(n.) The germinal membrane in an ovum, from which the embryo is developed.
Example Sentences:
(1) Laminin is a constituent of the basement membrane in both chicken and quail blastoderms.
(2) The blastoderm stage of Drosophila embryogenesis is a time of crucial transitions in RNA transcription, the cell cycle and segment determination.
(3) Their posterior domains of expression at blastoderm stage are under the control of the maternal pattern organizer gene nanos.
(4) This expansion involves the migration over the inner surface of the vitelline membrane of a specialized band of 'edge cells' at the blastoderm periphery.
(5) Three sets of muscles separated by lineage restrictions are observed, even when cells are marked as early as the blastoderm stage.
(6) (1) Removal of both the area opaca and the marginal zone of the area pellucida from a blastoderm stripped of its hypoblast (type-IV operation) prevents the regeneration of a normally functioning primary hypoblast.
(7) The latter covers the blastoderm anlages which are involved in the development of abdomen, and the genital imaginal disc.
(8) Three experiments were conducted to determine the temperature required to initiate blastoderm development of Bobwhite quail eggs.
(9) Laminin immunogold labeling was not detected in the blastoderm at stage X.
(10) The tissues were examined using fluorescent antibody procedures and the earliest detection from positive tissues were: day 6, blastoderm (10%); day 8, sinus (44%) and peritoneum (55%); day 19, lung (11%) and trachea (44%); day 23, air sacs (62%).
(11) Microtubule distribution was examined in whole mounts of Drosophila embryos from the cellularization of the syncytial blastoderm (stage 6) to the completion of the gastrulation (stage 7) by fluorescence microscopy.
(12) We propose that postcellular blastoderm su(wa) expression is repressed by preventing splices necessary to produce a functional mRNA.
(13) These results indicate that both microtubules and microfilaments may be involved in determining centrosome shape during the syncytial mitoses which lead to the formation of the blastoderm in early Drosophila embryos.
(14) Chick blastoderms, incubated for 5 hrs., were wholly irradiated with ultraviolet light (2 537 A).
(15) These include transfection of avian sperm, development of germ line chimeras using primordial germ cells and blastodermal cells, and the development of embryonic stem cell lines.
(16) By 48 h of incubation all cells of the chick blastoderm seem to have lost the capacity to form colonies in agarose.
(17) Hence, the development of isolated blastoderms depends on the content of K+ in the medium and this dependence reduces with the age.
(18) They are also described for the subsequent mitoses of the syncytial blastoderm where the cortex and its well-developed cytoskeleton is reorganized into cell-like surface protrusions known as 'caps' or 'buds'.
(19) Cold treatment of embryos during the cellularization of the blastoderm results in marked fragmentation of the centrosomes, but nucleating capacity is preserved.
(20) Death in the unhatched eggs occurred prior to blastoderm formation indicating BM caused chromosome breakage.
Ectoblast
Definition:
(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.