Blastoderm
[Gr. blastos - germ, bud, shoot; Gr. derma - skin]. The divided germinal disc of a megalecithal egg lying on the yolk and composed of three regions: the area pellucida, the area opaca, and the syncytial periblast. Synonym: blastodisc.
blastoderm - cell layer formed during cleavage of telolecithal and centrolecithal eggs.
blastomere - any embryonic cell formed during cleavage.
blastoderm
The layer of cells formed by cleavage of the fertilized egg in the presence of large amounts of yolk.
blastomeres
Any cell that occurs in the blastula.
blastoderm "Primary epithelium" formed in early embryonic development of many arthropods when the nuclei migrate to the periphery and undergo superficial cleavage; usually encloses the central yolk mass.
The blastoderm now consists of three layers, named from without inward: ectoderm, mesoderm, and entoderm; each has distinctive characteristics and gives rise to certain tissues of the body. 6
4 ...
In the blastoderm stage of Drosophila morphogenesis four types of nuclear specification can be distinguished:
Anterior (head and thorax)
Posterior (abdomen)
Dorso-ventral
Terminal (special structures at the unsegmented ends of the embryo) ...
The blastoderm stage of the embryo is a syncytium (thousands of nuclei unconfined by cells) so that, for example, macromolecules like DNA injected into the embryo have easy access to all the nuclei.
The process of movements and infoldings of embryonic cells destined to become endoderm in early animal embryos, immediately following blastula (or blastoderm) stage, generating the blastopore.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...
 See also: Cells, Embryo, Trans, Organ, Egg
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