processing and is derived from 40S pre-rRNA and processed to 28S rRNA.
(2) Cells falling off from ectoderm were observed in normally developing gastrulae of the newt, Cynops pyrrhogaster, in light microscopic examination.
(3) Among such genes, particular interest is focused on three genes encoding putative transcription factors that are expressed specifically in the Spemann organizer region of the gastrula.
(4) Their synthesis is first detectable in stage IV oocytes and continues throughout early embryogenesis until the late gastrula.
(5) The tandemly repeated genes were expressed at a higher rate in blastula than in gastrula stage relative to the single-copy gene, when the two genes were injected into sea urchin zygotes.
(6) RA was applied for one hour at concentrations ranging from 10(-9) to 10(-6) M to embryos at 50% epiboly, the midgastrula stage, and at 10(-7) M to embryos at early and late gastrula stages.
(7) In gastrulae, spectrin accumulates near the embryo surface, especially at the forming amnioproctodeal invagination and cephalic furrow.
(8) The dynamics of protein synthesis in the loach embryos has been studied by means of autoradiography at the stages of cleavage, blastula and gastrula.
(9) GAD activity was undetectable at the early gastrula stage (stage 8a) and was slightly measurable at the early neurula stage (stage 14- onset of the culture).
(10) However, we established an enhanced level of [14C]acetate incorporation at the time of extensive gene activation during gastrulation as well as some quantitative differences in the pattern of acetylation during gastrula and organogenesis.
(11) RNase protection assays demonstrate that transcripts encoding alpha, gamma, and delta subunits are coordinately expressed at late gastrula and that the amount of each transcript increases in parallel with muscle-specific actin mRNA during the ensuing 12 h. After the onset of muscle activity the level of actin mRNA per somite remains relatively constant, whereas the level of alpha subunit and delta subunit transcripts decrease fourfold per somite and the level of gamma subunit transcript decreases greater than 50-fold per somite.
(12) When the supernatant proteins from eggs and gastrulae were subjected to size-exclusion HPLC the neural inducing activity was eluted in different size classes, suggesting a limited proteolysis of a precursor during early embryogenesis.
(13) Isolated neuroblasts from gastrula-stage Drosophila embryos divide and differentiate in vitro to produce clonally derived clusters of neurons.
(14) In both fish embryos, the COI and COII transcripts declined gradually after fertilization until late-blastula stage and then increased in early gastrula stage.
(15) Three of these clones are not represented in the maternal RNA population but are activated at the late gastrula stage; the other three increase from a maternal base.
(16) This led to an attempt to discover the molecular character of cell action by means of transfilter induction in early gastrula ectoderm of Xenopus laevis.
(17) We have demonstrated that a 'wave' of DNA synthesis occurs in the neurectoderm of Xenopus laevis gastrula.
(18) When Xenopus blastula or early gastrula ectoderm is disaggregated and cells are kept dispersed for up to 5 h prior to reaggregation, the resulting spheres will differentiate into large neural structures.
(19) Yolky tissue from the vegetal hemisphere of the gastrula or the archenteron floor of the neurula synthesized mainly polydisperse material of high molecular weight rather than discrete glycoproteins.
(20) The transgenome replicates intensively during the course of early development (until the blastula--early gastrula stages), but later the replication slows down which results in the elimination of the transgenome from the majority of embryos at more advanced stages.