What's the difference between ectoderm and entoderm?
Ectoderm
Definition:
(n.) The outer layer of the blastoderm; epiblast.
(n.) The external skin or outer layer of an animal or plant, this being formed in an animal from the epiblast. See Illust. of Blastoderm.
Example Sentences:
(1) Here we report direct measurements of protein kinase C (PKC) activity in uninduced ectoderm, and in neuroectoderm shortly after induction by the involuting mesoderm, in Xenopus laevis embryos.
(2) The Notch locus in Drosophila encodes a transmembrane protein required for the determination of cell fate in ectodermal cells.
(3) The factor was tested on Triturus alpestris by the implantation method, and on isolated ectoderm of Xenopus laevis in solution.
(4) Evx-1 RNA is first detected shortly before the onset of gastrulation in a region of ectoderm containing cells that will soon be found in the primitive streak.
(5) Cells falling off from ectoderm were observed in normally developing gastrulae of the newt, Cynops pyrrhogaster, in light microscopic examination.
(6) Anhidrotic ectodermal dysplasia is characterized by an absence of seromucous glands in the oropharynx and tracheobronchial tree, making children with this disease prone to viral and bacterial respiratory infections.
(7) The positive reaction for keratin and vimentin confirmed the presence of ectodermal and mesodermal elements respectively in the tumor.
(8) 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.
(9) In the present study, ectodermal explants from Xenopus blastulae were shown to have high affinity binding sites for 125I-aFGF (Kd = 1.4 X 10(-10) M).
(10) Ectoderm from Cynops pyrrhogaster reacts like that of Ambystoma when exposed to LiCl, but like Triturus ectoderm it is insensitive to cyclic nucleotides.
(11) Several mouse mutants in the distal region of the mouse t-complex affecting blastocyst and embryonic ectoderm formation also map to this region.
(12) PTN mRNA was also strongly expressed in the basal layers of the tongue epithelium, which is the only epithelium and ectodermal derivative to express PTN mRNA, and this only after birth.
(13) These genes encode membrane proteins with epidermal growth factor repeats and are essential in the decision of an embryonic ectodermal cell to take on the fate of neuroblast or epidermoblast.
(14) We have found that competence of the ectoderm to respond to induction is lost at the same early neurula stage for all three marker genes.
(15) 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.
(16) From the right wing bud of stage 19 and 20 (HH) embryos the rim ectoderm was removed in four ways: all of the rim, the anterior third, the middle third (most of the A.E.R.
(17) During feather follicle formation, N-CAM was expressed in the dermal papilla and was closely apposed to the L-CAM-positive papillar ectoderm, while the dermal papilla showed no evidence of laminin or fibronectin.
(18) Initially each primordium forms a shallow depression in the ectodermal surface.
(19) From stage 110 on, a basement membrane differentiates beneath a one-cell thick subperipheral layer, which thus becomes the ectodermal basal layer, the prospective epidermal basal layer.
(20) CAT mRNA was observed in gut, mesenchyme cells and oral ectoderm in these embryos.
Entoderm
Definition:
(n.) See Endoderm, and Illust. of Blastoderm.
Example Sentences:
(1) This fact shows that the localization of the prechordal lamina coincides with the disposition of the Seessel's pouch lining, the histological nature of its material being identical to the entoderm.
(2) It therefore seems that the initially described high preponderance of CEA positivity of entodermal organs, previously observed for later stages of gestation, can be confirmed.
(3) There are no essential differences in time between cranial and caudal parts of the esophagus which proofs an entodermal genesis of the epithelium.
(4) Vasoactive intestinal peptide (VIP) receptors are widely distributed in different tissues or carcinoma cells originating from entoderm and have been shown to regulate the growth of colonic adenocarcinoma cells through the action of cyclic AMP (cAMP).
(5) It was found that CEA was expressed by derivates of all three germ layers, although the strongest reactions and the highest incidence of positivity was found in organs derived from the entoderm.
(6) Vaginal differentiation occurs only if müllerian ducts contact the urogenital sinus, inducing proliferation of the entodermal epithelium and if the caudal ends of the müllerian ducts do not regress.
(7) It is considered that the junction between these 2 epithelia corresponds to the former site of the junction of the entoderm and ectoderm.
(8) Pulmonary (peribronchial) lesions have also been described in the same animals and are considered to be of similar origin and to represent a cross reaction with tissue of similar embryological (entodermal) origin.
(9) In 9,5-day embryos the primary sex cells are localized in the mesenchyma of the allantois and in the intestinal entoderm.
(10) The development of liver parenchyma starts from entodermal cells which grow out from the gut into the mesenchyma of the septum transversum.
(11) The group of hamartomas, tumors of "erroneous mixture of tissue", included 20 cases which can be considered a malformation of the entodermal bronchial anlage, and 3 cases which can be regarded as a malformation of the mesenchymal anlage.
(12) Embryonic neural crest cells have been traced to the primitive entoderm where they differentiate into a family of hormone-producing cells, APUD cells.
(13) Our findings lead us to believe that (a) the cortical differentiation of the thymic component and the active thymocyte proliferation could represent a factor leading to myasthenia gravis; and (b) thymolipoma could be a peculiar form of thymoma rather than a mixed tumor of mesenchymal and entodermal origin, a lipoma, or a hamartoma of the thymic gland.
(14) CEA is a normal constituent of fetal cells, which can reappear in entodermally-derived neoplasms, following a de-repression process.
(15) The cells form from the entodermal part of the rudiment of the last pharyngeal cavity.
(16) These data indicate that the levels of precursor-like antigens in entodermal tumours and their possible diagnostic value warrant detailed investigation.
(17) The results indicate that cells of different developmental lineages (entodermal and mesodermal) can produce identical TM beta gene splice products while regulating expression of those transcripts in a lineage-specific way.
(18) "Fingerprints" of metastatic adenomas of entodermal origin showed quantitative and qualitative increases in molecules with CEA determinants unlike these latter categories.
(19) The embryonic node consisted of the primary ectodermal cell mass and the primary entodermal cells, surrounding the former.
(20) The development of the different cells may start from a pool of omnipotent cells (entodermal stem cells of the foregut) present in the walls of the ductules, or from undifferentiated cells, reflecting their embryonic potential as a result of proliferation of duct cells (i.e.