Biomaterial Database

Developmental potencies of area opaca and marginal zone areas of early chick blastoderms. 1985

O Khaner, and E Mitrani, and H Eyal-Giladi

The marginal zone, in pregastrulating chick blastoderms, has been defined as the intermediate ring between the epiblast proper and the most external region, the area opaca (Spratt & Haas, 1960). Azar & Eyal-Giladi (1979) have shown that the marginal zone of a stage XIII blastoderm has the capacity of regenerating an inductive layer which when in contact with a competent stage XIII epiblast can cause the formation of axial structures. The present work demonstrates that at stage X (Eyal-Giladi & Kochav, 1976) the marginal zone can both induce and respond to its own inductive stimulus by forming an embryonic axis. By stage XIII the marginal zone seems to have lost its competence to respond to an inductive stimulus and cannot form an embryonic axis. It is further shown that at stages X--XIII the area opaca is neither competent to develop any sort of axial structures nor has the capacity to generate an inductive layer.

UI	MeSH Term	Description	Entries
D001756	Blastoderm	A layer of cells lining the fluid-filled cavity (blastocele) of a BLASTULA, usually developed from a fertilized insect, reptilian, or avian egg.	Blastoderms
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D004627	Embryonic Induction	The complex processes of initiating CELL DIFFERENTIATION in the embryo. The precise regulation by cell interactions leads to diversity of cell types and specific pattern of organization (EMBRYOGENESIS).	Embryonic Inductions,Induction, Embryonic,Inductions, Embryonic
D005775	Gastrula	The developmental stage that follows BLASTULA or BLASTOCYST. It is characterized by the morphogenetic cell movements including invagination, ingression, and involution. Gastrulation begins with the formation of the PRIMITIVE STREAK, and ends with the formation of three GERM LAYERS, the body plan of the mature organism.	Archenteron,Blastopore,Gastrocoele,Primitive Gut,Archenterons,Blastopores,Gastrocoeles,Gastrulas,Gut, Primitive,Guts, Primitive,Primitive Guts
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D046508	Culture Techniques	Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.	Culture Technique,Technique, Culture,Techniques, Culture