What does the Nieuwkoop center do?
Nieuwkoop center refers to a conceptual domain that generates intercellular signaling molecules to induce the dorsal organizer in early embryonic development.
What is the importance of the Nieuwkoop center and the Spemann organizer?
Background: In amphibians, the Nieuwkoop center – a primary inducing region – has a central role in the induction of dorsal mesodermal cells to form the Spemann organizer. In teleosts, such as the zebrafish, Danio rerio, the functional equivalent of the amphibian Spemann organizer is the dorsal shield.
What establishes the Nieuwkoop center?
The first is a process called cortical rotation, which takes place after fertilisation and triggers the relocalisation of dorsal determinants toward the future dorsal side of the embryo, thereby creating a first organising centre, the Nieuwkoop centre, in the dorsal vegetal cells (Figure 1a) [2].
How does the Nieuwkoop center stimulate the formation of the organizer?
According to the prevalent model of early development, the organizer is induced by the dorsalizing Nieuwkoop signal, which is secreted by the Nieuwkoop center. Formation of the center requires the maternal Wnt pathway, which is active on the dorsal side of embryos.
What does the Spemann organizer do?
The Spemann-Mangold organizer is a group of cells that are responsible for the induction of the neural tissues during development in amphibian embryos.
What is gastrulation biology?
Gastrulation is defined as an early developmental process in which an embryo transforms from a one-dimensional layer of epithelial cells (blastula) and reorganizes into a multilayered and multidimensional structure called the gastrula.
What is permissive induction?
Permissive induction occurs where the responding cell is already committed to a certain fate, and requires the inducing signal to proceed in the developmental pathway. The spacing of the differentiated cells would be regulated by the range of the signal and the strength of its effect.
Where is the Nieuwkoop center formed?
dorsal vegetal cells
The first is a process called cortical rotation, which takes place after fertilisation and triggers the relocalisation of dorsal determinants toward the future dorsal side of the embryo, thereby creating a first organising centre, the Nieuwkoop centre, in the dorsal vegetal cells (Figure 1a) [2].
What is the trilaminar disc?
A trilaminar embryo (or trilaminary blastoderm, or trilaminar germ disk) is an early stage in the development of triploblastic organisms, which include humans and many other animals. It is an embryo which exists as three different germ layers – the ectoderm, the mesoderm and the endoderm.
Which way does the primitive streak move?
At the same time, the primitive streak undergoes anteriorly-directed movement along the midline, driven by convergence and extension. These cells ingress prior to gastrulation and are implicated in primitive streak formation, eventually giving rise to mesoderm and endoderm (Stern & Canning, 1990).
What is secondary organizer?
a second grade organizer (for example, optic cup) that exerts influence on the developing lens of the eye.