(a.) Characterizing the ovum when it has two primary germinal layers.
Example Sentences:
(1) We report the nucleotide sequence of eveC, a cnidarian eve-class homeobox; this is the first homeobox to be identified in any diploblastic organism, and is only the second eve-class in an invertebrate.
(2) Triploblasts and diploblasts formed two clearly separated monophyletic units; this divergence, which apparently preceded the diversification of diploblastic animals (i.e.
(3) These results do not exclude the possibility that triploblasts and diploblasts arose independently from different protists.
(4) In order to study the origin of metazoans, we have compared sequences from the 5' end of the large subunit ribosomal RNA of a number of protists, fungi, plants and metazoans, including all diploblastic phyla (sequences of 10 new species have been determined, including that of the placozoan, Trichoplax adhaerens).
(5) the successive sponge, ctenophore, cnidarian radiations), showed a much more ancient origin of triploblasts with respect to diploblasts than classically assumed.
(6) We report here the first homeoboxes from cnidarians, a phylum of diploblastic organisms thought to occupy a near-basal position in metazoan phylogeny.
(7) From this analysis, several inferences on the eukaryogenesis can be made among which the ancient origin of the cytoskeleton, the late occurrence of the chloroplastic endosymbiosis and the simultaneous emergence of the triploblastic and diploblastic metazoan patterns.
(8) Sequences from the 5' end terminal part of 28S ribosomal RNA were obtained and compared for 22 animals belonging to all diploblastic phyla and for a large number of representatives of triploblastic Metazoa and protists.
(9) Short internodes between these radiations suggested an early rapid diversification of diploblasts.
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.