Formation and patterning of Mesoderm
If you culture the equatorial region of an early blastula in isolation it will form ectoderm. If you culture the equatorial region of a late blastula in isolation, it will form mesoderm.

Therefore the vegetal cells must have INDUCED the equatorial cells to become mesoderm by the late blastula stage.

Induction:
The switching of cells from one differentiation pathway into another by the influence of adjacent cells.

You can stimulate the inductive process that occurs before the late blastula stage by co-culturing the animal cap with the vegetal cells. The normal fate of cells of the animal cap is to form ectodermal cells. However if it the animal cap cells contact cells of the vegetal pole they can be enduced to form mesodermal cells. The dorsal vegetal cells induce dorsal mesoderm (notochord and muslce). The ventral cells induce blood.

Dorsalizing the mesoderm
Ventral mesoderm will normally become blood but if you place it adjacent to the Organizer it will become derivatives of lateral mesodermal cells.

Mesoderm induction is mediated by morphogens

Morphogen:
An inducing factor that can evoke more than one positive response from the responding tissue. In a gradient, cells respond according to the concentration of morphogen.

	Criado por Beckie Thorne quase 11 anos atrás

University Histology/developmental Notas sobre Mesoderm Induction, criado por Beckie Thorne em 20-05-2015.