blastoderm


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Related to blastoderm: blastodisc, area pellucida, Hensen's node

blastoderm

 [blas´to-derm]
a disk of cells lying betwen the yolk sac and the amniotic cavity, from which the embryo develops.

blas·to·derm

, blastoderma (blas'tō-derm, -tō-der'ma),
The thin, disc-shaped cell mass of a young embryo and its extraembryonic extensions over the surface of the yolk; when fully formed, all three primary germ layers (ectoderm, endoderm, and mesoderm) are present.
[blasto- + G. derma, skin]

blastoderm

(blăs′tə-dûrm′)
n.
1. The layer of cells that develops on the surface of the yolk in an avian or reptilian egg and gives rise to the germinal disk from which the embryo develops.
2. The layer of cells formed by the cleavage of a fertilized mammalian egg. It later divides into the three germ layers from which the embryo develops.

blas′to·der·mat′ic (-dər-măt′ĭk), blas′to·der′mic adj.

blastoderm

A superficial layer of a fertilised egg which, in birds, is a flat disc of cells at one pole, and in insects, an outer layer of cells surrounding the yolk mass. In eggs with a large amount of yolk, cell division (cleavage) may restricted to blastoderm (meroblastic cleavage).

blas·to·derm

, blastoderma (blas'tō-dĕrm, -dĕr'mă)
The thin, disc-shaped cell mass of young embryos (e.g., reptiles, birds), and its extraembryonic extensions over the surface of the yolk; when fully formed, all three primary germ layers (ectoderm, endoderm, and mesoderm) are present.
Synonym(s): germ membrane, germinal membrane.
[blasto- + G. derma, skin]

blastoderm

the layer of cells formed by cleavage of the fertilized egg in the presence of large amounts of yolk, e.g. in birds, so that the blastoderm forms on one side of the yolk mass, initially as a small blastodisc.
References in periodicals archive ?
The cellular blastoderm forms in the following cell divisions.
Dissociated cells from the fresh chicken blastoderm at stage X were initially cultured with STO feeder layers, primary chick embryonic fibroblast (CEF) feeder layers, or the DF-1 feeder layer which is an immortalized cell line of chicken embryo fibroblasts transformed from a 10-day chicken embryo.
The frequency of FPs with stage 1 ovaries decreased dramatically in FPs incubating stages 2-3 embryos (blastoderm distinct, no eye development); no FPs incubating stage 4 embryos (nearly hatching) had stage 1 ovaries.
The ostrich (Struthio camelus) blastoderm and embryo development following storage of eggs at various temperatures.
Blastula stage; after morula the developing embryo further divided into numerous cells and arranged in the form of a layer called blastoderm. Gradually the blastoderm formed into several layers due to further cell division which is called blastodisc.
The changes were accelerated when eggs were held beyond 7 days (Lapap et al., 1999), causing the blastoderm to move closer to egg shell resulting in early embryonic death from dehydration (Brake et al., 1993).
erythrogramma in detail, and they suggested that these embryos develop wrinkles in part because the fertilization envelope fits tightly over large, yolky eggs and leaves little room for the expanding blastoderm. The fertilization envelope of Brisaster leaves an unusually small perivitelline space (in some cases 10 [[micro]meter] or less between the zygote and envelope).
Moreover, before laying, the embryo blastoderm starts to differentiate, as eggs remain at room temperature after laying is complete, embryos cease to develop further, and this stage is characterized by the formation of zona pellucida.
Cell death in the avian blastoderm: resisstance to stres induced apoptosis and expression of antiapoptotic genes.
Traditional eggshell windowing has proven to be a powerful tool for preparing and processing host embryos for developmental biology experiments as well as to provide an access point to deliver a viral vector to the blastoderm for generating transgenic chickens (Speksnijder and Ivarie, 2000; Andacht et al., 2004; Chapman et al., 2005).
Microtubules and mitotic cycle phase modulate spatiotemporal distributions of F-actin and myosin II in Drosophila syncytial blastoderm embryos.
To determine whether a similar signaling mechanism is present in the long-finned squid, Loligo pealei, early cleavage stages and blastoderm stage embryos were studied by immunocytochemistry.