(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.
Mesoderm
Definition:
(n.) The layer of the blastoderm, between the ectoderm and endoderm; mesoblast. See Illust. of Blastoderm and Ectoderm.
(n.) The middle body layer in some invertebrates.
(n.) The middle layer of tissue in some vegetable structures.
Example Sentences:
(1) Small pieces of anterior and posterior quail wing-bud mesoderm (HH stages 21-23) were placed in in vitro culture for up to 3 days.
(2) 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.
(3) Cloacal exstrophy, centered on the maldevelopment of the primitive streak mesoderm and cloacal membrane, results in bladder and intestinal exstrophy, omphalocele, gender confusion, and hindgut deformity.
(4) However, the pattern in the central nervous system (CNS) and mesoderm is further restricted; the major expression located in the labial neuromere of the CNS and the mesoderm of the first thoracic segment.
(5) The positive reaction for keratin and vimentin confirmed the presence of ectodermal and mesodermal elements respectively in the tumor.
(6) Little deficit in total mesodermal cell number was found, though the entire mesoderm adopted the histological character proper to only some 40% of that in the normal pattern i.e.
(7) LIF inhibits differentiation under several conditions which lead to endodermal and mesodermal cell lineages including skeletal and cardiac muscle.
(8) The histochemical study of the LDH in the Trout embryo during the early organogenesis shows a specific localization in notochord cells, in mesodermic cells of the terminal knob and in some prosencephalic neuroblasts.
(9) This suggests that a factor in the lateral plate mesoderm in addition to the pronephric duct is inhibiting further ventral migration.
(10) While such speculation on how these spatially separated anomalies develop is probably simplistic, the concept of a mesodermal "malformation" spectrum is helpful in reminding the clinician to look for other mesodermal defects when one mesodermally derived defect or sequence is detected.
(11) Cell biological evidence suggests that mesoderm formation and specification of axial positions occur simultaneously.
(12) The tissues of the endodermal and mesodermal origin were also present in small quantities.
(13) There mesodermal expansion proximal to an arrested edge could be compared with that proximal to a moving edge by measuring the amount of vascular elongation occurring in each.
(14) We also assessed the ability of ta2 limb bud mesoderm to respond to a polarizing signal.
(15) Invaginating mesodermal cells of the lateral and ventral parts also form pseudopodia, and are in contact with the blastocoelic wall.
(16) The aim of this study is to test the ability of the intrinsic wing musculature to develop in the absence of somitic mesoderm.
(17) Maintenance of GHox-8 expression by the anterior mesoderm appears to be independent of the presence of the apical ridge.
(18) 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.
(19) A unique pattern for a carbohydrate antigen is displayed by cells of the primitive streak; antigenicity is lost with de-epithelialisation and ingression, but is regained in a pericellular distribution on the mesoderm cells that emerge from the primitive streak.
(20) In the mutants twist and snail, which fail to differentiate the ventrally derived mesoderm, mitoses specific to the mesoderm are absent.